JP2001218189A - Monitor camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitor camera system by which the disturbance of the visual field of a monitor camera is detected when it occurs and alarm is outputted. SOLUTION: The system is provided with a disturbance detecting means for detecting whether the visual field of an image pickup means is disturbed and an alarm means for outputting alarm based on the detection result of the detecting means. In the system, the disturbance detecting means is provided with an illuminance sensor for measuring the illuminance of a monitor area to detect a disturbing action when the luminance value of an image picked-up by the image pick-up means becomes equal to or below a prescribed value and also when the illuminance detected by the illuminance sensor becomes equal to or greater than a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera for monitoring a suspicious person's behavior and recording the surveillance camera by installing a surveillance camera in places where people enter and exit, such as stores and companies.

[0002]

2. Description of the Related Art Conventionally, a surveillance camera has been installed in a store or an entrance, which is a surveillance place, and an image transmitted from the surveillance camera is displayed on a monitor at a surveillance center, or this image is recorded for ex-post monitoring. Surveillance camera systems as evidence are known.

[0003]

However, in the above-mentioned conventional surveillance camera system, for example, after a fraudster sprays a surveillance camera or puts a cover on the surveillance camera to make it impossible to take an image, a crime is committed. There is. In addition, after turning off the lighting to darken the monitoring area, a crime may be committed. If observers are constantly monitoring the monitors, they can notice such misconduct,
When only the image of the surveillance camera is recorded, there is a problem that the image of the criminal act cannot be recorded. The present invention has been made in view of the above-described problems, and has as its object to provide a surveillance camera system that can detect when a field of view of a surveillance camera is obstructed and output an alarm.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and achieve the above-mentioned object, a surveillance camera system according to the present invention comprises an image pickup means for picking up an image of a surveillance area and a field of view of the image pickup means. In a surveillance camera system having an interference detecting means for detecting whether or not the alarm is detected and an alarm means for outputting an alarm based on the detection result of the interference detecting means, the interference detecting means includes an illuminance sensor for detecting an illuminance of a monitoring area. When the luminance value of the image picked up by the image pickup means is out of the predetermined range and the illuminance detected by the illuminance sensor is equal to or more than the predetermined value, it is detected as a sabotage.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a surveillance camera system according to the present invention will be described with reference to FIGS. FIG.
FIG. 1 is a configuration diagram of a surveillance camera system according to the present embodiment. 1
Reference numerals A to 1D denote surveillance cameras for imaging a surveillance area. 2
Is connected to the monitoring cameras 1A to 1D via a coaxial cable 5 by a controller, and receives and processes images and audio signals transmitted from the monitoring cameras 1A to 1D. Reference numeral 3 denotes a time lapse video, which is connected to the controller 2 via a coaxial cable 6, receives an image and an audio signal transmitted from the controller 2, and performs recording and recording. Reference numeral 4 denotes an alarm device that monitors improper actions on the surveillance camera 1 and sends an alarm to a remote security center (not shown) when an abnormality occurs.

FIG. 2 is a functional block diagram of the monitoring camera 1. An imaging unit 10 includes a lens, a CCD, and the like, and captures an image in the monitoring area and converts the captured image into a predetermined image signal. Reference numeral 11 denotes a sound collecting unit which is constituted by a microphone and collects sound in the monitoring area and converts the sound into a predetermined sound signal. Reference numeral 12 denotes a signal transmission unit, and the imaging unit 10 and the sound collection unit 11
Is converted into a predetermined output signal and transmitted to the controller 2 via the coaxial cable 5. Reference numeral 13 denotes a disturbance detection unit that detects a luminance value of an image captured by the imaging unit. Reference numeral 131 denotes an illuminance sensor that detects illuminance in the monitoring area.

FIG. 3 is a functional block diagram of the controller 2. Reference numeral 20 denotes an image processing unit which processes image signals received from the monitoring cameras 1A to 1D via the coaxial cables 5A to 5D and synthesizes them as one image divided into four. Further, it detects whether or not the image signal is normally received. Reference numeral 21 denotes an image output unit which sends out the quartered image synthesized by the image processing unit 20 to the time lapse video 3 via the coaxial cable 6.
Reference numeral 22 denotes a C operation unit which includes switches and the like, and allows an operator to perform various setting operations of the controller 2. Reference numeral 23 denotes a C control unit including a CPU and the like, which is connected to each unit and controls operation. Reference numeral 24 denotes an I / F unit configured by, for example, RS232C, which relays a signal from a C authentication unit 25 described later. 25
Is a C authentication unit composed of, for example, a card reader, and checks the qualification of an operator who operates the controller 2. 2
Reference numeral 6 denotes a C power supply unit that supplies power to each unit of the controller 2. Reference numeral 27 denotes a C power supply disconnection detecting unit which detects when the power supply of the C power supply unit 26 is disconnected and switches a relay contact (not shown). Reference numeral 28 denotes a C alarm output unit that outputs an alarm signal to the alarm device 4 when the image signal from the monitoring cameras 1A to 1D is interrupted by the image processing unit 20, for example.

FIG. 4 is a functional block diagram of the time lapse video 3. A recording unit 31 receives the four-divided image signal received from the controller 2 and records it on a video tape. Reference numeral 32 denotes a T operation unit for performing operations such as starting and stopping recording, timer operation, and insertion / removal of a video tape. Reference numeral 33 denotes a T control unit composed of a CPU and the like, which is connected to each unit to perform operation control. Reference numeral 34 denotes an I composed of, for example, RS232C.
The / F section relays a signal from a T authentication section 35 described later. Numeral 35 denotes a T authentication unit composed of, for example, a card reader, which checks the qualification of the operator who operates the time lapse video 3. Reference numeral 36 denotes a T power supply unit, and a time lapse video 3
Power is supplied to each section. Reference numeral 37 denotes a T power cutoff detecting unit.
When the power of the power supply unit 36 is cut off, this is detected and a relay contact (not shown) is switched. Reference numeral 38 denotes a T alarm output unit, which outputs an alarm signal to the alarm device 4 when the image signal from the controller 2 to the recording unit 31 is interrupted, for example.

Next, an operation of detecting an obstruction of visual field to the surveillance camera 1 and outputting an alarm in the surveillance camera system according to the present invention will be described with reference to FIG. First,
Turn on the power of each part of the surveillance camera system. Each of the monitoring cameras 1A to 1D captures an image of a monitoring area
0, and outputs an image signal to the signal transmission unit 12 via the interference detection unit 13. In the interference detection unit 13, step S
In step 1, an image from the image pickup 10 is captured. A luminance value (256 gradations of luminance) is calculated for each pixel of the image obtained in step S2. In step S3, the number of pixels having a predetermined brightness value or less is calculated. The number of pixels calculated in step S4 is compared with a predetermined number m of pixels. When the calculated number of pixels is smaller than m, the process returns to step S1, and when it is larger, the process proceeds to step S5. Step S5
Then, it is determined whether the illuminance detected by the illuminance sensor 131 is equal to or more than a predetermined value. This predetermined value is, for example, the illuminance when the lighting is turned off at night or in a room without a window. Here, when the illuminance is equal to or less than the predetermined value, the reason why the brightness of the image is equal to or less than the predetermined value is that nighttime or the lighting is turned off and the entire monitoring area is darkened without causing a visual field disturbance abnormality. Step S1
Return to If the illuminance sensor is equal to or more than the predetermined value, it means that the luminance value of the captured image has decreased despite the bright monitoring area, and it is determined that there has been a visual field obstruction act on the monitoring camera or the like. Proceeding to S6, the signal sending unit 12
Send an abnormal signal to

In step S3 of FIG. 5, the number of pixels, which is a predetermined range of luminance values, is calculated in advance. In step S4, the number of pixels is compared with a predetermined range m of pixels. Returning to S1, if it is larger, the process may proceed to step S5 (corresponding to claim 3). In this case, detection other than the above-described obstruction of the view of the camera by closing the camera lens can be performed. That is the case where light exceeding the dynamic range of the imaging unit 10 is illuminated on the camera lens by a searchlight or the like, causing saturation of luminance. If a determination is made for a luminance value equal to or greater than a predetermined value, it is possible to detect an action of obstructing the view of the camera due to the light. In the present embodiment, the brightness value is calculated for each pixel of the obtained image. However, the brightness value may be calculated in a pixel block including predetermined pixels. In this case, the brightness value of the pixel block may be obtained by adding the brightness values of the predetermined pixels and dividing by a predetermined number of pixels. Also, the illuminance sensor 131 is not installed on the monitoring camera,
It may be installed at a remote place in the monitoring area, and only the signal may be transmitted to the interference detection unit 13 of the monitoring camera and input. Thus, even when the entire surveillance camera is covered, it is possible to detect interference. FIG. 6 is an external appearance image diagram when the monitoring camera 1 is installed in a monitoring area. 2 shows a situation where the monitoring camera 1 is capturing an image of a person illuminated by an electric light. When the obstruction detection unit 13 detects the obstruction of the visual field, the signal transmission unit 12 converts it into a predetermined alarm signal and transmits the signal through the coaxial cables 5A to 5D.

When the illuminance sensor 131 detects an illuminance equal to or less than a predetermined value separately from the above-described interference detection operation,
An illuminance reduction warning is transmitted from the signal transmission unit 12. By separately transmitting the signal of the low illuminance warning and the abnormal signal due to the above-described interference detection, the situation can be easily grasped at a remote security center described later. The image of the monitoring area captured by the imaging unit 10 and output to the signal transmission unit 12 via the interference detection unit 13 is converted into, for example, an NTSC image signal and transmitted through the coaxial cables 5A to 5D. It is sent to the controller 2. The image processing unit 20 of the controller 2 creates the received four images of the surveillance cameras 1A to 1D as one image divided into four, and outputs the four images to the time lapse video 3 at the image output unit 21. The image processing unit 20 also monitors cameras 1A to 1A via coaxial cables 5A to 5D.
D. The interference detection signal and the illuminance reduction signal of D are received. Then, when receiving the interference detection signal and the illuminance reduction signal, the C control unit 23 outputs an alarm signal to the alarm device 4 at the C alarm output unit 28. In the alarm device 4, the controller 2
When an alarm output is received, the alarm is transmitted to a remote security center (not shown) through a telephone line or the like.

As described above, the surveillance camera system according to the present embodiment can detect an obstructive action on the imaging unit 10 of the surveillance camera 1 and output an alarm. Can be dealt with.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a surveillance camera system

FIG. 2 is a functional block diagram of a surveillance camera.

FIG. 3 is a functional block diagram of a controller.

FIG. 4 is a functional block diagram of a time-lapse video.

FIG. 5 is a flowchart for detecting a visual field obstruction act.

FIG. 6 is an external appearance image diagram when a surveillance camera is installed.

[Description of Signs] 1 ... Monitoring camera 13 ... Disturbance detector 131 ... Illuminance sensor 2 ... Controller 3 ... Time lapse video 4 ... Alarm device 5, 6 ... Coaxial cable

Continued on the front page F-term (reference) GG02 GG21 GG23 GG30 GG56 GG70

Claims (4)

[Claims] 1. An image pickup means for picking up an image of a monitoring area, an interference detection means for detecting whether or not the visual field of the image pickup means is disturbed, and an alarm means for outputting an alarm based on a detection result of the interference detection means. In the surveillance camera system having the above, the obstruction detection means includes an illuminance sensor for detecting illuminance of a monitoring area, and when a luminance value of an image captured by the imaging means has become a predetermined value or less, and the illuminance sensor A surveillance camera system characterized in that when the illuminance detected by (1) is equal to or more than a predetermined value, it is detected as a sabotage action. 2. An image pickup means for picking up an image of a monitoring area, an interference detection means for detecting whether or not the visual field of the image pickup means is disturbed, and an alarm means for outputting an alarm based on the detection result of the interference detection means. In a surveillance camera system having
The interference detection unit includes an illuminance sensor that detects illuminance of a monitoring area, and in an image captured by the imaging unit, when an image area having a predetermined luminance value or less is equal to or more than a predetermined value, and the illuminance sensor uses A surveillance camera system characterized in that when the detected illuminance is equal to or greater than a predetermined value, it is detected as a sabotage action. 3. The method according to claim 1, wherein when the luminance value of the image picked up by said image pickup means is out of a predetermined range and the illuminance detected by said illuminance sensor is equal to or more than a predetermined value, it is detected as an obstructive action. The surveillance camera system as described. 4. The surveillance camera system according to claim 1, wherein said alarm means outputs illuminance reduction information when the illuminance detected by said illuminance sensor is equal to or less than a predetermined value.