JP2890924B2 - Surveillance video recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring video recording apparatus, and more particularly to a monitoring video recording apparatus having a frame switcher for switching and recording video signals from a plurality of television cameras frame by frame.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a conventionally known surveillance video recording device U2 , and FIG.
Signal recorded during the vertical blanking period
FIG . In FIG. 3 , video signals from a plurality of television cameras 1 are sequentially switched for each frame by a changeover switch 2 forming a frame switcher and input to a recording signal output circuit 3. This recording signal output circuit 3
In the video signal recorder 9, signal processing such as maintaining the continuity of odd and even fields and subcarriers is performed on the fetched video signal.
) Is converted to a recording signal that can be recorded. The recording signal from the recording signal output circuit 3 is input to the superimposing circuit 4,
The identification signal 13 representing the camera number is superimposed on the vertical blanking period as shown in FIG. The recording signal on which the identification signal 13 is superimposed is recorded on the VTR 9. The reference numeral 12 is a video signal.

[0003] The signal reproduced from the VTR 9 is input to the discrimination circuit 5 to detect the superimposed discrimination signal 13 and to discriminate and select the video signal only during the video period of any specified television camera. Thus, a video signal for one frame is temporarily recorded in the memory 7. At this time, the video signal period of the other television camera is not recorded, and only the video signal of the same video camera is read out while being sequentially recorded in the memory 7, and the video signal of the same camera output from the video signal output circuit 8 is output. The image is displayed on the monitor 10. As a result, it is possible to selectively reproduce only the video of an arbitrary television camera.

[0004]

By the way, especially in a time-lapse VTR or a long-time VTR, a video signal recorded and reproduced on a tape may be disturbed in signal level within a vertical blanking period due to a tracking error or the like, or a synchronization signal may be lost. Synchronization may be disrupted. Therefore, in the conventional surveillance video recording device U2, the identification number 13 of the camera number is set to 1
By superimposing the horizontal period (1H) high level or superimposing circuit 4 a low-level signal over several H, proof identification errors caused by the tracking error from occurring
Is Kobe.

When the identification signal 13 is written over several H's in this way, information that can be superimposed within a vertical blanking period having a limited length is limited to only the camera number. The data of the year, month, day, minute, and second to be displayed and alarm information from an external sensor or the like could not be superimposed.

The present invention has been proposed to solve the problems of the prior art, and has been proposed to improve the detection accuracy of an identification signal representing a camera number, and to provide date and time information in addition to the camera number. It is another object of the present invention to provide a monitoring video recording apparatus capable of superimposing alarm information from an external sensor or the like on a vertical blanking period of a video signal.

[0007]

According to the present invention, there is provided a changeover switch for sequentially switching and outputting video signals from a plurality of television cameras each assigned a camera number for each frame. A recording signal output circuit that converts a video signal from the changeover switch into a recording signal that can be recorded on a video tape recorder and outputs the identification signal for identifying a camera number to a video signal corresponding to each television camera before recording on the video tape recorder. An identification signal superimposing circuit for superimposing the identification signal on the identification signal from the reproduction signal reproduced from the video tape recorder; and an identification circuit for arbitrarily selecting and outputting a reproduction signal corresponding to the camera number. A memory for temporarily storing the reproduction signal, and a reproduction signal read from this memory as a video signal that can be displayed on a monitor. In the monitoring image recording apparatus and a video signal output circuit for outputting said identification signal superimposing circuit
Is the vertical blanking of the video signal corresponding to each TV camera.
Camera number for each horizontal scanning period (1H)
An identification signal for identifying the video tape at least twice
In addition to superimposing before recording to the coder,
At least two or more discriminations detected by the discrimination circuit
M horizontal scanning of video signal during vertical blanking period
The same signal is detected twice during the inspection period (mH, m is an integer of 2 or more)
When issued, it is determined that the detected identification signal is valid.
A decision circuit that determines the
If so, write the playback signal for one frame to the above memory
After that, one frame worth of new video signal is stored in memory
From the memory, and write to the above memory if the judgment result is invalid.
Video signal for one frame before rewriting
The above method is used to read data from memory repeatedly.
The configuration is such that the operation of rewriting the reproduction signal to the memory is performed .

Further monitoring video recording apparatus according to the present invention, prior to
The identification signal for identifying the camera number is n bits (n
Is an integer of 2 or more) and corresponds to each TV camera.
Horizontal scanning period of vertical blanking period of video signal
(1H) is superimposed with a plurality of the identification signals, and
And m horizontal scanning periods (mH, m
Is an integer of 2 or more).
After being folded, the identification signal recorded on the video tape recorder
No.

[0009]

According to the above-described configuration, the same signal is output twice in the determination circuit and the horizontal signal is applied to m horizontal lines during the vertical blanking period of the video signal.
During the scanning period (mH, m is an integer of 2 or more), the judgment circuit
Is detected, it is determined that the identification signal is valid. At this time, the contents of the memory are rewritten. Therefore, when the identification signal cannot be detected due to a tracking error or the like, the memory is not rewritten based on the determination result of the determination circuit, and the video signal stored immediately before is repeatedly read from the memory. Only the video corresponding to the designated camera number can be output to the monitor without malfunction. In addition, since the detection accuracy of the identification signal is increased by this configuration, information other than the camera number can be superimposed during the vertical blanking period.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a monitoring video recording apparatus according to the present invention. FIG. 1 is a block diagram showing an embodiment of this monitoring video recording apparatus , and FIG.
Vertical blanking by this surveillance video recording device on the waveform diagram
4 shows an identification signal recorded during a recording period. In FIG. 1, video signals from a plurality of television cameras 1 to which camera numbers are assigned are switched by a changeover switch 2 on a frame-by-frame basis, taken into a recording signal output circuit 3, and converted into a recording signal recordable on a VTR 9. Will be fixed. The recording signal includes an identification signal 11 for identifying the camera number in the superimposing circuit 4.
However, as shown in FIG. 2, the same signal is superimposed at least twice in the 1H section of the vertical blanking period. The recording signal on which the identification signal 11 is superimposed is recorded on the VTR 9.

The recording / playback signal played back from the VTR 9 is
The identification signal is input to the identification circuit 5, and the identification circuit 5 detects the identification signal 11 corresponding to the designated camera number. The discrimination signal 11 from the discrimination circuit 5 is sent to the judgment circuit 6, where the discrimination circuit 6 performs the vertical blanking period of the video signal.
When the same identification signal 11 is detected twice during the m horizontal scanning periods (mH, m is an integer of 2 or more), it is determined that the detected identification signal 11 is valid. After the identification signal is read by the identification circuit 5 and the determination circuit 6, the video signal for one frame corresponding to the camera number is stored in the memory 7 for the first time. Therefore, while the identification signal 11 is not read, the video signal in the memory 7 is not rewritten. The video signal reproduced from the memory 7 is sent to the video signal output circuit 8, and the video corresponding to the same camera number output from the video signal output circuit 8 is displayed on the monitor 10.

The surveillance video recording apparatus U thus configured
In the case of No. 1, the video signal recorded and reproduced on the tape of the VTR 9 is disturbed in the signal level of the video signal within the vertical blanking period due to a tracking error or the like, or the synchronization of the synchronization signal is disturbed. Is disturbed and becomes unrecognizable or misidentified,
Since the rewriting of the video signal to the memory 7 is not performed by the operation of the determination circuit 6, the video signal of the correct camera number stored immediately before is repeatedly output as a video. In addition, in the monitoring video recording device U1, since the detection accuracy of the camera number is high, it is not necessary to superimpose the identification signal over a plurality of Hs as in the related art. Time information, alarm information from an external sensor or the like can be superimposed.

In the embodiment described above, the identification number 11 of the camera number is set to 1H and a 2-bit signal ( n = 2, and the same signal is set to 2).
H is repeated twice).
3 or more bits in the 1H and (n = 3 or more integer), if so as to overlap the same signal as a repeating two or more times,
The amount of information that can be superimposed during the vertical blanking period can be further increased.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist.

[0015]

As described above, according to the present invention, when the identification signal for identifying the camera number is superimposed in the vertical blanking period, the camera signal for identifying the camera number is identified.
The identification signal is an n-bit (n is an integer of 2 or more) signal.
Vertical blanking of video signals corresponding to each TV camera.
The identification signal is duplicated during one horizontal scanning period (1H) of the scanning period.
Several signals are superimposed and the same signal during the vertical blanking period
over m horizontal scanning periods (mH, m is an integer of 2 or more)
After being repeatedly superimposed at least twice,
The identification signal is recorded in the coder,
In road, m horizontal vertical blanking period of the video signal
The same identification twice in the scanning period (mH, m is an integer of 2 or more)
Since it is determined that the camera number has been read when the signal is detected, the detection accuracy of the camera number can be improved as compared with the related art. This makes it possible to superimpose date information, time information, and alarm information from an external sensor or the like on the vertical blanking period, which was not possible in the past. Since these pieces of information are important information when recording video signals from a plurality of surveillance cameras, the present invention has the effect of increasing the effectiveness of the surveillance video recording device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a monitoring video recording device according to the present invention.

FIG. 2 is a waveform diagram showing an identification signal recorded during a vertical blanking period by the monitoring video recording device of FIG. 1;

FIG. 3 is a block diagram showing one embodiment of a conventional monitoring video recording device.

FIG. 4 is a waveform diagram showing an identification signal recorded in a vertical blanking period by a conventional monitoring video recording device.

[Explanation of symbols]

U1 , U2 monitoring video recording device 1 TV camera 2 Changeover switch 3 Recording signal output circuit 4 Superposition circuit 5 Identification circuit 6 Judgment circuit 7 Memory 8 Video signal output circuit 9 VTR 10 Monitor 11 , 13 Identification signal 12 Video signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI H04N 7/088 7/18 (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/262-5/28 H04N 5/222-5/257 H04N 7/18

Claims (2)

(57) [Claims] 1. A changeover switch for sequentially switching and outputting video signals from a plurality of television cameras each assigned a camera number for each frame, and a recording signal capable of recording the video signals from the changeover switch on a video tape recorder. A recording signal output circuit that outputs the video signal corresponding to each TV camera, an identification signal superimposing circuit that superimposes an identification signal for identifying a camera number on the video signal corresponding to each television camera before recording on the video tape recorder, and a video signal reproduced from the video tape recorder. An identification circuit for detecting the identification signal from the reproduced signal, and arbitrarily selecting and outputting a reproduction signal corresponding to the camera number;
A memory for temporarily storing the reproduced signal from the identification circuit, the monitoring image recording apparatus and a video signal output circuit for outputting as a video signal Utsushidaseru a reproduction signal read from the memory to the monitor, the identification signal superimposed Circuits for each TV camera
One horizontal scanning period (1
For each H), at least the identification signal for identifying the camera number
Is also superimposed twice before recording on the video tape recorder.
And at least two or more times detected by the identification circuit.
From the identification signal, m water in the vertical blanking period of the video signal
During the horizontal scanning period (mH, m is an integer of 2 or more), the same signal
When detected twice, the detected identification signal is valid
A judgment circuit for judging whether or not the judgment result is valid.
After writing the playback signal for the frame, a new video signal
Is read from the memory for one frame, and the judgment result is
If invalid, rewrite without writing to the above memory
The video signal for the previous frame is repeated from the memory as it is.
Write the playback signal to the memory such that
A surveillance video recording device performing a replacement operation . 2. An identification signal for identifying the camera number.
The signal is an n-bit (n is an integer of 2 or more) signal.
Vertical blanking period of video signal corresponding to Levi camera
A plurality of the identification signals are superimposed in one horizontal scanning period (1H).
Is, run m horizontal vertical blanking period as the same signal
Over the inspection period (mH, m is an integer of 2 or more)
Is also superimposed twice and then to the video tape recorder
The identification signal is a recorded identification signal.
The surveillance video recording device according to the above.