GB2329273A - Computer theft alarm mounted on an expansion card - Google Patents

Abstract

A PC expansion card 22 comprises an alarm detector 24 comprising means 26, 28, 30 to sense a condition comprising tilt in two opposite directions 32, 34 angled to each other, in each of two planes, one parallel to the card and one perpendicular to the card and/or light. The tilt sensing means may comprise a bent tube (261 Fig.6) containing mercury (40) and with electrodes (42, 44, 46) at each end and/or the middle. The card comprises means 48 to produce an actuating signal for an alarm, comprising delay means (54 Fig.5) requiring a persistence of detection of said condition for a predetermined period before producing the signal (50); and to produce a first actuating signal (56) for a low volume alarm warning, comprising means (58) for timing a predetermined interval, and to produce a second actuating signal (60) for an alarm if detection of said condition persists beyond said period. The card comprises programming means (62) to adjust said period and/or interval, to adjust the level of light at which said condition is detected and/or the total period for which the alarm can be given, and to select from among different sound types of an alarm sounding device (52). The card comprises a password security system (74) on two levels, such that use of a first password (75) enables various functions to be accessed including change of itself (75), and use of a second password (77) enables various functions to be accessed including change of itself (77) and of the first password (75), but use of the first password does not enable access to change of the second password (77). The card is controlled from a keyboard (76 Fig.5) of a PC (78) to which the card is fitted; it comprises means (80) to produce a remote control signal (82) comprising a radio signal and/or an ultrasonic signal; it comprises battery means (82) rechargeable from a PC (78) to which the card is fitted.

Description

"Alarms" Field of the Invention This invention relates to alarms, more particularly for PCs, but may have other applications, and relates to items which may be used in such alarms.

Background It has been proposed to provide a PC expansion card to which is mounted a vibration switch, intended to be used to sense movement supposed to indicate that the PC is being stolen. This suffers from the disadvantage that, in order that it should not be over-sensitive to ordinary movements in the course of normal use, it requires a short, sharp knock to operate it, and considerable gentle movement of the PC can be effected without triggering the alarm, even as much as a complete vertical rotation of the PC.

The Invention According to one aspect of the invention there is provided a PC expansion card as claimed in claim 4. The use of tilt means in relation to the aforesaid proposal did not suggest itself because tilt means traditionally require too precise mounting and are too sensitive, while the vibration switch can be soldered into a PC card in any position, not critically sensitive to angle, and is cheap and easy to fit. However, the present inventor realised that the particular problems of a PC alarm could be solved by use of a tilt means detector, particularly if used with means having the equivalent effect of reducing or avoiding its critical sensitivity.

Also, it will be apparent that the invention can have wider applications than to a PC. According to another aspect of the invention there is provided a unit as claimed in claim 1. In such other applications, the unit may have the further features of claim 2 or 3. Indeed, the latter features may be useful in their own right and a further aspect of the invention consists in a unit as claimed in claim 37. The PC expansion card is an example of a unit used in or adapted for use in a transportable device which can be carried by hand.

The features of claim 5 serve to improve the sensitivity to detect tilt, the features of claim 6 serve to reduce the critical sensitivity mentioned above. The features of claim 7 provide a practicable range, with a preferred value of about 4", though other values from 2" up to 10 , 15 or even 20 may be usable in particular circumstances, e.g. for laptop computers. In order that the expansion card can be used universally in the vertical or horizontal position (depending upon the model of PC to which it is to be fitted) the features of claim 8 are useful. The features of claim 9 apply to such a case, and provide a practicable range, with a preferred value of about 4", though other values from 2" up to 10 , 15 or even 20 may be usable in particular circumstances, e.g. for laptop computers. The tilt-sensing means may have the features of claim 10 in order to use existing tilt-sensing devices or may have the features of claim 11 which effectively combines two devices into one and simplifies mounting to a printed circuit board, a very practical example having the features of claim 12. Such a device may be an invention in its own right, as also, more broadly, may the features of claim 5. Thus, according to another aspect of the invention, there are provided tilt-sensing means as claimed in claim 34, possibly with the added features of claim 35 or 36 with the advantages stated above.

The features of claim 13 can help to solve various problems; and, for example, complement the tilt-sensing means to detect, in effect, if the cover of the PC is removed, e.g. for the purpose of interfering with the alarm detecting means and/or trying to steal other internal components such as processors or memory chips. This can be made very effective with the features of claim 14. For convenience, the same card will have the features of claim 15.

The features of claim 17 can protect the unit against false alarms by allowing a short period of movement before the alarm proper is triggered; this will protect against e.g. accidental jolts. Further, the features of claim 19 can be used to protect against false alarms, for example due to deliberately taking the cover off the computer, and can be used to give a short warning period during which the alarm sounds at reduced volume to warn the user to stop moving the computer or replace the cover or programme in the necessary commands to stop the alarm, before the alarm sounds at full volume. The features of claim 20 provide a particularly economical and neat arrangement. These methods of protecting the unit against false alarms, and combining to economise on the generation of waming and alarm signals, may be inventions in their own right and, according to further aspects of the invention, there are, for example, provided PC cards as claimed in claims 38, 39 or 43.

The features of claims 14, 16, ls, 21 and 22 enable the card to be made extremely versatile and for the user to have improved and considerable control over its operating parameters, and facilitate detecting a theft (and possibly catching the thief), or even just unauthorised removal of a PC from a central store, by allowing optimum sensitivity to be chosen, which advantages are enhanced by the features of claim 23 which allow ease of choice and/or adjustment.

To enable the card to be made extremely versatile and for the user to have considerable control over its operating parameters, and for security, the card may have the features of claim 24, and to provide a much wider range of possible applications, the features of claim 25. The latter may be used, for example, in a case where a user is an employee and knows the first password and leaves his employment; his employer and/or supervisor can then use the second password to re-securitize the PC. It will be apparent that such features can be used particularly when the card interfaces with the computer, since these functions can then be carried out from the computer keyboard.

The features of claim 26, and preferably 27 for simplification, effectively give the whole arrangement watertight security against keyboard interference with the alarm card. Of course, such functions can be used in a wider context and, according to further aspects of the invention, there are, for example, provided PC cards as claimed in claims 32, 33 and 42. Another aspect of the invention consists, broadly, in a PC expansion card which comprises a password security system, e.g. for other use; for example, it may be required to insert a securitizing PC expansion card into an existing computer to securitize some of its functions. Of course, further levels can be added.

Clearly, it is a great convenience to have the features of claim 28 and such a card can be very versatile, particularly because it facilitates control by the user.

The features of claim 31 can reduce the equipment actually inside the PC and avoid radio interference with its operation. In such a case, a relay responsive to the remote signal may be located secretly in the same room or otherwise within "sensing distance" (e.g. 30 metres for a radio link) from the PC, e.g. to transmit a radio or electric-wire signal, which will remotely control an alarm. The feature of claim 32 substantially reduces the possibility that a thief can readily cut wires from a battery to the alarm's control gear. For a similar reason, the card can comprise the alarm (sounder, flasher, remote signal generator or the like). Since the PC expansion card interfaces with the PC, the features of claim 33 are particularly convenient.

It will be apparent to one skilled in the art that features of the various claims, embodiments described herein and other examples mentioned above, can be combined, selected and/or omitted and any new and useful combination thereby provided will constitute a further aspect of the invention.

Particular Descrintion Reference will now be made by way of example to the accompanying drawings, in which: Figure 1 is a diagrammatic, partially cut away, front plan view of a transportable device embodying the invention; Figure 2 is a diagrammatic side elevation of an expansion card comprising another embodiment of the invention; Figure 3 is a partial plan view corresponding to Figure 2; Figure 4 is a schematic block diagram corresponding to Figure 2; Figure 5 is a schematic block diagram corresponding to part of Figure 2; and Figure 6 is a schematic side elevation of a tilt switch comprising another embodiment of the invention.

Referring to the drawings, references with the same two digits at the beginning, in any of the Figures, refer to items having like functions.

Referring to Figure 1, a unit 10 comprises an alarm detector 12, used in, or adapted for use in (e.g. by being a PC expansion card), a transportable device 14 which can be carried by hand. The detector 12 comprises means 16 to sense a condition comprising tilt and possibly light. When comprising a tilt sensor 16, the detector has more application to a device 14 not normally likely to be moved (transportable but not portable), e.g. a PC, TV or video recorder, due to the movement possibly being like that to be detected as unauthorised, but could have application to a portable device 14, e.g. a laptop computer type of PC. The device 14 comprises a casing 18, and comprises adhesive means 20, e.g. a pad of adhesive material, to mount it in said casing 18. The battery could then be provided with a "low-charge" alarm, e.g. an intermittent (e.g. once per minute) bleep.

As more particularly envisaged, a PC expansion card 22 comprises an alarm detector 24, which itself comprises means 26, 28, 30 to sense a condition comprising tilt and possibly light. Of these means, tilt-sensing means 26, 28 are adapted to detect tilt in two opposite directions 32, 34, i.e. tilt of device 14 fitted with card 22 towards the direction 32 or 34. If one direction of tilt detection were used alone, tilt-sensing would be wholly absent in the opposite direction. As it is, if the directions were 1800 apart, tilt-sensing would be too sensitive in either direction and impractical.

Accordingly, the directions 32, 34 are angled to each other. The angle between each of the directions 32, 34 and a nominal horizontal 36 of the card is 3-5 . As can be seen by reference to both of Figures 2 and 3, the directions 32, 34 and 321, 341 are angled to each other in each of two planes, one (the plane of Figure 2) parallel to the card 22 and one (the plane of Figure 3) perpendicular to the card 22. This allows the alarm to be triggered when the card 22 is mounted in the computer 78 either horizontally or vertically. The angle between each of the directions 32, 34 and 321, 341 and a nominal horizontal 36 of the card is 3-5" in the plane parallel to the card 22 and in the plane perpendicular to the card 22.

The tilt-sensing means 26, 28 comprise two tilt-sensing devices 26, 28 mounted to the card 22 to detect tilt in said opposite directions 32, 34 and 321, 341 respectively. These may be conventional mercury tilt switches 26, 28. Alternatively, the tilt-sensing means 261, Figure 6, comprise a single device 261 that can detect tilt in two opposite directions 322, 342, e.g. angled to each other and to a nominal horizontal 362 of the card, e.g. a bent (e.g. curved) tube 38 containing mercury 40 and with electrodes 42, 44 at each end and/or with electrodes 46 at the middle. In either case, a sufficient movement in either direction will switch the device 261. In any of these cases, a make or a break can be used to provide a trigger actuating signal, or to start an actuating signal maintained until some other occurrence terminates it.

Referring to Figures 2, 4 and 5, the card 22 comprises means 48 adapted to produce an actuating (e.g. trigger or maintaining) signal 50 for an alarm. Means 48 comprise delay means 54 requiring a persistence of detection of said condition for a predetermined period before producing the signal 50. Means 54 can provide "jolt tolerance". This provides a method of protecting the card 22 against giving one kind of false alarm. It allows a short period of movement before the alarm is triggered, in order to protect against accidental jolts. The tolerance can be from about 0-2 seconds (preferably adjustable in 0.1 second increments, see below), preferably set to somewhat less than 1 second, assuming the mercury probably takes about 0.1 second to settle down after disturbance.

The means 48 are further adapted to produce a first actuating (e.g. trigger or maintaining) signal 56 for an alarm warning, for this purpose comprising means 58 for timing a predetermined interval and adapted, by inclusion of alarm signal generating means 59 to produce a second actuating (e.g. trigger or maintaining) signal 60 for an alarm if detection of said condition persists beyond said interval. Means 48 cause a sounding device 52 to produce a warning signal responsive to said first actuating signal 56 and an alarm signal responsive to said second actuating signal 60, such that said warning signal shall be a lower intensity form of said alarm signal.

This provides a method of protecting the card 22 against giving another kind of false alarm. It allows a short warning period during which the alarm sounds at reduced volume to warn the user to stop moving the computer 78 before the alarm sounds at full volume, e.g. if the user has forgotten that there is an alarm. The short warning period can be 0-10 seconds, preferably adjustable in 1 second increments, see below.

(Setting the warning period to zero increases sensitivity or responsiveness to theft at the expense of increased false alarms.) Detector 12 comprises means 30 to sense a condition comprising light. This light sensor 30 comprises a light-dependent resistor.

Programming means 62 (a microcontroller) serve to allow adjustment or choice of said period and/or interval by means of signals 64, 66 respectively, of the level of light at which said condition is detected and/or the total period for which the alarm can be given (its duration) by means of signals 68, 70 respectively, and possibly to switch off the light sensor 30 and/or tilt-sensing means 26, 28, e.g. to allow access to the inside of the PC casing without actuating the alarm detector 12.

As sold, the card 22 comprises alarm indicating device 52 adapted to produce said alarm signal in the form of a sound signal, comprising an alarm sounding device 52, preferably a piezo sounder; and comprises the programming means 62 which also serve to allow selection by the user from among different sound types by means of signal 72, e.g. sound types including warble, alternating two-tone, pips, and continuous.

The card 22 comprises a password security system 74 (part of the microcontroller 62). This controls functions of the card 22 (e.g. access to choice and adjustment of the various parameters mentioned above, and temporary suspension of various alarm functions, and/or, maybe only, as a gateway to access of some PC function, programme or data) and is on two levels, such that use of a first password 75 enables various functions to be accessed including change of itself 75, and use of a second password 77 enables various functions to be accessed including change of itself 77 and of the first password 75, but use of the first password does not enable access to change of the second password 77. For security, the passwords cannot be read from the microcontroller 62, which simply verifies that a password is correct before any changes can be actioned; this can be effected by pre-programming the microcontroller 62. For this purpose, the password security system 74 has an adaptation (partly the pre-programming) such that a said password cannot be retrieved by use of a keyboard of a PC to which the card is fitted, or otherwise by use of software, without physically accessing the card 22. To back up the security of this, and avoid the possibility of changing the pre-programming from the keyboard, said adaptation further comprises a signal terminal adapted to be used for programming the card and adapted not to be connected to a PC to which the card is fitted. This signal terminal is in contrast to the usual terminal of, for example, an EPROM, which has to be connected to high voltage to cancel the EPROM's programme and allow it to be re-programmed.

The card 22 is adapted to be controlled from a keyboard 76 of a PC 78 to which the card 22 is fitted, and further comprises means 80 to produce a remote control signal 82 to operate a remote receiver 84. The remote control signal 82 may comprise a radio signal and/or an ultrasonic signal.

As sold, the card 22 comprises battery means 82 adapted to be rechargeable from the PC 78 to which the card 22 is fitted.

The expansion card 22 comprises a printed circuit board 86 to which are mounted the usual fixing bracket 88, the tilt switches 26, 28 and all the other components.

The functional block diagrams of Figures 4 and 5 show the overall operation of the alarm. Tilt switches 26, 28 and light sensor 30 feed into a pickup unit 90 which feeds into the jolt tolerator delay means 54, which feeds into the warning maintaining signal generating means 58, which after a delay provides an alarm actuation signal to alarm maintaining signal generating means 59. This in turn feeds into a signal generator 61, which comprises a transistor drive 91 to a transformer 92 feeding piezo sounder 52. Programming means 62 comprise an electrically erasable microcontroller chip obtained under the trade name PIC 16 C 84 from Arizona Microchip Technology Ltd of Buckinghamshire, UK, which can be programmed by an external programming unit for 1024 words of internal programme and has a 64 byte memory that can be programmed by the internal programme, and is shown in Figure 4 for simplicity without the various timing and delay functions. This is connected through interface 93 to the address and data bus 94 of the PC 78 and hence to keyboard 76. The interface 93 to the computer address and data bus 94 is provided to enable passwords to be entered and changes to the settings described herein to be made from the computer keyboard 76 using a setup programme run on the personal computer 78. To simplify the interface to the computer 78 the data is transferred in serial format. For ease of installation the base address (port) of the unit 10 at which the computer 78 communicates with the unit 10 may be selected automatically by the setup programme, or chosen manually by the user. Battery 82 is connected from the computer power rails 95 and in turn feeds the power rails 96 of card 22.

Ajolt will not operate the alarm. A sufficient (assumed theft-like) movement will produce a low warning alarm signal. This can be stopped by the knowledgeable user (and possibly a thief) simply stopping the movement. A prolongation of the movement will cause a loud alarm signal, up to perhaps 20 minutes long. This, in increments of 1 minute, together with the other adjustments and selections mentioned above can be set by controlling through keyboard 76 the programme in the microcontroller 62.

It will be seen that all the alarm functions are controlled by a microcontroller (or similar circuitry) mounted on an expansion card 10 forming an alarm detector unit 10.

This unit 10 is mounted in one of the computer's expansion slots, and is powered by a selfcontained battery 82 comprising rechargeable cells such as nickel metal hydride cells. These are charged from the computer's power supply 95 when the computer 78 is switched on, and power the alarm 52 when an attempt is made to steal the computer 78.

Claims (45)

1. A unit comprising an alarm detector, used in or adapted for use in a transportable device which can be carried by hand, characterised in that the detector comprises means to sense a condition comprising tilt.

2. A unit as claimed in claim 1, characterised in that the detector comprises means to sense a condition comprising light.

3. A unit as claimed in claim 1 or 2, characterised in that it is used in or adapted for use in a transportable device comprising a casing, and comprises adhesive means to mount it in said casing.

4. A PC expansion card comprising an alarm detector, characterised in that the detector comprises means to sense a condition comprising tilt.

5. A card as claimed in claim 4, characterised in that it comprises tilt sensing means adapted to detect tilt in two opposite directions.

6. A card as claimed in claim 5, characterised in that the directions are angled to each other

7. A card as claimed in claim 6, characterised in that the angle between each of the directions and a nominal horizontal of the card is 3-5".

8. A card as claimed in claim 7, characterised in that the directions are angled to each other in each of two planes, one parallel to the card and one perpendicular to the card.

9. A card as claimed in claim 8, characterised in that the angle between each of the directions and a nominal horizontal of the card is 3-5" in the plane parallel to the card and in the plane perpendicular to the card.

10. Means as claimed in any one of claims 5 to 9, characterised in that the tilt sensing means comprise two tilt sensing devices mounted to the card to detect tilt in said opposite directions respectively.

11. A card as claimed in any one of claims 5 to 9, characterised in that the tilt sensing means comprise a single device that can detect tilt in two opposite directions.

12. A card as claimed in claim 11, characterised in that said single device comprises a bent tube containing mercury and with electrodes at each end and/or the middle.

13. A unit as claimed in any one of claims 4 to 12, characterised in that the detector comprises means to sense a condition comprising light.

14. A card as claimed in claim 13, characterised in that it is adapted for adjustment or choice of the level of light at which said condition comprising light is detected.

15. A card as claimed in any one of claims 4 to 14, characterised in that it comprises an alarm device adapted to produce an alarm signal.

16. A card as claimed in claim 15, characterised in that said alarm device is adapted to produce said alarm signal in the form of a sound signal and the card comprises means to make a selection from among different sound types thereof.

17. A card as claimed in any one of claims 4 to 16, characterised in that it comprises means adapted to produce an actuating signal for an alarm, comprising delay means requiring a persistence of detection of said condition for a predetermined period before producing the signal.

18. A card as claimed in claim 17, characterised in that it is adapted for adjustment or choice of said period.

19. A card as claimed in any one of claims 4 to ls, characterised in that it comprises means adapted to produce a first actuating signal for an alarm warning, comprising means for timing a predetermined interval and adapted to produce a second actuating signal for an alarm if detection of said condition persists beyond said interval.

20. A card as claimed in claim 19, comprising means to produce a warning signal responsive to said first actuating signal and an alarm signal responsive to said second actuating signal, such that said waming signal shall be a lower intensity form of said alarm signal.

21. A card as claimed in claim 19 or 20, characterised in that it is adapted for adjustment or choice of said interval.

22. A card as claimed in claim 21, characterised in that it is adapted for adjustment or choice of the duration of an alarm signal.

23. A card as claimed in any one of claims 14 to 22, characterised in that it comprises programming means to enable adjustment or choice of, as the case may be, said level and/or selection and/or period and/or interval and/or duration.

24. A card as claimed in any one of claims 4 to 23, characterised in that it comprises a password security system.

25. A card as claimed in claim 24, characterised in that the password security system is on two levels, such that use of a first password enables various functions to be accessed including change of itself, and use of a second password enables various functions to be accessed including change of itself and of the first password, but use of the first password does not enable access to change of the second password.

26. A card as claimed in claim 24 or 25, characterised in that the password security system has an adaptation such that a said password cannot be retrieved by use of a keyboard of a PC to which the card is fitted, or otherwise by use of software, without physically accessing the card.

27. A card as claimed in claim 26, characterised in that said adaptation comprises a signal terminal adapted to be used for programming the card and adapted not to be connected to a PC to which the card is fitted.

28. A card as claimed in any one of claims 4 to 27, characterised in that it is adapted to be controlled from a keyboard of a PC to which the card is fitted.

29. A card as claimed in any one of claims 4 to 28, characterised in that it comprises means to produce a remote control signal.

30. A card as claimed in claim 29, characterised in that said means to produce a remote control signal are adapted to produce such a signal comprising a radio signal.

31. A card as claimed in claim 29 or 30, characterised in that said means to produce a remote control signal comprises an alarm device adapted to produce an alarm signal in the form of a sound signal and adapted to produce a said remote control signal comprising an ultrasonic signal.

32. A card as claimed in any one of claims 4 to 31, characterised in that it comprises battery means.

33. A card as claimed in claim 32, characterised in that said battery means are adapted to be rechargeable from a PC to which the card is fitted.

34. Tilt sensing means, characterised in that they are adapted to detect tilt in two opposite directions.

35. Means as claimed in claim 34, characterised in that it comprises a bent tube with electrodes at each end and containing mercury.

36. Means as claimed in claim 34 or 35, characterised in that it comprises a bent tube with electrodes in the middle and containing mercury.

37. An alarm detector unit, characterised in that it is used in or adapted for use in a transportable device comprising a casing, and comprises adhesive means.

38. A PC expansion card, characterised in that it comprises means adapted to produce an actuating signal for an alarm, comprising delay means requiring a persistence of detection of said condition for a predetermined period before producing the signal.

39. A PC expansion card, characterised in that it comprises means adapted to produce a first actuating signal for an alarm warning, comprising means for timing a predetermined interval and adapted to produce a second actuating signal for an alarm if detection of said condition persists beyond said period.

40. A PC expansion card, characterised in that it comprises a password security system to control access to a function of the card.

41. A PC expansion card, characterised in that it comprises a password security system which is on two levels, such that use of a first password enables various functions to be accessed including change of itself, and use of a second password enables various functions to be accessed including change of itself and of the first password, but use of the first password does not enable access to change of the second password.

42. A PC expansion card, characterised in that it comprises a password security system that has an adaptation such that a password cannot be retrieved by use of a keyboard of a PC to which the card is fitted, or otherwise by use of software, without physically accessing the card.

43. An alarm unit, characterised in that it comprises means to produce a warning signal responsive to a first actuating signal and an alarm signal responsive to a second actuating signal, such that said warning signal shall be a lower intensity form of said alarm signal.

44. A unit, PC expansion card or tilt sensing means, substantially according to any example hereinbefore described.

45. A unit, PC expansion card or tilt sensing means, substantially according to any example hereinbefore described with reference to and illustrated in the accompanying drawings.

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