JPH0946636A - Monitoring image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely record an image signal before and after alarm input in the monitoring image recording and reproducing device in which an image signal from a camera is recorded onto a recording medium and the signal is reproduced from the recording medium. SOLUTION: An image signal from a camera 1a is overwritten continuously to a pre-recording memory 28. When an alarm is received from a sensor approaching the camera 1a, the image signals from the camera 1a over a prescribed time after the alarm input are stored in a recording memory 27 and the image signals just before alarm input are read from the recording memory 28 and stored in the recording memory 27. Then the image signals before and after the alarm input are surely stored in the recording memory 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring image recording apparatus for inputting and recording an image signal from a camera which images a monitoring target area.

[0002]

2. Description of the Related Art A photographed image signal from a camera installed at a place to be monitored is input, the input signal is recorded on a recording medium, and the photographed image is displayed as needed to store,
There is a monitoring image recording / reproducing apparatus that monitors various places such as a house to ensure its safety. Such monitoring image recording / reproducing devices are used for monitoring in-stores at financial institutions and convenience stores, for monitoring automated teller machines, for monitoring passengers at railway institutions, and monitoring at toll gates on expressways. It is used for various purposes in modern society, such as for use in offices and for monitoring visitors and suspicious people at the entrance of apartments.

In this type of surveillance image recording / reproducing apparatus, a system using a hard disk is being adopted in place of the conventional time-lapse VCR. The system using this hard disk has less image deterioration of recording due to frequent access, as compared with the time-lapse VCR,
It is excellent in that there is no wear of the head when it is used for a long time, and the operation is easy with a GUI (graphical user interface).

In the surveillance image recording / reproducing apparatus, in order to further enhance surveillance and improve security, a plurality of cameras are installed and input image signals from these cameras are switched and recorded. What has been developed is being developed. In such a type of monitoring image recording / reproducing apparatus, a recording program for starting recording of an input image signal from the camera is set in synchronization 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 an alarm from various sensors, a human body sensor is installed in the vicinity of a place where a camera is installed, and when a human approaches, an alarm is input from the human body sensor, and a door is opened / closed. There are used a method in which a sensor is installed and an alarm is input from an opening / closing sensor when a door is opened, a method in which an alarm is input when a user starts accessing an automatic teller machine, and the like.
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 usually indicates when it is time to strengthen 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 only started when the alarm is generated, and the image signal immediately before the alarm is generated cannot be recorded.

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

[0008]

A monitoring image recording apparatus according to the present invention is a monitoring image recording apparatus for recording image signals from a plurality of cameras for picking up a monitoring target area. 1, a second recording medium, a sensor for detecting a predetermined state change in the monitored area, and an image signal from one of the plurality of cameras is overwritten on the first recording medium to continue recording. When a predetermined state change is detected by the recording means and the sensor,
The recording operation in the recording means is interrupted, the image signal from the first camera is recorded on the second recording medium for a predetermined time, and the image signal recorded on the first recording medium is recorded on the second recording medium. And a means for alternately recording and recording.

According to the surveillance image recording apparatus of the present invention,
The image signal from one camera is continuously overwritten and recorded on a medium, and the other camera is normally recorded. Then, when an alarm is input from the sensor belonging to the one camera, the operation for continuing the recording is interrupted, and the image signal recorded immediately before the input of the alarm is re-recorded on another medium. With this configuration, after the alarm is input, the image signal immediately before the alarm is input can be surely recorded.

[0010]

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

FIG. 1 is a schematic diagram showing the overall configuration using the monitoring image recording apparatus of the present invention. In FIG. 1, 1a,
Reference numerals 1b and 1c are three cameras installed at the locations to be monitored. Each camera 1a, 1b, 1c automatically picks up an image and outputs the obtained image signal to the recording / reproducing apparatus 2. The recording / reproducing apparatus 2 records the input image signal in a built-in memory, 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 apparatus 2 is controlled by the operation of the mouse 4 by the user. Also, in the vicinity of each camera 1a, 1b, 1c,
Sensors 5a, 5b, 5c that generate alarms at the timings such as when a person approaches as described above, when the door opens, when a user accesses the automatic teller machine, etc. are installed. , 5b, 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 / playback device 2
Is a camera selection / switching input analog image signal from each camera 1a, 1b, 1c and converting it to a digital image signal.
An A / D conversion unit 21, a V-RAM 23 for temporarily storing a digital image signal, and an image signal for switching the input of the digital image signal from the camera selection / A / D conversion unit 21 and the digital image signal from the V-RAM 23. Switching circuit 22,
A compression / expansion unit 24 that compresses an image signal or expands a compressed image signal, a first switch 25, a second switch 26, and a recording memory 27 that records an image signal.
And a pre-recording memory 28 that constantly records image signals from one camera, and camera selection / A / D
Conversion unit 21, image signal switching circuit 22, compression / decompression unit 24,
A control unit 29 for controlling the operation of the first switch 25, the second switch 26, etc., a timer 30 for giving clock information as a reference clock to the control unit 29, and a digital image signal converted into an analog image signal to the monitor 3. It has 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. The pre-recording in which the image signal is continuously recorded during the normal recording is applied to only one important camera that is determined in advance. In this example, for example, the camera 1a is set as a pre-recording target camera.

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

First, the recording operation in the normal state when there is no alarm input from the sensor 5a will be described. According to the reference clock (FIG. 3A) from the timer 30 input to the control unit 29, the camera selection / A / D conversion unit 21 selects the pre-recording target camera 1a and the selected cameras 1b and / or 1c.
And are switched alternately. In addition, the first switch 25,
If the cameras 1b and / or 1c not subject to pre-recording are not recording, the state of being connected to the pre-recording memory 28 side and the state of being opened are switched alternately, and the cameras 1b and / or 1c not subject to pre-recording are switched. During recording, the state connected to the pre-recording memory 28 side and the state connected to the recording memory 27 side are switched alternately. On the other hand, the second switch 26 is always connected to the first switch 25 side.

Therefore, in the normal state, the analog image signal obtained from the pre-recording camera 1a is digitally converted by the camera selection / A / D conversion unit 21 and temporarily stored in the V-RAM 23. Later compression / decompression section 24
Then, the compressed image signal is compressed, and the compressed image signal is recorded in the pre-recording memory 28 through the first switch 25 (broken line in FIG. 3B). It should be noted that the pre-recording memory 28 has only a capacity to store image signals for four frames, and the compressed image signals from the camera 1a are continuously overwritten and recorded in the memory area for four frames. Also,
When the cameras 1b and / or 1c which are not the pre-recording target are selected, the image signals thereof are similarly digitally converted by the camera selection / A / D conversion unit 21 and V-RAM.
After being temporarily stored in 23, the compression / expansion unit 24 performs compression processing, and the compressed image signal is output to the first switch 25 and the second
It is recorded in the recording memory 27 via the switch 26 (solid lines in FIGS. 3C and 3D).

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

Therefore, the image signal obtained from the camera 1a to be pre-recorded for a predetermined time after the alarm is input from the sensor 5a is selected by the camera selection / A
After being digitally converted by the / D converter 21 and once stored in the V-RAM 23, it is compressed by the compressor / decompressor 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.

For a predetermined time (in this example, the solid line B1 to FIG.
As shown in B10, for example, when the time for which the image signals for 10 frames are recorded in the recording memory 27) elapses,
The first switch 25 is opened, while the second switch 26 is switched to the state of being connected to the pre-recording memory 28 side. Then, the image signal recorded in the pre-recording memory 28 immediately before the alarm input (in this example, the image signals for four frames of broken lines A1, A2, A3, and A4 in FIG. 3B) is output 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 is stored in an address having a smaller number than the image signals for the 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 reproduced correctly over time.

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

Next, the operation during 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 image signal input from the camera is prohibited and the image signal output mode from the V-RAM 23 is fixed.
The image signal expansion mode is fixed. 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 / compressed.
The image signal decompressed by the decompression unit 24 and restored 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. An image corresponding to the image signal output to the monitor 3 is displayed. By doing so, images before and after the alarm input can be displayed and provided to the monitor.

In the above example, when an alarm is input from the sensor 5a, the special recording mode is changed immediately after the input timing, but the special recording is performed at regular intervals. It is also possible to configure the mode to run. In this case, a timer alarm is input to the control unit 29 at regular time intervals. In addition,
The operation in this case is basically the same as the operation in the case where the trigger for starting the special recording mode is not the alarm from the sensor 5a but the timer alarm and is based on the alarm input from the sensor 5a.

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

[0025]

As described above, in the monitoring image recording apparatus of the present invention, when an alarm occurs, the image signal immediately before the alarm is recorded in the medium (pre-recording memory) for overwriting recording, Since it is re-recorded on another medium (recording memory), the image signals before and after the alarm is generated can be surely recorded, and the monitoring images before and after the alarm that the observer wants to see can be displayed to the observer. Can be provided. Further, since the image signal is cyclically recorded in the pre-recording memory which constantly records the image, its recording capacity may be small.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration using a surveillance 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 diagram showing an operation process of the present invention.

[Explanation of symbols]

 1a, 1b, 1c Camera 2 Recording / playback 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 Controller 30 Timer 31 D / A converter

Claims (1)

[Claims] 1. A monitoring image recording apparatus for recording image signals from a plurality of cameras for capturing an image of a monitoring target area, wherein first and second recording media for recording the image signal and a predetermined area in the monitoring target area. A sensor that detects a state change, a recording unit that continuously records an image signal from one of the plurality of cameras while overwriting the image signal on the first recording medium, and the sensor detects a predetermined state change. In case,
The recording operation of the recording means is interrupted, the image signal from the first camera is recorded on the second recording medium for a predetermined time, and the image signal recorded on the first recording medium is recorded on the second recording medium. An image recording apparatus for monitoring, characterized in that it comprises means for alternately performing recording on the image.