JPH04241095A - Monitoring device - Google Patents

Abstract

PURPOSE:To obtain the monitoring device, which enables multi-purpose use and reduces malfunction, by providing various monitoring functions like human sight at one monitoring device. CONSTITUTION:A television camera 1 using a CCD 2 having the comparatively small number of picture elements is provided, and video signals outputted from this television camera 1 are converted to digital signals by an A/D conversion circuit 5 and stored in a reference memory 6 later. A comparator circuit 9 compares data stored in this reference memory 6 with data outputted from the A/D conversion circuit 5 at all times, and this compared result is processed by a CPU 10. Thus, when it is judged that the brightness of an entire picture is changed, the stored data in the reference memory 6 are exchanged and when the specified picture element to be monitored in the picture is changed, an alarm is issued.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device that optically monitors a space to be monitored and outputs an alarm signal when an abnormal condition such as fire, theft, or human intrusion occurs.

0002

2. Description of the Related Art Conventionally, dedicated detectors have been installed for each detection target, such as fire, theft, human intrusion/approach, etc. These fires, thefts, human intrusions,
A wide variety of detectors, each with a different operating principle, have been developed and used for each type of detector, such as proximity detection.

[0003] Since it was not possible to detect the occurrence of various abnormal conditions with one detector, a detector had to be installed for each object to be detected.

0004

[Problem to be solved by the invention] Therefore, this invention solves the following problems:
By providing a single monitoring device with various monitoring functions such as human vision, it is possible to obtain a monitoring device that can be used for multiple purposes and has fewer malfunctions.

[0005]

[Means for solving the problem] C with a relatively small number of pixels
A television camera having a CD, a lens that projects a light beam within its field of view onto the CCD, an A/D conversion circuit that converts the video signal output from the CCD into a digital signal, and this A/D conversion circuit. A reference memory stores a digitized video signal for one screen output from the reference memory, and the video signal stored in this reference memory and the output of the A/D conversion circuit are compared for each corresponding pixel. A comparison circuit that outputs the difference between It is provided with a means for replacing the current video signal and an alarm signal generating means for processing the signal corresponding to the pixel of the part to be monitored out of the output signal of the comparison circuit and outputting an alarm signal.

[0006]

Embodiment As shown in FIG. 2, in a room to be monitored, a television camera 1 is installed on one wall near the ceiling so that the object to be monitored can be seen. This TV camera 1
As shown in Fig. 1, a CCD 2 with a small number of pixels,
A lens 3 that projects light within the field of view onto this CCD 2
and a drive circuit 4 for driving the CCD 2 to generate a video signal corresponding to the projected image, and the drive circuit 4 is controlled by clock pulses output from a clock pulse generator 13. horizontal and vertical synchronization signals are generated and applied to the CPU 10 via the PIO 8.

[0007] Since this television camera 1 is not intended for generating high-resolution video signals, but is mainly used for monitoring, the field of view is divided into a plurality of sections, and luminance information for each section is obtained. It is sufficient to use a small CCD with a pixel count of several tens to several hundreds.

Furthermore, an A/D conversion circuit 5 for converting the video signal output from the CCD 2 of the television camera 1 into a digital signal, and a standard for processing the signal output from the A/D conversion circuit 5, a reference memory 6 that stores a video signal, and a plurality of memory columns that sequentially store new data while scrolling through a plurality of video signals at regular intervals via a changeover switch 11, discarding the oldest data. 7, and a comparison circuit 9 that compares the signal of each corresponding pixel between the current video signal output from the A/D conversion circuit 5 and the video signal stored in the reference memory 6, and outputs the difference between the two. The output of this comparison circuit 9 is P
It is led to the CPU 10 via the IO8.

[0009] The CPU 10 monitors the data of one specific pixel out of the output signal of the comparator circuit 9, which has little relation to the monitored object, as a reference for the brightness of the screen, and if this data differs by more than a certain level. , and if the difference continues for a period of one scroll or more, it is determined that the brightness within the field of view has changed overall, and the reference memory 6
The past video signal stored in the memory is deleted, the current video signal is newly stored, and the re-stored video signal is used as a reference from now on.

Even if the overall brightness within the field of view changes, such as when a light is turned on or off, direct AGC control is not performed on the CCD 2 itself or the amplifier circuit that amplifies its output. The CPU 1 executes the operation of monitoring the output signal of a specific pixel among the output signals of the comparator circuit 9.
By replacing the data in the reference memory 6 with 0, an operation similar to AGC control is performed.

In the normal monitoring state, the reference memory 6
The data of each pixel stored in the A/D conversion circuit 5
The data of each corresponding pixel output from the pixel is compared with the data of each corresponding pixel, and when a change occurs between the two over a certain period of time, an alarm signal is issued from the terminal 14.

As a data processing method for generating this alarm signal, the output signal of the comparator circuit 9 and the synchronization signal from the drive circuit 4 which determines the coordinates on the screen are inputted.
By using the PU 10, various processing methods can be realized.

(1) When used for the purpose of detecting human intrusion or approach, the output signal of the comparator circuit 9 should be constantly monitored and an alarm signal should be generated when the data of one or more pixels changes. It's okay. In this case, for example,
Malfunctions can be reduced by monitoring only pixel data in selected areas necessary for monitoring, such as doors and windows.

(2) When used for the purpose of detecting theft, the output signal of the comparison circuit 9 is changed to the output signal of a pixel corresponding to an object to be monitored, such as a safe or an expensive picture frame displayed. It is sufficient to generate an alarm signal when this occurs.

(3) When used for the purpose of detecting a fire, monitor the upper and lower parts of the screen separately, and since smoke generated tends to collect on the ceiling in the early stages of a fire, It can be used as a smoke detector by configuring it to generate an alarm signal when the data of the lower pixels hardly changes even though the amount of change in pixel data is small but changes appear in many pixels. can.

When such an alarm signal is generated, the data stored in the plurality of memory columns 7 while scrolling in time together with the alarm signal is transferred to the changeover switch 1.
2, sent to a remote monitoring station, played back and displayed at the monitoring station, and further processed.
It is possible to accurately grasp the abnormal state that has occurred, and
If the writing operation of the memory column 7 is stopped when an alarm signal is generated, the data stored in the memory column 7 can be utilized as evidence of an incident.

[0017]

[Effects of the Invention] As explained above, according to the monitoring device of the present invention, its functions can be adjusted by software according to the purpose of use.
Since hardware can be easily changed, the hardware is suitable for mass production, can be produced and sold at low cost, and moreover, by installing one monitoring device, it can perform multiple types of monitoring functions. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an overview of an embodiment of a monitoring device of the present invention.

FIG. 2 is a diagram showing the installation state of the monitoring device of the present invention.

[Explanation of symbols]

1 TV/Camera 2 CCD 3. Lens 4 Drive circuit 5 A/D conversion circuit 6. Reference memory 7 Memory column 8 PIO 9 Comparison circuit 10 CPU 11, 12 Selector switch 14 Alarm signal output terminal

Claims (2)

[Claims] Claim 1: A CCD with a relatively small number of pixels;
A television camera having a lens that projects a light beam within its field of view onto a CD, an A/D conversion circuit that converts a video signal output from the CCD into a digital signal, and the A/D
A reference memory that stores one screen worth of digitized video signal output from the conversion circuit, and a comparison between the video signal stored in the reference memory and the output of the A/D conversion circuit for each corresponding pixel. a comparison circuit that outputs the difference between the two;
means for replacing the video signal stored in the reference memory with the current video signal when an output corresponding to a pixel serving as a brightness reference among the output signals of the comparison circuit continuously changes by a certain value or more; , an alarm signal generating means for processing a signal corresponding to a pixel of a portion to be monitored out of the output signals of the comparison circuit and outputting an alarm signal. 2. The monitoring device according to claim 1, further comprising a plurality of memory columns that sequentially store a plurality of video signals while scrolling them at regular intervals.