GB2149185A

GB2149185A - Device for protecting electronic equipment

Info

Publication number: GB2149185A
Application number: GB08329534A
Authority: GB
Inventors: Robert Ernest Barwick
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-11-04
Filing date: 1983-11-04
Publication date: 1985-06-05
Also published as: GB2149185B; GB8329534D0

Abstract

An anti-theft device for protecting mains powered electronic equipment such as video cassette recorders. The device comprises a key operated switch connected to electronic circuitry of the equipment such that actuation of the switch selectively disables at least one function of the equipment without disabling at least one other function of the equipment. The switch may be connected in series with the 30V supply rail of a video recorder, which results in disabling of playback whilst permitting recording and operation of the clock.

Description

SPECIFICATION Anti-theft device The present invention relates to an anti-theft device, and in particular to an anti-theft device for protecting electronic equipment.

High value domestic electronic equipment is now widely installed in many homes. Such equipment is very attractive to thieves as it is easy to steal, carry and resell. This is particularly the case with video cassette recorders (VCR's).

VCR's are almost always installed immediately adjacent to a television set and in most cases are permanently connected to the mains supply and the television. This makes it easy for a thief to locate and steal a VCR. It is of course possible to hide a VCR away when it is not in use but this is not often done for a variety of reasons. Firstly, if a VCR is unplugged from the mains its internal clock which controls automatic programme recording requires resetting when the VCR is plugged in again. Secondly, most people do not like to repeatedly interfere with the connections between the VCR and the television and its aerial. Thirdly, it is quite likely that the VCR will be damaged if it is constantly being carried between its place of use and a hiding place.

It is known to provide electronic equipment with a key operated disabling switch to prevent unauthorised use. The known disabling switches operate by disconnecting the main power supply to the equipment. Such switches are however easy to bypass as they operate on the easily traced main power supply and therefore do not provide much protection in the case of equipment which can be stolen and modified at leisure by the thief.

Furthermore, in the case of VCR's and any other equipment which is intended to operate automatically in the absence of its owner, disabling the equipment prevents the normal use for which the equipment is designed. For example if a VCR was fitted with a conventional disabling switch every time the equip ment was enabled for use the VCR clock would have to be set, and if the VCR was to be used to automatically record a programme in the absence of the user it could not be disabled.

It is an object of the present invention to obviate or mitigate the above problems.

According to the present invention, there is provided an anti-theft device for protecting electronic equipment, comprising a key operated switch connected to the equipment such that actuation of the switch selectively disables at least one function of the equipment without disabling at least one other function of the equipment.

For example the switch may be connected in series with a low voltage rail of the equipment so that when the switch is actuated functions dependent upon that rail are disabled. In the case of certain VCR's the switch may be connected in series with the 30 volt supply rail which disables the playback function of the VCR without disabling the VCR clock or automatic recording functions.

The key operated switch may be a conventional mechanical switch operated by a physi cal key or an electronic switch operated by keying in a coded 'key', for example a four figure personal identification number.

If the equipment is stolen it will be necessary for the thief to bypass the switch before the equipment can be used. If the switch is connected to the equipment by a multi-core cable the ends of which are embedded for example in opaque epoxy resin it will not be easy to determine which of the cable cores to connect together to bypass the switch. Most thieves will not have the necessary knowledge and/or instruments to make the necessary modifications. To further complicate bypassing of the switch, it can be used to disable more than one supply rail of the equipment or particular sub-components of the equipment.

An added advantage with providing a key operated switch on VCR's is that parents can prevent unauthorised use of the VCR by children. Viewing of unsuitable recordings by children can thus be prevented without it being necessary to lock away the tapes carrying those recordings.

Most currently available VCR's have sufficient space within them to be retrofitted with a key in accordance with the invention. Where this is not the case, a key could be provided to stand in its own box adjacent the VCR, the box being connected by a cable to the VCR.

As an example of the present invention a VHS type VCR marketed as the JVC 7200 model in England was fitted with a mechanical key operated switch. The key was mounted on the front panel of the VCR in a three quarter inch diameter hole to the right centre of the panel. The key operated switch was connected in series with the brown lead that is connected to the 10-1 plug within the VCR. With the switch open circuit, the VCR clock stays on and the automatic and manual recording functions operate. The playback function is however disabled as the 30 volts supply rail is isolated by the switch.

Claims

1. An anti-theft device for protecting mains powered electronic equipment, com prising a key operated switch connected to electronic circuitry of the equipment such that actuation of the switch selectively disables at least one function of the equipment without disabling at least one other function of the equipment, wherein the switch is connected to the electronic circuitry by three or more conductors at least two of which must be interconnected to bypass the switch, whereby unauthorised bypassing of the switch is rendered difficult.

2. A device according to claim 1, wherein the switch is connected in series with a low voltage rail of the equipment so that when the switch is actuated functions dependent upon that rail are disabled.

3. A device according to claim 2, wherein the switch is connected in series with a supply rail of a VCR which disables the playback function of the VCR without disabling the VCR clock or automatic recording functions.

4. A device according to any preceding claim, wherein the switch comprises at least two sets of switch contacts each arranged to disable a respective function of the equipment when the switch is actuated.

5. An anti-theft device substantially as hereinbefore described.