JPH0722368B2 - Recording device for security cameras - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a security camera recording device, and more particularly to an improvement in the configuration of a processing unit that processes a video signal output from a camera unit.

[Prior Art] Currently, many stores, banks, and the like are equipped with a recording device for a security camera including one or a plurality of camera units for patrol and security purposes.

Generally, a security camera recording device converts a video signal, which is output by one or a plurality of camera units picking up an image of the inside of a store or the like, into a digital signal, and then appropriately combining the digital signals. It is temporarily stored in the field memory of. Further, the security camera recording device sequentially reads the video signal temporarily recorded in the field memory, reconverts it into an analog signal, displays it as an image on a monitor, and records it on a magnetic tape. Therefore, an image captured by the camera unit at a predetermined time interval is displayed on the monitor. The user can monitor the inside of the store by visually observing the image displayed on the monitor.

Further, the security camera recording device as described above includes a security switch that the user operates in an emergency. When this security switch is pressed, the security camera recording device temporarily stores all the video signals from the camera unit, which have been converted into digital signals and then combined, in the field memory, and then sequentially reads them to obtain analog signals. It is converted back to and displayed as an image on the monitor and recorded on a magnetic tape.
Therefore, if the recorded information on this magnetic tape is reproduced,
After the crime prevention switch is pressed, the user can know the state of the store or the like in an emergency by continuous images in terms of time.

[Problems to be Solved by the Invention] The video signal output from the camera section of the security camera recording device has been conventionally processed as described above and before the security switch is pressed, that is, before the emergency, etc. This state is recorded on the magnetic tape as an image at a predetermined time interval. Therefore, by reproducing this magnetic tape, the user can only intermittently grasp the state of the store or the like before the emergency. Therefore,
It was extremely difficult to know exactly what happened immediately before an emergency. This is a problem to be improved in view of the role of the recording device for the security camera.

An object of the present invention is to solve the above-mentioned problems and to provide a recording device for a security camera capable of accurately grasping both the emergency situation and the situation inside the store before the emergency situation.

[Means for Solving the Problems] In order to achieve the above object, a security camera recording device according to the present invention includes at least one imaging device,
Image processing means for processing an image captured by the imaging device to provide a video signal, compression means for compressing the video signal from the image processing means, and the video signal compressed by the compression means over a plurality of fields. Field memory for continuously storing information, a reading means for reading the stored information from the field memory, an expanding means for expanding the information read by the reading means, and a video signal expanded by the expanding means. Recording means for recording, a switching means for switching between a normal time and an emergency, and a video signal continuously stored in the field memory is read out at a predetermined field interval in the normal time and is switched to an emergency state. Responds to the emergency switching output and controls the reading by the reading means so as to continuously read from the field next to the field read immediately before. And control means for.

[Operation] As described above, the security camera recording device according to the present invention stores all the video signals obtained from the image picked up by the image pickup device in the field memory and responds to the emergency switching output from the switching means. Then, the stored information is continuously read from the field memory. Therefore, unlike the prior art, it corresponds to the image captured by the imaging device before the emergency switching output is output from the switching unit, which is stored in the field memory at the time when the emergency switching output is output from the switching unit. All video signals are read. Therefore, the image before the emergency and the image during the emergency, which are continuous in time, are recorded in the recording means.

[Embodiment] FIG. 1 is a schematic block diagram of a security camera recording apparatus showing an embodiment of the present invention. Referring to the drawing, the security camera recording device includes a plurality of camera units 1 for capturing an image of the inside of a store or the like, capturing the image, and outputting a video signal,
A processing unit 10 that performs a predetermined process on the video signal from the camera unit 1 to create a final video signal, and a monitor unit 6 for displaying the final video signal from the processing unit 10 as an image.
A VTR (video tape recorder) 7 for recording the final video signal from the processing unit 10, an operation unit 8 for giving information to the processing unit 10 for the user to specify processing in the processing unit 10, and a crime prevention And a switch 9. When the crime prevention switch 9 is pressed, the operation unit 8 responds to this and provides the processing unit 10 with information corresponding to "emergency".

The processing unit 10 includes an A / D converter 2 provided for each of the plurality of camera units 1, an image processing unit 3, and a temporary storage unit 4.
And a D / A converter 5.

Referring to the drawing, each camera unit 1 outputs a video signal obtained by imaging the inside of a store or the like to a corresponding A / D converter 2 in the processing unit 10. The A / D converter 2 converts the video signal from the camera unit 1 into a digital signal and outputs it to the image processing unit 3. The image processing unit 3 responds to the digital video signal input from the A / D converter 2 based on information (including "emergency" information) designated by the user via the operation unit 8. The processing is performed and output to the temporary storage unit 4, and a control signal for controlling each functional unit of the temporary storage unit 4 is output based on the specified information.

FIG. 2A is a diagram showing an internal configuration of the temporary storage unit 4. Referring to the figure, the temporary storage unit 4 includes a compressor 41 and an expander 43, which are not provided in a conventional security camera recording device, and a larger number of units (here, for convenience sake, numbers 1 to n).
The number is up to n. ) A field memory unit 42 including a field memory. The compressor 41 has a compression function of converting the digital video signal input from the image processing unit 3 into a digital video signal represented by a smaller number of bits by performing non-linear quantization with a predetermined compression characteristic. . The decompressor 43 has a function of decompressing the digital video signal compressed as described above into the original digital video signal by converting it with an inverse function of the compression characteristic.

In the temporary storage unit 4, the compressor 41 compresses the digital video signal from the image processing unit 3 at a compression rate according to the control signal from the image processing unit 3 and outputs it to the field memory unit 42.

The field memory unit 42 sequentially stores the digital video signals from the compressor 41. FIG. 2B is a diagram showing the order in which the digital video signals are stored in the n field memories that form the field memory unit 42. In addition,
The figure shows the case where the compression rates in the compressor 41 are 1/1 and 1/4. Referring to the drawing, when the compression rate is 1/1, that is, when the digital video signal from image processing unit 3 is not compressed, one field memory stores one field of digital video signal. When the compression rate is 1/4, the digital video signal from the image processing unit 3 becomes 1 /
Since it is compressed to 4, digital video signals for 4 fields are stored in one field memory. At this time, the digital video signals are stored in order from the oldest to the first to nth field memories, and when the nth field memory is filled with the stored information, the digital video signals to be input next are again from the first to the first. Data is sequentially stored in the nth field memory, that is, the stored information in the 1st to nth field memories is sequentially rewritten with new stored information.

Extender 43 is normal (when crime prevention switch 9 is not pressed)
The digital video signal is read from the field memory unit 42 at a predetermined time interval according to the control signal from the image processing unit 3 and expanded to restore the original (uncompressed) digital video signal. Output to A converter 5. However, in an emergency, the decompressor 43 responds to the control signal indicating "emergency" from the image processing unit 3 to read the stored information at the time when the security switch 9 is pressed among the n field memories. All the digital video signals are sequentially read from the field memory next to the existing field memory, and when they are expanded, they are restored to the original (uncompressed) digital video signals and output to the D / A converter 5.

In the following description, the "digital video signal" is simply called "video signal".

FIG. 3A is a diagram showing the reading order of the stored information from the n field memories forming the field memory unit 42 at a certain time in the normal time. Referring to the figure, at this time, the storage information of the field memory No. 5 is read, and thereafter, the storage information of the field memory is read intermittently at predetermined field intervals corresponding to the intermittent time. The stored information in the field memories 1 to 4 is
Since it has already been read, the storage information newer than the storage information of the field memories No. 6 to n is already written in the field memories No. 1 to 4. Therefore,
When the n-th field memory is arranged in the oldest order of the stored information, it becomes 5, 5, 6, ..., N, 1, 2, 2 ,.

FIG. 3B is a diagram showing the reading order of stored information from the n field memories immediately after the security switch 9 is pressed in the above-mentioned state. Referring to the figure, when the security switch 9 is pressed, the security switch 9
The stored information in the field memory whose stored information has been read immediately before is pressed, that is, the field memory next to the fifth field memory, that is, the field memory after the sixth memory, is sequentially read out. Therefore, immediately after the stored information in one field memory is read out after the security switch 9 is pressed, the newest stored information, that is, the video signal immediately before the security switch 9 is pressed, is written in the 6th field memory. Get caught. Therefore,
When the n-th field memory is arranged in the oldest order of the stored information, it becomes 7th, 8th, ..., Nth, 1, 2nd ,. Therefore, reading the stored information in these field memories in order means that the video signal for a certain predetermined time until just before the security switch 9 is pressed is read continuously in time, that is, without an intermittent portion. Means that. As described above, the video signal immediately before the emergency read without the intermittent portion is all the information stored in the n field memories immediately after the security switch 9 is pressed. Therefore, the certain predetermined time is determined by the storage capacity of the entire field memory unit 42 and the compression rate of the compressor 41. That is, the greater the compression ratio in the compressor 41, the greater the amount of video signal that can be stored in the field memory unit 42, and the longer the predetermined time. The field memory from which the stored information has been read is newly written with the video code after the emergency, and these are all read in order.

As described above, by pressing the security switch 9,
The video signal for a predetermined time immediately before the emergency and the video signal in the emergency are read without an intermittent portion.

Referring again to FIG. 1, the D / A converter 5 includes the temporary storage unit 4
The video signal from the expansion unit 43 therein is converted into the original analog video signal and output to the monitor unit 6 and the VTR 7. Monitor unit 6
Displays the video signal from the D / A converter 5 as an image on the screen, and the VTR 7 records the video signal from the D / A converter 5 on a magnetic tape. Therefore, unlike the prior art, video signals for a predetermined time before and in an emergency are recorded on the magnetic tape of the VTR7 without an intermittent portion. Therefore, unlike the prior art, the user can view the inside of the store before the emergency as a temporally continuous image by reproducing the video signal recorded on the magnetic tape. During normal operation, a video signal at a predetermined time interval is displayed as an image on the screen of the monitor unit 6 and the VTR7
Recorded on a magnetic tape.

In the present embodiment, how many minutes before the emergency is recorded in the VTR7 without an intermittent portion, how many seconds the image is recorded in the normal time, that is, the intermittent time in the normal time. , And which of the plurality of camera units 1 captures an image to be displayed on the screen of the monitor unit 6. This is the designation information input to the image processing unit 3 via the operation unit 8. Next, a specific operation of the image processing unit 3 that has received these designation information will be described.

FIG. 4 is a schematic block diagram showing an example of the internal configuration of the image processing unit 3. Referring to the figure, the image processing unit 3 controls the functional units in the image processing unit 3 and the temporary storage unit 4 according to the designation information from the operation unit 8, and the control unit 33.
Is controlled to receive the video signals input via the plurality of A / D converters 2 and selectively select only the video signals from some (for example, four) A / D converters designated by the user. And a graphic RAM 32 which is controlled by the control unit 33 and synthesizes a video signal from the switching unit 31.

The control unit 33 further includes a CPU (central processing unit) 331,
It includes a RAM (random access memory) 332 and a ROM (read only memory) 333. A predetermined processing program is stored in the ROM 333.

The designation information input from the operation unit 8 to the image processing unit 3 is first input to the CPU 331. CPU331 sends this designation information to RO
It is processed by a predetermined processing program stored in M333,
The control signal according to the designation information is output to the switching unit 31. For example, when the user specifies that the images captured by the camera units 1, 3, 5, and 7 should be displayed on the screen of the monitor 6, the switching unit 31 displays the images 1, 3, 5, and 7. A control signal for selectively outputting only a video signal input via the A / D converter corresponding to each of the camera units is given from the CPU 331 to the switching unit 31.

Next, the graphic RAM 32 synthesizes the video signals from some of the camera units selectively output from the switching unit 31 using the RAM 332. For example, when the video signals from the four camera units are input from the switching unit 31, it is necessary to divide the screen of the monitor unit 6 into four and display the images captured by the respective camera units. That is, the video signals from the four camera units must be combined so as to form one such screen. The CPU 331 stores in the ROM 3 the designation information from the operation unit 8 indicating from which camera unit the video signal is displayed.
The graphic RAM 32 is processed according to the processing program 33, and the graphic RAM is controlled so that the graphic RAM 32 uses the RAM 332. In this way, the video signal synthesized by the graphic RAM 32 is output to the temporary storage unit 4.

The CPU 331 further determines, from one of the designation information input from the operation unit 8, the intermittent time in the normal time and the time before the emergency, which is recorded on the magnetic tape without the intermittent portion,
According to the processing program of the ROM 333, the read timing of the stored information in the temporary storage unit 4, the compression rate of the video signal in the temporary storage unit 4, and the like are determined, and a control signal corresponding thereto is given to the temporary storage unit 4.

With the system as described above, it is possible to display and record an image according to the information specified by the user.

In the present embodiment, the recording medium for finally recording the image captured by the camera unit is a magnetic tape, but any recording medium capable of reproducing the recorded information as an image after recording may be used. Further, the means for notifying the "emergency" inside the device is not limited to the crime prevention switch. Furthermore, although a plurality of camera units are used in this embodiment, a single camera unit may be used.

[Effects of the Invention] As described above, according to the present invention, it is possible to know the state of a store or the like before an emergency as a temporally continuous image. Therefore, the situation immediately before an emergency can be accurately grasped, and the function of the security camera recording device is greatly improved.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a security camera recording apparatus showing an embodiment of the present invention, and FIG. 2 is a diagram showing an internal configuration of a field memory section in FIG. 1 and a writing order of stored information in the field memory section. 3 is a diagram showing the state of the field memory before and after the crime prevention switch is pressed in the embodiment, and FIG. 4 is a diagram showing an example of the internal configuration of the image processing unit in FIG. In the figure, 1 is a camera unit, 2 is an A / D converter, 3 is an image processing unit, 4 is a temporary storage unit, 5 is a D / A converter, 6 is a monitor unit, 7 is a VTR, 8 is an operation unit, 9 is a crime prevention switch, 10 is a processing unit, 41 is a compressor, 42 is a field memory unit, and 43 is an expander. In each drawing, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. At least one image pickup device, image processing means for processing an image picked up by said image pickup device to give a video signal, compression means for compressing a video signal from said image processing means, and said compression means. A field memory for continuously storing the video signal compressed by the means over a plurality of fields; a reading means for reading the stored information from the field memory; and an expansion for expanding the information read by the reading means. Means, a recording means for recording the video signal expanded by the expansion means, a switching means for switching between a normal time and an emergency, and a video signal continuously stored in the field memory in a predetermined field in the normal time. The field next to the field read immediately before that in response to the emergency switching output when read out at intervals and switching to the emergency state And control means for controlling the reading of said reading means so et continuously read, a recording apparatus for security camera.