GB2309133A

GB2309133A - Video surveillance system including video recorder timing control device

Info

Publication number: GB2309133A
Application number: GB9600591A
Authority: GB
Inventors: Richad Thomas Fortescue
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-11
Filing date: 1996-01-11
Publication date: 1997-07-16
Also published as: GB9600591D0

Abstract

Video surveillance system includes a timing device which enables a user to preset the "on" and "off" times of a video recorder receiving the output of a television camera, thereby allowing more events to be recorded on a given length of recording media. The recorder is switched on for a preset period of time in response to an output from an event sensor eg a PIR detector, and is then switched off for a further preset period of time, remaining in the off state until triggered again by the sensor output. The timing device may be overridden to allow the camera output to be recorded as long as the PIR detects a presence.

Description

SPECIFICATION Timing device to control recording system(s).

This invention relates to a timing device which enables a user to preset the on and off times for a recording system. The device can be triggered by sensors and will maximise the useful unattended total recording time.

Description of the prior art.

Recording devices are usually switched on then off by an operator or switched on by (remote) sensors and then either off when the sensor ceases to detect a body presence or the recording device switches of when the end of the storage media is reached. For most devices this limits the recording to the length of the media and is typically 30 minutes to 6 hours.

Summary of the invention.

This device enables the operator to choose the 'on' time from the instant an event occurrs, and then to select a preset off time, enabling the device to be left unattended for much longer than would normally be the case.

The operator can allow the device to record only part of the occurrence, for many cases this is far preferable since knowing what happened during part of each event and recording more events can be more important than recording the whole event because more precise detail can be recorded over a short recording time and many more events can be recorded. Thus the system can be left unattended for much longer than would normally be the case. (This has been tested on intruders, night animals and general gatherings in public places, using video and tape recorders.) The device allows the recording system(s) to be switched on by local or remote sensor(s) , the recording system(s) then operate for a pre-set (adjustable) time and then the system(s) are switched off for a pre-set (adjustable) time, remaining in the off state until triggered again by the sensor(s).This allows simple recording system(s) to be utilised in surveillance operations. The device will also allow the operator to select options, specifically the ability to switch on the recording system and then leave the system recording until the end of the recording media is reached, or alternatively the device will keep the recording system(s) on during the time that the sensor(s) detect a presence.

According to the present invention there are provided switches to pre-set the on and off times, inputs provided to accept signals from various sensors and outputs to the recording device used. The timing circuit can be switched to allow for variations depending on the characteristics of the recording device(s) used.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows the box with on off switch, timing control switches, indicator lights and input and output sockets.

Figure 2 is of an overall schematic ciruit showing the essential fictions.

Figures 3,4,5 & show the specific circuit details used as a 'camera driver card', as used on a camcorder used for surveillance.

Figure 7 shows a block diagram with the circuit structured using a microcomputer.

Description of the preferred embodiments: In figure 1, the input is from a powered passive infra-red detector, the output goes to a remote (infra-red) camcorder control device to turn the camcorder on and off.

The on/off switch when switched on powered up the system.

One timing switch was used to preset the time the power would be held on for after activation by the PIR, the other was used to preset the dead time,( or the time that the sysem would be held off after finishing one recording).

The indicator leds were merely to indicate correct functioning, one showed that the power was on, one came on and indicated after a period of time that the system was 'live' and ready to operate- allowing the operator time to leave the scene, the third showed that a prescence had been detected and gave a signal at the same time as the camera pulse was activated.

(The last allowed the system to be checked out without the camera, and also with the camera present to ascertain whether the camera was working correctly) .

The override switch (if activated) will allow the timing circuits to be ignored and the circuit will allow the camera to operate as long as the PIR detects a prescence.

Figure 2 is self-explanatory and shows that the inputs are fed into the 'on' timing circuit, which has a switch to preset the timing, the 'off > timing circuit controls the 'on' timing circuit at the approriate time and the override switch merely overrides the timing circuits if required.

Figures 3 to 7 show circuit elements of the circuit used.

Extra requirements for this embodiment were a preset timer to allow the system to stabilise, this was set at a minute so that thePIR system would have time to settle down and the operator could leave the area. Also, most modern remotely controlled cam-corders have a 'power down' system, this means that if the power is on to 'record' but the 'record' button has not been pressed for exactly 5 minute then the system powers down and needs a double pulse from any remote operating system to restart, this embodiment generates this double pulse when required.

Claims

Claims:

This device enables an operator to select on and offdurations for a recording device which can be left unattended and controlled by remote sensors.

The device enables the operator to utilise standard recording devices for surveillance operations, greatly extending the time that the device can be left unattended.

The recording thus produced shows the specific detail required during part of an event for a shorter time than the whole duration of the event, allowing more events to be recorded for a given length of recording media.

Amendments to the claims have been filed as follows Claims:1.- A timing circuit for a recording system comprising: selector switches connected to a circuit which allow an operator to predetermine the length of time over which events will be recorded after initiation, input sockets or leads to the device from sensors which detect and initiate the recording sequence, output sockets or leads to the recording device(s) to turn the recording device(s) on and off
2. A timing circuit as claimed in claim 1 which allows the operator to leave the recording system unattended for longer periods than would be expected foi the case in which the recording device is simply be attached to a sensor or sensors which operate the recording device from the time when an event was detected by the sensor(s) until the sensor(s ) cease to detect the event.
3. A timing circuit as claimed in claims 1 and 2, wherein the pre-selection of various times by the operator forces a recording system to have preset times of recording for a remote event sensed by sensor(s) and thus increase the effective length oftime that the recording media can be utilised.
4. A timing circuit for a recording device or devices, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.