referring to fig1 , a portable computer and portable docking station arrangement in accordance with the first embodiment comprises a portable computer 3 . according to this embodiment , the portable computer 3 is a tablet pc , having a display screen 32 on the front side . under normal status of use , a touch pen 37 is used for input operation . referring to fig2 , in addition to the aforesaid portable computer 3 , the portable computer and portable docking station arrangement further comprises a portable docking station 1 , and a swinging bracket 2 . the portable docking station 1 is connectable to external power supply ( not shown ) by a power cable 16 , having a keyboard 12 provided at the top side 11 , and two first pivoting means 13 and 14 coaxially aligned near the rear side . according to this embodiment , the first pivoting means 13 and 14 are pivot holes . the swinging bracket 2 comprises two second pivoting means 23 and 24 symmetrically disposed coaxially at two opposite lateral sides . according to this embodiment , the second pivoting means 23 and 24 are also pivot holes . two pivots 4 are respectively connected between the first pivoting means 13 and 14 and the second pivoting means 23 and 24 to pivotally secure the swinging bracket 2 to the portable docking station 1 , for enabling the swinging bracket 2 to be rotated about the axis extending through the first pivoting means 13 and 14 relative to the portable docking station 1 . the swinging bracket 2 further comprises a receiving open chamber 21 , and a connection port 22 set in the receiving open chamber 21 at the center for data transmission . referring to fig2 and 3 again , an electric connector 31 is disposed at the center of the bottom side 33 of the portable computer 3 . the bottom side 33 of the portable computer 3 fits the receiving open chamber 21 of the swinging bracket 2 . the connection port 22 of the swinging bracket 2 is electrically connected to the internal circuit ( not shown ) of the portable docking station 1 . when inserted the bottom side 33 of the portable computer 3 into the receiving open chamber 21 of the swinging bracket 2 , the electric connector 31 of the portable computer 3 is electrically connected to the connection port 22 in the receiving open chamber 21 to achieve electric connection between the internal circuit of the portable computer 3 and the internal circuit of the portable docking station 1 for data transmission . after insertion of the portable computer 3 into the receiving open chamber 21 of the swinging bracket 2 , the user can use the keyboard 12 of the portable docking station 1 to input data into the portable computer 3 , and therefore the portable computer and portable docking station arrangement is used as a notebook computer . referring to fig4 and fig2 and 3 again , the portable computer and portable docking station arrangement can be used as a portable computer . for this operation mode , the portable computer 3 is detached from the swinging bracket 2 and then rotated horizontally through 180 ° ( see the arrow shown in fig3 ), and then the portable computer 3 is attached to the swinging bracket 2 again to have the back side of the display screen 32 facing the keyboard 12 of the portable docking station 1 . after insertion of the portable computer 3 into the receiving open chamber 21 of the swinging bracket 2 , the electric connector 31 of the portable computer 3 is electrically connected to the connection port 22 in the receiving open chamber 21 , and the user can then rotated the portable computer 3 downwards with the swinging bracket 2 and closed on the top side of the portable docking station 1 . at this time , the portable computer and portable docking station arrangement form a simple potable computer , and the user can use the touch pen 37 for input . as indicated above , the portable computer 3 and the swinging bracket 2 are detachable , and the portable computer 3 can be rotated with the swinging bracket 2 relative to the portable docking station 1 that is equipped with a keyboard 12 . therefore , the whole assembly of the portable computer and portable docking station arrangement of the present invention can alternatively used as a notebook computer or a simple portable computer as desired . further , the electric connector 31 of the portable computer 3 and the connection port 22 of the swinging bracket 2 are not limited to the center position . they can be respectively disposed near one lateral side biased from the center position and set corresponding to each other . referring to fig2 again , a spare battery pack 15 may be installed in the portable docking station 1 . during the use of the portable computer 3 , the spare battery pack 15 can be charged with electricity from external power supply through the power cable 16 at the same time . the spare battery pack 15 can provide electricity to the portable computer 3 ; therefore , the user can carry the portable docking station 1 with the portable computer 3 for use at different places . fig5 and 6 show a portable computer and portable docking station arrangement constructed according to the second embodiment of the present invention . this embodiment is similar to the aforesaid first embodiment with the exception that the portable computer 5 of this second embodiment comprises two electric connectors 53 and 54 respectively provided at the center of the top side 51 and the center of the bottom side 52 . when using the portable computer and portable docking station arrangement as a notebook computer , one electric connector 54 is electrically connected to the connection port 22 of the swinging bracket 2 ( see fig5 ). further , the user can rotate the portable computer 5 vertically through 180 ° and then connect another electric connector 53 of the portable computer 5 to the swinging bracket 2 , enabling the portable computer and portable docking station arrangement to be simply used as a portable computer . fig7 is an exploded view of a portable computer and portable docking station arrangement constructed according to the third embodiment of the present invention . according to this embodiment , the receiving open chamber 73 of the swinging bracket 7 is relatively deeper than the receiving open chambers of the aforesaid first and second embodiments . further , the swinging bracket 7 comprises two connection ports 71 and 72 disposed in the receiving open chamber 73 and equally spaced from the center of the receiving open chamber 73 at two sides . the portable computer 6 comprises an electric connector 61 disposed at the bottom side 62 and spaced from the center of the bottom side 62 at one side . when inserted the bottom side 62 of the portable computer 6 into the receiving open chamber 73 with the front side of the display screen 63 facing the portable docking station 1 , the electric connector 61 is connected to one connection port 71 . when rotating the portable computer 6 horizontally through 180 ° and then inserted into the receiving open chamber 73 with the back side of the display screen 63 facing the portable docking station 1 , the electric connector 61 is connected to the other connection port 72 . fig8 is an exploded view of a portable computer and portable docking station arrangement constructed according to the fourth embodiment of the present invention . according to this embodiment , the receiving open chamber 93 of the swinging bracket 9 is further deeper ; the swinging bracket 9 comprises two connection ports 91 and 92 disposed in the receiving open chamber 93 and equally spaced from the center of the receiving open chamber 93 at two sides ; the portable computer 8 comprises two electric connectors 81 and 82 disposed at the bottom side 83 corresponding to the connection ports 91 and 92 in the receiving open chamber 93 . when inserted the bottom side 83 of the portable computer 8 into the receiving open chamber 93 with the front side of the display screen 84 facing the portable docking station 1 , the electric connectors 81 and 82 are respectively connected to the connection ports 91 and 92 of the swinging bracket 9 . when inserted the bottom side 83 of the portable computer 8 into the receiving open chamber 93 with the back side of the display screen 84 facing the portable docking station 1 , the electric connectors 82 and 81 are respectively connected to the connection ports 91 and 92 of the swinging bracket 9 . according to the aforesaid embodiments of the present invention , the locations of the electric connectors at the portable computer and the connection ports in the receiving open chamber of the swinging bracket may be properly changed to fit different conditions of use . fig9 is an exploded view of a portable computer and portable docking station arrangement constructed according to the fifth embodiment of the present invention . according to this embodiment , data transmission between the portable computer 96 and the portable docking station 95 is achieved by means of a wireless transmission arrangement , i . e ., a first wireless transmission apparatus 951 is provided at the portable docking station 95 and a second wireless transmission apparatus 961 is provided at the portable computer 96 . the first wireless transmission apparatus 951 and the second wireless transmission apparatus 961 according to this embodiment are infrared transmission apparatus . through these two infrared transmission apparatus , a wireless data transmission operation can be done . a prototype of portable computer and portable docking station arrangement has been constructed with the features of fig1 – 9 . the portable computer and portable docking station arrangement functions smoothly to provide all of the features discussed earlier . although particular embodiments of the present invention have been described in detail for purposes of illustration , various modifications and enhancements may be made without departing from the spirit and scope of the invention . accordingly , the invention is not to be limited except as by the appended claims .