JP3177413B2 - Surveillance image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a monitoring image recording apparatus for inputting and recording an image signal from a camera for imaging a monitoring target area.

[0002]

2. Description of the Related Art A photographed image signal from a camera installed at a monitoring target location is input, the input signal is recorded on a recording medium, and the photographed image is displayed as necessary, so as to be used in a store, office,
2. Description of the Related Art There is a monitoring image recording / reproducing apparatus that monitors various places such as a house to ensure safety. Such a monitoring image recording / reproducing apparatus is used for monitoring the inside of a store at a financial institution or a convenience store, for monitoring a cash dispenser, for monitoring a passenger at a railway institution, and for monitoring at a toll payment point on an expressway. It is used for various purposes in modern society, such as for monitoring of visitors and suspicious persons at the entrance of an apartment house.

In this type of monitoring image recording / reproducing apparatus, a system using a hard disk is being used instead of a conventional time-lapse VCR. A system using this hard disk has less image degradation in recording due to frequent access compared to a time-lapse VCR,
It is excellent in that the head is not worn out when used for a long time, and the operation is simple due to a GUI (graphical user interface).

In a surveillance image recording / reproducing apparatus, a plurality of cameras are installed in order to further enhance surveillance and improve security, and input image signals from the plurality of cameras are switched and recorded. Is being developed. In such a type of monitoring image recording / reproducing device, a recording program is set such that recording of an input image signal from the camera is started in accordance with an alarm input timing from a sensor installed near each camera. The recording process is performed according to the setting program.

Here, as an automatic method of inputting alarms from various sensors, a method of inputting an alarm from a human body sensor when a human body sensor is installed near a camera installation location and a human approaches, and a method of opening / closing a door. A method of inputting an alarm from an open / close sensor when a door is opened with a sensor installed, a method of inputting an alarm when a user starts accessing a cash dispenser, and the like are used.
Of course, a method of inputting an alarm by human operation is also possible.

[0006]

By the way, in the monitoring image recording / reproducing apparatus linked with such an alarm function, when an alarm is inputted from various sensors,
It generally indicates when it is time to increase surveillance. Therefore, the image signal before and after the alarm is input from the sensor is important, and it is necessary to record and save the image signal before and after the alarm input so that the image can be confirmed later. .
However, in the conventional system, the recording of the image signal is started only when the alarm is generated, and the image signal immediately before the alarm is generated cannot be recorded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a monitoring image recording apparatus capable of reliably recording images before and after the occurrence of an alarm when an alarm is issued from a sensor. The purpose is to provide.

[0008]

A surveillance image recording apparatus according to the present invention is a surveillance image recording apparatus for recording image signals from a plurality of cameras for imaging a monitoring target area. 1, a second recording medium, and the plurality of
An image signal from one of the cameras is stored in the first
First recording means for continuing recording on a recording medium;
Image signals from cameras other than the one of the cameras
A second recording means for recording the information on the second recording medium;
A predetermined state change in the surveillance area of another camera
And a recording operation of the first recording unit is interrupted when a predetermined state change is detected by the sensor , and the image signal from the first camera is recorded on the second recording medium for a predetermined time. And means for recording an image signal recorded on the first recording medium on the second recording medium with time .

In the monitoring image recording apparatus according to the present invention, a certain
An image signal from one camera is continuously overwritten and recorded on a certain medium, and the other camera performs normal recording. When an alarm is input from a sensor belonging to the one camera, the operation of continuing the recording is interrupted, and the image signal recorded immediately before the input of the alarm is re-recorded on another medium. In this way, after the alarm is input, the image signal immediately before the alarm input can be reliably recorded.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below.

FIG. 1 is a schematic diagram showing an overall configuration using a monitoring image recording apparatus of the present invention. In FIG. 1, 1a,
Reference numerals 1b and 1c denote three cameras installed at the monitoring target location. Each of the cameras 1a, 1b, and 1c automatically captures an image and outputs the obtained image signal to the recording / reproducing device 2. The recording / reproducing device 2 records the input image signal in a built-in memory, and reproduces the image signal as necessary and outputs it to the monitor 3. The monitor 3 displays an image according to the image signal. The processing operation in the recording / reproducing device 2 is controlled by the operation of the mouse 4 by the user. In the vicinity of each camera 1a, 1b, 1c,
Sensors 5a, 5b, and 5c that generate alarms when a person approaches as described above, when a door is opened, or when a user accesses a cash dispenser are installed. , 5b and 5c output the generated alarm to the recording / reproducing apparatus 2.

FIG. 2 shows the recording / reproducing apparatus 2 shown in FIG.
FIG. 2 is a block diagram showing an internal configuration of the device. Recording / reproducing device 2
Is a camera selector for switching the input analog image signal from each of the cameras 1a, 1b, 1c and converting it into a digital image signal.
An A / D converter 21, a V-RAM 23 for temporarily storing a digital image signal, and an image signal for switching input between a digital image signal from the camera selection / A / D converter 21 and a digital image signal from the V-RAM 23. A switching circuit 22,
A compression / expansion unit 24 for compressing the image signal or expanding the compressed image signal, a first switch 25, a second switch 26, and a recording memory 27 for recording the image signal
A pre-recording memory 28 for continuously recording image signals from a certain camera, and a camera selection / A / D
Conversion section 21, image signal switching circuit 22, compression / decompression section 24,
A control unit 29 for controlling the operation of the first switch 25 and the second switch 26; a timer 30 for providing clock information as a reference clock to the control unit 29; And a D / A converter 31 for outputting.

Next, the operation will be described. FIG. 3 is a timing chart showing an operation example of the present invention. Pre-recording, which continues to record image signals during normal recording, is applied to only one important camera determined in advance. In this example, for example, the camera 1a is set as a pre-recording target camera.

First, the operation at the time of recording will be described. In the case of this recording, the image signal switching circuit 22 is always fixed to the mode of the image signal input from the camera and the image signal input to the V-RAM 23, and the compression / decompression unit 24
The image signal compression mode is always fixed.

First, a normal recording operation without an alarm input from the sensor 5a will be described. The camera 1a to be pre-recorded and the camera 1b and / or 1c selected by the camera selection / A / D converter 21 according to the reference clock (FIG. 3A) from the timer 30 input to the controller 29.
And are alternately switched. Also, the first switch 25
If the cameras 1b and / or 1c not to be pre-recorded are not recording, the state connected to the pre-recording memory 28 and the open state are alternately switched, and the cameras 1b and / or 1c not to be pre-recorded are During recording, the state connected to the pre-recording memory 28 and the state connected to the recording memory 27 are alternately switched. On the other hand, the second switch 26 is always connected to the first switch 25 side.

Therefore, in the normal case, an analog image signal obtained from the camera 1a to be pre-recorded is digitally converted by the camera selection / A / D converter 21 and temporarily stored in the V-RAM 23. Later, the compression / decompression unit 24
The compressed image signal is subjected to the compression process, and is recorded in the pre-recording memory 28 via the first switch 25 (broken line in FIG. 3B). Note that the pre-recording memory 28 has only a capacity for storing image signals for four frames, and the compressed image signal from the camera 1a is continuously overwritten and recorded in the memory area for four frames. Also,
When the camera 1b and / or 1c which is not to be pre-recorded is selected, the image signal is similarly digitally converted by the camera selection / A / D converter 21 and is converted to a V-RAM.
After the image signal is once stored in the first switch 25 and the second switch 25, the compressed image signal is compressed by the compression / decompression unit 24.
The data is recorded in the recording memory 27 via the switch 26 (solid lines in FIGS. 3C and 3D).

Next, a recording operation when an alarm is input from the sensor 5a will be described. In this case,
The camera selection / A / D converter 21 selects only the camera 1a to be pre-recorded. In the first switch 25,
The state connected to the recording memory 27 and the open state are alternately switched. On the other hand, the second switch 26 is connected to the first switch 25 side.

Therefore, for a predetermined time after the alarm is input from the sensor 5a, the image signal obtained from the camera 1a to be pre-recorded is selected by the camera selection A
After being digitally converted by the / D conversion unit 21 and temporarily stored in the V-RAM 23, the data is subjected to compression processing by the compression / decompression unit 24, and the compressed image signal passes through the first switch 25 and the second switch 26. It is recorded in the recording memory 27.

A predetermined time (in this example, solid lines B1 to B1 in FIG. 3B)
As shown in B10, for example, when the image signal for 10 frames is recorded in the recording memory 27),
The first switch 25 is opened, while the second switch 26 is switched to the state connected to the pre-recording memory 28 side. Then, the image signal immediately before the alarm input recorded in the pre-recording memory 28 (in this example, the image signal for four frames of broken lines A1, A2, A3, and A4 in FIG. 3B) is transmitted to the second switch 26. Recording memory through
Recorded at 27. At this time, in the recording memory 27, the image signals for four frames immediately before the alarm input are stored at addresses of smaller numbers than the image signals for ten frames immediately after the alarm input. That is, these image signals are stored in the recording memory 27 over time. Then, the image signals are read out in the order of the address numbers, and the image signals are correctly reproduced with time.

Pre-recording memory as described above
When the transfer of the image signal immediately before the alarm is input from the recording memory 28 to the recording memory 27 is completed, the state returns to the normal recording state.

Next, the operation at the time of reproduction will be described. At the time of this reproduction, the monitor issues a reproduction instruction with the mouse 4 to the control unit.
Enter in 29. In this case, the image signal switching circuit 22
The mode is fixed to the mode of prohibiting the input of the image signal from the camera and the output of the image signal from the V-RAM 23.
The mode is fixed to the image signal decompression mode. Also, the first switch
25 is fixed to the second switch 26 side, and the second switch 26 is fixed to the first switch 25 side.

Then, the compressed image signal is reproduced from the recording memory 27, and the reproduced compressed image signal is compressed /
The decompressed image signal subjected to the decompression process by the decompression unit 24 is temporarily stored in the V-RAM 23 and then converted into an analog image signal by the D / A conversion unit 31 via the image signal switching circuit 22. The image is output to the monitor 3 and an image corresponding to the image signal is displayed. By doing so, images before and after the alarm input can be displayed and provided to the monitor.

In the above-described example, when an alarm is input from the sensor 5a, the configuration is changed to the above-described special recording mode immediately after the input timing. It is also possible to configure to execute the mode. In this case, a timer alarm is input to the control unit 29 at regular intervals. In addition,
The operation in this case is basically the same as the operation based on the alarm input from the sensor 5a, except that the special recording mode start trigger is a timer alarm instead of the alarm from the sensor 5a.

In the example described above, the number of cameras to be installed is three, but this number is merely an example, and it goes without saying that any number of cameras may be installed when a plurality of cameras are installed. Further, the number of frames of the image signal that can be recorded in the pre-recording memory 28 and the number of frames of the image signal that is recorded in the recording memory 27 at the time of alarm recording are not limited to the four frames and the ten frames described in this example, respectively.

[0025]

As described above, in the surveillance image recording apparatus of the present invention, when an alarm occurs, the image signal immediately before the occurrence of the alarm, which has been recorded on the medium (pre-recording memory) for performing overwrite recording, is used. Re-recording to another medium (recording memory) ensures that image signals before and after the alarm is generated can be recorded, and the monitor images before and after the alarm that the monitor wants to see can be sent to the monitor. Can be provided. Further, in a pre-recording memory that constantly records an image, an image signal is recorded cyclically, and thus the recording capacity may be small.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration using a monitoring image recording apparatus of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the recording / reproducing apparatus in FIG.

FIG. 3 is a timing chart showing an operation process of the present invention.

[Explanation of symbols]

 1a, 1b, 1c Camera 2 Recording / reproducing device 3 Monitor 4 Mouse 5a, 5b, 5c Sensor 21 Camera selection / A / D converter 22 Image signal switching circuit 23 V-RAM 24 Compression / expansion unit 25 First switch 26 Second Switch 27 Recording memory 28 Pre-recording memory 29 Control unit 30 Timer 31 D / A conversion unit

Claims (1)

(57) [Claims] 1. A monitoring image recording apparatus for recording an image signal from a plurality of cameras for imaging the monitored zone, and the first and second recording medium for recording the image signal, the plurality
The image signal from one of the cameras
First recording means for continuing recording on a recording medium;
Image signals from cameras other than the one camera
Second recording means for recording a signal on the second recording medium;
Detects a predetermined state change in the monitoring area of one camera
A sensor for, when detecting a predetermined state change at the sensor, interrupts the recording operation in the first recording means,
The recording of the image signal from the one camera on the second recording medium for a predetermined time and the recording of the image signal recorded on the first recording medium on the second recording medium are performed over time.
Monitoring image recording apparatus characterized by comprising means for performing the.