JP2003069866A - Monitoring camera device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete configuration for suppressing sensor sensitivity so as to prevent a monitoring camera device from needlessly operating by a characteristic of an infrared sensor in particular concerning the monitoring camera device that has a video camera for converting an image formed through a lens into a video signal and the infrared sensor for passively detecting far- infrared radiation and starts the driving of the video camera when the infrared sensor detects far-infrared radiation that is equal to or more than a prescribed amount. SOLUTION: A filter 6 in which the transmittance of far-infrared radiation of a central part of the infrared sensor 4 in a detection direction is made smaller than the transmittance of parts other than the central part is disposed in front of the infrared sensor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a video camera for converting an image formed through a lens into a video signal, and an infrared sensor for passively detecting far infrared rays. The present invention relates to a surveillance camera device configured to start driving the video camera when far infrared rays are detected, and particularly to a specific configuration for suppressing the sensitivity of the sensor so that the surveillance camera device does not operate unnecessarily. It has characteristics.

[0002]

2. Description of the Related Art A surveillance camera device as described above is installed, for example, at a front door, and when a person enters or leaves a place to be monitored, the wavelength emitted from the human body is 8 to 12 μm.
Far infrared rays are detected by the infrared sensor, and the video camera in the standby state is driven to be displayed on the monitor or recorded.

Therefore, the infrared sensor needs to reliably detect the entrance and exit of a person within a range in which it can be discriminated whether or not a person is a suspicious person from the image displayed on the monitor, but it is impossible to identify the person in a distant place. It is better not to detect in the place of.

On the other hand, the infrared sensor is generally shown in FIG.
It has the following characteristics. In FIG. 4, the X axis indicates the distance from the sensor on the central axis of the sensor, and the Y axis indicates the distance in the horizontal direction perpendicular to the X axis.

A black circle in FIG. 4 indicates a position where a detection object which emits a certain far infrared ray can be detected. That is, at the position separated by the distance a on the sensor center axis, Y
It is shown that the detection object up to the distance b in the positive axis direction and the distance c in the negative Y axis direction can be detected. This Figure 4
As shown in (1), the infrared sensor has a roughly fan-shaped sensitivity distribution in a region close to the sensor, but the sensitivity near the X axis projects at a certain distance.

If the surveillance camera device is constructed with such an infrared sensor, it is inconvenient for a detection object located in the vicinity of the central axis of the sensor to be detected even at a position beyond the identifiable distance. In order to eliminate this inconvenience, the following two methods have been conventionally used. One of them is a method of electrically adjusting the sensitivity of the sensor, which compares the output level of the detection signal detected by the sensor or whether the output reaches a predetermined detection level. This is a method of adjusting the substantial sensitivity of the sensor by changing the detection level of the volume by a volume or the like. The second method uses two sensors for reliable person detection. The first sensor is oriented substantially horizontally, and the second sensor is oriented downward, and is responsible for detection in the vicinity of the camera.

Then, the AND of the first sensor and the second sensor is taken, and only when both the first sensor and the second sensor detect the presence or absence of a person in the detection range is determined. ing. By adopting this configuration, for example, a heat source that emits far-infrared rays that is approximately the same as a human body in the distance is detected by the first sensor, but is not detected by the second sensor. It is determined that there is no heat source, that is, no person enters or leaves the detection range.

[0008]

However, the above-mentioned first and second conventional surveillance camera devices have the problems described below. First, the first conventional surveillance camera device
Since this is an adjusting method that suppresses the sensitivity of the entire detection range of the sensor, even if the sensor is originally in a proper state in the direction where the sensitivity is high, the sensitivity is lowered more than necessary in other directions. For example, the sensor detects an automobile or the like that is far away, which is annoying, so if the sensitivity of the sensor is adjusted by this method, the sensitivity of the front of the sensor becomes a favorable state but the sensitivity of the side decreases, and The detection range will be narrowed. Next, the second conventional surveillance camera device performs the AND operation of the “detection” of the first sensor oriented substantially horizontally and the “detection” of the second sensor oriented downward as described above. Is configured to take. However, the radiation amount of far infrared rays differs between the upper body and the lower body depending on the difference in body temperature depending on the body part and the state of clothing. That is, there are cases where the second sensor does not detect even if it is detected by the first sensor. Furthermore, in order to adjust the sensitivity of the entire detection range, it is necessary to adjust the sensitivity of the first sensor and adjust the mounting angle of the sensor itself of the second sensor, which is a large-scale device. Therefore, it becomes an expensive surveillance camera device in addition to using two sensors. In view of the above problems, the present invention provides a surveillance camera device that has a simple configuration and is capable of suppressing the sensitivity of the sensor and setting the detection range.

[0009]

In order to solve the above-mentioned problems, the surveillance camera device of the present invention comprises a filter on the front surface of an infrared sensor having a far infrared ray transmittance near the center of the sensor smaller than that of its peripheral portion. With a simple configuration, it is possible to reduce unnecessarily high sensitivity in the vicinity of the sensor center axis without reducing sensitivity in the periphery away from the sensor center axis. It will no longer react to cars, etc. that are in an indistinguishable distance.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
A video camera for converting an image formed through a lens into a video signal, and an infrared sensor for detecting far infrared rays. When the infrared sensor detects far infrared rays of a predetermined amount or more, the video camera In the surveillance camera device configured to start driving, the far-infrared transmittance of the central portion in the detection direction of the infrared sensor is smaller than the transmittance other than the central portion of the filter on the front surface of the infrared sensor. It is a surveillance camera device characterized by being arranged, and with a simple configuration of arranging a filter, unnecessarily high sensitivity in the vicinity of the sensor center axis can be achieved without reducing the sensitivity in the periphery away from the sensor center axis It can be lowered, and it will not react to a car or the like located at a distance where a person cannot be identified by a camera image. In the invention according to claim 2 of the present invention, the filter is formed of a translucent resin material, and a matte pattern is formed at a position corresponding to a central portion in a detection direction of the infrared sensor during molding processing. The surveillance camera device according to claim 1, wherein the satin pattern for adjusting the substantial sensitivity of the sensor can be formed at the same time when the filter is molded, which is convenient.

In the invention according to claim 3 of the present invention, the filter is formed of a light-transmitting resin material, and at the time of molding processing thereof, the thickness of a position corresponding to the central portion in the detection direction of the infrared sensor. 2. The surveillance camera device according to claim 1, wherein the thickness is formed to be thicker than a peripheral portion thereof, and in this configuration, the thickness for adjusting the substantial sensitivity of the sensor can be formed at the same time when the filter is molded. It is convenient.

The invention according to claim 4 of the present invention is characterized in that the filter is fixed to a housing, and a cap made of a translucent material is detachably attached to the front surface of the filter. According to the surveillance camera device of the first aspect, the detection capability of the sensor can be maintained in the initial state by exchanging the cap at appropriate times.

(Embodiment) The following is a description of claim 1 of the present invention.
Through the embodiment of the invention described in claim 4,
This will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a side sectional view showing a schematic configuration of a surveillance camera device of the present invention. In FIG. 1, reference numeral 1 denotes a translucent cover 14 fitted in a through hole formed in a front upper portion of a housing 7. Condensing means for condensing the passed light to form an image on the imaging means 2, and 3 is a video signal processing for processing the video signal received and converted by the imaging means 2 to obtain a predetermined video signal. There is a means. The condensing means 1, the imaging means 2 and the video signal processing means 3 constitute a normal video camera, and the output video signal is sent to a monitor device (not shown) and displayed as an image.

Reference numeral 6 denotes a filter, which is a feature of the present invention and is attached to a through hole formed in the lower part of the front surface of the housing 7, and far infrared rays passing through the filter 6 are irradiated to the infrared sensor 4. Has been done. Reference numeral 5 denotes a switching circuit means, which is configured to drive the video camera in a standby state for a predetermined period when the amount of far infrared rays received by the infrared sensor 4 is larger than a predetermined amount.

The filter 6 is made of a resin that is substantially transparent or semi-transparent for wavelengths of 8 to 12 μm, for example, high-density polyethylene, and is formed so as to project from an annular outer frame as shown in FIG. Through holes 10 of the two protruding parts,
11 is made to penetrate the bosses 8 and 9 formed on the housing 7,
It is fixed to the housing 7 by melting its tip with heat. The central portion 12 of the filter 6 is, for example, satin finished at the same time when the filter 6 is formed. The satin finish at the peripheral portion is made rougher than the central portion, and far infrared rays are dispersed by the satin finish. The far infrared ray transmission amount is less than that of the peripheral portion. Further, instead of the satin finish, the central portion may be formed thicker than the peripheral portion, so that the far infrared ray transmission amount in the central portion may be smaller than that in the peripheral portion.
That is, the infrared sensor 4 is passed through the filter 6.
By arranging so that far infrared rays are radiated onto the sensor, the unnecessarily high sensitivity in the vicinity of the sensor center axis shown in FIG. It will not react to automobiles. If the surveillance camera device is installed outdoors, the sensor may respond to the wind.
The filter 6 also serves as a cover for preventing the sensor from being exposed to the outside air. Further, when exposed to wind and rain or ultraviolet rays, the performance of the filter 6 may be deteriorated, but as shown in FIG. By engaging and fixing, this cap 13
It is possible to maintain the detection capability of the sensor in the desired state by replacing the sensor with time.

[0016]

As described above, according to the present invention, it is possible to realize a surveillance camera device with a simple structure that does not respond unnecessarily due to the characteristics of the infrared sensor.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a surveillance camera device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a filter used in the surveillance camera device.

FIG. 3 is a cross-sectional view of a main part of a surveillance camera device according to another embodiment of the present invention.

FIG. 4 is a diagram showing a sensitivity distribution of an infrared sensor.

[Explanation of symbols]

1 light collecting means 2 Imaging means 3 Video signal processing means 4 infrared sensor 5 Switching circuit means 6 filters 7 housing 8, 9 boss 13 cap

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) H04N 7/18 H04N 7/18 HF term (reference) 2H048 CA14 DA01 DA04 DA11 DA21 2H083 AA04 AA25 AA32 5C022 AA05 AA06 AB67 AC55 5C054 AA01 CA05 CG07 CH06 HA18 HA22 5C086 AA27 CA12 CA25 CB16 DA04 DA15 EA31 EA40 EA45 FA18

Claims (4)

[Claims] 1. A video camera for converting an image formed through a lens into a video signal, and an infrared sensor for detecting far infrared rays. When the infrared sensor detects far infrared rays of a predetermined amount or more. In the surveillance camera device configured to start driving the video camera, a filter in which a far infrared ray transmittance of a central portion in a detection direction of the infrared sensor is smaller than a transmittance other than the central portion is provided. A surveillance camera device characterized by being placed in front of an infrared sensor. 2. The filter is formed of a translucent resin material, and a satin pattern is formed at a position corresponding to a central portion in a detection direction of the infrared sensor during the molding process. The surveillance camera device according to claim 1. 3. The filter is formed of a translucent resin material, and a thickness of a position corresponding to a central portion in a detection direction of the infrared sensor is formed thicker than a peripheral portion of the infrared sensor during a molding process. The surveillance camera device according to claim 1, wherein: 4. The surveillance camera device according to claim 1, wherein the filter is fixed to a housing, and a cap made of a translucent material is detachably attached to a front surface of the filter.