CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority to Taiwan Patent Application No. 100124481, filed on Jul. 11, 2011, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an optical lens for image pickup, and more particularly to the optical lens for image pickup comprised of five lens elements with great image quality for applying to electronic products. 
     2. Description of the Related Art 
     In compact electronic products such as digital still cameras or mobile phone cameras, an optical lens for image pickup is generally installed for capturing images of an object, and the optical lens for image pickup tends to be developed with a compact design and a low cost, while meeting the user requirements for good aberration correction ability, high resolution, and high image quality. 
     In general, a conventional optical lens for image pickup of a compact electronic product comes with different designs, including the two-lens, three-lens, four-lens, and five-or-more lens designs. However, if the imaging quality is taken into consideration, the optical lens for image pickup with the four-lens or five-lens designs has advantages on image aberration and modulation transfer function (MTF) performance. 
     In various compact designs of the five-lens optical lens for image pickup having a fixed focal length, the prior arts adopt different combinations of positive and negative refractive powers. As disclosed in U.S. Pat. No. 7,663,813 which adopts a group of stacked lens elements, in which the two cemented glass lenses incur a higher manufacturing cost, and such conventional optical lens for image pickup is unfavorable for the cost control of mass production. Another conventional technique is the combination of a first lens element with negative refractive power and a second lens element with positive refractive power as disclosed in U.S. Pat. No. 7,480,105, but such conventional optical lens for image pickup cannot reduce the total length of the optical system easily to meet the requirement of the compact design. 
     Therefore, the present invention provides a more practical design to shorten the optical lens for image pickup, while using a combination of refractive powers and a combination of convex and concave surfaces of five lens elements to lower the cost for mass production easily and apply the optical lens for image pickup to compact electronic products. 
     SUMMARY OF THE INVENTION 
     Therefore, it is a primary objective of the present invention to provide an optical lens for image pickup, sequentially arranged from an object side to an image side along an optical axis, comprising: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element has negative refractive power; the third lens element has refractive power; the fourth lens element with positive refractive power is made of plastic, and has a convex object-side surface and a convex image-side surface, and at least one of the object-side surface and the image-side surface is aspheric; the fifth lens element with negative refractive power is made of plastic and has a concave image-side surface and at least one of the object-side surface and the image-side surface is aspheric, and at least one of the object-side surface and the image-side surface has at least one inflection point, and the following relation is satisfied:
 
−1.0 &lt;R   7   /R   8 &lt;0;  (1)
 
     wherein, R 7  is the curvature radius of the object-side surface of the fourth lens element, and R 8  is the curvature radius of the image-side surface of the fourth lens element. 
     On the other hand, the present invention provides an optical lens for image pickup, as described above, wherein the second lens element has a concave image-side surface; and the optical lens for image pickup satisfies one or more of the following relations in addition to the relation (1):
 
0 &lt;f/f   4 &lt;1.0;  (2)
 
0&lt;( R   3   +R   4 )/( R   3   −R   4 )&lt;1.8;  (3)
 
1.2 &lt;f/f   1 &lt;1.8;  (4)
 
0.2 &lt;CT   4   /CT   5 &lt;1.4;  (5)
 
     wherein, f is the focal length of the optical lens for image pickup, f 1  is the focal length of the first lens element, f 4  is the focal length of the fourth lens element, R 3  is the curvature radius of the object-side surface of the second lens element, R 4  is the curvature radius of the image-side surface of the second lens element, CT 4  is the central thickness of the fourth lens element on the optical axis, and CT 5  is the central thickness of the fifth lens element on the optical axis. 
     On the other hand, the present invention provides an optical lens for image pickup, as described above, wherein the second lens element has a concave image-side surface, and the optical lens for image pickup satisfies one or more of the following relations in addition to the relation (1):
 
1.7 &lt;v   1   /v   2 &lt;3.0;  (6)
 
0 &lt;R   4   /f&lt; 1.5;  (7)
 
0.2 &lt;CT   2   /CT   3 &lt;0.8;  (8)
 
     wherein, v 1  is the Abbe number of the first lens element, v 2  is the Abbe number of the second lens element, R 4  is the curvature radius of the image-side surface of the second lens element, f is the focal length of the optical lens for image pickup, CT 2  is the central thickness of the second lens element on the optical axis, and CT 3  is the central thickness of the third lens element on the optical axis. 
     On the other hand, the present invention provides an optical lens for image pickup, as described above, wherein at least one of the object-side surface and the image-side surface of the fourth lens element has at least one inflection point, and the optical lens for image pickup satisfies the following relation in addition to the relation (1):
 
−1.0 &lt;R   7   /R   8 &lt;0;  (9)
 
     wherein, R 7  is the curvature radius of the object-side surface of the fourth lens element, and R 8  is the curvature radius of the image-side surface of the fourth lens element. 
     Another objective of the present invention is to provide an optical lens for image pickup, sequentially arranged from an object side to an image side along an optical axis, comprising: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element with negative refractive power has a concave image-side surface; the third lens element with refractive power has a concave object-side surface; the fourth lens element with positive refractive power is made of plastic and has a convex object-side surface and a convex image-side surface, and at least one of the object-side surface and the image-side surface is aspheric; the fifth lens element with negative refractive power is made of plastic and has a concave image-side surface, and at least one of the object-side surface and the image-side surface is aspheric, and at least one of the object-side surface and the image-side surface has at least one inflection point, and the following relations are satisfied:
 
0 &lt;f/f   4 &lt;1.0;  (2)
 
0.2 &lt;CT   4   /CT   5 &lt;1.4;  (5)
         wherein, f is the focal length of the optical lens for image pickup, f 4  is the focal length of the fourth lens element, CT 4  is the central thickness of the fourth lens element on the optical axis, and CT 5  is the central thickness of the fifth lens element on the optical axis.       

     On the other hand, the present invention provides an optical lens for image pickup, as described above, wherein, the third lens element has a convex image-side surface, and the optical lens for image pickup satisfies one or more of the following relations in addition to the relations (2) and (5):
 
1.2 &lt;f/f   1 &lt;1.8;  (4)
 
1.7 &lt;v   1   /v   2 &lt;3.0;  (6)
 
−0.7 &lt;f/R   8 &lt;0;  (10)
 
−0.5 &lt;R   7   /R   8 &lt;0;  (9)
 
0&lt;( R   3   +R   4 )/( R   3   −R   4 )&lt;1.8;  (3)
 
     wherein, f is the focal length of the optical lens for image pickup, f 1  is the focal length of the first lens element, v 1  is the Abbe number of the first lens element, v 2  is the Abbe number of the second lens element, R 3  is the curvature radius of the object-side surface of the second lens element, R 4  is the curvature radius of the image-side surface of the second lens element, R 7  is the curvature radius of the object-side surface of the fourth lens element, and R 8  is the curvature radius of the image-side surface of the fourth lens element. 
     Another objective of the present invention is to provide an optical lens for image pickup, sequentially arranged from an object side to an image side along an optical axis, comprising: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element; wherein the first lens element with positive refractive power has a convex object-side surface; the second lens element with negative refractive power has a concave image-side surface; the third lens element with refractive power has a concave object-side surface and a convex image-side surface; the fourth lens element with positive refractive power is made of plastic and has a convex object-side surface and a convex image-side surface, and at least one of the object-side surface and the image-side surface is aspheric; the fifth lens element with negative refractive power is made of plastic and at least one of the object-side surface and the image-side surface is aspheric, and at least one of the object-side surface and the image-side surface has at least one inflection point, and the following relations are satisfied:
 
0 &lt;f/f   4 &lt;1.0;  (2)
 
0 &lt;R   4   /f&lt; 1.5;  (7)
 
−0.7 &lt;f/R   8 &lt;0;  (10)
 
     wherein, f is the focal length of the optical lens for image pickup, f 4  is the focal length of the fourth lens element, R 4  is the curvature radius of the image-side surface of the second lens element, and R 8  is the curvature radius of the image-side surface of the fourth lens element. 
     On the other hand, the present invention provides an optical lens for image pickup, as described above, wherein the optical lens for image pickup satisfies one or more of the following relations in addition to the relations (2), (7) and (10):
 
1.7 &lt;v   1   /v   2 &lt;3.0;  (6)
 
0.2 &lt;CT   4   /CT   5 &lt;1.4;  (5)
 
1.2 &lt;f/f   1 &lt;1.8;  (4)
 
0.2 &lt;CT   2   /CT   3 &lt;0.8;  (8)
 
     wherein, v 1  is the Abbe number of the first lens element, v 2  is the Abbe number of the second lens element, f is the focal length of the optical lens for image pickup, f 1  is the focal length of the first lens element, CT 2  is the central thickness of the second lens element on the optical axis, CT 3  is the central thickness of the third lens element on the optical axis, CT 4  is the central thickness of the fourth lens element on the optical axis, and CT 5  is the central thickness of the fifth lens element on the optical axis. 
     In the optical lens for image pickup of the present invention, the optical lens for image pickup comprises a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Wherein the first lens element provides most of the refractive power required by the system, and the second lens element with negative refractive power can correct aberrations produced by the lens element with positive refractive power effectively and correct the Petzval sum of the system to make the image surface on the edge flatter. If the second lens element has a concave image-side surface, the intensity of the negative refractive power of the second lens element can be adjusted appropriately according to the surface shape to provide a good aberration correction effect for the system. If the third lens element is a meniscus lens element having a concave object-side surface and a convex image-side surface, the effect of correcting astigmatism can be improved. If the curvature at the position of the periphery is greater than the curvature at the center of the image-side surface, the angle of the incident light from the periphery of the system can be suppressed within a range of projecting onto the sensor to improve the light sensitivity of the image sensor. In addition, the supplementary installation of the fourth lens element with positive refractive power and the fifth lens element with negative refractive power can produce a telecentric effect to facilitate reducing the focal length and the total length of the optical system. If the fourth lens element has a convex image-side surface, the correction of the astigmatism and the high-order aberration of the optical lens for image pickup can be improved. If the fifth lens element has a concave image-side surface, the principal point of the optical system can be maintained at a position far from the image plane to facilitate reducing the total length of optical imaging lens assembly and miniaturizing the size of the optical system. With such configuration of the optical lens for image pickup, the image sensor can achieve a greater effective pixel range with the same total length. 
     If the fifth lens element has an inflection point, the inflection point can be used for guiding the image light projecting out the edge of the fifth lens element at an angle, such that the image light is guided to the image sensor at the off-axis view angle and received by the image sensor. In addition, the fourth lens element and the fifth lens element are made of plastic to facilitate the manufacture and lower the cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view of an optical lens for image pickup in accordance with the first preferred embodiment of the present invention; 
         FIG. 1B  is a schematic view of a series of aberration curves of the first preferred embodiment of the present invention; 
         FIG. 2A  is a schematic view of an optical lens for image pickup in accordance with the second preferred embodiment of the present invention; 
         FIG. 2B  is a schematic view of a series of aberration curves of the second preferred embodiment of the present invention; 
         FIG. 3A  is a schematic view of an optical lens for image pickup in accordance with the third preferred embodiment of the present invention; 
         FIG. 3B  is a schematic view of a series of aberration curves of the third preferred embodiment of the present invention; 
         FIG. 4A  is a schematic view of an optical lens for image pickup in accordance with the fourth preferred embodiment of the present invention; 
         FIG. 4B  is a schematic view of a series of aberration curves of the fourth preferred embodiment of the present invention; 
         FIG. 5A  is a schematic view of an optical lens for image pickup in accordance with the fifth preferred embodiment of the present invention; 
         FIG. 5B  is a schematic view of a series of aberration curves of the fifth preferred embodiment of the present invention; 
         FIG. 6A  is a schematic view of an optical lens for image pickup in accordance with the sixth preferred embodiment of the present invention; and 
         FIG. 6B  is a schematic view of a series of aberration curves of the sixth preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIG. 1A , the present invention provides an optical lens for image pickup, sequentially arranged from an object side to an image side along an optical axis, comprising: a first lens element  110 , a second lens element  120 , a third lens element  130 , a fourth lens element  140  and a fifth lens element  150 ; wherein the first lens element  110  with positive refractive power has a convex object-side surface  111 ; the second lens element  120  has negative refractive power; the third lens element  130  has refractive power; the fourth lens element  140  with positive refractive power is made of plastic and has a convex object-side surface  141  and a convex image-side surface  142 , and at least one of the object-side surface  141  and the image-side surface  142  is aspheric; the fifth lens element  150  with negative refractive power is made of plastic, and has a concave image-side surface  152 , and at least one of the object-side surface  151  and the image-side surface  152  is aspheric, and at least one of the object-side surface  151  and the image-side surface  152  has at least one inflection point. The optical lens for image pickup further comprises a stop and an IR-filter  160 , and the stop can be an aperture stop  100 , which is a front aperture stop installed between a photographed object and the first lens element  110 . The IR-filter  160  is installed between the fifth lens element  150  and the image plane  170  generally made of a panel optical material without affecting the focal length of the optical lens for image pickup of the present invention. The aspheric surfaces of the first lens element  110 , the second lens element  120 , the third lens element  130 , the fourth lens element  140  and the fifth lens element  150  comply with the aspherical surface formula as given in Equation (11). 
     
       
         
           
             
               
                 
                   
                     X 
                     ⁡ 
                     
                       ( 
                       Y 
                       ) 
                     
                   
                   = 
                   
                     
                       
                         ( 
                         
                           
                             Y 
                             2 
                           
                           / 
                           R 
                         
                         ) 
                       
                       
                         1 
                         + 
                         
                           
                             ( 
                             
                               1 
                               - 
                               
                                 
                                   ( 
                                   
                                     1 
                                     + 
                                     K 
                                   
                                   ) 
                                 
                                 ⁢ 
                                 
                                   
                                     ( 
                                     
                                       Y 
                                       / 
                                       R 
                                     
                                     ) 
                                   
                                   2 
                                 
                               
                             
                             ) 
                           
                         
                       
                     
                     + 
                     
                       
                         ∑ 
                         i 
                       
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         
                           ( 
                           
                             A 
                             i 
                           
                           ) 
                         
                         · 
                         
                           ( 
                           
                             Y 
                             i 
                           
                           ) 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   11 
                   ) 
                 
               
             
           
         
       
     
     Wherein, 
     X is the relative height from a point on the aspherical surface with a distance Y between the optical axis and a tangent plane at the tip of the optical axis of the aspherical surface; 
     Y is the distance between a point on the curve of the aspherical surface and the optical axis; 
     R is the curvature radius; 
     K is the conic coefficient; and 
     A i  is the i th  level aspherical surface coefficient. 
     In the optical lens for image pickup of the present invention, the first lens element  110 , second lens element  120 , and third lens element  130  have aspheric surfaces, the curvature radius of the optical surface can be used for changing the refractive power to reduce or eliminate aberrations, so as to reduce the number of lenses used in the optical lens for image pickup and reduce the total length of the optical lens for image pickup effectively. With the installation of the first lens element  110 , second lens element  120 , third lens element  130 , fourth lens element  140 , and fifth lens element  150 , the optical lens for image pickup satisfies the relation (1). 
     In the optical lens for image pickup of the present invention, the major positive refractive power is provided by the first lens element  110  and the fourth lens element  140 . If the ratio of the curvature radius R 7  of the object-side surface  141  of the fourth lens element  140  to the curvature radius R 8  of the image-side surface  142  is limited according to the relation (1), the variation of surface shape of the object-side surface  141  and the image-side surface  142  of the fourth lens element  140  can be limited, not only facilitating the correction of the spherical aberration of the fourth lens element  140 , but also appropriately adjusting the complementary correction of the refractive power of the fourth lens element  140  and the refractive power of the fifth lens element  150  if the relation (2) is satisfied, such that the telecentric effect is produced to facilitate reduction of the focal length and the total length, thereby achieving the effect of miniaturizing the lens. 
     If the relation (10) is satisfied, the curvature radius R 8  of the image-side surface  142  of the fourth lens element  140  is greater than the focal length f of the optical lens for image pickup to facilitate limiting the positive refractive power of the fourth lens element  140  in order to compensate the near-axis aberration more easily. If the ratio of the focal length f 1  of the first lens element  110  to the focal length f of the optical lens for image pickup is limited according to the relation (4), the positive refractive power of the first lens element  110  can be allocated appropriately to adjust the focal length of the optical system and reduce the total length appropriately. If the relation (7) is satisfied, and the second lens element  120  has a concave image-side surface  122 , the curvature radius R 4  of the image-side surface  122  of the second lens element  120  is smaller than the focal length f of the optical lens for image pickup, which facilitates increasing the refractive power of the second lens element  120  and compensating the near-axis aberration more easily. If the ratio in the relation is too large, then the negative refractive power is relatively weaker, and the chromatic aberration correction ability becomes weaker. If the ratio in the relation is too small, then the negative refractive power is relatively stronger, so that the total length cannot be reduced effectively, so that if this relation is limited within an appropriate range, the effects of correcting the aberration and reducing the total length can be achieved to facilitate the allocation of the refractive power of the first lens element  110  and the second lens element  120 . 
     If the ratio of the curvature radius R 3  of the object-side surface  121  of the second lens element  120  to the curvature radius R 4  of the image-side surface  122  is limited according to the relations (3), the change of the surface shape of the second lens element  120  can be limited to facilitate the aberration correction function of the second lens element  120  with negative refractive power. In addition, the fourth lens element  140  has a convex image-side surface  142 . If the ratio of the curvature radius of the object-side surface  141  to the curvature radius of the image-side surface  142  is limited according to the relation (9), the refractive power of the fourth lens element  140  can be allocated appropriately to achieve the effects of reducing the sensitivity of the manufacture, improving the yield rate, and saving the production cost. 
     If the relation (6) is satisfied, the difference between the Abbe number v 1  of the first lens element  110  and the Abbe number v 2  of the second lens element  120  falls within an appropriate range, and the chromatic aberration produced by the first lens element  110  and the second lens element  120  can be corrected effectively. If the relation (5) or (8) is satisfied, the thickness of the second lens element  120 , third lens element  130 , fourth lens element  140  and fifth lens element  150  can be adjusted to facilitate reduction of the total length of the optical lens for image pickup, and the optical lens for image pickup thick enough to maintain the yield rate of the manufacturing process. 
     The optical lens for image pickup of the present invention is described by means of preferred embodiments with relevant drawings as follows. 
     First Preferred Embodiment 
     With reference to  FIGS. 1A and 1B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the first preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  100  and an IR-filter  160 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: a plastic first lens element  110  with positive refractive power, having a convex object-side surface  111  and a convex image-side surface  112 , and both object-side surface  111  and image-side surface  112  being aspheric; an aperture stop  100 ; a plastic second lens element  120  with negative refractive power, having a concave object-side surface  121  and a concave image-side surface  122 , and both object-side surface  121  and image-side surface  122  being aspheric; a plastic third lens element  130  with negative refractive power, having a concave object-side surface  131  and a convex image-side surface  132 , and both object-side surface  131  and image-side surface  132  being aspheric; a plastic fourth lens element  140  with positive refractive power, having a convex object-side surface  141  and a convex image-side surface  142 , and both object-side surface  141  and image-side surface  142  being aspheric; a plastic fifth lens element  150  with negative refractive power, having a convex object-side surface  151  and a concave image-side surface  152 , both object-side surface  151  and image-side surface  152  being aspheric, and at least one of the object-side surface  151  and the image-side surface  152  having at least one inflection point; and an IR-filter  160  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  100  and the IR-filter  160 , an image of the photographed object can be formed at the image plane  170 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.30 mm, Fno = 2.60, HFOV = 32.5 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                   
                 1.543340 (ASP) 
                 0.565 
               
               
                   
                 Lens 1 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 2.76 
               
               
                 2 
                   
                 −50.020500 (ASP)  
                 −0.006 
               
               
                 3 
                 Ape. Stop 
                 Plano 
                 0.149 
               
               
                 4 
                   
                 −28.968700 (ASP)  
                 0.250 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −5.16 
               
               
                 5 
                   
                 3.696800 (ASP) 
                 0.526 
               
               
                 6 
                   
                 −1.997210 (ASP)  
                 0.374 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −17.54 
               
               
                 7 
                   
                 −2.611270 (ASP)  
                 0.144 
               
               
                 8 
                   
                 7.082200 (ASP) 
                 0.433 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 10.50 
               
               
                 9 
                   
                 −28.985500 (ASP)  
                 0.659 
               
               
                 10 
                   
                 1.318510 (ASP) 
                 0.406 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 −20.77 
               
               
                 11 
                   
                 1.052660 (ASP) 
                 0.700 
               
               
                 12 
                   
                 Plano 
                 0.300 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.512 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 1, wherein the object-side surfaces and the image-side surfaces of the first lens element  110  to the fifth lens element  150  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 2 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −3.06355E−01 
                 −3.00000E+01 
                 −2.00000E+01 
                 2.88304E+00 
                 4.27633E−02 
               
               
                 A4 = 
                 2.50446E−03 
                 −4.94200E−02 
                 −6.14490E−03 
                 4.99730E−02 
                 −7.67470E−02 
               
               
                 A6 = 
                 −1.55993E−02 
                 2.47780E−02 
                 9.23046E−02 
                 4.34781E−02 
                 2.50419E−02 
               
               
                 A8 = 
                 1.52702E−02 
                 −2.25423E−02 
                 −1.89711E−02 
                 9.45095E−02 
                 −3.96334E−02 
               
               
                 A10 = 
                 −4.34215E−02 
                 −2.73589E−02 
                 −6.14602E−03 
                 −1.62870E−01 
                 3.46322E−02 
               
               
                 A12 = 
                   
                 2.53422E−02 
                 3.76475E−02 
                 1.56936E−01 
                 −2.39569E−02 
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 2.87761E+00 
                 −2.00000E+01 
                 −2.00000E+01 
                 −6.29779E+00 
                 −4.56785E+00 
               
               
                 A4 = 
                 −8.66151E−02 
                 −5.08900E−02 
                 −1.28834E−02 
                 −7.52268E−02 
                 −5.78631E−02 
               
               
                 A6 = 
                 6.72960E−02 
                 8.88439E−03 
                 −3.94794E−03 
                 8.16349E−03 
                 1.00587E−02 
               
               
                 A8 = 
                 −1.73962E−02 
                 −4.10142E−04 
                 8.50755E−04 
                 3.31543E−04 
                 −1.68186E−03 
               
               
                 A10 = 
                 1.33287E−02 
                 −6.15772E−04 
                 8.77634E−05 
                 −6.50499E−05 
                 3.97827E−05 
               
               
                 A12 = 
                 1.68817E−03 
                 2.04068E−04 
                 −6.24845E−05 
                   
                 2.08062E−05 
               
               
                 A14 = 
                   
                   
                   
                   
                 −1.24326E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 1 and  FIG. 1B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.30 (mm), an overall aperture stop value (f-number) Fno=2.60, and a half of the maximum view angle HFOV=32.5°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 3 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.24 
               
               
                   
                 CT 2 /CT 3   
                 0.67 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 0.77 
               
               
                   
                 CT 4 /CT 5   
                 1.07 
                 f/f 1   
                 1.56 
               
               
                   
                 R 4 /f 
                 0.86 
                 f/f 4   
                 0.41 
               
               
                   
                 f/R 8   
                 −0.15 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 1 and the series of aberration curves as shown in  FIG. 1B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     Second Preferred Embodiment 
     With reference to  FIGS. 2A and 2B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the second preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  200  and an IR-filter  260 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: an aperture stop  200 ; a plastic first lens element  210  with positive refractive power, having a convex object-side surface  211  and a concave image-side surface  212 , and both object-side surface  211  and image-side surface  212  being aspheric; a plastic second lens element  220  with negative refractive power, having a convex object-side surface  221  and a concave image-side surface  222 , and both object-side surface  221  and image-side surface  222  being aspheric; a plastic third lens element  230  with negative refractive power, having a concave object-side surface  231  and a convex image-side surface  232 , and both object-side surface  231  and image-side surface  232  being aspheric; a plastic fourth lens element  240  with positive refractive power, having a convex object-side surface  241  and a convex image-side surface  242 , and both object-side surface  241  and image-side surface  242  being aspheric; a plastic fifth lens element  250  with negative refractive power, having a convex object-side surface  251  and a concave image-side surface  252 , and both object-side surface  251  and image-side surface  252  being aspheric, and at least one of the object-side surface  251  and the image-side surface  252  having at least one inflection point; and an IR-filter  260  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  200  and the IR-filter  260 , an image of the photographed object can be formed at the image plane  270 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.05 mm, Fno = 2.60, HFOV = 34.3 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Ape. Stop 
                 Plano 
                 −0.194 
               
               
                 2 
                   
                 1.506920 (ASP) 
                 0.496 
               
               
                   
                 Lens 1 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 2.85 
               
               
                 3 
                   
                 48.167000 (ASP)  
                 0.114 
               
               
                 4 
                   
                 12.736100 (ASP)  
                 0.250 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −5.62 
               
               
                 5 
                   
                 2.763530 (ASP) 
                 0.490 
               
               
                 6 
                   
                 −1.891750 (ASP)  
                 0.323 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −9.92 
               
               
                 7 
                   
                 −2.884420 (ASP)  
                 0.097 
               
               
                 8 
                   
                 5.273100 (ASP) 
                 0.477 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 7.61 
               
               
                 9 
                   
                 −18.719600 (ASP)  
                 0.548 
               
               
                 10 
                   
                 1.287060 (ASP) 
                 0.404 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 −147.94 
               
               
                 11 
                   
                 1.126680 (ASP) 
                 0.700 
               
               
                 12 
                   
                 Plano 
                 0.300 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.624 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 4, wherein the object-side surfaces and the image-side surfaces of the first lens element  210  to the fifth lens element  250  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 5 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 −2.90585E−01 
                 9.96023E+00 
                 −2.00000E+01 
                 2.49495E+00 
                 −7.07887E−01 
               
               
                 A4 = 
                 3.37557E−03 
                 −5.04837E−02 
                 −1.20356E−02 
                 4.51108E−02 
                 −5.47589E−02 
               
               
                 A6 = 
                 −1.50709E−02 
                 1.96828E−02 
                 8.29217E−02 
                 4.24263E−02 
                 2.55587E−02 
               
               
                 A8 = 
                 1.20870E−02 
                 −2.39993E−02 
                 −2.65473E−02 
                 9.10951E−02 
                 −3.40833E−02 
               
               
                 A10 = 
                 −5.71916E−02 
                 −3.33644E−02 
                 −6.80586E−03 
                 −1.65955E−01 
                 4.12585E−02 
               
               
                 A12 = 
                   
                 1.23073E−02 
                 4.80467E−02 
                 1.64550E−01 
                 −2.83912E−02 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 3.10741E+00 
                 −7.17143E+00 
                 −2.00000E+01 
                 −3.88861E+00 
                 −3.41767E+00 
               
               
                 A4 = 
                 −9.59479E−02 
                 −5.27367E−02 
                 −4.11369E−03 
                 −8.40582E−02 
                 −6.99738E−02 
               
               
                 A6 = 
                 7.13936E−02 
                 9.03915E−03 
                 −6.85160E−03 
                 7.75131E−03 
                 1.19781E−02 
               
               
                 A8 = 
                 −1.75694E−02 
                 −9.53755E−04 
                 8.78711E−04 
                 5.42326E−04 
                 −1.74102E−03 
               
               
                 A10 = 
                 1.27269E−02 
                 −6.83563E−04 
                 2.08012E−04 
                 −8.36623E−05 
                 1.87210E−05 
               
               
                 A12 = 
                 1.49857E−03 
                 3.97972E−04 
                 −6.10219E−05 
                   
                 1.98415E−05 
               
               
                 A14 = 
                   
                   
                   
                   
                 −1.05144E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 4 and  FIG. 2B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.05 (mm), an overall aperture stop value (f-number) Fno=2.60, and a half of the maximum view angle HFOV=34.3°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 6 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.28 
               
               
                   
                 CT 2 /CT 3   
                 0.77 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 1.55 
               
               
                   
                 CT 4 /CT 5   
                 1.18 
                 f/f 1   
                 1.42 
               
               
                   
                 R 4 /f 
                 0.68 
                 f/f 4   
                 0.53 
               
               
                   
                 f/R 8   
                 −0.22 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 4 and the series of aberration curves as shown in  FIG. 2B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     Third Preferred Embodiment 
     With reference to  FIGS. 3A and 3B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the third preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  300  and an IR-filter  360 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: a plastic first lens element  310  with positive refractive power, having a convex object-side surface  311  and a convex image-side surface  312 , and both object-side surface  311  and image-side surface  312  being aspheric; an aperture stop  300 ; a plastic second lens element  320  with negative refractive power, having a concave object-side surface  321  and a concave image-side surface  322 , and both object-side surface  321  and image-side surface  322  being aspheric; a plastic third lens element  330  with positive refractive power, having a concave object-side surface  331  and a convex image-side surface  332 , and both object-side surface  331  and image-side surface  332  being aspheric; a plastic fourth lens element  340  with positive refractive power, having a convex object-side surface  341  and a convex image-side surface  342 , and both object-side surface  341  and image-side surface  342  being aspheric; a plastic fifth lens element  350  with negative refractive power, having a concave object-side surface  351  and a concave image-side surface  352 , and both object-side surface  351  and image-side surface  352  being aspheric, and at least one of the object-side surface  351  and the image-side surface  352  having at least one inflection point; and an IR-filter  360  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  300  and the IR-filter  360 , an image of the photographed object can be formed at the image plane  370 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.71 mm, Fno = 3.50, HFOV = 28.0 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                   
                  1.614961 (ASP) 
                 0.575 
               
               
                   
                 Lens 1 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 2.91 
               
               
                 2 
                   
                 −75.802175 (ASP) 
                 0.082 
               
               
                 3 
                 Ape. Stop 
                 Plano 
                 0.115 
               
               
                 4 
                   
                 −41.465666 (ASP) 
                 0.300 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −3.88 
               
               
                 5 
                   
                  2.622202 (ASP) 
                 0.189 
               
               
                 6 
                   
                 −12.279317 (ASP) 
                 0.755 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 6.37 
               
               
                 7 
                   
                  −2.761231 (ASP) 
                 0.333 
               
               
                 8 
                   
                  11.494253 (ASP) 
                 0.353 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.607 
                 26.6 
                 15.55 
               
               
                 9 
                   
                 −52.356021 (ASP) 
                 0.596 
               
               
                 10 
                   
                  −4.528541 (ASP) 
                 0.940 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.535 
                 56.3 
                 −3.42 
               
               
                 11 
                   
                  3.292141 (ASP) 
                 0.400 
               
               
                 12 
                   
                 Plano 
                 0.210 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.384 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 7, wherein the object-side surfaces and the image-side surfaces of the first lens element  310  to the fifth lens element  350  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 8 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 3.77232E−01 
                 2.00000E+01 
                 −2.00000E+01 
                 2.83420E+00 
                 9.93468E+00 
               
               
                 A4 = 
                 −5.22870E−03 
                 −1.75425E−02 
                 −1.21265E−01 
                 −1.29426E−01 
                 −9.55645E−02 
               
               
                 A6 = 
                 6.96863E−03 
                 1.17248E−02 
                 1.55859E−01 
                 9.41042E−02 
                 −1.99603E−01 
               
               
                 A8 = 
                 −2.65604E−02 
                 4.20783E−02 
                 −1.90005E−01 
                 7.51996E−03 
                 5.27565E−01 
               
               
                 A10 = 
                 4.52653E−02 
                 −1.18182E−01 
                 3.92269E−01 
                 −3.64954E−02 
                 −1.18794E+00 
               
               
                 A12 = 
                 −3.33437E−02 
                 7.28858E−02 
                 −4.44021E−01 
                 3.07005E−01 
                 1.43618E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −3.43499E+00 
                 −1.99975E+01 
                 −1.97680E+01 
                 −1.83019E+01 
                 −1.53251E+01 
               
               
                 A4 = 
                 −1.11705E−01 
                 −4.79359E−02 
                 −3.18944E−02 
                 −2.08847E−01 
                 −8.60770E−02 
               
               
                 A6 = 
                 −4.64337E−02 
                 −4.82513E−02 
                 −3.06928E−02 
                 3.31188E−02 
                 2.54167E−02 
               
               
                 A8 = 
                 5.15033E−02 
                 8.33360E−02 
                 7.70559E−02 
                 1.41605E−02 
                 −6.30106E−03 
               
               
                 A10 = 
                 −9.87530E−03 
                 −1.77482E−02 
                 −4.24349E−02 
                 −3.43286E−03 
                 7.08448E−04 
               
               
                 A12 = 
                 2.62131E−03 
                 −1.07602E−02 
                 1.21395E−02 
                 −4.42682E−03 
                 2.17917E−05 
               
               
                 A14 = 
                   
                 2.96551E−03 
                 −2.39441E−03 
                 −1.10330E−03 
                 −2.35145E−05 
               
               
                 A16 = 
                   
                   
                   
                 8.47509E−04 
                 2.64648E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 7 and  FIG. 31B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.71 (mm), an overall aperture stop value (f-number) Fno=3.50, and a half of the maximum view angle HFOV=28.0°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 9 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.22 
               
               
                   
                 CT 2 /CT 3   
                 0.40 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 0.88 
               
               
                   
                 CT 4 /CT 5   
                 0.38 
                 f/f 1   
                 1.62 
               
               
                   
                 R 4 /f 
                 0.56 
                 f/f 4   
                 0.30 
               
               
                   
                 f/R 8   
                 −0.09 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 7 and the series of aberration curves as shown in  FIG. 3B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     Fourth Preferred Embodiment 
     With reference to  FIGS. 4A and 4B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the fourth preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  400  and an IR-filter  460 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: a plastic first lens element  410  with positive refractive power, having a convex object-side surface  411  and a concave image-side surface  412 , and both object-side surface  411  and image-side surface  412  being aspheric; an aperture stop  400 ; a plastic second lens element  420  with negative refractive power, having a convex object-side surface  421  and a concave image-side surface  422 , and both object-side surface  421  and image-side surface  422  being aspheric; a plastic third lens element  430  with positive refractive power, having a concave object-side surface  431  and a convex image-side surface  432 , and both object-side surface  431  and image-side surface  432  being aspheric; a plastic fourth lens element  440  with positive refractive power, having a convex object-side surface  441  and a convex image-side surface  442 , and both object-side surface  441  and image-side surface  442  being aspheric; a plastic fifth lens element  450  with negative refractive power, having a concave object-side surface  451  and a concave image-side surface  452 , and both object-side surface  451  and image-side surface  452  being aspheric, and at least one of the object-side surface  451  and the image-side surface  452  having at least one inflection point; and an IR-filter  460  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  400  and the IR-filter  460 , an image of the photographed object can be formed at the image plane  470 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 10 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.53 mm, Fno = 3.22, HFOV = 29.2 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                   
                  1.514160 (ASP) 
                 0.577 
               
               
                   
                 Lens 1 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 3.01 
               
               
                 2 
                   
                  17.543860 (ASP) 
                 0.074 
               
               
                 3 
                 Ape. Stop 
                 Plano 
                 0.102 
               
               
                 4 
                   
                  17.737217 (ASP) 
                 0.300 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −4.01 
               
               
                 5 
                   
                  2.208734 (ASP) 
                 0.189 
               
               
                 6 
                   
                 −15.360763 (ASP) 
                 0.780 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 6.13 
               
               
                 7 
                   
                  −2.790952 (ASP) 
                 0.287 
               
               
                 8 
                   
                  12.987013 (ASP) 
                 0.400 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.607 
                 26.6 
                 18.72 
               
               
                 9 
                   
                 −90.090090 (ASP) 
                 0.559 
               
               
                 10 
                   
                 −10.474284 (ASP) 
                 0.867 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.535 
                 56.3 
                 −3.79 
               
               
                 11 
                   
                  2.581608 (ASP) 
                 0.400 
               
               
                 12 
                   
                 Plano 
                 0.210 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.385 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 10, wherein the object-side surfaces and the image-side surfaces of the first lens element  410  to the fifth lens element  450  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 11 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 11 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 4.33467E−01 
                 −1.55764E+01 
                 −2.22007E+02 
                 1.36817E+00 
                 −2.00000E+01 
               
               
                 A4 = 
                 −4.31086E−03 
                 −1.92155E−02 
                 −1.46656E−01 
                 −1.38578E−01 
                 −8.33916E−02 
               
               
                 A6 = 
                 1.17717E−02 
                 2.62316E−02 
                 1.43155E−01 
                 8.33036E−02 
                 −2.05246E−01 
               
               
                 A8 = 
                 −2.12038E−02 
                 3.79660E−02 
                 −1.78028E−01 
                 −1.57603E−02 
                 5.19052E−01 
               
               
                 A10 = 
                 3.66170E−02 
                 −8.77626E−02 
                 3.53989E−01 
                 −2.21605E−02 
                 −1.21057E+00 
               
               
                 A12 = 
                 −1.25855E−02 
                 4.73149E−02 
                 −4.03871E−01 
                 2.34487E−01 
                 1.39276E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −3.38929E+00 
                 −2.00000E+01 
                 2.00000E+01 
                 −2.00000E+01 
                 −1.05408E+01 
               
               
                 A4 = 
                 −1.09889E−01 
                 −4.83088E−02 
                 −3.12307E−02 
                 −1.98321E−01 
                 −9.13884E−02 
               
               
                 A6 = 
                 −3.96557E−02 
                 −4.77036E−02 
                 −2.99784E−02 
                 3.36464E−02 
                 2.78482E−02 
               
               
                 A8 = 
                 5.13883E−02 
                 8.46369E−02 
                 7.67749E−02 
                 1.88927E−02 
                 −6.62067E−03 
               
               
                 A10 = 
                 −7.41303E−03 
                 −1.69914E−02 
                 −4.28530E−02 
                 −2.75259E−03 
                 7.01131E−04 
               
               
                 A12 = 
                 1.00431E−02 
                 −1.09091E−02 
                 1.23684E−02 
                 −3.93993E−03 
                 2.85277E−05 
               
               
                 A14 = 
                   
                 3.31574E−03 
                 −1.91642E−03 
                 −8.14534E−04 
                 −2.24962E−05 
               
               
                 A16 = 
                   
                   
                   
                 8.67020E−04 
                 2.18414E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 10 and  FIG. 4B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.53 (mm), an overall aperture stop value (f-number) Fno=3.22, and a half of the maximum view angle HFOV=29.2°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 12 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 12 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.14 
               
               
                   
                 CT 2 /CT 3   
                 0.38 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 1.28 
               
               
                   
                 CT 4 /CT 5   
                 0.46 
                 f/f 1   
                 1.51 
               
               
                   
                 R 4 /f 
                 0.49 
                 f/f 4   
                 0.24 
               
               
                   
                 f/R 8   
                 −0.05 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 10 and the series of aberration curves as shown in  FIG. 4B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     Fifth Preferred Embodiment 
     With reference to  FIGS. 5A and 5B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the fifth preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  500  and an IR-filter  560 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: a plastic first lens element  510  with positive refractive power, having a convex object-side surface  511  and a convex image-side surface  512 , and both object-side surface  511  and image-side surface  512  being aspheric; an aperture stop  500 ; a plastic second lens element  520  with negative refractive power, having a convex object-side surface  521  and a concave image-side surface  522 , and both object-side surface  521  and image-side surface  522  being aspheric; a plastic third lens element  530  with positive refractive power, having a concave object-side surface  531  and a convex image-side surface  532 , and both object-side surface  531  and image-side surface  532  being aspheric; a plastic fourth lens element  540  with positive refractive power, having a convex object-side surface  541  and a convex image-side surface  542 , and both object-side surface  541  and image-side surface  542  being aspheric; a plastic fifth lens element  550  with negative refractive power, having a concave object-side surface  551  and a concave image-side surface  552 , and both object-side surface  551  and image-side surface  552  being aspheric, and at least one of the object-side surface  551  and the image-side surface  552  having at least one inflection point; and an IR-filter  560  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  500  and the IR-filter  560 , an image of the photographed object can be formed at the image plane  570 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 13 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.48 mm, Fno = 3.22, HFOV = 28.7 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                 Lens 1 
                 1.708317 (ASP) 
                 0.562 
                 Plastic 
                 1.544 
                 55.9 
                 3.06 
               
               
                 2 
                   
                 −58.917670 (ASP)  
                 0.073 
               
               
                 3 
                 Ape. Stop 
                 Plano 
                 0.074 
               
               
                 4 
                   
                 8.998329 (ASP) 
                 0.382 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −4.15 
               
               
                 5 
                   
                 2.001436 (ASP) 
                 0.209 
               
               
                 6 
                   
                 −7.567571 (ASP)  
                 0.780 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.535 
                 56.3 
                 5.22 
               
               
                 7 
                   
                 −2.111134 (ASP)  
                 0.304 
               
               
                 8 
                   
                 35.714286 (ASP)  
                 0.425 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.607 
                 26.6 
                 35.47 
               
               
                 9 
                   
                 −54.020176 (ASP)  
                 0.590 
               
               
                 10 
                   
                 −12.568290 (ASP)  
                 0.786 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.535 
                 56.3 
                 −3.76 
               
               
                 11 
                   
                 2.442242 (ASP) 
                 0.400 
               
               
                 12 
                   
                 Plano 
                 0.210 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.385 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 13, wherein the object-side surfaces and the image-side surfaces of the first lens element  510  to the fifth lens element  550  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 14 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 14 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 5.01344E−01 
                 2.00000E+01 
                 −3.37287E+01 
                 6.38742E−01 
                 8.04940E+00 
               
               
                 A4 = 
                 5.80923E−04 
                 −1.71929E−02 
                 −1.44558E−01 
                 −1.51931E−01 
                 −9.03802E−02 
               
               
                 A6 = 
                 1.34203E−02 
                 3.53134E−02 
                 1.29822E−01 
                 5.71148E−02 
                 −2.40787E−01 
               
               
                 A8 = 
                 −2.00447E−02 
                 5.17815E−02 
                 −1.90141E−01 
                 −3.69484E−02 
                 5.80249E−01 
               
               
                 A10 = 
                 4.06848E−02 
                 −1.61866E−01 
                 3.86920E−01 
                 4.24833E−02 
                 −1.41041E+00 
               
               
                 A12 = 
                 −2.04723E−02 
                 1.08002E−01 
                 −4.36764E−01 
                 1.50909E−01 
                 1.57713E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −2.16113E+00 
                 −2.00000E+01 
                 2.00000E+01 
                 −2.00000E+01 
                 −1.11424E+01 
               
               
                 A4 = 
                 −1.17821E−01 
                 −3.53736E−02 
                 −1.69724E−02 
                 −2.17953E−01 
                 −9.99872E−02 
               
               
                 A6 = 
                 −4.73365E−02 
                 −4.98915E−02 
                 −3.10401E−02 
                 3.93066E−02 
                 2.98735E−02 
               
               
                 A8 = 
                 3.98001E−02 
                 8.36341E−02 
                 7.61110E−02 
                 1.48074E−02 
                 −6.86161E−03 
               
               
                 A10 = 
                 −2.31086E−03 
                 −1.80145E−02 
                 −4.39385E−02 
                 −3.43509E−03 
                 6.32190E−04 
               
               
                 A12 = 
                 3.92033E−03 
                 −1.20726E−02 
                 1.22644E−02 
                 −3.48487E−03 
                 3.29092E−05 
               
               
                 A14 = 
                   
                 3.69488E−03 
                 −1.88950E−03 
                 −7.06487E−04 
                 −2.07173E−05 
               
               
                 A16 = 
                   
                   
                   
                 4.15543E−04 
                 1.55927E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 13 and  FIG. 5B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.48 (mm), an overall aperture stop value (f-number) Fno=3.22, and a half of the maximum view angle HFOV=28.7°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 15 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.66 
               
               
                   
                 CT 2 /CT 3   
                 0.49 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 1.57 
               
               
                   
                 CT 4 /CT 5   
                 0.54 
                 f/f 1   
                 1.47 
               
               
                   
                 R 4 /f 
                 0.45 
                 f/f 4   
                 0.13 
               
               
                   
                 f/R 8   
                 −0.08 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 13 and the series of aberration curves as shown in  FIG. 5B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     Sixth Preferred Embodiment 
     With reference to  FIGS. 6A and 6B  for a schematic view and a series of aberration curves of an optical lens for image pickup in accordance with the sixth preferred embodiment of the present invention respectively, the optical lens for image pickup comprises five lens elements, an aperture stop  600  and an IR-filter  660 . More specifically, the optical lens for image pickup of the present invention, sequentially arranged from an object side to an image side along an optical axis, comprises: a plastic first lens element  610  with positive refractive power, having a convex object-side surface  611  and a convex image-side surface  612 , and both object-side surface  611  and image-side surface  612  being aspheric; an aperture stop  600 ; a plastic second lens element  620  with negative refractive power, having a convex object-side surface  621  and a concave image-side surface  622 , and both object-side surface  621  and image-side surface  622  being aspheric; a plastic third lens element  630  with positive refractive power, having a concave object-side surface  631  and a convex image-side surface  632 , and both object-side surface  631  and image-side surface  632  being aspheric; a plastic fourth lens element  640  with positive refractive power, having a convex object-side surface  641  and a convex image-side surface  642 , and both object-side surface  641  and image-side surface  642  being aspheric; a plastic fifth lens element  650  with negative refractive power, having a convex object-side surface  651  and a concave image-side surface  652 , and both object-side surface  651  and image-side surface  652  being aspheric, and at least one of the object-side surface  651  and the image-side surface  652  having at least one inflection point; and an IR-filter  660  made of panel glass for adjusting a wavelength section of the light of an image. With the combination of the five lens elements, the aperture stop  600  and the IR-filter  660 , an image of the photographed object can be formed at the image plane  670 . 
     
       
         
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 16 
               
             
             
               
                   
               
               
                 Optical data of this preferred embodiment 
               
               
                 f = 4.45 mm, Fno = 3.22, HFOV = 28.7 deg. 
               
             
          
           
               
                   
                   
                   
                   
                   
                   
                   
                 Focal 
               
               
                 Surface # 
                   
                 Curvature Radius 
                 Thickness 
                 Material 
                 Index 
                 Abbe # 
                 length 
               
               
                   
               
             
          
           
               
                 0 
                 Object 
                 Plano 
                 Infinity 
                   
                   
                   
                   
               
               
                 1 
                   
                  1.638650 (ASP) 
                 0.573 
               
               
                   
                 Lens 1 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 2.86 
               
               
                 2 
                   
                 −27.469360 (ASP) 
                 0.070 
               
               
                 3 
                 Ape. Stop 
                 Plano 
                 0.071 
               
               
                 4 
                   
                  10.089853 (ASP) 
                 0.414 
               
               
                   
                 Lens 2 
                   
                   
                 Plastic 
                 1.634 
                 23.8 
                 −3.80 
               
               
                 5 
                   
                  1.911857 (ASP) 
                 0.209 
               
               
                 6 
                   
                 −14.310631 (ASP) 
                 0.718 
               
               
                   
                 Lens 3 
                   
                   
                 Plastic 
                 1.535 
                 56.3 
                 8.14 
               
               
                 7 
                   
                  −3.395472 (ASP) 
                 0.313 
               
               
                 8 
                   
                  10.989011 (ASP) 
                 0.404 
               
               
                   
                 Lens 4 
                   
                   
                 Plastic 
                 1.607 
                 26.6 
                 16.15 
               
               
                 9 
                   
                 −90.090090 (ASP) 
                 0.571 
               
               
                 10 
                   
                  17.111567 (ASP) 
                 0.707 
               
               
                   
                 Lens 5 
                   
                   
                 Plastic 
                 1.544 
                 55.9 
                 −4.49 
               
               
                 11 
                   
                  2.104890 (ASP) 
                 0.400 
               
               
                 12 
                   
                 Plano 
                 0.210 
               
               
                   
                 IR-filter 
                   
                   
                 Glass 
                 1.517 
                 64.2 
                 — 
               
               
                 13 
                   
                 Plano 
                 0.390 
               
               
                 14 
                 Image 
                 Plano 
                 — 
               
               
                   
               
               
                 Note: 
               
               
                 Reference wavelength is 587.6 nm. ASP stands for aspherical surfaces. 
               
             
          
         
       
     
     The optical data of this preferred embodiment are listed in Table 16, wherein the object-side surfaces and the image-side surfaces of the first lens element  610  to the fifth lens element  650  comply with the aspheric surface formula as given in Equation (11), and their aspheric coefficients are listed in Table 17 as follows: 
     
       
         
               
             
               
               
             
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 17 
               
               
                   
               
               
                 Aspheric coefficients of this preferred embodiment 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 1 
                 2 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 k = 
                 3.66023E−01 
                 −1.99951E+01 
                 6.32623E+01 
                 1.09364E+00 
                 −2.00000E+01 
               
               
                 A4 = 
                 −4.85078E−03 
                 −1.45884E−02 
                 −1.20935E−01 
                 −1.37739E−01 
                 −8.80160E−02 
               
               
                 A6 = 
                 7.11596E−03 
                 3.11616E−02 
                 1.28812E−01 
                 6.72334E−02 
                 −1.82389E−01 
               
               
                 A8 = 
                 −2.21036E−02 
                 2.27265E−02 
                 −2.13314E−01 
                 −2.80833E−02 
                 5.65492E−01 
               
               
                 A10 = 
                 3.65925E−02 
                 −1.18546E−01 
                 3.89854E−01 
                 −2.97941E−02 
                 −1.27337E+00 
               
               
                 A12 = 
                 −2.38189E−02 
                 8.90471E−02 
                 −3.85898E−01 
                 2.62832E−01 
                 1.45486E+00 
               
               
                   
               
             
          
           
               
                   
                 Surface # 
               
             
          
           
               
                   
                 7 
                 8 
                 9 
                 10 
                 11 
               
               
                   
               
               
                 k = 
                 −4.23008E+00 
                 −1.99999E+01 
                 2.00000E+01 
                 1.65493E+00 
                 −8.32051E+00 
               
               
                 A4 = 
                 −1.09047E−01 
                 −4.69959E−02 
                 −3.52395E−02 
                 −2.34936E−01 
                 −1.13465E−01 
               
               
                 A6 = 
                 −3.47073E−02 
                 −5.09155E−02 
                 −2.80445E−02 
                 3.97669E−02 
                 3.53511E−02 
               
               
                 A8 = 
                 5.54561E−02 
                 8.45530E−02 
                 7.72181E−02 
                 2.05252E−02 
                 −7.80932E−03 
               
               
                 A10 = 
                 −2.70381E−03 
                 −1.65643E−02 
                 −4.37089E−02 
                 −3.36388E−03 
                 6.59440E−04 
               
               
                 A12 = 
                 1.01805E−02 
                 −1.12117E−02 
                 1.21480E−02 
                 −4.20622E−03 
                 3.74149E−05 
               
               
                 A14 = 
                   
                 3.44416E−03 
                 −1.77911E−03 
                 −7.56833E−04 
                 −2.24339E−05 
               
               
                 A16 = 
                   
                   
                   
                 6.98503E−04 
                 1.97035E−06 
               
               
                   
               
             
          
         
       
     
     With reference to Table 16 and  FIG. 6B  for an optical lens for image pickup of this preferred embodiment, the optical lens for image pickup has a focal length f=4.45 (mm), an overall aperture stop value (f-number) Fno=3.22, and a half of the maximum view angle HFOV=28.7°. After the optical data of this preferred embodiment are calculated and derived, the optical imaging system for pickup satisfies related conditions as shown in Table 18 below, and the related symbols have been described above and thus will not be described again. 
     
       
         
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 18 
               
             
             
               
                   
               
               
                 Data of related relations of this preferred embodiment 
               
             
          
           
               
                   
                 Relation 
                 Data 
                 Relation 
                 Data 
               
               
                   
                   
               
             
          
           
               
                   
                 v 1 /v 2   
                 2.35 
                 R 7 /R 8   
                 −0.12 
               
               
                   
                 CT 2 /CT 3   
                 0.53 
                 (R 3  + R 4 )/(R 3  − R 4 ) 
                 1.47 
               
               
                   
                 CT 4 /CT 5   
                 0.57 
                 f/f 1   
                 1.56 
               
               
                   
                 R 4 /f 
                 0.43 
                 f/f 4   
                 0.28 
               
               
                   
                 f/R 8   
                 −0.05 
               
               
                   
                   
               
             
          
         
       
     
     According to the optical data as shown in Table 16 and the series of aberration curves as shown in  FIG. 6B , the optical lens for image pickup in accordance with this preferred embodiment of the present invention provides good correction results in aspects of the longitudinal spherical aberration, astigmatic field curving, and distortion. 
     In the optical lens for image pickup of the present invention, the lens elements can be made of glass or plastic. For the lens elements made of glass, the optical lens for image pickup can be installed more flexibly. For the lens elements made of plastic, the production cost can be lowered. 
     As used throughout the specification and claims, in the optical lens for image pickup of the present invention, if the lens element has a convex surface, then the surface of the lens element is convex at a position proximate to the optical axis; and if the lens element has a concave surface, then the surface of the lens element is concave at a position proximate to the optical axis. 
     In the optical lens for image pickup of the present invention, at least one aperture stop such as a glare stop or a field stop is provided for reducing stray lights to improve the image quality. 
     In the optical lens for image pickup of the present invention, the aperture stop can be a front or middle aperture stop. If the aperture stop is a front aperture stop, a longer distance between the exit pupil of the optical lens for image pickup and the image plane can be achieved to provide the telecentric effect and improve the efficiency of receiving images by the image sensor such as a CCD or CMOS image sensor. If the aperture stop is a middle aperture stop, the view angle of the system can be increased, such that the optical lens for image pickup has the advantage of a wide-angle lens. 
     Tables 1 to 18 show changes of values of an optical lens for image pickup in accordance with different preferred embodiments of the present invention respectively, and even if different values are used, products of the same structure are intended to be covered by the scope of the present invention. It is noteworthy to point out that the aforementioned description and the illustration of related drawings are provided for the purpose of explaining the technical characteristics of the present invention, but not intended for limiting the scope of the present invention.
An optical lens for image pickup, sequentially arranged from an object side to an image side along the optical axis comprising: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with refractive power; a plastic fourth lens element with positive refractive power having biconvex surfaces with at least one aspheric surface; and a plastic fifth lens element with negative refractive power having a concave image-side surface, with at least one aspheric surface and at least one inflection point. By such arrangements, the optical lens for image pickup satisfies conditions related to shorten the total length and to reduce the sensitivity for use in compact cameras and mobile phones with camera functionalities.