Abstract:
A portable device has an openable cover, the cover being open in normal operation. A method is provided for automatic deactivating the portable device. When the cover is detected to be in an open position and a key operated switch is in a locked position, the portable device is deactivated. The deactivation can be by means of a fusible element or by corruption of a non-volatile storage device required for the operation of the machine, such as a hard disk storing an operating system.

Description:
FIELD OF THE INVENTION 
     The present invention relates to portable devices and more specifically to deterring theft of portable computers. 
     BACKGROUND OF THE INVENTION 
     As portable computers such as laptop and notebook computers have become more popular and more powerful, they have become increasingly attractive targets for theft, including in the workplace of the computer&#39;s user. Portable computers, such as the ThinkPad laptop from IBM Corporation, are designed to be easily portable and it is this characteristic which also makes them easy to steal (ThinkPad and IBM are trademarks of IBM Corporation). The main factors which make them so easy to steal is that they are relatively small and can be easily concealed in a briefcase, bag or simply carried under the arm. This results in office theft of a portable computer being much simpler than the theft of larger equipment such as personal computers. 
     As such thefts have become more common and more costly, an assortment of devices and systems have been proposed for securing portable computers from theft. Solutions such as password protection on BIOS, hard drive and operating system have been implemented. In a related field, items such as car radios have a security code which must be entered whenever power has been removed from the unit. This may be either because the unit has been removed from the car or because the car&#39;s battery has been removed from the car. 
     However, these do not provide a visual deterrent against the stealing of a portable computer. A solution which does provide a visual deterrent is to fix machines to desks but this solution detracts from the advantages of having a portable computer. Another solution which does provide a visual deterrent is the use of a keylock which has to be operated before the machine will function. Typically such a keylock temporarily disables the keyboard and/or display screen, thus preventing use of the computer. Such a solution has been in use for many years, in, for example, the 3270 range of display terminals from IBM Corporation and the PC/AT personal computer from IBM Corporation (IBM and PC/AT are trademarks of IBM Corporation). However, such a system is relatively easy to bypass so as to enable operation of the computer without the key associated with the keylock. 
     There is thus a need for a device as a visual deterrent against the theft of a portable computer which is not easily bypassed. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides a method for automatic deactivating a portable device having an openable cover, the cover being open in normal operation, the method comprising the steps of: detecting whether the cover is in an open position; detecting whether a key operated switch is in a normal operating position or a locked position; and responsive to a determination that the cover is in an open position and that the key operated switch is in a locked position, deactivating the portable device. 
     The invention also provides apparatus for automatic deactivation of a portable device comprising: an openable cover, the cover being open in normal operation; means for detecting whether the cover is in an open position; a key operated switch having a normal operating position and a locked position, the cover being locked closed in said locked position; and means for deactivating the portable device, the means for deactivating being responsive to a determination that the cover is in an open position and that the key operated switch is in a locked position. 
     Preferably, the key operated switch operates by an interchange of electronic codes between a key and the key operated switch. 
     In an embodiment, the apparatus further comprises a fusible element which acts to deactivate the portable device in response to the means for deactivating the portable device. 
     In another embodiment, the apparatus further comprises a non-volatile memory means essential for normal operation of the portable device and means to damage the non-volatile memory means in response to the means for deactivating the portable device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a portable computer incorporating a keylock according to the present invention; 
     FIG. 2 is a block diagram of the portable computer of FIG. 1; 
     FIG. 3 is a perspective view showing the construction of a keylock mechanism in a first key position; and 
     FIG. 4 is a perspective view showing the construction of a keylock mechanism in a second key position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a portable electronic device such as a laptop or notebook computer  100  having a base  102  and a cover  104 . The base  102  and cover  104  are rotatably connected by a hinge  106 . Located in the base  102  is a lock  108  which is operated by a key  110 . The lock  108  co-operates with a mechanism  112  located on the cover  104  of the portable computer  100  so as to allow the cover  104  to be opened relative to the base  102  of the computer  100  when a key  110  has been correctly inserted into the lock  108 . This allows normal operation of the portable computer  100  when the cover  104  is open. The lock  108  also co-operates with the mechanism  112  so as to prevent the cover  104  from being opened relative to the base  102  of the computer  100  when no key  110  or the wrong key  110  has been inserted into the lock  108 . This prevents normal operation of the portable computer  100  when the cover  104  is closed. 
     FIG. 2 shows a prior art portable computer  100 , comprising a keyboard  212 , a pointing device  213  and a display  214  depicted in block diagram form. The portable computer  100  includes a system bus or plurality of system buses  221  to which various components are coupled and by which communication between the various components is accomplished. The microprocessor  222  is connected to the system bus  221  and is supported by read only memory (ROM)  223  and random access memory (RAM)  224  also connected to system bus  221 . In many typical computers the microprocessors including the  386 ,  486  or Pentium microprocessors (Intel and Pentium are trademarks of Intel Corp.). However, other microprocessors including, but not limited to, Motorola&#39;s family of microprocessors such as the 68000, 68020 or the 68030 microprocessors and various Reduced Instruction Set Computer (RISC) microprocessors such as the PowerPC chip manufactured by IBM, or other microprocessors from Hewlett Packard, Sun, Motorola and others may be used in the specific computer. 
     The ROM  223  contains among other code the Basic Input-Output System (BIOS) which controls basic hardware operations such as the interaction between the CPU and the disk drives and the keyboard. The RAM  224  is the main memory into which the operating system and application programs are loaded. The memory management chip  225  is connected to the system bus  221  and controls direct memory access operations including, passing data between the RAM  224  and hard disk drive  226  and floppy disk drive  227 . The CD ROM  232  also coupled to the system  221  is used to store a large amount of data, e.g. a multimedia program or presentation. CD ROM  232  may be an external CD ROM connected through an adapter card or it may be an internal CD ROM having direct connection to the motherboard. 
     Also connected to this system bus  221  are various I/O controllers: the keyboard controller  228 , the pointing device controller  229 , the video controller  230  and the audio controller  231 . As might be expected, the keyboard controller  228  provides the hardware interface for the keyboard  212 , the pointing device controller  229  provides the hardware interface for pointing device  213 , the video controller  230  is the hardware interface for the display  214 , and the audio controller  231  is the hardware interface for the speakers  215   a  and  215   b . The power management controller  234  is connected to the system bus and receives power from a battery or from an external power supply which converts the ac voltage from a building supply to a predetermined lower dc voltage used to operate the portable computer  100 . An I/O controller  240  such as a Token Ring adapter card enables communication over a network  246  to other similarly configured data processor systems. These I/O controllers may be located on the motherboard within the portable computer or they may be located on adapter cards or cartridges which plug into the motherboard. The adapter cards may communicate with the motherboard using a PCI interface, an ISA or EISA interface or other interfaces. 
     Referring to FIG. 1, the lock  108 , in addition to co-operating with mechanism  112  to physically prevent the cover  104  being opened relative to the base  102  of the computer  100 , incorporates a keylock microswitch so that the state of the lock can be determined by the computer  100 . 
     Referring to FIG. 3, the lock mechanism comprises a key  110 , a key hole  108 , a cylinder  302  and a bracket  304 . The position of the bracket  304  can be changed by rotating the key  110 , but the relative orientation of the bracket  304  and the key  110  are always the same. The key  110  may operate the cylinder  302  mechanically or it may operate the cylinder  302  by the interchange of electronic codes between the key  110  and the cylinder  302 . The lock mechanism of FIG. 3 is shown in a first position. In the first position, the cover  104  may be opened relative to the base  102  and the computer  100  operates normally. 
     FIG. 4 shows the lock of FIG. 3 in a second position. In the second position, the cover  104  is locked relative to the base  102  and the computer  100  does not operate normally. In the second position, a extended portion  306  provided on one end of the bracket  304  contacts a switch terminal  310  of the keylock microswitch, thus providing an indication as to whether a correct key  110  has been inserted and the lock mechanism operated correctly. The lock mechanism should not be capable of being moved from a normal operating position to a locked position whilst the cover is open, otherwise inadvertent operation of the deactivating mechanism will occur. In a variation of the present invention, the meanings of the first position being a normal operating position and the second position being a locked position may be reversed and the microswitch activated in an unlocked position, rather than in the locked position. 
     Mechanism ( 112  in FIG. 1) includes a switch which indicates whether the cover  104  is open or whether the cover  104  is closed. In the circumstances that the keylock microswitch  308  detects that the correct key has not been inserted and the lock mechanism has not been operated correctly AND that the mechanism ( 112  in FIG. 1) indicates that the cover is open, then in accordance with the present invention, the portable computer is disabled either permanently or semi-permanently. These circumstances could arise if a wrong key was inserted and the lock forced or if the cover  104  of the portable computer  100  was prised open without the use of a key. Such a method of opening is likely to be used if the unit was stolen. 
     The portable computer  100  may be disabled either permanently or semi-permanently in a number of different ways. Each of the different ways is intended to disable the portable computer  100  in such a manner that re-enablement of the computer is either not possible at all or is only possible if the computer is taken to a service centre or the like. In a first embodiment, a fuse in the power management circuit ( 234  in FIG. 2) may be forced to be blown by having a circuit operated that causes excessive current to flow through the fuse. The fuse should not be user-replaceable, but should be either not replaceable or service centre only replaceable. In a second embodiment, the fixed disk drive  226  may be caused to be corrupted so as to be unusable. Preferably, such corruption should not be such that it is possible to easily recover from the corruption by, for example, reformatting the hard disk. Alternatively, if the protection of the information stored on the hard disk is of primary consideration and the value of the machine itself is of secondary consideration, then reformatting the hard disk to restore the machine may be allowed. In this situation, protection against disclosure of the information stored on the hard disk of the computer is obtained. Corruption of the hard disk may be achieved by, for example, over-writing the control areas of the disk, such as for example, the File Allocation Table or Tables. 
     The invention described above means that the computer is not operable without the use of the correct key and if there is an indication of this placed on the outside of the computer, then a deterrent against theft is provided.