[ 0020 ] fig1 shows a port replicator docking unit , which has been constructed according to the principles of the present invention . generally , the port replicator 100 comprises a computer docking bay 110 , which is configured to receive a compatible portable computer on the port replicator 100 . to this end , the right and left tabs 112 , 114 are provided on a front wall 111 of the docking unit 100 . the tabs 112 , 114 project rearward from the front wall 111 and are located over wells 116 , 118 . as detailed in fig1 a , tabs 112 , 114 mate with rectangular recesses on the front of a compatible portable computer 10 , allowing the front of the portable computer to be physically connected into the docking unit . specifically , the portable computer 10 is aligned in the computer docking bay area 110 so that the rectangular recesses 12 in the portable computer &# 39 ; s housing are aligned in front of each of the projecting tabs 112 , 114 . the computer is then moved in the direction of arrow 14 so that the tabs 112 , 114 engage the recesses 12 . this connection has the effect of hinging the front of the computer 10 to the port replicator 100 . returning to fig1 in the central section of the docking unit 100 , a cutout 120 is formed . in the preferred embodiment , this extends entirely through the docking unit . this has the advantage of providing an easy means for carrying the docking unit , forming an improvised handle . rearward of the cutout 120 is battery charging cradle 122 . better shown in fig2 the cradle 122 is sized and adapted to receive battery 124 . when inserted into the cradle , the battery &# 39 ; s electrodes 126 electrically mate with the charging connector 127 in the charging cradle 122 . [ 0025 ] fig3 shows the battery 124 installed in the charging cradle . preferably , the top wall 125 of the battery 124 is flush or level with a bay wall 129 of the docking unit 100 . a battery charging unit 128 is located in an electronics section 127 under bay wall 129 of the docking unit 100 . in the preferred embodiment , the battery is a lithium ion battery and the charger 128 is adapted to provide the charging profile required for lithium ion batteries . behind the battery charging cradle 122 on the top bay wall 129 of the docking unit 100 is a combination connector 130 . as shown in fig4 installing the portable computer 10 onto the docking unit is accomplished by engaging the tabs 112 , 114 with the rectangular recesses 12 to provide the hinging action at the point of connection between the computer 10 and the front of the docking unit 100 . as the rear portion of the computer 10 descends into the docking bay 110 , the docking unit &# 39 ; s combination connector 130 electrically mates with the compatible connector 14 on the bottom of the portable computer 10 . this allows the portable computer &# 39 ; s communication ports to be replicated at the communication port connectors 131 on the port replicator 100 . also , the combination connector 130 provides electrical power to the portable computer 10 . the rear of the docking unit 100 has the array of communication port connectors or jacks 131 . preferably , these connectors comprise an rj - 45 connector 142 for connection to a network , a usb connector 144 , a power supply connector 146 , a parallel printer port connector 148 , a serial port connector 150 , a vga video port connector 149 , mouse port connector 152 , and a keyboard port connector 154 . these replicated port connectors 140 function as the replicated port connectors of the portable computer installed in the docking bay area . the ports of the portable computer connect to the replicated port connectors via the combination connector 130 . in the preferred embodiment , the docking unit 100 comprises a rear wall 182 that projects upward , over the docking bay 110 at the rear side of the unit 100 . this projecting wall 182 is preferably arcuate and projects in front of the communication port connectors 18 of the portable computer . this effectively prevents the simultaneous connection of devices to the portable computer &# 39 ; s communication port connectors and the same connectors of the docking unit , preventing incompatible electrical connection . the set of communication port connectors 18 of the portable computer include a parallel printer port connector 45 , a serial port connector 46 , and a vga video port connector 47 . these connectors 18 are accessed during mobile operation by opening the door 20 . however , as the portable computer 10 is inserted into the docking bay 110 of the docking unit 100 , projecting wall 182 engages the door 20 , if it is in the open position . this forces the door 20 closed as the portable computer 10 is completely seated into the docking bay 110 . it thus prevents access to the communication port connectors 18 of the portable computer 10 , requiring these connections to be made from the replicated port connectors 131 of the docking unit 100 . the final docked state is shown in fig5 when the computer 10 is installed on the docking unit 100 , the projecting wall 182 holds the door 20 closed , preventing access to the portable computer &# 39 ; s communication port connectors . according to the invention , the docking unit 100 has a wedge lateral cross - section . as shown , when the portable computer 10 is installed on the docking unit , the docking unit &# 39 ; s wedge shape inclines the portable computer &# 39 ; s keyboard 180 and pointing device 182 towards the user at an angle of between 7 ° and 13 °, preferably 10 °. this provides a more comfortable typing angle for the user , allowing the use of the portable computer &# 39 ; s keyboard when the portable computer is connected into the docking unit 100 without necessitating an extra , desktop - version keyboard . as best shown in fig4 docking unit 100 and portable computer 10 have a system for securing the computer to the unit . the docking unit has two latching elements 132 , 134 in the docking bay 110 . they allow the portable computer 10 to be latched on docking unit . in more detail , lowering the portable computer 10 onto the docking bay causes the bottom wall of the portable computer , surrounding the right and left latching holes 22 , 24 to engage latch release buttons 168 , 170 . this causes the latching elements 132 , 134 shown in their retracted position in fig4 to extend upward and toward the rear of the docking unit 100 . the latching elements 132 , 134 thus extend into the right and left latching holes 22 , 24 of the portable computer 10 to securely hold the rear of the portable computer 10 against the docking unit 100 in the docking bay 110 . this in combination with the engagement of the tabs 112 , 114 at the front of the portable computer , retain the portable computer 10 securely in the docking bay 110 . the latching system forms part of a security system for the portable computer . the latching elements 132 , 134 prevent the portable computer 10 from being removed from the docking unit 100 , and the docking unit is , in turn , secured at a work area via a locking cable arrangement that engages locking port 184 . in one example , a kensington ( trade name ) cable system is used that engages the port 184 to lock and secure the docking unit 100 to a workstation via a cable 221 shown schematically . the right and left latching elements 132 , 134 release the computer 10 and are returned to the retracted position by depressing right and left latch release buttons 136 , 138 , respectively . in the preferred embodiment , the latch release buttons 136 , 138 in combination with an undock request button 184 prevent removal of the portable computer 10 when it is docked to the docking unit 100 by unauthorized persons . [ 0036 ] fig6 is a schematic plan view showing the latch control system that operates the latching elements , which is located in the electronic section 127 of the docking unit 100 , according to the present invention . the right and left latch release buttons 136 , 138 each comprise elongate , metal rods 302 , 304 , respectively . additionally , the body portion of the buttons 136 , 138 each have camming surfaces 306 , 308 . when each of the latch release buttons 136 , 138 is depressed , the camming surfaces 306 and 308 engage arm portions 310 , 312 of the latching elements 132 , 134 . this causes the latching elements 132 , 134 to be retracted , and thereby release the computer 10 from the docking unit 100 . in order to provide security , the depression of the latch release buttons 136 , 138 is prevented in software . specifically , each of the metal arms 302 , 304 extends to a spring loaded locking element 314 . specifically , spring 316 biases the locking element 314 in the direction of arrow 318 against wall 320 . in an unlocked state , depression of of the latch release buttons 136 , 138 causes the pointed , distal ends of the metal rods 304 , 308 to engage the inclined surfaces 322 , 324 of the locking element 314 . the locking element 314 is free to rotate counter to arrow 318 to accommodate the movement of each of the rods in the direction of arrows 326 . in the locked state , however , an arm 330 of solenoid 332 is extended as shown in fig6 . this prevents the rotation of the locking element 314 counter to the direction of arrow 318 and thus in turn prevents the movement of the rods 302 , 304 in the direction of arrows 326 . by stopping the depression of buttons 136 , 138 , the retraction of the latching elements 132 , 134 is prevented , thereby retaining the portable computer on the docking unit 100 . the state of the solenoid arm 330 is sensed by switch 336 . [ 0040 ] fig7 shows a latch control system for operating the solenoid 332 . specifically , a microcontroller 342 located in the portable computer system 10 monitors for depression of the undock request button 186 , which is located on the docking unit &# 39 ; s right sidewall , see fig1 . when the depression of the undock request button 186 is detected , the microcontroller 342 communicates to the computer system &# 39 ; s operating system to request the entrance of a password by the user . if the proper password is entered , the operating system 342 communicates this to the microcontroller 340 , which signals , via an i 2 c bus , a latch 344 in the dock . the latch generates a pulse to a release bjt transistor 346 , which activates on retracting mosfet 348 . capacitor 350 controls the period of time the mosfet is turned on . this operates the solenoid 332 to retract the arm 330 . successful retraction of the arm 330 is detected by switch 336 . if the latch 344 fails to detect the change in state of the arm 330 of the solenoid 332 via switch 336 , the latch again issues a pulse to bjt 346 to try to attempt to retract the arm again . this continues until the arm 330 is successfully retracted . a similar process is used to lock the portable computer system 10 on the dock 100 . the microcontroller 340 functions as a docking detection system to detect the coupling of the computer &# 39 ; s connector 14 to the combination detector 130 on the dock 100 . when this event is detected , and an automatic locking state has been selected by the user in the operating system 342 , the microcontroller 340 issues a signal to latch 344 to enter a locked state . the latch generates a pulse via a locking bjt transistor 354 which operates mosfet 356 to extend the arm 330 of the solenoid 332 . capacitor 351 maintains the on state of mosfet 356 for the time required for the solenoid to change states . again , the successful movement of the solenoid arm 330 is detected by the feedback from the switch 336 to latch 344 . the latch continues to attempt to extend the arm 330 until it is successful . extension of the solenoid arm prevents the rotation of the locking element 314 shown in fig6 . this prevents the depression of buttons 136 , 138 and thus the undocking of the portable computer 10 from the docking unit 100 . in additional embodiments , the portable computer comprises a middle docking unit such that the portable computer unit is latched to the middle docking unit and the middle docking unit is latched to the port replicator . for example , such middle docking units provide extended multimedia capabilities to the portable computer . this system allows all three sections to be secured to the work area with a single locking cable . while this invention has been particularly shown and described with references to preferred embodiments thereof , it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims . those skilled in the art will recognize or be able to ascertain using no more than routine experimentation , many equivalents to the specific embodiments of the invention described specifically herein . such equivalents are intended to be encompassed in the scope of the claims .
a docking unit for a portable computer has a wedge - shaped . as a result , a portable computer , which has been installed on the docking unit , is inclined toward the user . this places the keyboard of the portable computer at a more comfortable angle for typing . thus , the portable computer &# 39 ; s keyboard remains usable even when it is installed on the docking unit . moreover , the wedge - shape need not substantially raise the height of the keyboards since the leading edge is relatively thin , keeping the computer &# 39 ; s keyboard as a comfortable height .