fig1 shows for a first exemplary embodiment of a handheld reader 2 according to the invention , whose internal structure will firstly be explained by using various embodiments , before the features that are visible from the outside are discussed per se . fig2 shows , in a schematic illustration , a first exemplary embodiment of a structure of the components of the handheld reader , with which the information which is contained in a dot distribution of a computer - generated lithogram written on a storage medium 4 can be acquired . the structure has as basic components a light source 6 for generating a light or laser beam 8 , recording means 10 for acquiring the image data of the hologram reproduced from the dot distribution of the lithogram by the light beam 8 ( beam path 12 ) and display means 14 for displaying the display data generated from the image data . the recording means 10 are connected to the display means 14 via a data line 16 . in the structure illustrated in fig2 , a beam splitter 11 and a projection lens 13 are additionally provided in order to couple the light of the reproduced hologram out of the beam path of the light beam 8 and in order to achieve a suitable image of the reproduced hologram on the image plane of the recording means 10 . all the components 6 , 10 and 14 ( and also , likewise , further components of the reader described in the following text ) are combined in a portable handheld unit . this can be seen in particular in fig1 in the housing 18 of the handheld unit . the housing 18 has , inter alia , the display means 14 which can be seen from outside and which , for example , is formed as a flat monitor , in particular as a display of a mobile telephone or as a monitor of a handheld computer ( pda ). the housing 18 has an ergonomic external shape and can easily be held in one hand by a user . the recording means 10 illustrated in fig2 are electronic , for example formed as a conventional cmos or ccd chip . therefore , a conventional and thus inexpensive standard technology is also used at this point . in the exemplary embodiment illustrated in fig2 , the recording means 10 are connected directly to the display means 14 , and the display means 14 display the image data directly as display data . this is shown in fig6 a . the display means 14 display the image data in the manner in which they have been generated by the recording means 10 . it is possible to detect the hologram reproduced from the storage medium 4 having a black / white pattern of individual regions of a two - dimensional bar code in the upper section of the hologram , and a combination of symbols comprising letters and numbers at the lower edge of the hologram . fig3 shows a second exemplary embodiment of a handheld reader 2 according to the invention , in which identical designations identify identical components , as have been explained previously using the first exemplary embodiment . in addition to the structure already described , in the second exemplary embodiment , evaluation means 20 , which are connected to the recording means 10 and the display means 14 via data lines 16 , are provided . using the evaluation means 20 , the image data is evaluated and the display data is generated . the evaluation means 20 are electronic and comprise at least one microprocessor , storage means and input and output interfaces . the storage means are used in this case in particular for storing a plurality of items of recorded image data or evaluation data . here , too , recourse can be had to conventional and thus inexpensive technology , for example a handheld computer ( pda ) can be used as display means 14 and evaluation means 20 . with the aid of the evaluation means 20 , it is possible to prepare the image data before display . in this case , firstly , the display data can comprise at least part of the image data , preferably all of the image data . secondly , the display data can represent at least part of the data derived from the image data . in other words , the display data could firstly be one or more parts of the image data recorded by the recording means 10 . on the other hand , the display data can contain the information which is generated by the evaluation of the information contained in the reproduced hologram . in this regard , reference is again made to an image of a one - dimensional or two - dimensional bar code , whose information can be obtained only following evaluation of the bar code pattern . the two different information contents of the items of information displayed on the display means 14 are illustrated in fig6 a and 6 b . while the handheld reader according to fig6 a — as already described — shows the image data of the reproduced hologram recorded by the recording means 10 , in the case of the handheld reader according to fig6 b , the information from the two - dimensional barcode of the reproduced hologram is displayed legibly in text . in the present case , this is an example of production data from a commercially available product which , during production , has been provided with a forgery - proof hologram label . it is thus possible for the originality of the product to be checked . for this purpose , use is likewise made of the sequence of symbols in the reproduced hologram according to fig6 a . it is also possible to draw conclusions about the originality of the product from this sequence of symbols , possibly only in combination with the derived data according to fig6 b . moreover , it can be seen in fig1 that switching means 22 in the form of a trigger for setting the type of image data are provided . therefore , the user can change over between the display modes illustrated in fig6 . likewise , it is possible to combine various display modes with one another , that is to say to combine at least two of the display contents illustrated in fig6 with one another . as illustrated in fig2 and 3 , the handheld reader 2 has a magnifying lens 24 as adjusting means . the magnifying lens 24 makes it possible for a user ( indicated by the eye ) to observe directly the region of the storage medium 4 illuminated by the light beam 8 , or the object on which the storage medium 4 is arranged . since the region occupied by the computer - generated lithogram can have a dimension of 1 mm 2 or less , it is not entirely simple to hit the lithogram without magnification . for this purpose , not illustrated in the figures , a further light source can be provided , which illuminates the region of the lithogram , in particular with white light . as a result , the ability to detect the lithogram is improved . the light source can be formed as an led . in addition , a target or crosswire can also be illuminated , whose reflected image can be registered by the viewer or by the further recording remains explained below . in fig2 , the magnifying lens 24 is arranged outside the beam path of the light beam 8 , so that the light beam 8 is not influenced by the lens 24 . this configuration can also be seen in fig1 . in the upper right - hand corner of the front side of the handheld reader 2 , it is possible to see the magnifying lens 24 , through which the user can observe the storage medium . in fig3 , the magnifying lens 24 is arranged within the beam path 8 . this structure results in the light beam 8 being generated by the light source 6 with a slight divergence , which is cancelled when it passes through the magnifying lens 24 . a further aid when adjusting the handheld reader relative to the storage medium 4 is that the evaluation means 20 according to fig3 continually analyze the image data acquired by the recording means 10 and , given a suitable position of the reproduced hologram , record the image data on the recording means 10 . the adjustment procedure is therefore assisted by the evaluation means , so that the adjustment carried out by hand can proceed more quickly and more reliably . furthermore , an acoustic and / or optical signal generator can be provided , which is activated when the evaluation means 20 have determined the optimum adjustment . the user is therefore informed immediately when the reproduction of a hologram has been recorded successfully . fig4 shows a third exemplary embodiment of a handheld reader according to the invention , identical designations identifying identical components , as have been explained previously using the first two exemplary embodiments . the structure of the third exemplary embodiment corresponds substantially to the structure of the first exemplary embodiment . in the third exemplary embodiment , recording means 26 are provided for recording the light reflected from the storage medium 4 . the recording means 26 therefore replace the eye of the user of the handheld reader 2 . the recording means 26 are connected to the display means 14 via a data line 28 , so that the real image of the storage medium 4 can be displayed directly and observed by the user . when configuring the optics , it is necessary to take account of the fact that the magnifying lens 24 ′ has a different focal length than the magnifying lens 24 in fig2 , in order that the projection of the area of the lithogram onto the recording means is improved , that is to say is magnified more highly . this technical success can also be achieved by means of an additional lens that can be pivoted into the beam path , in order firstly to display a larger area for searching for the lithogram and secondly to offer a higher magnification for detecting the microtext or the micropicture . fig5 shows a fourth exemplary embodiment of a handheld reader according to the invention , identical designations identifying identical components , as have been explained previously using the first three exemplary embodiments . the structure of the fourth exemplary embodiment corresponds substantially to the structure of the second exemplary embodiment . in the fourth exemplary embodiment , recording means 26 are likewise provided for recording the light reflected from the storage medium 4 . the recording means 26 represent an alternative to the eye of the user of the handheld reader 2 . this is because the recording means 26 are coupled in via a beam splitter 30 , without interfering with the direct path for the observing eye . the recording means 26 have additional magnifying optics 32 and are connected to the display means 14 via a data line 28 , so that the real image of the storage medium 4 can be displayed directly and observed by the user . the representation of the real image of the dot distribution of the lithogram is illustrated in fig6 c . here , it is possible to see the dot distribution of the computer - generated lithogram in the left - hand upper corner and a sequence of symbols in microtext and a logo as a micropicture . depending on the structure of the third or fourth exemplary embodiment , the images illustrated in fig6 a and 6 b can also be displayed on the display means 14 when observing the hologram . fig7 shows a further refinement of the present invention . in the exemplary embodiment illustrated , the handheld reader 2 is subdivided into an optical block 34 and an evaluation block 36 , that is to say constructed modularly . in the interior , the optical block 34 has at least the light source and the recording means and also possible further components previously described . the evaluation block 36 has at least the evaluation means and the display means 14 . the optical block 34 and the evaluation block 36 are connected to each other via an electronic interface 38 . the electronic interface has , for example , a flat ribbon cable and corresponding plug - in connections on both sides . in this case , the standard interfaces for interface cards , for example a compactflash card ( cf plug - in card ) are possible . the interface can also be formed optically , for example as an infrared interface , or as a radio interface . the optical block 34 and the evaluation block 36 are preferably arranged on a common holder ( not illustrated ), in order to form the handheld unit and to be easier to handle . in this case , one of the two blocks 34 or 36 can have a holder formed integrally therewith , into which the respective other block can be inserted . in this case , the optical block 34 preferably has the holder . this is because it is preferable for the evaluation block 36 to be formed as a mass - production handheld computer . therefore , in combination with the optical block 34 subjected to less change over time , a combination which can be used in the long term is created , in which replacement of the late evaluation unit 36 is possible even when the original handheld computer can no longer be repurchased .