JP3260924B2 - Intermittent magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent magnetic recording / reproducing apparatus, and more particularly to an apparatus for controlling a plurality of video cameras, for example, a store,
The present invention relates to an intermittent magnetic recording / reproducing apparatus that sequentially records and reproduces a plurality of video signals obtained by imaging a monitoring target such as a factory or an event hall.

[0002]

2. Description of the Related Art Conventionally, in order to simultaneously monitor various places such as stores and factories, a plurality of surveillance video cameras are installed in these places, and video signals from the plurality of surveillance video cameras are monitored. While monitoring the display on a television, the video is recorded sequentially on a video tape. In this type of intermittent magnetic recording / reproducing apparatus, video signals from a plurality of monitoring video cameras are sequentially switched at predetermined intervals, and each video signal is sequentially recorded for each field.

For example, when video signals of three channels are recorded, as shown in FIG. 16, the video signals of channels (hereinafter abbreviated as "ch") 1, 2, and 3
The data is recorded on the diagonal track on the magnetic tape while being sequentially repeated in the order of 1 → ch2 → ch3 → ch1 → ch2 → ch3, and on the diagonal track, the odd (odd) field and the even (even) field are alternately repeated. To be formed.

Next, at the time of reproduction, recorded diagonal tracks are sequentially traced, and only predetermined channels (for example,
In the example of FIG. 17, ch1) is sequentially written to the image memory, and the image memory is read out for each field to select and output an image of only a predetermined channel.

[0005]

SUMMARY OF THE INVENTION As described above,
When the recorded channels are three channels (odd number) and only a single channel (for example, ch1) is reproduced, the image memory is exemplified in the column of “memory write operation” in FIG. As described above, the video of the odd or even field is alternately written at intervals according to the number of channels. Thereafter, at the time of memory read, as illustrated in the column of “memory read operation”, the single c
The video corresponding to h is read for an interval corresponding to the number of channels. As a result, as shown in the column of "video output field", the video originally odd or even field in the image memory is alternately reproduced every field as odd and even fields.

For this reason, as shown in the lowermost column of FIG. 17, the field of the original video signal written and read and the field of the synchronization signal added at the time of reproduction are
The coincidence and the difference between the odd / even fields occur in a repetitive manner. By repeating the coincidence and the difference, when the recording channel is an odd number (excluding one channel), FIG.
As described by way of example in the above description, the image is periodically shifted from the predetermined screen position by one line (with respect to the total number of lines of the odd and even fields) in the upward or downward direction, and the screen is displayed on the reproduced video screen. There is a problem that the whole vertical deflection occurs.

This problem will be described in more detail with reference to FIGS. FIG. 18 is an example of a screen display with a diagonally downward-sloping line because the state of the screen display sequentially changed by the occurrence of the match and the difference shown in FIG. 17 is shown for each reproduction field.

When the images shown in FIGS. 18 (a), (c), (d), and (f) are displayed, the video and the reproduction synchronization fields match, and each pixel point (Po (1), Po (1), Po)
(2), Pe (1), Pe (2)) are all displayed normally. However, when the display shown in FIGS. 18B and 18E is made, the original field of the video read and written differs from the field of the synchronization signal added at the time of reproduction, and one line is shifted upward or downward. The display is shifted only from the predetermined screen position, and the screen display operation as shown in FIG. 19 is performed.

For example, paying attention to the pixel point Po (1), the screens [i] and [c] are black and normal, but the screen [e] is white and black is shifted by one line. Will be done. Similarly, the pixel point Po
Focusing on (2), the screens [i] and [c] are white and normal, but the screen [e] is black and white is shifted by one line.

[0010] Therefore, in the reproduction screen, these are sequentially repeated, and as shown in FIG. 20, vertical fluctuation is periodically generated by being shifted upward or downward by one line. .

An object of the present invention is to eliminate the above-mentioned problems of the prior art, and to display and monitor video signals from a plurality of surveillance video cameras on a monitor television while transmitting video signals from the plurality of surveillance video cameras. In a device that sequentially switches at predetermined intervals and records on an oblique track on a magnetic tape, and uses this recording to select and output an image of only a predetermined channel, even if the number of recording channels is odd, the entire screen is displayed on the reproduced video screen. It is an object of the present invention to provide an intermittent magnetic recording / reproducing apparatus capable of obtaining a good reproduced image without vertical fluctuation of the magnetic recording / reproducing apparatus.

[0012]

According to the present invention, in order to solve the above-mentioned problems, an odd-number input detection control means for detecting whether the number of channels of a plurality of input video signals supplied is odd or even, and a plurality of video signals are provided. Video switching means for sequentially switching and outputting signals, video signal generating means for generating another video signal synchronized with the plurality of input video signals, and recording / reproduction of a continuous video signal from the video switching means Magnetic recording / reproducing means, an image memory means for storing a video signal, and a reproduced video signal from the magnetic recording / reproducing means selected for each channel, temporarily stored in the image memory means, and only a video signal of a predetermined channel is stored. A memory control means for controlling the image memory means so as to read out the image data; when an input video signal is an odd channel (excluding one channel), a white screen is displayed;
A temporary video channel such as a black screen or an input video channel is added, and the number of recording video channels is evenly recorded, and each channel is written to, read from, and reproduced from a predetermined image memory.

[0013]

The video switching means is controlled in accordance with the output from the odd input detection control means indicating whether the number of input video signal channels is odd or even. That is, in the video switching means,
When the number of input video channels is odd, not only the input video signal of the odd channel but also another video signal synchronized with the input video signal from the video signal generating means is added, and the video channels are even-numbered and sequentially. Then, the magnetic recording means records the continuous video signal from the video switching means on a magnetic tape. Further, the reproduced video signal from the magnetic recording / reproducing means is controlled by the memory control means so as to read out only the video signal of a predetermined channel after being written into the image memory means.

Therefore, even when the number of input video channels is odd, one of the odd or even fields of the original video signal field is always written in the image memory means, and the video signal read from the image memory means is always written. One of the odd and even fields. For this reason, even if the sync field of the reproduced video signal alternately repeats the odd / even field, if the display is normal in one of the reproduction fields, the display is always shifted by one line in the other reproduction field. 1 upward or downward
A vertical reproduction of the entire screen which is periodically shifted by the line does not occur, and a good reproduced image can be realized.

Further, instead of another video signal synchronized with the input video signal from the video signal generating means, one or an odd number of channels of the input video signal are added, and Even in the case of sequential switching output, similarly, vertical fluctuation of the entire screen does not occur, and a good reproduced image can be realized.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an intermittent magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numerals 1, 2, 3, and 4 denote a video camera, 5 a synchronization generation circuit for generating a synchronization signal, 6, 7,
Reference numerals 8 and 9 denote a synchronization supply video output circuit for supplying a synchronization signal to each of the video cameras 1, 2, 3, and 4 according to the synchronization signal from the synchronization generation circuit 5 and outputting a video signal from each video camera to the next stage. Reference numeral 10 denotes a camera driving unit including a synchronization generation circuit 5 and synchronization supply video output circuits 6, 7, 8, and 9.
Reference numerals 1, 12, 13, and 14 denote first, second, third, and fourth synchronization separation circuits for separating synchronization signals, and reference numeral 15 denotes a reference synchronization from the first, second, third, and fourth synchronization separation circuits. It is a synchronization signal switching means for selecting and outputting a signal. Also, 16, 17,
Reference numerals 18 and 19 denote first, second, third and fourth video signal switching means for switching and outputting each video signal from the camera driving means 10 and the synchronizing signal from the synchronizing signal switching means 15, and 20 each video signal. A video channel switching means for sequentially switching and outputting signals from the switching means 16, 17, 18, 19;
Reference numeral 1 denotes a code creation / addition unit for creating and adding a code corresponding to the channel number of each video signal to the switched video signal, and 22 denotes a magnetic recording / reproduction unit for recording and reproducing the input video signal.

Reference numerals 23, 24, 25 and 26 denote monitor reproduction video switching means for switching and outputting a video signal from the camera driving means 10 and a video signal from the magnetic recording / reproducing means 22, and 27, 28, 29 and 30. Is a decoder for converting a composite video signal into a luminance signal (Y) and a color difference signal (RY, BY), and 31, 32, 33, and 34 are switching color difference signals (RY, BY) for output. Color-difference signal switching means 35, an A / D converter 35 for digitizing an input video signal, 36 an image memory means, 37 a D / A converter for converting a video signal into an analog signal, 38 a luminance signal (Y) and a color difference signal. This is an encoder that converts signals (RY, BY) into a composite video signal. Further, reference numeral 39 denotes an input detecting means for detecting the presence or absence of each video output from the camera driving means;
0 is an odd input detection control means for detecting whether the number of video signal inputs is odd or even and controlling the video channel switching means 20;
Reference numeral 1 denotes a reference channel selection control means for selecting and controlling a video signal of a video camera as a reference. Reference numerals 42 and 43 switch and output one of the separated horizontal and vertical synchronization signals as reference horizontal and vertical synchronization signals. First and second synchronizing signal switching means 44 are system control means (hereinafter abbreviated as syscon) for controlling the entire operation, and 45 is a channel code and odd / even field of a reproduced video signal based on the code. Code / field discriminating means for discriminating
Camera field determination means for determining the odd / even field of the video signal from the video camera 6, 47 A / D converter 35, the image memory unit 36, D / A converter 37, et emissions <br/> coder 38 And a memory control means for controlling writing and reading to and from the memory.

Next, the operation of this embodiment will be described in detail with reference to FIG. The camera driving means 10 supplies the synchronization signal from the synchronization generation circuit 5 to the video cameras 1, 2, 3, and 4 at the synchronization supply video output circuits 6, 7, 8, and 9, and In steps 3 and 4, the video signal of each scene to be monitored, which is generated based on the supplied synchronization signal and whose synchronization timing matches, is returned to the camera driving means 10. Camera driving means 1 having synchronization signals whose synchronization timings coincide with each other
0 is output to each of the sync separation circuits 11, 1
2, 13, 14; monitor playback video switching means 23, 24;
25, 26 and the first, second, third, and fourth video signal switching means 16, 17, 18, and 19.

Here, the input detecting means 39 detects whether or not a video signal of each channel is input based on each horizontal synchronizing signal separated by the synchronizing separation circuits 11 to 14. The odd input detection control means 40 detects whether the number of input video channels is odd or even based on the output from the input detection means 39. In addition, the reference channel selection control means 41 sets a reference channel among channels having a video signal from a video camera in a predetermined order based on an output from the input detection means 39 (for example, first, channel 1 is set as a reference channel). If there is no video output of channel 1, channel 2 is used as the reference channel,
If there is no video output for channels 1 and 2, channel 1 is used as a reference channel for channel 3.
(2, 3 order) is generated, and the synchronization signal switching means 15 converts the synchronization signal of the reference channel selected in accordance with the reference channel selection control signal into the first, second, and second synchronization signals.
Third and fourth video signal switching means 16, 17, 18, 19
To supply.

Further, the first, second, third, and fourth video signal switching means 16, 17, 18, and 19 respond to the output from the odd-number input detection control means 40 to output the channel having no video input. The reference synchronization signal from the synchronization signal switching means 15 is switched and supplied. Next, the system controller 44 controls the operation of the video channel switching means 20 according to the output of the odd input detection control means 40. That is, when the number of input video channels is an odd number, the video channel switching means 20 adds the reference synchronization output from the channel without the video input to the video signal from the channel with the input video signal to make the total number of channels even, and Channels are sequentially switched and output. Next, the video signal converted to the even-numbered channels is added with a code corresponding to each channel number by the code creation / addition means 21 and then the magnetic recording / reproduction means 2
2 is recorded on the tape.

Accordingly, for example, when the input of the video channel 3 is not performed and the total number of channels is 3, a description will be given by referring to FIG.
As shown in (a), video channel 1,
2. Black screen video signal with only synchronization signal, video channel 4
Are sequentially recorded. As a result, when the number of input video channels is an odd number (except 1), as another video signal synchronized with the input video signal, for example, in the embodiment shown in FIG. By adding a video signal, the total number of video channels to be recorded can be made even, and only one of odd and even fields can be set for each recording video channel. In the illustrated example, 1ch may be an odd field, 2ch may be an even field, 3ch may be an odd field, and 4ch may be an even field.

Next, at the time of reproduction, the magnetic recording / reproducing means 22
The video signal reproduced by the A / D converter 35 is sequentially converted into a digital signal by the A / D converter 35 via the monitor reproduction video switching means 23 to 26, the decoders 27 to 30, and the color difference signal switching means 31 to 34. . At this time, in this embodiment, the same reproduced video signal is output in parallel to the monitor reproduced video switching means 2.
The signals are converted into digital signals by the A / D converter 35 via the signals 3 to 26, the decoders 27 to 30, and the color difference signal switching means 31 to 34. Here, the decoder 27
30 are respectively a luminance signal (Y) and a color difference signal (R−
Y, BY) are decoded and output. The color difference signal is supplied to the A / D converter 35 via the color difference signal switching means 31 to 34.

Next, the memory control means 47 converts the video signal of each same channel in the reproduced video signal, that is, the luminance signal and the color difference signal, into an image in accordance with the output from the reproduced code / field discriminating means 45. The data is temporarily stored in each predetermined memory area of the memory means 36. For example, the reproduced video signal of 1ch is stored in a predetermined first area of the image memory means 36, and the reproduced video signal of 2ch is stored in the image memory means 36.
Is stored in another predetermined second area. The same applies to reproduced video signals of 3 and 4 ch.

When the video signal is read from the image memory means 36, the memory control means 47 controls the read processing in such a manner that only the reproduced signal of a certain video channel or a plurality of video channels is displayed in a multi-divided manner. Also,
The memory control means 47 sends a clock and an operation control signal to the D / A converter 37 to control the operation of the D / A converter 37, and outputs a luminance signal, which is a video signal read from the image memory means 36, D / A conversion of the color difference signal is performed.

Further, the memory control means 47 supplies a synchronizing signal to the encoder 38 to restore the D / A converted video signal to a composite video signal. Display on a full screen or multi-segment screen.

In this case, for example, when the video channel 1 is reproduced on a full screen, as shown in FIG.
Since the reproduced video signal is only one of the odd and even fields for each channel, the image memory originally has only one of the odd and even fields (in the example of FIG. 2, FIG.
(C) As shown in the column of "ch1 memory write operation", odd fields are sequentially written at intervals corresponding to the number of channels. Thereafter, at the time of memory reading, an image which is originally an odd or even field in the image memory (an odd field as shown in the column of “ch1 memory reading operation” in FIG. 2C in FIG. As shown in the "field of output" column, the data is alternately reproduced every field as odd and even fields.

Therefore, as shown in FIG.
The coincidence and the difference of the odd / even fields between the original video field read / written and the synchronization field added during reproduction are alternately repeated. However, when the above fields differ, the field at the time of the original recording (FIG. In the example, the video of the odd field) is always displayed on the screen by shifting one line as the other field (the even field in the example of FIG. 2) at the time of reproduction. Vertical shake of the entire screen does not occur,
There is an effect that a good reproduced video screen which is easy to see can be obtained.

This will be described in more detail with reference to FIGS. FIG. 3 is an example of a screen display with a diagonally downward-sloping line because the state of the screen display sequentially changed by the occurrence of the coincidence and difference shown in FIG. 2 is shown for each reproduction field.
In the case of FIG. 3A, the video and the field of the reproduction synchronization match, and each pixel point (Po (1), Po (2)) is normally displayed. However, in the case of FIG. The original field of the reproduced video is different from the field of the synchronization signal added at the time of reproduction. For example, at each pixel point (Pe (1), Pe (2)), the upward video is shifted from the predetermined screen position by one line. And a screen display operation as shown in FIG. 4 is performed. Therefore, even if these are sequentially repeated, as shown in FIG. 5A, the reproduced screen does not appear to be periodically shifted, and no vertical fluctuation occurs. Note that each pixel point (Pe (1), P
e (2)), it is needless to say that, even if the image in the downward direction is shifted from the predetermined screen position by one line, the vertical displacement does not occur at all, as shown in FIG. 5B.

FIG. 6 shows the operation when each video channel is displayed on a 4-split screen.
6 (a), the video signal reproduced as shown in FIG. 6 (a) is odd or odd for each channel as shown in FIGS. 6 (b), (c), (d) and (e). The video of only one of the even fields is written to the image memory of each channel. Thereafter, at the time of memory reading, as shown in FIGS. 6 (f), (g), (h) and (i), an image (ch1 is odd) which is originally an odd or even field in the image memory for each channel. , Ch2 is even, ch3 is odd, and ch4 is even field) are reproduced as odd and even fields alternately in each field and halved in both horizontal and vertical directions. As in the case of the full screen display of FIG. Even if the normal display in which the video and playback synchronization fields match and the video display in the field at the time of the original recording is always repeated as the other field and the screen display shifted by one line are alternately repeated, they appear to be periodically shifted. And no vertical shaking occurs at all.

For this reason, as shown in FIG. 7, the channel 3 originally having no video signal is displayed as a black screen, and the channel having the video signal does not have the vertical fluctuation of the entire screen and obtains a good 4-split playback screen. be able to.

Next, FIG. 8 is a diagram for explaining the case where the number of video inputs is 3, and the video channel without input and the reference video channel are different, as in FIGS. 8 (1) is the same as FIG. 6 without ch4 video and ch1 is the reference video channel. FIG. 8 (3) is the same as FIG. 6 and FIG. 8 (3) is ch1 as the reference video channel without ch2 video. ,
In (4) of FIG. 8, it is sufficient to record ch2 as a reference video channel without a video of ch1 and to set a channel without a video as a black screen. FIG. 9 shows the 4th case in the case of (4) in FIG.
It is a display example of a split screen and a ch2 full screen.

In the embodiment shown in FIG. 2, four video cameras synchronized as video input are shown. However, the input video signal may be a video signal other than the video camera or an asynchronous video signal such as a time base corrector (TBC). , The same effect can be obtained. Also, FIG. 2 illustrates the case where the maximum total number of video inputs is 4 channels. However, even when the maximum number of total video inputs increases and the number of video inputs becomes odd,
For example, in the case of eight channels, the number of video inputs is an odd three,
At the time of 5, 7, another or odd number of video signals synchronized with the input video signal is added, and the number of video channels to be recorded is set to an even number of 4, 6, or 8, and sequentially switched by the video switching means. If output and recorded on tape, it is possible to record only one of the odd and even fields for each video channel, and by writing and reading the image memory for each channel, the vertical fluctuation of the entire screen is similarly reduced. Needless to say, good reproduction images can be realized without generation.

FIG. 10 shows the operation in the case where the number of video input channels is 4 as an example of an even number. As in FIG. 2, it is possible to obtain a good reproduced image without vertical fluctuation. It is obvious.

FIG. 11 is a block diagram of a main part of the present embodiment, and the same or equivalent parts as in FIG. 1 are denoted by the same reference numerals. In FIG. 11, a three-input detection circuit 4
In step 8, the output from the input detection means 39 is used to generate a low output when the number of input video channels is 3, and a high output otherwise. On the other hand, when there is a video input for each channel, a high output is supplied to the odd-number input detection control means 40, and when there is no video input, a low output is supplied from the input detection means 39. As a result, when the number of inputs is other than three, rows are output from the NOR gates 49 to 52, and
A video signal or a synchronizing signal is supplied to the video channel switching means 20 according to the presence or absence of a video input. on the other hand,
NOR gate corresponding to no video input when the number of inputs is three
A high signal is output from the channel and a synchronization signal is supplied to the video channel switching means 20 only for that channel.

The channel switching control means 53 controls the switching of the video channel switching means 20 through the system controller 44 at the time of inputting the image 3 as in the case of inputting the image 4. The synchronization switching means 15 switches the synchronization signal of channel 1 or 2 in accordance with the presence or absence of the video channel 1 and outputs it to each of the video signal switching means 16 to 19. As is clear from the above description, the circuit of the main part of the present embodiment can be realized with a simple configuration when the maximum total number of video inputs is four channels.

FIG. 12 is a block diagram showing a second embodiment of the present invention, wherein the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals. FIG. 12 shows a fifth video signal switching means 54 in place of the synchronization signal switching means 15 of the embodiment shown in FIG.
Is different from the circuit of FIG.

The fifth video switching means 54 selects and outputs the video signal of the channel selected as the reference among the video signals from the camera driving means 10 in accordance with the output of the reference channel selection control means 41, and Signal switching means 16
~ 19.

For this reason, when the number of video input channels is odd, it is possible to record even numbers by adding a certain channel of video input redundantly, and to obtain the same effect as in the embodiment of FIG. Can be.

FIG. 13 shows an example of a 4-split playback image in the embodiment of FIG. 12, and FIG.
When h1 is replaced, FIG.
FIG. 13 (c) shows ch3 at the time of reproduction display.
13D, a black screen is displayed in place of the image of the reference channel 1 recorded as “1”. Similarly, FIG. 13D shows a black screen in place of the image of the reference channel 2 recorded as “ch1”.
Channels for which no input has been made are displayed clearly.

As another video signal synchronized with the input video signal generated to be added to the odd-numbered channel input video signal, not only a video signal having an input or a black screen by a synchronization signal, but also, for example, white or gray Of course, a generation screen of blue, blue, etc. may be used.

FIG. 14 is a block diagram showing a third embodiment of the present invention, wherein the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals. In FIG. 14, video cameras 1-4,
Input terminals 55 to 5 corresponding to respective video inputs are provided for a portion 63 for mainly performing magnetic recording / reproduction other than the camera driving means 10.
8 and output terminals 59 to 62 for branch output of the signal of each input terminal as they are. Here, when the number of video inputs is odd, as shown by the connection line 64, the video signal of the reference channel (any channel may be used as long as all the input video signals are synchronized) are input to the input terminal 57 of the empty channel. By supplying the signal through the output terminal 59, the number of video channels to be recorded can be easily made even, and a reproduced image without vertical fluctuation can be obtained.

FIG. 15 is a block diagram showing a fourth embodiment of the present invention, and the same or equivalent parts as in FIG. 1 are denoted by the same reference numerals. In FIG. 15, video cameras 1 to
4. An input terminal 55 corresponding to each video input to a portion 63 for mainly performing magnetic recording / reproduction other than the camera driving means 10
To 58, and when the number of video inputs is odd, the connection line 6
As shown by reference numeral 5, by supplying the synchronization signal from the synchronization generation circuit 5 in the camera driving means 10 to the input terminal 58 of the empty channel, the number of video channels to be recorded can be easily made even, and a good reproduced image can be obtained. In the above description of each embodiment, when the input video signal channel is an odd number, another synchronization signal synchronized with the input video signal is added to make the even number. However, the present invention is not limited to this. It goes without saying that the above odd number may be added to make the number even.

[0044]

As described above, according to the present invention, even when the number of input video signal channels is odd, another video signal synchronized with the input video signal is added to one or odd number to be even, and sequentially switched. Since recording is performed, when a reproduction screen is created from a reproduction image signal of a desired one channel, a good reproduction image can be realized without generating vertical fluctuation of the entire reproduction screen.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram illustrating the operation of one embodiment of the present invention.

FIG. 3 is a diagram showing each playback field image according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating a screen operation according to an embodiment of the present invention.

FIG. 5 is a diagram showing a playback screen according to one embodiment of the present invention.

FIG. 6 is a diagram illustrating the operation of one embodiment of the present invention.

FIG. 7 is a diagram showing an example of a four-divided display according to an embodiment of the present invention.

FIG. 8 is a diagram for explaining the operation at the time of 3ch input according to the present invention.

FIG. 9 is a diagram showing an example of a screen display at the time of 3ch input according to the present invention.

FIG. 10 is a diagram illustrating the operation of the present invention when inputting 4 channels.

FIG. 11 is a main block diagram of one embodiment of the present invention.

FIG. 12 is a block diagram showing a second embodiment of the present invention.

FIG. 13 is a diagram showing a playback screen according to a second embodiment of the present invention.

FIG. 14 is a block diagram showing a third embodiment of the present invention.

FIG. 15 is a block diagram showing a fourth embodiment of the present invention.

FIG. 16 is a diagram illustrating a conventional recording tape pattern.

FIG. 17 is a diagram illustrating the operation of a conventional example.

FIG. 18 is a diagram showing each playback field image in the conventional example.

FIG. 19 is a diagram illustrating a playback screen operation of a conventional example.

FIG. 20 is a diagram showing a playback screen of a conventional example.

[Explanation of symbols]

1, 2, 3, 4 ... video camera, 5 ... synchronization generation circuit,
6, 7, 8, 9: synchronous supply video output circuit, 10: camera driving means, 11, 12, 13, 14 ... synchronous separation circuit, 1
5. Synchronous signal switching means, 16, 17, 18, 19, 54
... Video signal switching means, 20 ... Video channel switching means,
21: code creation / addition means, 22: magnetic recording / reproduction means,
23: monitor playback video switching means, 35: A / D converter,
36 ... Image memory means, 37 ... D / A converter, 39 ... Input detection means, 40 ... Odd number input detection control means, 41 ... Reference channel selection control means, 45 ... Reproduction code / field discrimination means, 47 ... Memory control means .

Continued on the front page (72) Inventor Michio Masuda 1410 Inada, Katsuta, Ibaraki Pref., AV Equipment Division, Hitachi, Ltd. (72) Inventor Tetsuo Sakai 1410 Inada, Katsuta, Ibaraki Pref. 56) References JP-A-64-65989 (JP, A) JP-A-3-133287 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/76-5/956 H04N 7/18 G11B 5/027

Claims (5)

(57) [Claims] An odd number input detection control means for detecting whether the number of channels of a plurality of input video signals is odd or even,
Video switching means for sequentially switching and outputting the plurality of input video signals, video signal generation means for generating another video signal synchronized with the plurality of input video signals, and a series of the video switching means. A magnetic recording / reproducing means for recording / reproducing a video signal, an image memory means for storing a video signal, and a reproducing video signal from the magnetic recording / reproducing means selected for each channel and temporarily stored in the image memory means, Memory control means for controlling the image memory means to read only the video signal of the channel, wherein the video switching means, in response to the output from the odd input detection control means, a plurality of input video signals When the number of channels is an odd number, not only a plurality of input video signals but also another video signal synchronized with the input video signal from the video signal generating means is added and sequentially turned off. An intermittent magnetic recording / reproducing apparatus characterized in that the intermittent magnetic recording / reproducing means is supplied to the magnetic recording / reproducing means instead, and the magnetic recording / reproducing means records an even number of video channels. 2. The intermittent magnetic recording / reproducing apparatus according to claim 1, wherein said video signal generation means includes: a synchronization separation means for separating and generating a composite synchronization signal from said plurality of input video signals; Reference channel selection control means for selecting and controlling a video signal of a video camera as a reference, wherein a video signal is output from the sync separation means as a reference in accordance with an output from the reference channel selection control means. An intermittent magnetic recording / reproducing apparatus which supplies a video signal from a signal generation unit to the video switching unit. 3. An odd number input detection control means for detecting whether the number of channels of the plurality of input video signals is odd or even,
Video switching means for sequentially switching and outputting the plurality of input video signals, magnetic recording / reproducing means for recording / reproducing continuous video signals from the video switching means, and image memory means for storing video signals, Memory control means for selecting a reproduced video signal from the magnetic recording / reproducing means for each channel, temporarily storing the reproduced video signal in the image memory means, and controlling the image memory means so as to read out only a video signal of a predetermined channel. In the video switching means, according to the output from the odd input detection control means, when the number of channels of the plurality of input video signals is odd, not only the plurality of input video signals, but also the The video signal of one of the channels is added and sequentially switched and supplied to the magnetic recording / reproducing means. The magnetic recording / reproducing means records even video channels. An intermittent magnetic recording / reproducing apparatus characterized by recording. 4. A plurality of video cameras, a camera driving unit the generated synchronization signal is supplied to the plurality of video cameras and from said plurality of video cameras you outputs the video signal synchronized with the synchronizing signal, the Video switching means for sequentially switching and outputting a plurality of video signals; magnetic recording / reproducing means for recording / reproducing a continuous video signal from the video switching means; image memory means for storing video signals; Memory control means for selecting a reproduced video signal from the recording / reproducing means for each channel, temporarily storing the reproduced video signal in the image memory means, and controlling the image memory means to read only the video signal of a predetermined channel, When the number of channels of multiple input video signals is odd,
A predetermined channel is branched out from the plurality of input video signals and supplied to an empty channel, and the video switching means sequentially switches by adding not only the plurality of input video signals but also the branched video signal. An intermittent magnetic recording / reproducing apparatus, wherein the intermittent magnetic recording / reproducing device supplies the data to the magnetic recording / reproducing means, and records the even number of video channels in the magnetic recording / reproducing means. 5. A plurality of video cameras, a camera driving unit the generated synchronization signal is supplied to the plurality of video cameras and from said plurality of video cameras you outputs the video signal synchronized with the synchronizing signal, the Video switching means for sequentially switching and outputting a plurality of video signals; magnetic recording / reproducing means for recording / reproducing a continuous video signal from the video switching means; image memory means for storing video signals; Memory control means for selecting a reproduced video signal from the recording / reproducing means for each channel, temporarily storing the reproduced video signal in the image memory means, and controlling the image memory means to read only the video signal of a predetermined channel, When the number of channels of the plurality of input video signals is an odd number, the synchronization signal generated by the camera driving means is supplied to an empty channel, and the video switching means In the intermittent magnetic recording apparatus, not only the plurality of input video signals but also the synchronizing signal are added and sequentially switched and supplied to the magnetic recording / reproducing means, and the magnetic recording / reproducing means records even-numbered video channels. Recording and playback device.