JP4148151B2 - Security monitoring system for containers for storing objects - Google Patents

Description

  The present invention relates to a crime prevention monitoring system for containers for storing items such as safes and drawers.

In order to prevent the keys such as safes and drawers from being opened and the items in them to be stolen, a sensor is provided to detect that the keys for safes and drawers have been opened inadvertently. Signals are sent to the building management department to notify the abnormality.
In addition, a security camera is installed in one corner of a room where safes and drawers are installed, and the images are sent to the monitoring center of the building to help identify the criminals.
JP 2000-295598 A JP 2000-231674 A

However, in the above-described crime prevention monitoring system, the camera is placed at one corner of the room, so that the presence of the camera may be recognized. It is desirable to install a camera in a place where the existence of the camera is unknown.
Therefore, the present invention can place the camera in a place where the existence of the camera is absolutely unknown, and a container for storing an object that can surely photograph the user when the opening / closing part is opened. The purpose is to provide a crime prevention monitoring system.

According to the security monitoring system for a container for storing an object of the present invention, the inside of the container is normally in a dark state where no light enters, and a camera for periodically imaging is installed inside the container, and the image is taken by the camera. When the brightness of the image is detected for a plurality of frames and it is detected that the opening / closing part of the container is opened by the change in brightness, the brightness of the image captured by the camera and the detection time point in the past frame are detected. When the difference from the brightness of the image becomes less than a predetermined threshold value, the image data captured by the camera is stored in an image memory, or is provided with control means for transmitting the image data to the outside. .

According to the above system configuration, since the camera is provided inside the container, the presence of the camera is not known from the outside until the container is opened. The camera always shoots, and when it is detected that the opening / closing part of the container is opened, the surroundings of the camera become bright, and the brightness of the image captured by the camera changes. By capturing this change in luminance, it is possible to store image data captured by the camera or transmit the image data to the outside. In addition, since the image data is stored or transmitted when the change in luminance of the image captured by the camera is reduced, a clear image can be obtained that avoids a transient state in which the luminance of the image changes. .

As an effect of this system , even if there is no sensor that detects that the door of the safe or drawer is opened, the camera can detect that the door of the safe or drawer is opened. Can be omitted. Therefore, it is advantageous in terms of cost. Further, in order to take in and out the container, the inside of the container is often looked into. By installing the camera inside the container, the user's face can be clearly photographed. Also, the user does not know the presence of the camera until the container is opened.

The control means may send an alarm signal to the outside when it is detected that the opening / closing part of the container is opened due to a change in luminance. According to this, an alarm signal can be transmitted from the control means to the outside, and an immediate response is possible .

Further, according to the security monitoring system for a container for storing an object according to another aspect of the present invention, the control means stores the image data captured by the camera or transmits the image data to the outside, and then re-alarms. In order to prevent this, a transition is made to the standby mode. After the transition to standby mode, transmission or any alarm release interruption by manipulation of the switch from the outside, or when the container detects the decrease in brightness of the image due to the closed, Ru enter the monitoring mode again.
Examples of the container include a safe and a drawer.
The control means may be installed inside the container or outside the container.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing the overall configuration of a container crime prevention monitoring system according to the present invention. An example of a “container” is a safe.
The security monitoring system is composed of a monitoring center 1, a safe 2, and a network such as the Internet connecting them.

The monitoring center 1 includes a computer that receives image information and a warning message and performs predetermined processing.
The safe 2 houses therein a camera 21 for taking a picture of a person looking into the safe and a control board 22. The camera 21 is a digital camera, and this data output is supplied to the control board 22. The installation location of the control board 22 is not necessarily in the safe 2 but may be outside the safe 2.

The control board 22 is equipped with a computer, and functions of the computer are an A / D conversion unit 31, an average luminance calculation unit 32, a threshold check unit 33, a luminance stability check unit 34, and an image memory 35. And a mail client 36.
The camera 21 performs imaging according to a predetermined schedule under the control of the control board 22. The schedule is, for example, every n frames (n is a positive integer, 1 frame is 1/30 second) after the computer of the control board 22 is started. The exposure time and aperture during imaging depend on the settings of the camera 21, but are usually set to automatic exposure. Therefore, when the safe door is closed and dark, the exposure time is longest and the aperture is maximum. When the door of the safe is opened, the exposure time and aperture are automatically controlled to optimum values according to the brightness. The focus is also usually autofocus.

The A / D converter 31 converts the image output signal of the camera 21 into a digital value representing the luminance from 0 to 255.
The average luminance calculation unit 32 calculates the average luminance of the output image of the camera 21. For this calculation, the luminance of a plurality of points in the image is sampled, and the average of those luminances is taken. In addition to the average value, other statistical values such as the median may be calculated.

The threshold value check unit 33 is a circuit that outputs a signal to that effect when the average luminance exceeds the threshold value. This threshold value is set so that the brightness is lower than this threshold value when the safe door is closed, and the brightness is higher than this threshold value when the safe door is open and the room is illuminated.
The threshold stability check unit 34 checks whether or not the luminance is stable by measuring a temporal change in luminance (for example, a difference from the previous cycle). Since the brightness suddenly increases when the safe door is opened, it is determined that the brightness is not stable. In such a transitional state, it is difficult to discriminate an object that has a large amount of unevenness in the camera image. Also, the autofocus process is not in time, and it is highly possible that the subject is out of focus.

The image memory 35 stores captured image data when the luminance exceeds a threshold value and is stable.
The mail client 36 transmits the image data recorded in the image memory 35 to the monitoring center 1 through the network. At this time, a warning message may be transmitted to the monitoring center 1 together with the transmission of the image data.

Further, when the luminance exceeds a threshold value and is stable, an alarm sound may be emitted from a speaker installed in the room, or a light installed in the room may be turned on.
Once the computer of the control board 22 transmits image data and a warning message, the computer cancels the monitoring mode in order to avoid re-transmission. As a result, the control board 22 stops the image data transmission operation and the warning message transmission operation of the mail client 36.

After receiving the warning message and the image data, the monitoring center 1 sends alarm release data to the mail client 36 when the post-processing is completed. As a result, the control board 22 resumes monitoring.
Even when the safe is under maintenance, the computer of the control board 22 cancels the monitoring mode.

FIG. 2 is a flowchart for explaining the control operation of the computer of the control board 22.
First, a measurement flag indicating that monitoring is being performed at the time of starting the system is turned on, and it is checked whether an alarm cancellation interrupt (command to enter the monitoring mode) is entered (step S2). If an alarm cancellation interrupt has been entered, the measurement flag is turned on (step S12). The alarm cancellation interrupt may be transmitted from the monitoring center 1 or may be activated by operating any switch on the safe body.

  When the shooting period (every n frames) is reached (step S3), image data is input from the camera 21 (step S4), and the average luminance of the image is calculated and compared with a threshold value (step S5). If the average luminance is less than the threshold value (step S6), it is determined that the safe door is closed, and the measurement flag is turned on to enter the monitoring mode (step S7). And it returns to step S2 and continues monitoring.

  If the average luminance is not less than the threshold value in step S6, that is, if the safe door is open, the state of the measurement flag is confirmed (step S8). If the measurement flag is off, it is not in the monitoring mode (referred to as standby mode), so monitoring is not performed and the process returns to step S2. If the measurement flag is on, the stability of the brightness is checked (step S9). If the difference in brightness from the previous period is equal to or less than a certain value, the brightness is determined to be stable and recorded in the image memory 35. The image data is taken out, attached to the warning message, and transmitted to the monitoring center 1 (step S10). Thereafter, the measurement flag is turned off (step S11) so as not to re-alarm immediately, and the process returns to step S2. The measurement flag is turned on next time when the next alarm cancellation interrupt is entered (step S2).

  FIG. 3 is a graph showing the transition of luminance when the safe door is opened. The horizontal axis represents the cycle number for each frame, and the vertical axis represents the average luminance (average value of luminance 0 to 255). When the cycle number is 6 and 7, the safe door is opened. The average luminance rises and stabilizes after the cycle number 10 is reached. Within an unstable time with a cycle number of 7 to 9, the luminance is greatly different from the luminance of the previous cycle, and the image taken at this time is disturbed. When the luminance is stabilized around 160, an image that can be easily discriminated is obtained.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, a desk drawer, storage box, storage furniture, etc. may be assumed as the “container” in addition to the safe. An implementation without the mail client 36 is also possible. That is, when the brightness of the image captured by the camera exceeds the threshold and is stable, the captured image data is only stored in the image memory 35. In this case, when the clerk notices theft, the image data stored in the image memory 35 can be played back to help identify the criminal.

  In the embodiments so far, the average brightness of the output image of the camera 21 is calculated in order to detect that the container opening / closing part has been opened. I was judged to have been. However, an independent sensor that detects that the opening / closing part of the container has been opened may be installed inside or outside the container without using the output image of the camera 21. This sensor may be a switch that mechanically detects that the opening / closing part is opened, or may be an optical sensor such as a phototransistor that optically detects that the opening / closing part is opened. The computer of the control board 22 stores the output image of the camera 21 and transmits it to the monitoring center 1 when it is determined by this sensor that the opening / closing part of the container has been opened. The camera 21 is installed from the inside of the container at a position and an angle at which the user (particularly the face) can be photographed.

  In addition, various modifications can be made within the scope of the present invention.

It is a block diagram which shows the whole structure of the crime prevention monitoring system of the container of this invention. 4 is a flowchart for explaining the operation of a computer mounted on a control board 22; It is a graph which shows transition of the brightness | luminance when opening the door of a safe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Monitoring center 2 Safe 21 Camera 22 Control board 31 A / D conversion part 32 Average brightness calculation part 33 Threshold value check part 34 Brightness stability check part 35 Image memory 36 Mail client

Claims (7)

A security monitoring system for containers for storing objects,
The inside of the container is usually dark without light,
A camera that periodically captures images is installed inside the container,
When the brightness of the image captured by the camera is detected for a plurality of frames and it is detected that the opening / closing part of the container has been opened by the change in brightness, the brightness of the image captured by the camera and the past Control that stores image data captured by the camera in an image memory or transmits the image data to the outside when the difference from the luminance at the time of detection in the frame of the frame becomes less than a predetermined threshold value A security monitoring system for a container for storing an object characterized by comprising means. A security monitoring system for containers for storing objects,
The inside of the container is usually dark without light,
A camera that periodically captures images is installed inside the container,
When the brightness of the image captured by the camera is detected and it is detected that the opening / closing part of the container is opened by the change in brightness, the image data captured by the camera is stored in the image memory or A control means for transmitting image data to the outside;
The control means saves the image data captured by the camera in an image memory or transmits the image data to the outside, then shifts to a standby mode indicating that the monitoring is not being performed. warning termination by transmission or any switch operation from the interrupt or when the container detects the decrease in brightness of the image due to the closed container for accommodating a material characterized by input Rukoto monitoring mode security Monitoring system. 3. The object according to claim 1 , wherein said control means is configured to send a warning signal to the outside when it is detected that the opening / closing part of the container is opened due to a change in luminance. Security monitoring system for containers to be used. The said container is a safe, The crime prevention monitoring system of the container which accommodates the thing in any one of Claims 1-3 . The said container is a drawer, The crime prevention monitoring system of the container which accommodates the thing in any one of Claims 1-3 . The said control means is a crime prevention monitoring system of the container which accommodates the thing in any one of Claims 1-5 installed in the inside of a container. The crime prevention monitoring system for a container for storing an object according to any one of claims 1 to 5 , wherein the control means is installed outside the container.

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