JPH06223276A - Crime prevention alarm system - Google Patents

Abstract

PURPOSE:To obtain fine pictures even at night in a crime prevention alarm system using a TV camera. CONSTITUTION:The detecting area of a pyroelectric element 5 is set up so as to almost coincide with the visual field of the TV camera 1. When an alarm signal is outputted from a signal processing part 6, a switch 10 is closed and a video signal is sent from the TV camera 1 to a receiver. An illuminance detecting part 9 detects illuminance in the visual field based upon the video signal and opens a switch 12 when the illuminance exceeds a prescribed value, or closes the switch 12 when the illuminance is less than the prescribed value. When the alarm signal is outputted from the processing part 6, a switch 11 is closed for a prescribed time. Since a light 7 is turned on at the time of photographing the inside of the visual field by the camera 1 due to the existence of an intruder at night, a fine picture can be sent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crime prevention alarm system using a television camera.

[0002]

2. Description of the Related Art Conventionally, a crime prevention alarm system including a television camera (hereinafter referred to as a TV camera) and a heat ray sensor is known. In such a system, the detection area of the heat ray sensor is set within the field of view of the TV camera,
When there is an alarm from the heat ray sensor, that is, when a signal indicating the presence of an intruder is output from the heat ray sensor, the TV camera is activated and the intruder is photographed.

[0003]

However, the intruder mostly invades at night, and the illuminance is often lower than the minimum subject sensitivity of the TV camera, so that there is a problem that the intruder cannot be photographed well. It was

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a crime prevention alarm system capable of taking good pictures even at night.

[0005]

In order to achieve the above-mentioned object, a security alarm system of the present invention comprises a television camera,
A crime prevention alarm system comprising: an intruder detection means having a detection area approximately the same as the field of view of the television camera, and transmitting a video signal from the television camera when the intruder detection means detects an intruder, Illumination means and illuminance detection means for detecting illuminance in a range including at least the field of view of the television camera, and the illumination means, when the illuminance detected by the illuminance detection means does not reach a predetermined illuminance, It is characterized in that the illuminating means is turned on, and when the intruder detection means detects an intruder in the lit state, it is turned on for a predetermined time.

[0006]

The function and the effect of the present invention are as follows.
A TV camera, an intruder detection means, a lighting means, and an illuminance detection means are provided. The detection area of the intruder detection means is TV
It is set to almost match the field of view of the camera. Further, the illuminance detecting means detects the illuminance in a range including at least the field of view of the TV camera.

Then, the TV camera sends a video signal when the intruder detecting means detects an intruder. The illuminating means is put into a lighting standby state when the illuminance detected by the illuminance detecting means does not reach a predetermined illuminance, and is set to a predetermined state when the intruder detecting means issues a warning while in the lighting standby state. Lights for hours.

Therefore, if there is an intruder at night,
The TV camera shoots in the field of view and sends out the video signal thereof, but at that time, since the illumination means is turned on, a good image can be sent out. In addition, this lighting is also a threat to intruders.

Here, the illuminance can be detected based on the video signal obtained by the TV camera as described in claim 2.

In addition, the detection area of the intruder detection means, T
Since it can almost match the field of view of the V camera,
It is possible to avoid shooting extra things.

Further, the TV camera, the intruder detecting means, the illuminating means and the illuminance detecting means can be housed in one housing, in which case there is an effect that no extra wiring is required. .

[0012]

Embodiments will be described below with reference to the drawings.
In the following examples, a heat ray sensor using a pyroelectric element is used as the intruder detection means, but it is obvious to those skilled in the art that a reflection type beam sensor including a light projector and a light receiver or other sensors can be used. Is.

FIG. 1 is a diagram showing the configuration of an embodiment of a crime prevention warning system according to the present invention, in which 1 is a TV camera,
2 is an image pickup unit, 3 is a video signal processing unit, 4 is a reflecting mirror, 5 is a pyroelectric element, 6 is a signal processing unit, 7 is a light, 8 is a power source, 9 is an illuminance detection unit, 10, 11 and 12 are switches. , 13 denote housings.

The TV camera 1 is provided with an image pickup section 2 composed of a CCD image pickup element and the like, and a video signal processing section 3, and is always operating. The video signal processing unit 3 adds a synchronization signal to the video signal output from the imaging unit 1 and performs a predetermined process such as amplification for transmission.

The reflecting mirror 4, the pyroelectric element 5 and the signal processing section 6 constitute a heat ray sensor. The pyroelectric element 5 is arranged at the focal point of the reflecting mirror 5, and its output is subjected to predetermined processing such as amplification by the signal processing unit 6 and comparison with a reference signal. When the signal processing unit 6 detects a moving body that emits heat rays, the signal processing unit 6 issues an alarm and outputs an alarm signal to a predetermined device (not shown) such as a receiver. Since the signal processing in the heat ray sensor is well known, its details are omitted.

Then, as shown in FIG. 2, the detection area B of the pyroelectric element 5 of the heat ray sensor is preferably set to be substantially the same as the field of view of the TV camera 1 shown by A in the figure. This is because this eliminates the need to capture extra areas. 2A is a view of the field of view of the TV camera 1 and the detection area of the heat ray sensor as seen from the front, and FIG. 2B is a view as seen from the side.

The video signal from the video signal processor 3 is input to the switch 10 and the illuminance detector 9. The switch 10 is normally open as shown in the figure, and is closed when an alarm signal is output from the signal processing unit 6. Therefore, TV
Although the camera 1 is always operating, it is sent to a predetermined device such as a receiver only when the heat ray sensor issues an alarm.

The illuminance detector 9 takes in the video signal and detects the average illuminance in the visual field. Specifically, for example, a video signal of a scanning line at a predetermined position is captured, an average luminance level of the captured video signal is obtained for each field or frame, and the average luminance level is compared with a predetermined reference level. This reference level is preferably set to a level corresponding to the minimum subject illuminance of the image pickup unit 2. Then, when the average brightness level is equal to or lower than the reference level, a high level is output.

The output of the illuminance detector 9 is supplied to the switch 12. The switch 12 is in a closed state when the output of the illuminance detecting section 9 is at a high level, and is in an open state when the output is at a low level. Further, the output of the signal processing unit 6 is supplied to the switch 11, and the switch 11 is closed for a predetermined time when an alarm signal is output, and is opened for no alarm signal. Become.

Therefore, when the heat ray sensor is issued, the switch 11 is always closed for a certain period of time, but when the illuminance during daytime exceeds a predetermined value, the switch 12 is not closed so that the light 7 is turned on. Does not illuminate, and when the illuminance at night is below a predetermined value, the switch 12 is closed and the light 7 is illuminated.

By performing the above operation, when there is an intruder when the illuminance is equal to or lower than the minimum subject sensitivity of the image pickup unit 2 such as at night, the light 7 is turned on for a certain period of time. Good images will be sent. The light 7 also plays a role of intimidating an intruder.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications can be made. For example, it will be apparent to those skilled in the art that the illuminance detection unit 9 can be variously configured in addition to the above-described embodiment. Further, regarding the illuminance detection, an illuminance meter may be used instead of detecting the illuminance based on the video signal as shown in the above embodiment.

Further, the structure for driving the light 7 is not limited to the above-mentioned embodiment. In short, the illuminance within the field of view of the TV camera 1 is below a predetermined level, and the alarm signal is sent from the intruder detecting means. Any structure is acceptable as long as it can be turned on when it is output.

Furthermore, in the above embodiment, the TV camera 1
The heat ray sensor as the intruder detecting means and the light 7 as the illuminating means are housed in one housing 13, but they may be separately provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a field of view of the TV camera 1 and a detection area of a heat ray sensor.

[Explanation of symbols]

1 ... TV camera, 2 ... Imaging unit, 3 ... Video signal processing unit, 4
... Reflecting mirror, 5 ... Pyroelectric element, 6 ... Signal processing unit, 7 ... Light, 8 ... Power supply, 9 ... Illuminance detecting unit, 10, 11, 12 ... Switch, 13 ... Housing.

Claims (2)

[Claims] 1. A television camera, and an intruder detection means having a detection area substantially in the same area as the field of view of the television camera, and an image from the television camera when the intruder detection means detects an intruder. In a crime prevention alarm system for transmitting a signal, an illumination unit and an illuminance detection unit for detecting an illuminance in a range including at least the field of view of the television camera are provided, and the illumination unit has a predetermined illuminance detected by the illuminance detection unit. When the illuminance is not reached, the lighting means is turned on, and when the intruder detection means detects an intruder in the lightable state, it is turned on for a predetermined time. Alarm system. 2. The crime prevention alarm system according to claim 1, wherein the illuminance detecting means detects illuminance based on a video signal obtained by the television camera.