JPS62240823A - Image sensor for monitor control - Google Patents

Abstract

PURPOSE:To enable the detection of an object to be detected such as a human body correctly free from the effect of slow temperature change with time, by updating reference image with an original image when a difference between the two images does not exceed a threshold at any part. CONSTITUTION:Infrared rays radiated from an object M to be detected such as human body is reflected with a reflector 2 through a lens 1 to form an image on infrared rays detectors 3.... The detectors 3 are arranged in a plurality in the Y axis while the reflector 2 is driven to turn side ways at a fixed speed an hence, the views of the detectors 3... are scanned in the X axis on the surface of an image to obtain 2-D image information from output thereof. Then, the output through an amplifier 4 and the like from this information is memorized as current information of an original image into a data memory section 7 and a data memory section 8 memorizes a reference image to be subtracted from the original image at each pixel. A computing section 13 performs the subtraction between the reference image and the original image to compare the result with a predetermined threshold and updates the original image with the reference image when the difference does not exceed the threshold while outputting a judging data with a judging output section 14 when it exceeds the threshold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a surveillance control image sensor used for monitoring intruders and the like.

[Background I Subsidiary J Conventionally, when obtaining two-dimensional image information to count people, etc., images obtained using a visible light TV camera, etc. +? There was a method of subtracting the value from the reference image for each pixel and adding up to that value and converting it into a binary value to count the number of people, but when using visible light in this way, it is easily affected by disturbances, and the reference It was difficult to update the image. In addition, many devices that obtain two-dimensional image information by detecting infrared radiation are used simply as temperature detectors7), and even when used for human body detection, they are detected only by the temperature difference with the surrounding area, so sunlight When a part of a room is gradually warmed by heating, even if it is not detected at first, it may be determined that a person is present after a certain period of time.

[Object of the Invention] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a monitoring i! that prevents false detection when the temperature gradually changes due to the influence of sunlight, etc. 717
The dramatic image sensor for lj is provided.

[Disclosure of the invention] The present invention reflects infrared rays emitted from an object and focused by a lens by a reflecting mirror that rotates in the direction of horizontal force, and forms an image on a plurality of infrared 4Q detectors arranged in a vertical direction. In a supervisory control image sensor that detects the presence of an object by comparing the original image obtained from this image information with a reference image stored in advance, the two-dimensional image information is obtained by the output of the infrared detector. , an updating means is provided for updating the reference image to the original image when the difference between the reference image and the original image does not exceed a certain threshold in any part, and by immediately updating the reference image to the original image, sunlight, etc. This feature is characterized in that the temperature gradually changes due to the influence of the temperature, thereby preventing false detection in favorable cases.

This will be explained below using examples.

Figure 1 shows a schematic configuration of the ground side. In this embodiment, infrared rays emitted from an object to be detected M such as a human being are reflected by a reflecting mirror 2 through a lens X1. The image is formed on an infrared detector D3... A plurality of infrared detectors 3 are arranged in the vertical direction, that is, in the Y-axis direction in the figure, and the force reflecting mirror 2 is rotated at a constant speed by a motor or the like in the lateral force direction in the arrow A direction in the figure. Therefore, the field of view of the infrared detectors 3... is scanned in the X-axis direction on the image plane, and as a result, two-dimensional image information is obtained from the outputs of the infrared detectors 3.... The amplifier 4 is for amplifying the output of each infrared detector 3 manually operated via the multiplexer 10.
The amplified signal is passed through a filter 5 to an A/D converter 6.
A/D conversion is performed. The data storage unit 7 is for storing image information of the current original image that has been A/D converted. The data storage unit 8 is for storing a reference image that is subtracted for each pixel from the original image.

When one rotation of the reflector 2 is detected by the synchronous circuit-equipped reflective type 7 sensor 12, a synchronizing signal is output, and the output of the infrared detector 3 in the same field of view is A/D converted by this intermittent signal. It's time to set the timing. A clock generator 11 is used to create a reference signal for each circuit. The processing section 13 controls writing and reading of image information of the original image into and from the data storage section 7, reading of image information of the reference image to the data storage section 8, and updating the reference image and the original image. This is a means of calculating M by subtracting from □ and comparing it with a predetermined threshold value, and the judgment output unit 14 determines the presence or absence of the detected object M based on the detection signal detected by the comparison. This is for determining the number of objects and outputting determination data.

The operation of the image sensor for monitoring and controlling dogs according to the present invention will be explained using FIG. In order to simplify the explanation, the operation of one infrared detector 3 will be basically assumed. First, assuming that the waveform obtained by reflecting the output of the infrared detector 3 during one rotation of the infrared detector 3 at the time of starting is as shown in FIG. 2(a),
This waveform is A/D converted by the A/D converter 6 at a fixed sampling period at the end of one rotation of the reflecting mirror 2, and this A/D converted information is stored in the data storage unit 8 as reference image information. . Now, if the temperature of a part of the installation location rises due to sunlight or the like, the output of the infrared detector 3 increases in the central part as shown in the infrared detector. This output is A
/D conversion and stored in the data storage section 7 as original image information. Next, the performance section 13 reads out the image information stored in each data storage section 7 and 8, and stores the reference image and original image of each field of view, such as the respective data A' and A1 [3° and B, which correspond to the same field of view. Figure 2 (
Obtain the calculation result shown in d). Here, the temperature rise due to the solar tube occurs gradually, so the difference is very small. Therefore, if the threshold value is set to a value larger than this difference, the value of the calculation result will not exceed the threshold value L. However, the reference image is not updated and remains as shown in Figure 2 (a).
If the temperature of a part of the installation location further increases gradually and an output as shown in Fig. 2(c) is obtained the next time the reflector 2 rotates, the result of the subtraction operation will be as shown in Fig. 2(C). so that the threshold L
If the value exceeds 6, that is, it is affected by sunlight, etc., an erroneous detection will occur. Therefore, if the reference image is updated to the information in Figure 2 (b), the Hikie result is shown in Figure 2 (f). There is no chance of it happening.

The image information of the first reference image is stored in the areas R1 to RN of the data storage unit 8, and the next image information, that is, the information of the original image, is stored in the areas R1 to R2N of the data storage unit 7. and calculate RN++4+ R+ (1≦i≦N) as 1≦
This is performed within the range of i≦N, and if each difference does not exceed a predetermined threshold of 1, the data in the data storage unit 8 is updated to the value of RH++++, and if it exceeds the value of R1. is left as is, and the calculation results that exceed the threshold are binarized using a predetermined threshold and sent to the judgment output unit 14, and the judgment output unit 14 determines the detected object based on the connection, number, etc. of the binarized data. The presence or absence of M, the number WL (number of people), etc. are determined, and the determined data is output.6 Then, the image information of the next original image is again transmitted from RN++ to R2,
The data is stored in the area of the data storage section 7 of the book, and the same scanning as above is repeated.

[Effect of the Invention 1] The present invention, in the above-mentioned grooved image sensor for monitoring and control, updates the reference image to the original image if the difference between the reference image and the original image does not exceed a predetermined threshold in any part. Since it is equipped with an update means, it can accurately reproduce the temperature of the human body without being subjected to MS'll of gradual temperature changes over time, such as when a part of the installation location or the entire installation location is gradually heated by sunlight, etc. This has the effect that the object to be detected can be detected.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the same operation, in which 1 is a lens, 2 is a reflecting mirror, 3 is an infrared detector, 7 and 8 are data storage units, and 13 is the calculation section. Agent Patent Attorney Ishi FTI Ai Seven Procedures Ro J-E
19861 Patent M No. 85413 2, Name of the invention Image sensor for monitoring and control 3, Person making the amendment Relationship to the case Patent applicant address Oaza Kadoma, Yaman City, Osaka Prefecture 1048 address name (58
3) Matsushita Electric Works Co., Ltd. Representative Sadao Ii 0 Agent Zip code 530 Address 1-12-17-5 Umeda, Kita-ku, Osaka City Date of amendment order 6 Number of inventions increased by amendment None 7. N-elephant diagram for correction Figure 1

Claims (1)

[Claims] (1) Infrared rays emitted from the object to be detected and focused by a lens are reflected by a horizontally rotating reflecting mirror and imaged on a plurality of infrared detectors arranged vertically. In an image sensor for monitoring and control, which obtains two-dimensional image information by outputting it and detects the presence of a detected object by comparing the original image obtained from this image information with a reference image stored in advance, the reference image and the original image are used. 1. An image sensor for monitoring and control, comprising updating means for updating a reference image to an original image when the difference between the reference image and the reference image does not exceed a predetermined threshold in any part.