JPS58161097A - Monitoring system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monitoring system using a pyroelectric vidicon or a pyroelectric photoelectric conversion element.

As a monitoring device for disaster prevention and crime prevention in shops, buildings, building grounds, etc., or for disaster prevention and crime prevention in factories, dangerous areas, etc., systems that capture images with visible image television cameras and display them on monitors are conventionally used. has been done. In such a monitoring system, it is extremely difficult to keep an eye on the monitor 24/7. For this reason, efforts have been made to issue an alarm when something abnormal occurs.

For example, in order to issue an alarm when the image changes, the current image is always compared with an image one to several fields before, and an alarm is issued when there is a change in the image. However, this method requires that an image from one to several fields ago be stored in a storage device, and then read out again and compared with the current image, making the device very expensive and not widely used. .

The present invention makes use of the special characteristics of the pyroelectric vidicon, and does not use a storage device as in the case of a visible image television camera.
This is an inexpensive and simple monitoring system.

A pyroelectric vidicon is an image pickup tube that captures a thermal image from a subject, and outputs changes in the thermal image from the subject over time in the form of electrical signals. Therefore, an output signal cannot be obtained unless there is a temporal change in the thermal image from the subject. Therefore, when capturing a thermal image using a camera using a pyroelectric vidicon in panning mode,
If there is no moving object within the field of view of the camera, no output signal is generated; an output signal is taken only when a moving object is present. This means that the pyroelectric camera device has moving object detection characteristics, and the pyroelectric camera device can reliably and easily monitor and warn when a moving object is present or in an abnormal state. be exposed.

The figure is a block diagram showing the overall configuration of a monitoring system according to the present invention.

1 in the figure is a pyroelectric vidicon (or pyroelectric photoelectric conversion element) operated in panning mode.

As the lens 13, a germanium lens or the like that can transmit far infrared rays of about 8 μm to 14 μm is used. The thermal imaging light beam transmitted through this lens is imaged on the face plate of the vidicon 1. This image becomes a line-scan conversion signal of 15.75 KH2 horizontally and eoH2 vertically by the scanning beam of the vidicon. When the thermal image moves or the camera is panned, a signal is instantaneously obtained from the target of the vidicon 1 according to the temperature of the subject and the speed of movement and is amplified to 1. This output signal is 60
The signal is applied to the gate circuit 4 via a band pass filter 3 (hereinafter abbreviated as BPF) having a frequency band of approximately KH2 to 3MH2. The output signal of the BPF 3 contains a mixture of a hiecon target/y-tring image and an instantaneous thermal image signal from the subject, and either of these is applied to the gate circuit 4.

8 is a gate pulse generation circuit, which generates a gate pulse for setting a desired monitoring range within the effective scanning area of the pyroelectric vidicon 1 based on the horizontal and vertical deflection pulses of the pyroelectric vidicon 1. . This gate pulse is applied to the gate circuit 4
Only the signal portion obtained within the desired monitoring range is extracted from the output signal of the BPF 3, that is, the mixed signal of the vidicon target ring image and the instantaneous thermal image signal from the subject. At this time, all unnecessary signals caused by the IJ song and signal components outside the monitoring range are removed. The pulsed signal extracted from the gate circuit 4 is converted into a positive or negative square wave pulse by a waveform shaping circuit, and is applied as a trigger, f pulse, to the timer circuit 6. The output of the timer circuit 6 is a square wave lasting for about 1 to 3 seconds, which drives the alarm buzzer 7 to emit an alarm buzzer sound.

A part of the output of the gate pulse generator 8 is applied to a linear display signal generation circuit 9 for displaying the monitoring range, and a dog-shaped display that multiplexes the monitoring range in a rectangular shape or the like on the playback screen of the monitor 11 is performed. A line image signal is generated, added to the thermal image signal from the preamplifier 2 by an adder circuit 1o, and applied to a monitor 11, where a monitoring range display line image 12 is displayed multiplexed on the thermal image.

The monitoring range set by the gate pulse generator 8 can be freely set by changing the rise and fall positions of the gate pulse based on the counted numbers of horizontal and vertical deflection pulses.

According to the monitoring system according to the present invention configured as described above, the gate pulse generator 8 detects changes and movements of the thermal image within a predetermined monitoring range, issues an alarm, and sends an alarm to the monitoring device as necessary. Since the information is also displayed, it is possible to reliably monitor intrusion of suspicious persons, occurrence of fire, occurrence of abnormality in industrial furnaces, etc. with an inexpensive and simple system configuration.

In addition, if a video tape recorder is prepared separately that stores the image on the monitor 11, and the recording operation of the video tape recorder is controlled by the output pulses of the waveform shaping circuit 6, an alarm will be generated when an abnormal state occurs. In addition to displaying an image on the monitor 11 that emitted the image, it is also possible to record the image at that time on a videotape.

As described above, the present invention detects a thermal image signal from a space including a range to be monitored using a pyroelectric vidicon or a pyroelectric photoelectric conversion element, and detects a signal component corresponding to the range to be monitored from this thermal image signal. This is a monitoring system that extracts the signal component and drives an alarm device based on this signal component.It has an inexpensive and simple system configuration, and can monitor and warn of intrusion by suspicious persons, fires, abnormalities in industrial furnaces, etc. I can be smart. In addition, generated from pyroelectric vidicon or pyroelectric photoelectric conversion element (
Of the total of 1, only 1 small A is captured, so that fluctuations in the DC component (setup level) included in the image signal become irrelevant, and stable alarm driving is possible.

Furthermore, since only the signals of the desired area within the effective scanning plane generated by the focal plane vidicon or pyroelectric photoelectric conversion element are extracted, other unnecessary signals from the target ring are removed, resulting in stable alarms. It can be driven.

Further, if the thermal image signals from the pyroelectric vidicon or the pyroelectric light weight conversion element are simultaneously displayed on the monitor device, visual monitoring can be performed at the same time. In this case, the range of the monitoring area can be displayed on the displayed thermal image screen, and the area can be moved to a desired position, making alarm monitoring even easier.

[Brief explanation of the drawing]

The figure is a block diagram showing the overall configuration of a monitoring system based on the present invention. 1...Pyroelectric vidicon, 2...Video amplifier, 3...Band pass filter, 4...Cate circuit, 5...Waveform shaping circuit, 6...Timer circuit, 7...Alarm buzzer, 8...
・Gate pulse generator, 9...Line display signal generation circuit, 1o...Addition circuit, 11...Monitor, 12...Monitoring range display line image, 13・
...Germanium lens.

Claims (2)

[Claims] (1) Detect a thermal image signal from a space including the range to be monitored using a pyroelectric vidicon or a pyroelectric photoelectric conversion element, extract a signal component corresponding to the range to be monitored from this thermal image signal, and extract the signal component corresponding to the range to be monitored from this thermal image signal. A monitoring system characterized by driving an alarm device based on signal components. (2) The monitoring site A according to claim 1, further comprising a device for displaying a thermal image signal, and displaying a range to be monitored in a multiplex manner together with the thermal image signal.