GB2190192A

GB2190192A - Security systems

Info

Publication number: GB2190192A
Application number: GB08709443A
Authority: GB
Inventors: Christopher Newton
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-04-23
Filing date: 1987-04-21
Publication date: 1987-11-11
Also published as: GB8609947D0; GB2190192B; GB8709443D0

Abstract

A security system particularly for use on game estates to detect the presence of poachers comprises a number of pyroelectric detectors (12) arranged to transmit a signal to a radio receiving and transmitting means (14). The transmitted signals from the means (14) activates a paging unit (16) which has a number of lights (44) each corresponding to one of the pyroelectric detectors (12). <IMAGE>

Description

SPECIFICATION Improvements in or relating to security systems This invention relates to security systems and is particularly though not exclusively concerned with a security system to detect the presence of poachers on game estates.

The provision of security systems to protect large areas of countryside, for example, estates in which game birds are kept is very difficult to achieve. Usually only selected areas are protected such as normal roosting sites or locations where young birds are reared. Some existing security systems involve pressure pads which are connected to an alarm system by wiring and it is quite difficult to conceal the pressure pads and the associated wiring.

Other security systems use infra-red systems, but these tend to be bulky, are relatively easily seen, require clear lines of sight and can be set off by animals or birds.

The present invention seeks to provide a security system in which the need for wiring is avoided and the detectors are relatively small and easy to conceal. Accordingly the present invention provides a security system comprising one or more pyroelectric detectors arranged to transmit a radio signal upon detecting the presence of an intruder, a radio receiving and transmitting means adapted to receive the transmitted signals from the or each detector, and to transmit a signal or signals to a paging means.

The present invention will now be more particularly described with reference to the accompanying drawings in which Fig. 1 shows in diagrammatic form one embodiment of a security system according to the present invention, and Fig. 2 shows a modified form of the invention shown in Fig. 1.

Referring to Fig. 1, a security system 10 comprises one or more pyroelectric detectors or heat sensors 12, a radio receiving and transmitting means 14 and at least one paging unit 16. Each sensor 12 is a self-contained, weather-proof unit powered by a NiCad rechargeable battery 18, a transmitter, an on-off switch 20, a sensitivity control 22 and an aerial pick-up 24. Each sensor 12 is arranged to detect the presence of human intruders by the detection of heat radiated from the intruder, ie. changes in infra-red levels, and the sensitivity control 22 is adjusted to detect a human intruder and to ignore the presence of animals such as dogs, cats, foxes, badgers etc. Each sensor 12 is relatively small and can be easily concealed in shrubbery, undergrowth, or in trees so that it is difficult to detect by eye.

Each sensor 12 is arranged to transmit its signal at a unique frequency within the allotted wave band so as to activate the corresponding indicator lamp 44 on the paging unit 16.

Each sensor 12 also has a timer so that a signal is transmitted for a given period, say 2 to 4 seconds, once the sensor has been triggered by a change in infra-red level of sufficient magnitude. The provision of a timer avoids the need for a re-set button on the paging unit.

The receiving and transmitting means 14 has a receiving aerial 26 an amplifier and transmitter, an on-off switch 28, a power-on indicator lamp 30 and a transmitting aerial 32.

The receiving and transmitting unit 14 is powered from a domestic mains supply via a plug 34.

Each paging unit is portable and approximately pocket sized, having a receiver, a speaker 36, a battery 38, an on-off switch 40, a re-set button 42, and a number of indicator lamps 44.

Referring to Fig. 2 in which corresponding components have been given the same reference numerals as in Fig. 1, each sensor 12 includes a pyroelectric detector 12A, a Fresnel lens formed from a plastics material to allow the passage of infra-red rays and a transmitter 12C having an aerial 12D. The paging means 16 is only varied by the detection of the reset button 42.

In operation, the sensors 12 are located at the appropriate places around and within the area in which intruders are likely to be detected, for example adjacent likely access and escape routes, nesting and roosting sites, and rearing sites. The receiving and transmitting unit 14 will be located within the transmitting range of all of the sensors 12 and the paging unit will be carried by the game keeping or security guard as the case may be. When more than one sensor is used, then each unit will be numbered and will have a unique transmitting frequency so that the receiving and transmitting means 14 can transmit an appropriate signal to the paging unit to illuminate the respective one of the indicator lamps on the paging unit.

This will enable the guard or the game keeper to know which sensor unit is in operation and thus the approximate location of the intruder. As well as operating one or more of the indicator lamps the paging unit also has an audible warning. When a sensing unit detects the presence of a human intruder a signal will be transmitted to the receiving and transmitting means 14 and a signal or signals will be transmitted to the paging unit which will thengive out an audible warning and one or more of the indicator lamps will be illuminated. The game keeper or guard will know immediately that intruders are present and will also know their approximate location. He will then be able to summon assistance and proceed to intercept the intruders.

The use of a security system according to the present invention is not limited for use in detecting poachers or estates, but can also be used in any large open areas requiring protection such as vehicle compounds, builders yards and construction sites.

Each paging unit can have a re-set button so that upon depression any or all of the heat sensing units which have been activated are re-set, if the sensor units do not have a timer or other means to switch off the sensor once activated.

The radio receiver and transmitter 14 can have logic gates to determine the identity of incoming signals so that the correct signals can be transmitted to the paging unit.

Groups of sensors all having the same digital transmitting frequency can be arranged in a particular area so as to increase the sensitivity of the security system to intrusion in that particular area.

The signals from the receiving and transmitting means can be arranged to trigger not only the paging unit 16, but also floodlights and audible, alarms, if required.

Claims

1. A security system comprising one or more pyroelectric detectors arranged to transmit a radio signal upon detecting the presence of an intruder, a radio receiving and transmitting means adapted to receive the transmitted signals from the or each detector and to transmit a signal or signals to a paging means.

2. A security system as claimed in claim 1 in which each pyroelectric detector comprises a housing containing a detector arranged to sense changes in infra-red levels, a Fresnel lens of a material able to transmit infra-red rays, a transmitter arranged to transmit a signal when triggered by a change of sufficient magnitude in the infra-red level detected by the detector and a power source.

3. A security system as claimed in claim 1 or claim 2 in which the transmitter of each detector is of a relatively low power and the transmitter of the audio receiving and transmitting means is of a relatively high power.

4. A security system as claimed in any one of the preceding claims in which the transmitter of each detector has a unique transmitting frequency.

5. A security system as claimed in any one of the preceding claims in which the paging means comprises an audio output means arranged to be activated upon receiving a signal from the radio receiving and transmitting means and indicator lamps of sufficient number so that for each detector there is a corresponding indicator lamp on the paging means.

6. A security system as claimed in any one of the preceding claims in which the radio receiving and transmitting means has an input logic gate arranged to identify the incoming signal or signals so that the correct output can be transmitted to activate the corresponding indicator lamp on the paging means.

7. A security system constructed and arranged substantially as herein described, and with reference to Fig. 1 or Fig. 2 of the accompanying drawings.