JPH0449785A - Video signal recorder - Google Patents

Abstract

PURPOSE:To record a video signal from a prescribed time before switching time when it is switched from intermittent recording to continuous recording by recording a delay video signal in a continuous recording action mode in a video signal recorder with an intermittent recording action mode and the continuous recording action mode. CONSTITUTION:When the signal AS of an alarm and so on is impressed a control part 4 generates input switching control output to an output terminal 4b, drives a input signal switching circuit 6, switches an intermittent recording action mode into a continuous recording action mode, controls so that a delayed video signal VD which is the output of a delay means 5 is inputted to a video signal recording part 3 and controls so that a continuous recording action is executed to the video signal recording part 3. Accordingly, even when crime prevention, monitoring system, etc., to be switched from intermittent recording into continuous recording based on the alarm signal and so on are used, the continuous recording is executed from a condition before the alarm signal and so on are generated.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a video signal recording device capable of switching between intermittent recording operation and continuous recording operation, and particularly when switching from intermittent recording to continuous recording. The present invention relates to a video signal recording device that is capable of recording video signals from a predetermined time before a point in time.

(Prior Art) FIG. 4 is a block diagram of a conventional video signal recording device.

For crime prevention systems, surveillance systems, etc., monitor cameras 10
There is a system that is equipped with a video signal VS and records the video signal VS, and a video signal recording device 102 that can switch between intermittent recording operation and continuous recording operation is known as a video signal recording device 102 suitable for such uses. There is.

For example, so-called VT that uses magnetic tape as a recording medium
In the video signal recording device 102 whose basic configuration is R, when a signal AS such as an alarm is not applied from a crime prevention or monitoring system, etc., the control section! 03 is video signal recording section 1
By instructing the tape running servo system in the 04 to intermittent feed of the magnetic tape and recording video signals at predetermined time intervals, long-term recording can be realized. The signal recording unit 104 is controlled to perform continuous recording operation.

(Problem to be Solved by the Invention) However, the conventional video signal recording device 102 simply switches from intermittent recording to continuous recording operation mode when fg AS such as an alarm is applied. Images from the time of occurrence and before that time are not recorded. For this reason, there are cases where the redness that causes an alarm or the like is not recorded, and an improvement has been desired.

This invention was made to solve these problems, and its purpose is to: When switching from intermittent recording to continuous recording,
It is an object of the present invention to provide a video signal recording device that can continuously record video signals from a predetermined period of time before the switching point.

(Means for Solving the Problems) In order to solve the above problems, a video signal recording device according to the present invention includes a delay means for delaying a video signal by a predetermined time, and at least in the continuous recording operation mode, the output of the delay means It is characterized in that it is configured to record a delayed signal.

(Operation) When the intermittent recording operation is switched to the continuous recording operation, the output of the delay means is recorded, so the video from the time point before the switching point by the delay time of the delay means is recorded.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 is a block diagram of a video signal recording apparatus according to the present invention.

This video signal recording device 1 includes a video signal recording section 3 that records an analog video signal vI output from a monitor camera 2 as an analog signal, and an operation mode of this video signal recording section 3 at least at predetermined time intervals. Choose between an intermittent recording operation mode in which one frame or one field worth of video signal is intermittently recorded, or a continuous recording operation mode in which the video signal V1 sent from the monitor camera 2 is continuously recorded. A control unit 4 that performs switching, a delay unit 5 that delays the analog video signal v1, and a video signal recording unit 3 that directly records the analog video signal VI output from the monitor camera 2.
An input f3 switching circuit 6 is provided for switching between inputting the video signal VD delayed by the delay means 5 and inputting the video signal VD delayed by the delay means 5. The video signal recording device 1 also includes a time information generating means that generates time information such as month, day, hour, minute, etc., and a superimposition circuit 8 that superimposes this time information on the analog video signal Vl.

The video recording section 3 is based on a VTR using a magnetic tape as a recording medium, and the operation of the traveling servo system and the video signal recording system is controlled based on the operating element designation information M given from the control section 4. It consists of

The control unit 4 controls the video signal recording unit 3 to enter the intermittent recording operation mode when a signal AS such as an alarm is not applied to the input terminal 4a. In this intermittent recording operation 10-F, the analog video signal Vl input manually is directly input to the video signal recording section 3 via the superimposing circuit 8. The control unit 4 receives a signal AS such as an alarm.
When is applied, a manual switching control output is generated at the output terminal 4b to drive the manual signal switching circuit 6, and the delayed video signal VD, which is the output of the storage means 5, is transferred to the video Gi recording unit 3.
It is controlled so that it is manually operated, and it is also controlled so that continuous recording operation is performed in the video biography 17 section 3.

Further, the control unit 4 controls the continuous recording operation to be switched to the intermittent recording operation when the signal AS such as an alarm is no longer inputted manually. Note that this control unit 4 performs continuous recording operation only for a preset time from the time when the hot water AS such as an alarm is manually activated, and then automatically switches to intermittent recording operation (such as performing control to make old). It may be configured as follows.

The control unit 4 is also equipped with a circuit that detects the vertical blanking period of the video signal input to the input terminal 4c, and is configured to perform large switching of the human signal switching circuit 6 within the detected vertical blanking period. The configuration is such that the manual switching control output is output to the output terminal 4b, thereby preventing the occurrence of partial interruption of the recorded image due to switching.

The delay means 5 includes an A/D converter 5a that converts the manually input analog video signal Vl into a digital video signal via the superimposing circuit 8, and a RAM (RAM) that stores the A/D converted signal.
a memory circuit 5b using a random access memory) or the like;
A memory circuit controller 5c that controls writing and reading of the memory circuit 5b, and a D/A converter 5d that converts the digital video signal read from the memory circuit 5b into an analog video signal.
It consists of.

The storage circuit 5b has at least a storage capacity corresponding to the delay time of the video signal. The memory circuit control unit 5C is an A/D
The contents of the memory circuit 5b are read out from the converter 5a in accordance with the preset address order for each preset zelkova cycle and output to the D/A converter 5d, and the A/D converter i5a outputs the data to successive addresses. /D conversion output is written. Therefore, the output terminal 5 of the delay means 5
An analog video signal VD that is delayed by a delay time corresponding to the capacity of the storage circuit 5b with respect to the analog video signal input to the input terminal 5f is output to the input terminal 5f.

Note that this delay means 5 does not include a memory circuit 5b such as a RAM, but manually inputs the output of the A/D converter 5d to a first-in-first-out type shift 1~register, etc., and outputs the output delayed by a shift register or the like. It is also possible to adopt a configuration in which the signal is inputted to the D/A converter 5d.

The time information generating means 9 includes a clock circuit with a clock function and a character generator that generates character information corresponding to data such as month, date, hour, and minute output from the clock circuit.

The superimposition circuit 8 includes a circuit for superimposing the time information outputted from the time information generation means 9 onto the analog video signal VW outputted from the monitor camera 2.

In addition to superimposing time-related information with character information in L7, output data of a clock circuit with a calendar function or a character code may be multiplexed within, for example, a vertical blanking period of the video signal.

With the above configuration, when switching from intermittent recording operation to continuous recording operation, the video signal delayed by the delay means 5 is input to the video signal No. 3 recording section 3. Continuous recording can be performed from images at a certain point in time.

Furthermore, since the time information is superimposed on the analog video signal vr at the input terminals of the delay means 5 and the input signal switching means 6, even when the video signal VD via the delay means 5 is recorded, the video and The relationship with the time will not deviate, and time management is easy.

In this embodiment, the video signal recording section 3 has been described as a VTR using a magnetic tape, but the video signal recording section 3 may be configured using a disk or the like as a recording medium. Furthermore, although this embodiment has described a configuration in which the analog video signal I output from the monitor camera 2 is recorded in an analog manner, a configuration in which a digital video signal is recorded may also be used. Instead of using the A/D converter 5a and the D/A converter 5d, the delay means 5 may be configured with a memory circuit 5b, a shift register, etc., by using a device that outputs a video signal.

Furthermore, the input signal switching circuit 6 is not provided, and the output 5e of the delay means 5 is configured to be recorded in the video signal recording section 3 in any recording operation mode, thereby switching from intermittent recording to continuous recording operation mode. Also, the time order of recorded videos may not be reversed.

FIG. 2 is a block diagram showing another example of the configuration of the delay means.

The delay means 50 shown in FIG. 2 includes a field/frame delay circuit 50b for delaying the digital video signal 50a, which is the conversion output of the A/D converter 5a, by one field or one frame, and five digital video signals 50a and field/frame delay circuits 50b for delaying the digital video signal 50a, which is the conversion output of the A/D converter 5a, for a period of one field or one frame. A difference detection circuit 50d manually extracts only motion components between fields or frames from the digital signal 50e delayed by the frame delay circuit 50b, compresses the amount of data supplied to the storage circuit 5b, and continuously outputs the data from the storage circuit 5b. The data is reproduced by a demodulation circuit consisting of an arithmetic circuit 50e and a field/frame delay circuit 50f, and a delayed analog signal VD is outputted via a D/A converter 5d.

When switching from intermittent recording operation mode to continuous recording operation mode, it is desirable to record video signals from 10 seconds to several tens of seconds ago, but in order to obtain such a delay time, a large storage capacity or a large number of A step shift resist, etc. is required. On the other hand, in crime prevention and surveillance systems, most of the images captured by the monitor camera 2 do not change, and in most cases there are only a few moving parts.

Therefore, if only the motion component is extracted from such an image, the amount of data will be small, and the storage capacity per unit time will also be small, making it easy to realize a long delay time. can.

FIG. 3 is a block diagram of a video signal recording device according to another embodiment.

This video signal recording device 61 digitally records a digital video signal from a monitor camera 62 that outputs a digitized video signal, and records the digital video signal delayed by a delay means 65 constituted by a shift register or the like. a digital recording type video signal recording section 63;
Based on the operation mode designation signal from the control section 64b), it is possible to switch between recording at predetermined frame intervals and continuous recording.

Note that the control unit 64 is configured to include a clock circuit to supply data related to time and the like to the digital recording type video signal recording unit 63, and to perform recording so that the relationship between video and time is associated. is desirable.

Further, if the video No. 42 recording unit 63 is provided with an image memory for one frame, for example, and the image data to be recorded next matches the data stored in the image memory,
Record only the number information or time information, or
The recording operation may be performed for a long time by not performing any recording operation.

(Effects of the Invention) As explained above, the video signal recording device according to the present invention is equipped with a delay means that delays the input video signal by a predetermined time, so even when switching from intermittent recording to continuous recording, the video signal recording device according to the present invention It is possible to record a video signal from a point in time earlier than the time by the delay time of the delay means. Therefore, even when used in crime prevention or surveillance systems that switch from intermittent to continuous recording based on alarm signals, etc., continuous recording is performed from the state before the alarm signal, etc. is generated, so there is no possibility that the alarm signal, etc. will be generated. This has the effect of being able to record the progress made.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a video signal recording device according to the present invention, FIG. 2 is a block diagram showing another example of the configuration of the delay means, and FIG. 3 is a block diagram of a video signal recording device according to another embodiment. FIG. 4 is a block diagram of a conventional video signal recording device. 1.61... Video signal recording device, 2, 62... Monitor control unit, 5.50.65... Delay means, 6... Input signal switching circuit, 7... Time information generation means, 8...Superimposition circuit.

Claims (1)

[Claims] In a video signal recording device that has an intermittent recording operation mode that records an input video signal intermittently at predetermined time intervals and a continuous recording operation mode that records the input video signal continuously, the video signal is delayed by a predetermined time. 1. A video signal recording apparatus, comprising a delay means for causing the delay to occur, and is configured to record a delayed video signal that is an output of the delay means, at least in the continuous recording operation mode.