GB2316211A

GB2316211A - A security device

Info

Publication number: GB2316211A
Application number: GB9616462A
Authority: GB
Inventors: Philip James Henderson
Original assignee: DASHCROWN Ltd
Current assignee: DASHCROWN Ltd
Priority date: 1996-08-05
Filing date: 1996-08-05
Publication date: 1998-02-18
Also published as: GB9616462D0

Abstract

There is described a security device for inhibiting unauthorised interference with electrical and/or electronic apparatus The security device comprises: vibration detection means B having a low vibration sensitivity setting and a high vibration sensitivity setting; switching means 70 operable to switch the vibration detection means between said low sensitivity and said high sensitivity in response to the electrical and/or electronic apparatus being switched off or being disconnected from its power source; and means C, D, E, for initiating an alarm signal, the means for initiating being connected to the vibration detection means and operable to initiate an alarm signal in response to a signal from the vibration detection means that a vibration has been detected. At least one of the sensitivities may be adjustable and the low sensitivity may in fact be zero. A security system comprising a plurality of such devices, for a plurality of items of apparatus, is also disclosed.

Description

A SECURITY DEVICE This invention relates to a security device, electrical and/or electronic apparatus, and a security system.

Theft of electrical and/or electronic apparatus, in particular the theft of computers, their peripherals, or internal components, is a major problem.

A wide variety of security devices exist and are well known, including mechanical locks and vibration detectors able to detect movement during attempted removal of, or disturbance to, the apparatus to which the security device is attached. Problems with mechanical locks are that secure attachment to the apparatus may be difficult to achieve, given sufficient time a thief may be able to defeat them, and no alarm is signalled during the thief's attempt to remove the apparatus. Security devices incorporating vibration or movement detectors are known for the protection of computers, and which transmit an alarm signal via a network link or a dedicated hardwired link to an alarm system when activated. Typically, these devices are set or switched on either by entering a code via a keypad, or by operating a key-switch. However, a problem with these kind of devices is that the necessary hardwired links may be expensive and/or inconvenient to install, and in any case may be broken. In addition, these devices have only one sensitivity as determined by the vibration detection element composition, may inadvertently be activated or triggered during the periods of normal use of the computer if switched on, and rely on users remembering to leave them switched on overnight or over any period during which their protection is desired. A user is also required to remember a code, or carry a key to operate the keyswitch.

Therefore, it is desirable to produce a security device incorporating a vibration detector which may be attached to a wide variety of electrical and/or electronic apparatus without the provision of wiring in addition to that required for the normal operation of the apparatus, transmits an alarm signal when activated, is less likely to be activated inadvertently, and yet provides sensitive protection for the apparatus outside its periods of use.

According to a first aspect of the present invention there is provided a security device for inhibiting unauthorised interference with electrical and/or electronic apparatus, said apparatus being connected to a power source, the security device comprising: vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of said apparatus; and means for initiating an alarm signal, said means for initiating being connected to said vibration detection means and operable to initiate an alarm signal in response to an indication from said vibration detection means that a vibration has been detected.

Advantages of the first aspect of the present invention are that: 1) by having two levels of sensitivity, the device may be operated at a reduced sensitivity during periods of normal operation of the protected apparatus, thereby reducing the frequency of inadvertent triggering of the vibration detector, and at higher sensitivity at other times; and 2) the switching means may automatically switch the device to high sensitivity according to the state of the apparatus, for example when it is switched off at night, thereby obviating the need for a user to remember to set the device outside the periods of normal use of the protected apparatus.

According to a second aspect of the present invention there is provided electrical and/or electronic apparatus comprising: means for connecting a power source; vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of said apparatus; and means for initiating an alarm signal, said means for initiating being connected to said vibration detection means and operable to initiate an alarm signal in response to an indication from said vibration detection means that a vibration has been detected.

According to a third aspect of the present invention there is provided a security system for inhibiting unauthorised interference with a plurality of pieces of electrical and/or electronic apparatus, each piece of said apparatus being connected to a power source, the security system comprising: at least one remote sensor for receiving signals, the or each remote sensor connected to an alarm system operable to raise an alarm; and a plurality of security devices, each security device being associated with a respective piece of said apparatus, each security device comprising: vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of the respective piece of said apparatus; and a transmitter including an aerial, said transmitter connected to said vibration detection means and operable to transmit a signal for reception by the or at least one of said remote sensors in response to an indication from said vibration detection means that a vibration has been detected.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a security device in accordance with a first embodiment of the present invention, attached to electronic apparatus; Figure 2 is a block diagram of the first embodiment; Figure 3 is a circuit diagram of the first embodiment; Figure 4 shows a second embodiment; and Figure 5 shows a third embodiment.

Referring now to figure 1, in a first embodiment of the present invention, the security device 50 contains a rechargeable battery, and is additionally provided with electrical power from a mains electricity supply 60 by means of an input cable 61. The security device 50 is attached, by means not shown, to the apparatus 40 to be protected and is connected in line with the mains electricity supply to the apparatus 40.

Electrical power is thus supplied to the apparatus 50 via the security device 40 by means of a second cable 62. Any attempt to remove the apparatus would therefore necessitate either the disconnection of the cable between the security device 50 and the apparatus 40, or disconnection of the security device 50 from the mains supply 60. As will be described below, both of these operations would result in the vibration device switching to high sensitivity, causing any further movement of the apparatus to trigger the alarm.

The operation of the security device 50 in accordance with the first embodiment will now be described in detail, firstly by referring to figure 2.

The security device 50 comprises a power supply and rechargeable backup battery A, a two-stage vibration detector B having two levels of sensitivity, switching means for switching the vibration detector B between its two sensitivities, a flip-flop C, an encoder circuit D, and a transmitter circuit E Connected to the transmitter circuit E is a transmitter aerial 90, and connected to the encoder circuit D are a code memory 100 and an address memory 110.

When the device 50 is connected to a mains electricity supply 60 via input lead 61, the backup battery is trickle charged, and power to blocks B, C, D and E is provided from the mains supply 60. When the mains supply 60 is disconnected, power to these blocks is provided by the battery.

The two-stage vibration detector B has two levels of sensitivity, and includes a vibration detection element which senses movement of the device 50. The switching means is operable to switch the vibration detector B between its two sensitivities, such that the more sensitive level is selected when the mains supply to the device 50 is disconnected (i.e. while power is being provided by the battery) or the apparatus 50 is switched off. If the mains supply is connected to the device 50 and the apparatus is connected to the device 50 (by the lead 62) and switched on, then the switching means ensures that the lower sensitivity is selected.

When vibration or movement is detected a pulse is produced by the vibration detector which enables blocks C, D and E.

The flip-flop circuit C, after being triggered by block B, is set for approximately two seconds and then resets. Whilst set it enables the encoder D and transmitter E circuits.

The encoder circuit D receives and processes an input from the flip-flop C, and encodes the code stored in the code memory 100 and the address stored in the address memory 110. It then emits a code to the transmitter circuit E.

The transmitter circuit E receives the encoded information from the encoder E, processes the information, and then transmits it from the aerial 90 with AM or FM modulation.

The operation of the first embodiment will now be described in yet more detail, with reference to figure 3.

When the mains supply 60 is connected to the device 50, 240VAC is applied to the transformer T1, the secondary providing 15VAC. The diodes D10, Dll, D12 and D13 form a bridge rectifier with capacitor C1 smoothing the output and resulting in 15VDC being applied to the voltage regulator IC3. IC3 regulates the voltage to l2VDC. This is fed through diode D1 and current limiting resistor R2, The 12V input is also fed through D2 and R1 to charge the backup battery B1. When the power is turned off, B1, the backup battery, supplies power through D3. D14 is a reverse polarity protection diode.

Vibration detection is achieved in the following manner. Components R3, R4, R5, the relay RLA1, the vibration detecting element V1, C4, C11 and D8 form a two-stage pulse shaping circuit for the flip flop IC1.

The contacts of relay RLA1 are closed when the unit has mains voltage applied and when the protected apparatus 40 is connected to the power output terminals 140 and is switched on. This has the effect of connecting R4 and Cli into the vibration detection circuit so that its sensitivity is reduced during the periods of operation of the apparatus 40 (typically during the day-time). The component values are chosen so that this reduced sensitivity is sufficiently low to allow small disturbances resulting from normal operation of the apparatus 40 to pass without triggering the vibration detector.

When the mains power supply to the device 50 is disconnected, or the apparatus 40 switched off, R4 and C11 are removed from the vibration detection circuit, thereby increasing sensitivity.

The relay RLA1 and power output terminals 140 thus provide means for switching the vibration detector between its two levels of sensitivity, where the switching means is responsive to the state of the apparatus 40 (i.e. in this case whether it is on or off) and to the power supply to the security device 50.

The sensitivity of the vibration detector is switched automatically according to the state of the apparatus and the power supply to the device 50.

When movement is detected, V1 momentarily closes and charges C4 through R3. This puts a voltage on pin 3 of IC1. When this voltage exceeds 2/3 of the supply to IC1, pin 1 goes high, turning on transistor TR1 through R7/R8. After approximately two seconds the voltage on C5 which has been charging through R6 exceeds 2/3 supply voltage and causes the flip-flop to reset, discharging C5 through D5 in the process.

When pin 1 of IC1 goes high, TR1 is turned on, and in turn the base of transistor TR2 is pulled low causing TR2 to supply power to IC2, code memory SW1 100, address memory SW2 110, and transmitter module TXM1.

The address memory is in the form of a DIP switch.

The oscillator circuit in 1C2 is activated. IC2 encodes the code set by SW1 and address set by SW2.

This is fed through R16 to the transmitter module TXM1. Transmitter module TXM1 operates at 400 to 450 Mhz with either AM or FM modulation. Other frequencies can be catered for by substituting TXM1 for the appropriate part.

In this first embodiment, the security device 50 is connected in line such that the protected apparatus 40 receives its electrical power via the device 50. An advantage of this embodiment is that any attempt to remove the protected apparatus necessitates the disconnection of the power supply to the apparatus 40 or to the security device 50, and so results in the vibration detector switching to the more sensitive mode. Thus, even if a user forgets to switch the apparatus 40 off at night, or after use, high sensitivity anti-movement protection will automatically be provided should any attempt to remove the apparatus be made.

A second advantage is that the security device may be attached quickly and easily, for example by using adhesive pads, to a wide range of electronic and/or electrical apparatus, requiring the provision of no other services in addition to mains electricity supply. This apparatus may include computers, monitors, printers, fax machines and photocopiers.

Installation of the security device is further facilitated by the fact that its attachment to the apparatus need not be strong, as any attempted separation of the two should result in triggering of the vibration detector switched to either sensitivity.

Advantageously, the security device may be provided with means for attaching it to the apparatus. For example, attachment may be achieved bv means of

complementary Velcrlstrips glued to the apparatus and device.

Advantageously, the casing of the security device may be designed so as to be highly distinctive and easily visible so as to provide a deterrent to a potential thief.

A further advantage of the first embodiment is that the vibration detector is automatically switched to its more sensitive setting when the protected apparatus is switched off. The user need not remember specifically to set the security device.

Also, while the apparatus and security device are switched on, the vibration detector, although operating at a reduced sensitivity, provides a degree of protection against relatively large disturbances to the apparatus, such as those resulting from an attempt to open its casing.

It will be apparent to those skilled in the art that a plurality of security devices in accordance with the first embodiment may be used to protect a plurality of different pieces of apparatus simultaneously, for example computers, printers, photocopiers and fax machines. Each security device may have a unique code or address stored in its memory, such that when the vibration detector of a particular security device is triggered, the alarm signal transmitted may contain information indicative of the piece of equipment being tampered with.

Although not shown in any figure, one or more receiver units for receiving transmitted signals may be positioned in the vicinity of the apparatus.

These receivers may be hidden or disguised, for example to look like standard PIR 's, and may of course be set to activate a variety of different alarms, including lights, bells and/or sirens, a call to the Police or Security Company/Guards, or any other signal/warning device.

Also, it will be apparent that the levels of sensitivity of the vibration detector, rather than being fixed, may be adjustable. For example, variable capacitors and/or resistors may be incorporated in the vibration detection circuit, whilst retaining the same vibration detection element, providing the advantage that the security device may be adjusted to provide optimum sensitivity levels for a variety of applications.

In the first embodiment described above, the security device 50 is connected in line with the mains electricity supply to the protected apparatus 40, and is attached to the outside of the apparatus 40.

Figure 4 shows a second embodiment in which the security device 50 is attached to the inside of the apparatus 40, and mains power supply to the security device 50 is from the protected apparatus 40 by means of an internal connection 150. In this embodiment, the switching means switches the vibration detector to its higher sensitivity when the mains supply to the device is disconnected, and to its lower sensitivity when the mains supply is connected.

Figure 5 shows a third embodiment in which the security device 50 is supplied directly with mains power, but does not have a mains power output, such that separate power supplies are required for the device and apparatus. In addition, the device is provided with a radio receiver, connected to the switching means, and the switching means is operable to switch the sensitivity of the vibration detector in response to signals received by the receiver.

Advantages of this embodiment are that the vibration detector may be set to high sensitivity remotely, without the need for a user to remember to switch the apparatus or security device off after use, and can be used to provide high sensitivity anti-tampering protection to equipment which is left switched on by accident or for a purpose.

In a further embodiment, the security device again comprises a receiver, and is solely battery powered, no means for connecting a power supply being provided.

The switching means is responsive to the state of the attached apparatus, and to signals received by the receiver.

In yet another embodiment, the security device is again connected in line with the mains supply to the apparatus, but the lower level of sensitivity of the vibration detector is in fact zero, i.e. in this setting the vibration detector cannot be triggered.

The device switches to high sensitivity when the apparatus is switched off, or when the mains supply to the device is disconnected.

Thus, no alarm can be triggered during operation of the protected apparatus, providing advantages in applications where inadvertent triggering would be unacceptable, or in which large movements are encountered during normal use of the protected apparatus.

In a further embodiment, a signal is transmitted from the security device 50 each time the mains electricity supply to it is switched on, thereby alerting an alarm system to any attempt to reduce the sensitivity of the vibration detector prior to an attempt to separate the security device from the apparatus, or to tamper with the casing of the apparatus.

In a final described embodiment, the security device is in fact an integral part of a piece of electrical and electronic apparatus, the apparatus being connected to a power source. The switching means switches the vibration detector to high sensitivity when the power source to the apparatus is disconnected, or the apparatus switched off.

It will be apparent to those skilled in the art that any reference in the description or claims to a vibration detector or vibration detection means also contemplates a movement detector or movement detection means. Equally, any reference to the detection of vibration contemplates the detection of movement, and vice versa.

Also, although in the embodiments described, the switching means switched the vibration sensitivity according to whether the apparatus was in the on state or the off state, it will be apparent that the switching means could be responsive to other states, for example whether the apparatus was hot or cold, or in fully active mode or idle mode (drawing reduced, but non-zero, power).

It will also be apparent that the present invention contemplates the inhibition of unauthorised interference with electrical and/or electronic apparatus supplied with electrical power from sources other than the mains, or from a mains supply having an output voltage other than 240V, for example 110V.

Claims

CLAIMS:

1. A security device for inhibiting unauthorised interference with electrical and/or electronic apparatus, said apparatus being connected to a power source, the security device comprising: vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of said apparatus; and means for initiating an alarm signal, said means for initiating being connected to said vibration detection means and operable to initiate an alarm signal in response to an indication from said vibration detection means that a vibration has been detected.

2. The device of claim 1 wherein at least one of said high sensitivity and said low sensitivity is adjustable.

3. The device of claims 1 or 2 wherein said low sensitivity is zero, such that at this sensitivity, no vibration or movement may be detected by said vibration detection means.

4. The device of claims 1-3 wherein said switching means is operable to switch said vibration detection means to said high sensitivity in response to said apparatus being disconnected from said power source.

5. The device of claims 1-4 wherein said switching means is operable to switch said vibration detection means to said high sensitivity in response to said apparatus being switched off.

6. The device of any preceding claim, wherein said device is operated electrically and further comprises a battery.

7. The device of claim 6 wherein said means for initiating an alarm signal comprises a transmitter including an aerial, said transmitter operable to transmit a signal for reception at a remote sensor.

8. The device of claims 6 or 7, further comprising means for connecting a power supply.

9. The device of claim 8, wherein said switching means is operable to switch said vibration detection means to said high sensitivity when said device is disconnected from said power supply.

10. The device of claims 7-9, further comprising an encoder and memory means, said encoder operable to encode information stored in said memory means together with an output from said vibration detection means and to pass the encoded material to said transmitter for transmission.

11. The device of claim 10, wherein said memory means contains an address.

12. The device of claims 6-11, further comprising a receiver connected to said switching means, said switching means operable to switch said vibration detection means between said low and high sensitivities in response to signals received by said receiver.

13. The device of claims 8-12, further comprising power output means for supplying power to said apparatus, whereby said apparatus may be connected to said power source via said device.

14. The device of claims 8-13, wherein said transmitter is operable to transmit a signal each time said power supply is connected to said device.

15. The device of any preceding claim, wherein the casing of the device is highly distinctive and visible.

16. A security device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

17. Electrical and/or electronic apparatus comprising: means for connecting a power source; vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of said apparatus; and means for initiating an alarm signal, said means for initiating being connected to said vibration detection means and operable to initiate an alarm signal in response to an indication from said vibration detection means that a vibration has been detected.

18. The apparatus of claim 17 wherein at least one of said high sensitivity and said low sensitivity is adjustable.

19. The apparatus of claims 17 or 18 wherein said low sensitivity is zero, such that at this sensitivity, no vibration or movement may be detected by said vibration detection means.

20. The apparatus of claims 17-19 wherein said switching means is operable to switch said vibration detection means to said high sensitivity in response to said apparatus being disconnected from said power source.

21. The apparatus of claims 1-4 wherein said switching means is operable to switch said vibration detection means to said high sensitivity in response to said apparatus being switched off.

22. The apparatus of claims 17-21, further comprising a battery.

23. The apparatus of claim 22 wherein said means for initiating an alarm signal comprises a transmitter including an aerial, said transmitter operable to transmit a signal for reception at a remote sensor.

24. The apparatus of claim 23, further comprising an encoder and memory means, said encoder operable to encode information stored in said memory means together with an output from said vibration detection means and to pass the encoded material to said transmitter for transmission.

25. The apparatus of claim 24, wherein said memory means contains an address.

26. The apparatus of claims 17-25, further comprising a receiver connected to said switching means, said switching means operable to switch said vibration detection means between said low and high sensitivities in response to signals received by said receiver.

27. The apparatus of claims 23-26, wherein said transmitter is operable to transmit a signal each time said power source is connected to said apparatus and/or when said apparatus is switched on.

28. Electrical and/or electronic apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

29. A security system for inhibiting unauthorised interference with a plurality of pieces of electrical and/or electronic apparatus, each piece of said apparatus being connected to a power source, the security system comprising: at least one remote sensor for receiving signals, the or each remote sensor connected to an alarm system operable to raise an alarm; and a plurality of security devices, each security device being associated with a respective piece of said apparatus, each security device comprising: vibration detection means having a low sensitivity and a high sensitivity; switching means operable to switch said vibration detection means between said low sensitivity and said high sensitivity in response to the state of the respective piece of said apparatus; and a transmitter including an aerial, said transmitter connected to said vibration detection means and operable to transmit a signal for reception by the or at least one of said remote sensors in response to an indication from said vibration detection means that a vibration has been detected.

30. The system of claim 29 wherein at least one security device further comprises a battery for providing electrical power to said vibration detection means and said transmitter.

31. The system of claims 29 or 30 wherein in at least one security device at least one of said high sensitivity and said low sensitivity is adjustable.

32. The system of claims 29-31 wherein in at least one security device the low sensitivity is zero, such that at this sensitivity, no vibration or movement may be detected by said vibration detection means.

33. The system of claims 29-32 wherein the switching means of at least one security device is operable to switch said vibration detection means to said high sensitivity in response to the respective piece of said apparatus being disconnected from said power source.

34. The system of claims 29-33 wherein the switching means of at least one security device is operable to switch said vibration detection means to said high sensitivity in response to the respective piece of said apparatus being switched off.

35. The system of claims 29-34, wherein at least one security device further comprises means for connecting a power supply.

36. The system of claim 35, wherein the switching means of said at least one security device comprising means for connecting a power supply is operable to switch said vibration detection means to said high sensitivity when the respective security device is disconnected from said power supply.

37. The system of claims 29-36, wherein at least one security device further comprises an encoder and memory means, said encoder operable to encode information stored in said memory means together with an output from said vibration detection means and to pass the encoded material to said transmitter for transmission.

38. The system of claim 37, wherein said memory means contains an address.

39. The system of claims 29-38, wherein at least one security device further comprises a receiver connected to said switching means, said switching means operable to switch said vibration detection means between said low and high sensitivities in response to signals received by said receiver.

40. The system of claims 35-39, wherein said at least one security device comprising means for connecting a power supply further comprises power output means for supplying power to the respective piece of said apparatus.

41. The system of claims 35-40, wherein the transmitter of said at least one security device comprising means for connecting a power supply is operable to transmit a signal each time said power supply is connected to the respective security device.

42. A security system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.