JPH06292137A - Two-screen recording device and one-screen selection reproduction device - Google Patents

Abstract

PURPOSE:To obtain a video image whose aspect ratio is normal when a conventional reproduction device is used to reproduce the image from the video tape by recording a video signal of 1st screen and a video signal of 2nd screen respectively to a position of a first half and a position of a second half of one field period on a video tape without thinning a horizontal line. CONSTITUTION:A frame memory 15 stores a digital data signal d1 (Y) of one frame based on a write clock signal m1 of a frequency A. A frequency B of a write clock signal n1 from a read clock signal generating circuit 22 is set to be twice the frequency A of the write clock signal m1. The frame memory 15 uses the write clock signal n1 whose frequency is B to read the signal, then the information quantity for one horizontal period is twice that at the time of write and data by two lines at the time of write are read for one horizontal period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-screen recording device for recording two-screen video signals on one video tape, and one-screen selection for reproducing one screen of the video signals recorded in this way. Reproduction device

[0002]

2. Description of the Related Art Generally, a video tape recorder (hereinafter referred to as VT
A screen recording device such as R) is one system (one screen) selected by a switch or the like from a video signal reproduced from a television broadcast signal from a built-in tuner and a video signal from an external video signal input terminal. The video signal of is recorded on a video tape. Here, as a method of simultaneously recording video signals of two systems (for two screens), there is a method of simply using two recording devices, but this requires two recording media (video tape or the like), There is a problem in that it requires twice as much space and costs two.

Therefore, various methods of recording video signals for two screens on one tape have been considered.

The first method is picture-in
There is a method of recording the video of the two screens into the main screen and the sub screen by the picture system and recording it on the video tape. However, in this case, the position of the sub screen in the video of the main screen is completely lost. , Is inconvenient.

As a second method, considering the NTSC system, the recording apparatus records the video signal of the first screen on the track corresponding to the odd field of the video tape and the second signal on the track corresponding to the even field. When the video signal of the screen is recorded and the video signal of the first screen is played back, the video signal of the odd field recorded on the video tape is played back using a dedicated one-screen selection playback device.
An even field video signal is created from the odd field video signal and output next to the odd field. Also,
When reproducing the video signal of the second screen, the video signal of the even field recorded on the video tape is reproduced, and the video signal of the odd field is created from the video signal of the even field to generate the video signal of the even field. Then output. This makes it possible to prevent partial loss of the video, but the actual number of frames per second in the video played back using the dedicated single-screen selection playback device is about half that of the original video. Since it will be 30 frames, the video will be awkward. Further, when the video tape on which the video signals of the first and second screens are recorded as described above is reproduced using a normal device, completely different videos are alternately output in the odd field and the even field. Therefore, there is a drawback that the contents of the image are hardly understood.

As a third method, the recording device takes out the odd lines of the video signal of the first screen, takes out the even lines of the video signal of the second screen, and takes out even lines between the taken out odd lines. A video signal for one screen is created by inserting lines and recorded on a video tape. When the video signal of the first screen is played back, a dedicated 1-screen selection playback device is used to separate the odd lines from the video signal played back from the video tape, and the even number of the same video signal as the previous odd line. A line is inserted and output as a reproduced video signal of the first screen. When reproducing the video signal of the second screen, the even line is separated from the video signal reproduced from the video tape, the odd line of the same video signal as the subsequent even line is inserted, and the reproduction of the second screen is performed. Output as a video signal. This can eliminate the awkwardness of moving images, but even with this, a normal device is used to alternately output odd lines and even lines of completely different images.
The drawback is that the contents of the image are almost unknown.

Corresponding to this, recording of the video signal of two screens on the video tape is performed so that the content of the video can be understood even when the video signal recorded in the video stream is reproduced by using the usual reproducing apparatus. A dual screen recording device has been developed.

FIG. 6 is a block diagram showing such a conventional two-screen recording device.

In FIG. 6, reference numeral 61 is an input terminal to which the video signal a21 of the first screen from the first system (for example, the first tuner) is introduced, and the video signal introduced to this input terminal is Analog / digital conversion circuit (hereinafter A /
(Referred to as a D conversion circuit) 62.

The video signal a22 of the second screen from the second system (for example, the second tuner) is led to the input terminal 71, and the second video signal a22 is led to the input terminal 71.
The video signal a22 on the screen of is guided to the A / D conversion circuit 72.

The A / D conversion circuits 62 and 72 convert the video signals a21 and a22 of the first and second screens from the input terminals 61 and 71, respectively, into digital data signals b21 and b22, and the frame memories 63, respectively. , 73.

In the frame memories 63 and 73, input terminals 64 and 7 are created based on the vertical and horizontal synchronizing signals of the video signals a21 and a22 of the first and second screens, respectively.
4 from the first and second write clocks c21, c22
Are being supplied. This write clock c
21 and c22 are created so that the video signals of one horizontal scanning period are written every two horizontal scanning periods in synchronization with the even lines of the video signals a21 and a22, respectively.

The frame memories 63 and 73 write the digital data signals b21 and b22 based on such write clocks c21 and c22.

The television synchronizing signal generator 64 reads the read clock signals d21 and d for causing the frame memories 63 and 64 to alternately read at one field cycle.
22 is created and supplied to the frame memories 63 and 73, respectively. The frame memory 63 switches the digital data of the video signal stored in one field in the first half field of one field period as the digital data signal e21 based on the read clock signal d21 from the television synchronization signal generator 64. 65 to the first input terminal A1. The frame memory 73 switches the digital data of the video signal stored for one field in the latter half field of one field period as the digital data signal e22 based on the read clock signal d22 from the television synchronization signal generator 64. 65 to the second input terminal A2.

The switch 65 selects the input terminal A1 in the first half field of one field period and connects it to the common terminal C in response to a control signal (not shown), and the latter half 1 / field.
The input terminal A2 is selected in two fields and connected to the common terminal C.

The common terminal C of the switch 65 has a digital / analog conversion circuit (hereinafter referred to as a D / A conversion circuit) 6
6 are connected to the input terminals. As a result, the digital data signal e21 from the frame memory 63 is guided to the input terminal of the D / A conversion circuit 66 in the first half field of the one field period, and in the second half field of the one field period. The digital data signal e22 from the frame memory 73 is introduced.

The A / D conversion circuit 66 converts the digital data signal from the common terminal C of the switch 65 into an analog video signal f21 and supplies it to the output terminal 66. The video signal f21 output from the input terminal 66 input terminal is VTR.
It is supplied to the circuit and recorded on video tape.

The operation of such a conventional two-screen recording apparatus will be described with reference to the explanatory view showing the video signal lines in FIG.

As shown in FIG. 7, the video signal a21 of the first screen guided to the input terminal 61 is the video signal of the first screen 81 having odd lines and even lines.
The video signal a21 of such a first screen is converted into a digital data signal b21 by the A / D conversion circuit 62,
Only even lines are written in the frame memory 63, and D / A
By the D / A conversion in the first half field of one field period by the conversion circuit 66, the odd lines are thinned out and the video signal f2 compressed to 1/2 in the vertical direction is generated.
It becomes 1.

On the other hand, the video signal a22 of the second screen guided to the input terminal 71 is the video signal of the second screen 82 having even lines and even lines, as shown in FIG. The video signal a22 of the second screen is A /
The digital data signal b22 is converted by the D conversion circuit 72, and only even lines are written in the frame memory 73.
By the D / A conversion circuit 66, 1 in the latter half of one field period
Owing to the D / A conversion in the / 2 field, the odd lines are thinned out to become the video signal f21 compressed in the vertical direction to 1/2.

The video signal f21 thus created
7, the odd line of the video signal a21 of the screen 81 is inserted in the period corresponding to the upper half of the screen 83, and the odd line of the video signal a22 of the screen 82 is the screen 83.
Is inserted in the period corresponding to the lower half.

When the video signal of the first screen on the video tape on which such a video signal is recorded is reproduced by the dedicated one-screen selection reproducing device, the one-screen selection reproducing device reads the composite image from the tape. The video signal in the first half field horizontal period of the 1 field period is extracted from the signal, and the odd line of the same video signal as the subsequent even line is inserted to extend the vertical direction, and the first screen is displayed. Output as the reproduced video signal of. In the screen 84 of the reproduced video signal of the first screen thus created, as shown in FIG. 7, an odd line and an even line are created from one horizontal line of the upper half of the video signal of the screen 83. Will be.

When the video signal of the second screen of the video tape is reproduced by the dedicated one-screen selection reproduction device, the one-screen selection reproduction device outputs one from the composite video signal read from the tape.
The video signal in the second half of the field period, which is the horizontal field, is extracted and the odd-numbered line of the same video signal as the subsequent even-numbered line is inserted to extend the vertical direction, thereby reproducing the image on the second screen. Output as a signal. Screen 8 of the reproduced video signal of the second screen created in this way
5, the odd line and the even line are created from one line in the lower half of the video signal of the screen 83, as shown in FIG.

FIG. 8 is an explanatory diagram showing the format of a video tape recorded by the two-screen recording apparatus of FIG.

In FIG. 8, the video tape 91 has a length of 8 m.
It is an alloy powder metal tape with a width of m. In the first half 95 of the video signal recording area 94 of the trace 92 of the video head, the video signal a31 obtained by FM-modulating the video signal a21 of the first screen is recorded, and the latter half 96 of the video signal recording area 94 is recorded.
Then, a video signal a32 obtained by FM-modulating the video signal a22 of the first screen is recorded. A pulse coded modulation signal 97 for audio is recorded on the left side of the tape running direction.

FIG. 9 is an explanatory view showing a screen image in the state of inputting, recording and reproducing a video signal by the dual screen recording apparatus of FIG.

First and second input to the two-screen recording device
Image 101,10 by the image signal a21,22 of the screen of
2, the vertical and horizontal are in a normal state, but the image 103 recorded on the video tape is in a state in which the vertical direction of the images 101 and 102 is compressed and arranged vertically. When the video signal thus recorded is reproduced by a dedicated reproducing device, the vertical and horizontal video images 104 and 105 are obtained.

However, in such a two-screen recording device, the reproduced video images 104 and 105 have the same line two times.
By displaying the two images side by side, the horizontal direction of the screen is expanded, so that the horizontal resolution is reduced to 1/2.

FIG. 10 is an explanatory view showing the details of the screen image in the input and reproduction states of the image signal of such a dual screen recording apparatus, and FIG. 10 (a) is the image signal a of the first screen.
11 shows an image according to No. 11, and FIG. 10B shows an image according to the reproduction image signal of the first screen reproduced by the dedicated one-screen selection reproducing apparatus.

In FIG. 10, a solid line shows an odd field line, and a broken line shows an even field line. As shown in FIG. 10A, the video signal a11 of the first screen supplied to the two-screen recording device is the oblique video 11
When displaying 1, 1 is displayed as shown in FIG.
The image of the reproduced image signal of the first screen reproduced by the screen selection reproducing device becomes the broken line image 112, and the image quality is considerably deteriorated.

In response to such drawbacks, a method of vertically compressing and recording a screen has been developed.

FIG. 11 is a block diagram showing a conventional two-screen recording apparatus for vertically compressing and recording such a screen.

In FIG. 11, reference numeral 201 is a first tuner into which an RF signal from an antenna (not shown) is guided, and the first tuner 201 selects the RF signal on the first channel and amplifies the intermediate frequency. Then, the signal is detected, converted into a composite video signal a51, and supplied to the decoder 202. The decoder 202 creates a luminance signal (Y signal) b51 (Y) and a sync signal c51 from the composite video signal a51 and supplies them to the A / D conversion circuit 203 and the sync signal generation circuit 204 for the Y signal, respectively. Also, the decoder 202
Is a red-Y color difference signal (hereinafter R-
(Y signal) b51 (RY), blue-Y color difference signal (hereinafter referred to as RY signal) b51 (BY) are created, and a circuit system (not shown) similar to the case of Y signal b51 Supply to. The A / D conversion circuit 203 is supplied with a pulse signal 2fsc having a frequency twice as high as the color subcarrier frequency, and the pulse signal 2fsc is used as a sampling point to perform A / D conversion of the Y signal b51 (Y) and perform digital conversion. The data signal d51 (Y) is supplied to the frame memory 205.

On the other hand, the synchronizing signal generation circuit 204 separates the horizontal synchronizing signal e51 (HD) and the vertical synchronizing signal e51 (VD) from the synchronizing signal c51 and supplies them to the frame memory.
Further, the synchronization signal generation circuit 204 creates a field discrimination signal e51 (FI) from the synchronization signal c51 and supplies it to the frame memory 205.

The frame memory 205 has a horizontal synchronizing signal e.
The digital data signal d51 (Y) of one frame is stored based on 51 (HD), the vertical synchronization signal e51 (VD), and the field determination signal e51 (FI).

On the other hand, the second tuner 301 performs channel selection, intermediate frequency amplification and detection on the RF signal from the antenna (not shown) on the second channel, and outputs the composite video signal a5.
It is converted into 2 and supplied to the decoder 302. Decoder 3
02 generates a Y signal b52 (Y) and a synchronization signal c52 from the composite video signal a52, and A / D for the Y signal respectively.
It is supplied to the conversion circuit 303 and the synchronization signal generation circuit 304. Further, the decoder 302 outputs the composite video signals a52 to R
-Y signal b52 (RY), BY signal b52 (BY-
Y) and horizontal and vertical synchronization signals c52 are created and supplied to the same circuit system (not shown) as in the case of the Y signal b52. The A / D conversion circuit 303 is supplied with a pulse signal 2fsc having a frequency twice as high as the color subcarrier frequency. The Y signal b52 is used as a sampling point of this pulse signal.
(Y) A / D conversion is performed to perform digital data signal d52
(Y) is supplied to the line memory 305.

On the other hand, the sync signal generation circuit 304 separates the horizontal sync signal e52 (HD) and the vertical sync signal e52 (VD) from the horizontal and vertical sync signals c52 to separate the line memory 3 from each other.
05 to the encoder 501 described later. The sync signal generation circuit 304 creates a field discrimination signal e52 (FI) from the horizontal and vertical sync signals c52 and supplies it to the line memory 305 and the encoder 501.

The line memory 305 has a horizontal synchronizing signal e5.
The digital data signal d52 (Y) for one horizontal scanning period is stored based on 2 (HD), the vertical synchronization signal e52 (VD), and the field determination signal e52 (FI).

Further, the line memory 305 reads the digital data signal f52 (Y) for one line and supplies it to one input terminal of the adder 502 during the second half of the horizontal scanning period.

On the other hand, the frame memory 205 has 1 / half of the first half of the horizontal scanning period of the line read by the line memory 305.
In the period of 2, the digital data signal f51 for one line is
(Y) is read and supplied to the other input terminal of the adder 502. Accordingly, the digital data signal f51 for one line from the frame memory 205 is output from the adder 502.
(Y) and the digital data signal f52 (Y) for one line from the line memory 305, a total of two lines are horizontally compressed, and a digital data signal g50 (Y) for one line is obtained.
Will be output. The digital data signal g50 (Y) from the adder 502 is supplied to the A / D conversion circuit 503. The D / A conversion circuit 503 is supplied with the pulse signal 4fsc having a frequency four times as high as the color subcarrier frequency. By performing the D / A conversion using the pulse signal 4fsc as a sampling point, the Y signal is obtained. h
50 (Y) is output. In addition, the RY signal b51 (R-
Y), b52 (RY), BY signal b51 (B-
Y) and b52 (BY) are processed in the same manner as the Y signal, and the RY signal g50 (RY) and BY signal g
50 (BY) is supplied to the encoder 501.
The encoder 501 has a Y signal h50 and an RY signal g50.
(RY), BY signal g50 (BY), horizontal synchronization signal e52 (HD), vertical synchronization signal e52 (VD), and field discrimination signal e52 (FI) to create a composite video signal j50. Supply to the VTR circuit. In this case V
As the TR circuit, one having the ability to record at a resolution twice or close to the resolution of the video signals a51, a52 from the tuners 201, 202 is used.

FIG. 12 is a block diagram showing a reproducing circuit for reproducing the video tape recorded by the dual screen recording apparatus of FIG. 11 and for separating the screen.

In FIG. 12, reference numeral 601 is 2 in FIG.
VTR for playing back video tape recorded by screen recorder
And the composite video signal a6 reproduced by the VTR unit 601.
1 is supplied to the decoder 602. The decoder 602 creates a Y signal b60 (Y) and a sync signal c60 from the composite video signal a50 and supplies them to the A / D conversion circuit 603 and the sync signal generation circuit 604 for the Y signal, respectively. Also,
The decoder 602 converts the composite video signal a60 to the RY signal b.
60 (RY) and BY signal b60 (BY) are created and supplied to a circuit system (not shown) similar to the case of the Y signal b60.

The A / D conversion circuit 603 is supplied with the pulse signal 4fsc having a frequency four times as high as the color subcarrier frequency, and the pulse of the pulse signal 4fsc is used as a sampling point to A / D the Y signal b60 (Y). The D data is converted and the digital data signal d60 (Y) is converted into the frame memory 605.
Supply to.

On the other hand, the sync signal generation circuit 604 separates the horizontal sync signal e60 (HD) and the vertical sync signal e60 (VD) from the horizontal and vertical sync signals c60 and supplies them to the frame memory 605 and the encoder 701 described later. To do. The sync signal generation circuit 604 creates a field discrimination signal e60 (FI) from the horizontal and vertical sync signals c60 and supplies it to the frame memory 605 and the encoder 701.

The frame memory 605 has a horizontal synchronizing signal e.
The digital data signal d60 (Y) of one frame is stored based on 60 (HD), the vertical synchronization signal e60 (VD), and the field determination signal e60 (FI).

Further, the frame memory 605 has a structure shown in FIG.
Selection signal k60 for selecting and reproducing the video signal from the tuner 201 and the video signal from the tuner 301
Is being supplied. The frame memory 605 stores 1 in the first half or the second half of the horizontal scanning period based on the selection signal k60.
One of the data recorded in the period of / 2 is selected, read as a digital data signal f60 (Y), and supplied to the D / A conversion circuit 606. The D / A conversion circuit 606 outputs the pulse signal 2f having a frequency twice the color subcarrier frequency.
sc is supplied, and the Y signal h60 (Y) is output by performing D / A conversion using the pulse period of the pulse signal 2fsc as a sampling point. Also, the RY signal b
60 (RY) and b60 (RY) are processed in the same manner as the Y signal, and the RY signal h60 (RY), B
The -Y signal h60 (BY) is supplied to the encoder 701. The encoder 701 uses the Y signals g60, RY
Signal g60 (RY), BY signal g60 (BY),
Horizontal sync signal e60 (HD), vertical sync signal e60 (V
D) and the field discrimination signal e60 (FI) are used to create the composite video signal j60 and supply it to the television receiver.

In such a conventional two-screen recording device, the video signal a51 of the first screen selected by the tuner 201 is the decoder 202 and the A / D conversion circuit 203.
Is converted into a digital data signal d51 (Y) by
Frames are stored in the frame memory 205.

On the other hand, the video signal a52 of the second screen selected by the tuner 301 is the decoder 302, A / D
Digital data signal d52 (Y) by the conversion circuit 303
Is converted into the line memory 305 and one frame is stored in the line memory 305.

The line memory 305 reads the digital data signal f52 (Y) for one line during the latter half of the horizontal scanning period, and the frame memory 205 scans the line read by the line memory 305 horizontally. During the first half of the period, the digital data signal f51 for one line
Read (Y). As a result, the adder 502 outputs 2
A digital data signal g50 (Y) for one line, in which two screens are compressed in the horizontal direction and joined together, is introduced. Such a digital data signal g50 (Y) is converted into a Y signal h50 (Y) by the D / A conversion circuit 503, and the RY signal g50 (RY), B- is converted by the encoder 501.
Y signal g50 (BY), horizontal synchronization signal e52 (H
D), the vertical synchronizing signal e52 (VD) and the field discrimination signal e52 (FI) are combined and recorded as a composite video signal j50 in the VTR circuit.

FIG. 13 is a diagram showing the format of a video tape on which recording is performed in this manner.

In FIG. 13, the video tape 791 is
It is an alloy powder metal tape with a width of 8 mm. Video one horizontal scanning period (1H) of the trace 792 of the video head
In the first half of 795, the video signal a51 of the first screen is FM
The modulated video signal a71 is recorded, and in the second half 796 of one horizontal scanning period, the video signal a72 obtained by FM-modulating the video signal a52 of the second screen is recorded.

In the reproducing circuit shown in FIG. 12, when reproducing an image by the tuner 201, a selection signal k60 for selecting and reproducing an image signal by the tuner 201 of FIG. 11 is stored in the frame memory 605. Supplied. In this state, the VTR unit 601 outputs the video signal a50 by reproducing the video signals a71 and a72 recorded on the video tape 791 in the first half and the second half of one horizontal scanning period, respectively. The video signal a50 reproduced in this manner is converted into a Y signal b60 (Y) by the decoder 602, and converted into a digital data signal d60 (Y) by the A / D conversion circuit 603, and one frame worth is stored in the frame memory 605. Stored in. As a result, the frame memory 605 selects the data recorded during the first half of the horizontal scanning period, and the digital data signal f60 (Y) is selected.
And is supplied to the D / A conversion circuit 606. D /
The A conversion circuit 606 uses the digital data signal f60 (Y).
To the Y signal h60
(Y) is output. The encoder 701 uses the Y signal g60 thus created, and the RY signal g60 (RY) and BY signal g60 (B) created in the same manner.
-Y), and the composite video signal j60 is created and supplied to the television receiver.

When a video image is reproduced by the tuner 301, the frame memory 605 stores the tuner 3 shown in FIG.
A selection signal k60 for selecting and reproducing the 01 video signal is supplied. In this state, the VTR section 601 outputs the video signal a50 by reproducing the video signals a71 and a72 recorded on the video tape 791. The video signal a50 reproduced in this way is transmitted to the decoder 60.
A Y signal b60 (Y) is converted by 2 and a digital data signal d60 (Y) is converted by the A / D conversion circuit 603, and one frame is stored in the frame memory 605. As a result, the frame memory 605 selects the data recorded in the latter half period of the horizontal scanning period, reads it as the digital data signal f60 (Y), and supplies it to the D / A conversion circuit 606. After this, the D / A conversion circuit 60
6 and the encoder 701 perform the same processing as in the case of reproducing the video by the tuner 201, and the composite video signal j
60 is prepared and supplied to the television receiver.

FIG. 14 is a diagram showing a screen image in the state of inputting, recording and reproducing a video signal of such a dual screen recording apparatus.

First and second input to the two-screen recording device
901,90 by the video signals a51,52 of the screen of
2 has a normal vertical and horizontal state, but the image 903 recorded on the video tape has a vertical direction in which the horizontal directions of the images 901 and 902 are compressed and arranged side by side. When the video signal thus recorded is reproduced by a dedicated reproducing device, the vertical and horizontal images 904, 905 are obtained.

According to such a conventional two-screen recording apparatus, since the video is compressed in the horizontal direction without thinning out the horizontal lines, the reproduced videos 904 and 905 are the first images.
And the image 9 by the image signals a51 and a52 of the second screen
The same vertical resolution as 01 and 902 can be obtained. However, when the image recorded by the dual-screen recording device is reproduced by the normal reproducing device, it becomes very unsightly as it is not a vertically long image as shown in the image 903. Since the video signal of the first screen and the video signal of the second screen are separately recorded in the first half and the second half of the horizontal scanning period on the video tape, the video signals of the first and second screens are recorded. When only one of them is rewritten, the video head must be turned on and off 26 times on average during one video head trace, which is technically difficult.

[0057]

In the conventional two-screen recording apparatus described above, the image is compressed in the horizontal direction, and
Although the video signals for the screen are recorded, when the video signals recorded by such a dual screen recording device are reproduced by a normal reproducing device, the aspect of the video is different, which is very unsightly. In addition, the video signal of the first screen and the second
Since the video signal of the screen is alternately recorded in the first half and the second half of the horizontal scanning period, it is difficult to rewrite only one of the video signals of the first and second screens.

The present invention eliminates the above-mentioned problems, and makes the video signal of the first screen and the video signal of the second screen the first half of one field period on the video tape without thinning out the horizontal lines. A dual-screen recording device capable of recording in the latter half positions and obtaining a video with a normal aspect ratio even when the video signal recorded by the dual-screen recording device is reproduced by a normal reproducing device. For the purpose of provision.

[0059]

[Constitution of the invention]

[0060]

A two-screen recording apparatus according to the present invention as set forth in claim 1, and a decoder for extracting a video signal from a composite video signal and for extracting horizontal and vertical synchronizing signals from the composite video signal, and this decoder. The analog-to-digital conversion circuit that performs analog-to-digital conversion on the video signal from to create a digital data signal and the digital data signal from this analog-to-digital conversion circuit for one frame Minute digital data signals are selected from the first half or the latter half of one field period and the selected one of them is read out in order from the horizontal lines to obtain the digital data signals of the odd-numbered horizontal lines and the even-numbered horizontal lines. A frame memory that reads digital data signals in one horizontal period, and from this frame memory A composite video signal composed of a digital-analog conversion circuit that performs digital-analog conversion of the output digital data signal to create a video signal, and a video signal from this digital-analog conversion circuit and horizontal and vertical synchronization signals from the encoder. And a recording means for recording the composite video signal from the decoder on a video tape.

[0061]

According to this structure, the digital data signals for one field stored in the frame memory are sequentially read during the first half or the latter half of the one field period, so that the horizontal lines are read in order to make the odd number Since the horizontal lines and the even-numbered horizontal lines are read in one horizontal period, the image recorded on the video tape is composed of the odd-numbered horizontal lines in the upper half or the lower half of the screen and the even-numbered horizontal lines. The images formed by are arranged in the horizontal direction. As a result, the video signal of the first screen and the video signal of the second screen can be recorded in the first half and the second half of one field period on the video tape without thinning out the horizontal lines. Even when the video signal recorded by the dual-screen recording device is reproduced by a normal reproducing device, a video having a normal aspect ratio can be obtained.

[0062]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a dual-screen recording apparatus according to the present invention, which is applied to recording (dubbing) two video signals with a time difference.

In FIG. 1, reference numeral 11 is a tuner to which an RF signal from an antenna (not shown) is introduced. The tuner 11 selects a predetermined channel for the RF signal,
Intermediate frequency amplification and detection are performed, converted into a composite video signal a1, and supplied to the decoder 12. The decoder 12 creates a Y signal b1 (Y) and a sync signal c1 from the composite video signal a1 and supplies them to the A / D conversion circuit 13 and the sync signal generation circuit 14 for the Y signal, respectively. Further, the decoder 12 outputs the composite video signal a1 to the RY signal b1 (RY), B-.
A Y signal b1 (BY) is created and supplied to a circuit system (not shown) similar to the case of the Y signal b1. The A / D conversion circuit 13 is supplied with a pulse signal 2fsc having a frequency twice as high as the color subcarrier frequency. The Y signal b1 (Y) is A / D converted by using this pulse signal as a sampling point to obtain digital data. The signal d1 (Y) is transferred to the frame memory 15
Supply to.

On the other hand, the synchronizing signal generating circuit 14 outputs the synchronizing signal c
1 to horizontal synchronization signal e1 (HD) and vertical synchronization signal e1
(VD) is separated and supplied to the frame memory. Also,
The sync signal generation circuit 14 creates a field discrimination signal e1 (FI) from the sync signal c1 and supplies it to the frame memory 15.

The write clock signal generation circuit 21 is a write clock of the frequency A for causing the write operation of the frame memory 15 based on the horizontal synchronizing signal e1 (HD), the vertical synchronizing signal e1 (VD) and the field discrimination signal e1 (FI). The signal m1 is created and supplied to the frame memory 15.

The frame memory 15 has a write clock signal m1 of frequency A, a horizontal synchronizing signal e1 (HD), a vertical synchronizing signal e1 (VD) and a field discriminating signal e1 (F).
I) of one frame of digital data signal d1
Memorize (Y).

In the read clock signal generation circuit 22, the read timing of the frame memory 15 is set to the first half of the one field period or the second half of the one field period.
Selection signal k1 for selecting the period and reading
Is being supplied.

The read clock signal generation circuit 22 performs the read operation of the frame memory 15 based on the selection signal k1, the horizontal synchronizing signal e1 (HD), the vertical synchronizing signal e1 (VD) and the field discrimination signal e1 (FI). A read clock signal n1 having a frequency B is generated and supplied to the frame memory 15.

Here, the frequency B of the write clock signal n1 is set to twice the frequency A of the write clock signal m1.

By reading the frame memory 15 with the write clock signal n1 having the frequency B, the amount of information in one horizontal period is double that in writing, and two lines in writing are read in 1 horizontal period. . Further, the frame memory 15 reads the recorded data for one field in the first half or the second half of the one field period and supplies it to the D / A conversion circuit 16 as a digital data signal f1 (Y). The D / A conversion circuit 16 uses a pulse signal 4fsc having a frequency four times the color subcarrier frequency.
Is supplied, and the D / A conversion of the digital data signal f1 (Y) is performed based on the pulse signal 4fsc to output the Y signal g1 (Y). Also RY
The signal b1 (RY) and the BY signal b1 (BY) are also processed in the same manner as the Y signal, and the RY signal g1 (R
-Y), BY encoder g1 (BY) as encoder 1
7 is supplied.

Further, the encoder 17 uses the Y signal g1
(Y), RY signal g1 (RY), BY signal g1
(BY), the horizontal synchronizing signal e1 (HD), the vertical synchronizing signal e1 (VD), and the field discrimination signal e1 (FI) have a video signal in one of the first half or the second half of the field, and the other has no signal. A composite video signal j1 in a state is created and supplied to the VTR unit 30. In this case, as the VTR unit 30, a VTR unit having the capability of recording at a resolution twice or close to the resolution of the video signal a1 from the tuner 11 is used.

FIG. 2 is a block diagram showing a one-screen selection / reproduction device for selecting and reproducing one screen of the video signals recorded by the two-screen recording device of FIG.

In FIG. 2, reference numeral 31 is a VTR section for reproducing the video tape recorded by the dual screen recording apparatus of FIG. 1, and the composite video signal a3 reproduced by the VTR section 31 is supplied to the decoder 32. The decoder 32 uses the composite video signal a3
A Y signal b3 (Y) and a sync signal c3 are created from the supplied Y signal b3 (Y) and the sync signal c3, and are supplied to the Y signal A / D conversion circuit 33 and the sync signal generation circuit 34, respectively. Further, the decoder 32 uses the composite video signal a3 to the RY signal b3 (RY) and the BY signal b3.
(BY) is created and supplied to a circuit system (not shown) similar to the case of the Y signal b3.

The A / D conversion circuit 33 is supplied with the pulse signal 4fsc having a frequency four times as high as the color subcarrier frequency, and the pulse of the pulse signal 4fsc is used as a sampling point for A / D conversion of the Y signal b3 (Y). D conversion is performed and the digital data signal d3 (Y) is supplied to the frame memory 35.

On the other hand, the synchronizing signal generating circuit 34 separates the horizontal synchronizing signal e3 (HD) and the vertical synchronizing signal e3 (VD) from the horizontal and vertical synchronizing signals c3 to separate the frame memory 35, the write clock signal generating circuit 41, and the read clock. The signal is supplied to the signal generation circuit 42 and the encoder 43. Further, the synchronization signal generation circuit 34 creates a field discrimination signal e3 (FI) from the synchronization signal c3 and supplies it to the frame memory 35, the write clock signal generation circuit 41, the read clock signal generation circuit 42 and the encoder 43.

The write clock signal generation circuit 41 causes the frequency B (FIG. 1) for performing the write operation of the frame memory 15 based on the horizontal synchronizing signal e3 (HD), the vertical synchronizing signal e3 (VD) and the field discrimination signal e3 (FI). A write clock signal m3 having the same frequency as the read clock signal n1) is generated and supplied to the frame memory 35.

The frame memory 35 has a write clock signal m3 of frequency B, a horizontal synchronizing signal e3 (HD), a vertical synchronizing signal e3 (VD) and a field discriminating signal e3 (F).
I) of one frame of digital data signal d1
Memorize (Y).

The read clock signal generation circuit 42 performs the read operation A of the frame memory 15 based on the horizontal synchronizing signal e3 (HD), the vertical synchronizing signal e3 (VD) and the field discriminating signal e3 (FI) (see FIG. 1). A read clock signal m3 having the same frequency as the write clock signal m1) is generated and supplied to the frame memory 35.

Here, the frequency B of the read clock signal n3 is set to 1/2 times the frequency A of the write clock signal m3.

Further, the frame memory 35 is supplied with a selection signal k3 for selecting and reproducing the video signal recorded in the first half and the video signal recorded in the latter half of the field in the trace of the video tape. In the frame memory 35, one of the data recorded in the first half or the second half of the field is selected based on the selection signal k3, read as the digital data signal f3 (Y), and the D / A conversion circuit 36 is selected. Supply to. D / A conversion circuit 36
Is supplied with a pulse signal 2fsc having a frequency twice the color subcarrier frequency.
The Y signal g3 (Y) is output by performing D / A conversion using c as the pulse period as the sampling point. Also RY
The signal b3 (RY) and the BY signal b3 (BY) are processed in the same manner as the Y signal, and the RY signal g3 (R) is generated.
-Y), BY encoder g4 (BY) as encoder 4
3 is supplied. The encoder 43 outputs the Y signal g3, R-
The composite video signal j3 based on the Y signal g3 (RY), the BY signal g3 (BY), the horizontal synchronization signal e3 (HD), the vertical synchronization signal e3 (VD), and the field determination signal e3 (FI). Is created and supplied to the television receiver.

The operation of this embodiment will be described below.

FIG. 3 is a diagram showing an operation in the case where the two-screen recording device of FIG. 1 records a video signal in the first half of the field in the trace of the video tape.

In FIG. 3, a broken line shows an odd line of the video signal a1 selected by the tuner 11, and a solid line shows an even line of the video signal a1. Video signal a1
Is a video signal of the screen 801 of the first system having an odd line and an even line.

Video signal a selected by the tuner 11
1 is converted into a digital data signal d1 (Y) by the decoder 2 and the A / D conversion circuit 3, and one frame is stored in the frame memory 15 as the write clock signal m1 having the frequency A.

Here, the read clock signal generation circuit 22
Is supplied with a selection signal k1 for causing the frame memory 15 to select and read the first half of the one-field period as the read timing.

As a result, the frame memory 15 performs the read operation with the read clock signal n1 of the frequency B in the first half of the one-field period, so that the amount of information in one horizontal period is doubled at the time of writing, and the write operation is performed. Two lines of time will be read in one horizontal period. Further, the frame memory 15 reads the data for one field recorded in the first half of the one-field period and supplies it to the D / A conversion circuit 36 as a digital data signal f1 (Y). As a result, the image is compressed in the horizontal direction as shown in the screen 802 of FIG. 3, and the screen is divided into screens 803 and 804 having an odd aspect ratio and an even line and having a normal aspect ratio. The screens of odd line 807 and the screen of even line 808 are arranged in the horizontal direction in the first half of the period, and the second half of one field is in the empty state. The digital data signal f1 (Y) in such a state is converted into a Y signal g1 (Y) by the D / A conversion circuit 16, and the RY signal g1 (RY) and the BY signal g1 are converted by the encoder 17. (B-
Y), horizontal synchronization signal e1 (HD), vertical synchronization signal e1
(VD) and field discriminating signal e1 (FI) to form a composite video signal j1 in the VTR unit 30 in the first half of one field period in the trace of the video tape 808.
It is recorded in the area of the period of / 2.

FIG. 4 is a diagram showing an operation in the case where the two-screen recording apparatus of FIG. 1 records a video signal in the latter half of the field in the trace of the video tape.

In FIG. 4, the video signal a1 is the video signal of the screen 821 having odd lines and even lines.

Video signal a selected by the tuner 11
1 is converted into a digital data signal d1 (Y) by a decoder 12 and an A / D conversion circuit 13, and one frame is a write clock signal m1 having a frequency A and the frame memory 15
Stored in.

Here, the read clock signal generation circuit 22
, A selection signal k1 is supplied to the frame memory 15 for selecting the read timing in the latter half of the one-field period to perform the read. As a result, the frame memory 15 reads by the read clock signal n1 of the frequency B in the latter half of the one-field period, so that the amount of information in one horizontal period is twice as much as that in writing, and 2 in writing. The line portion is read in 1 horizontal period. In addition, the frame memory 15 is
Data for one field recorded in the latter half of the field period is read out and supplied to the D / A conversion circuit 36 as a digital data signal f1 (Y). As a result, the image is horizontally compressed as shown in the screen 822 of FIG. 4, and the screen is divided into screens 823 and 824 having normal aspect ratios of odd lines and even lines. Screens 827 of odd lines and screens of even lines 828 are arranged side by side in the second half period, and the first half period of one field becomes empty.
The digital data signal f1 (Y) in such a state is D
Is converted into a Y signal g1 (Y) by the / A conversion circuit 16,
The encoder 17 allows the RY signal g1 (RY), B-
Y signal g1 (BY), horizontal synchronization signal e1 (HD), vertical synchronization signal e1 (VD) and field discrimination signal e1
(FI) is combined and recorded as a composite video signal j1 in the VTR unit 30 in the area 810 in the first half period of one field period in the trace of the video tape 808.

Next, the operation of the one-screen selection reproducing apparatus shown in FIG. 2 will be described.

When reproducing the video signal recorded in the first half of the field on the trace of the video tape, the frame memory 35 is supplied with the selection signal k3 for selecting and reproducing the first half of the field on the trace of the video tape. To be done. In this state, the VTR section 31 outputs the video signal a3 recorded on the video tape. The video signal a3 thus reproduced is converted into a Y signal b3 (Y) by the decoder 32, and the A / D conversion circuit 33 is provided.
Is converted into a digital data signal d3 (Y), and one frame is stored in the frame memory 35. here,
Since the frequency B of the read clock signal n3 is set to 1/2 times the frequency A of the write clock signal m3,
As a result, the frame memory 35 selects the data recorded in the first half of the 1-field period, reads it as the digital data signal f3 (Y) in the 1-field period, and supplies it to the D / A conversion circuit 36. D / A conversion circuit 36
Outputs a Y signal g3 (Y) by performing D / A conversion on the digital data signal f3 (Y). The encoder 43 uses the Y signal g3 thus created.
And the RY signal g3 (R-
Y), a composite video signal j3 is created based on the BY signal g3 (BY) and supplied to the television receiver.

When the video signal recorded in the latter half of the field on the trace of the video tape is reproduced by the dedicated reproducing device of FIG. 2, the latter half of the field on the trace of the video tape is selected in the frame memory 35. A selection signal k3 for reproduction is supplied. In this state, the VTR section 31 outputs the video signal a3 recorded on the video tape.
Is output. The video signal a3 reproduced in this way
Is converted into a digital data signal d3 (Y) and one frame is stored in the frame memory 35. Since the frequency B of the read clock signal n3 is set to 1/2 times the frequency A of the write clock signal m3, the frame memory 35 has a half of the latter half of one field period.
The data recorded in the period is selected and read as the digital data signal f3 (Y) in the one field period, and the D / A
It is supplied to the conversion circuit 36. The D / A conversion circuit 36 outputs a Y signal g3 (Y) by performing D / A conversion on the digital data signal f3 (Y). The encoder 43 produces the Y signal g3 thus produced and the RY signals g3 (RY), B- produced similarly as above.
A composite video signal j3 is created based on the Y signal g3 (BY) and supplied to the television receiver.

FIG. 5 shows the video signal recorded in the latter half of the field in the trace of the video tape as the dedicated 1 of FIG.
It is a figure which shows the screen image at the time of reproducing with a screen selection reproducing apparatus.

The screen 830 based on the video signal recorded on the video tape is such that screens 807 of odd lines and screens of even lines 808 are laterally arranged in the first half of one field, and the latter half of one field. During the period of / 2, the screen 827 of the odd lines and the screen 828 of the even lines are arranged side by side in the horizontal direction. The video signal thus recorded is converted into a digital data signal d3 (Y), and one frame is stored in the frame memory 35. The data stored in this manner is read from the frame memory 35 based on the selection signal k3 and the read clock pulse n3, so that the even line 828 of the screen 828 is inserted between the odd lines of the screen 827. The screen 831 is stretched in the direction, and further, the screen 832 is stretched in the horizontal direction to have a normal aspect ratio.

According to such an embodiment, the video signal of the first screen and the video signal of the second screen can be recorded at the positions of the first half and the latter half of one field period on the video tape, respectively. It is possible to rewrite only one of the video signal of the screen and the video signal of the second screen.
Further, since the horizontal lines are not thinned out, it is possible to prevent the horizontal resolution and the vertical resolution of the video from being lowered when the video signal of one screen is played back by the dedicated one-screen selection playback device.
Furthermore, when reproduced by a normal reproducing apparatus, a video having a normal aspect ratio is obtained as shown in the screen 830 of FIG. This is very convenient for users who only have a normal playback device.

In the embodiment of FIG. 1, the encoder 17
Has a video signal in one of the first half or the second half of the field and supplies the composite video signal j1 in which the other has no signal to the VTR unit 30. It is also possible to have a signal and insert the horizontal and vertical synchronization signals equivalent to those in the one period into the other period. In the embodiment of FIG. 1, the first screen video signal and the second screen video signal are recorded at different times. However, the first screen video signal and the second screen video signal are recorded. It may be applied to those that record signals simultaneously.

[0099]

According to the present invention, the video signal of the first screen and the video signal of the second screen are located on the first half and the second half of one field period on the video tape without thinning out horizontal lines. It is possible to rewrite only one of the video signal of the first screen and the video signal of the second screen because it can be recorded in each. Further, since the horizontal lines are not thinned out, it is possible to prevent the horizontal resolution and the vertical resolution of the video from being lowered when the video signal of one screen is played back by the dedicated one-screen selection playback device. When played back by a normal playback device, an image with a normal aspect ratio can be obtained. This is very convenient for users who only have a normal playback device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a two-screen recording device according to the present invention.

FIG. 2 is a block diagram showing a one-screen selection reproducing device for selecting and reproducing one screen of the video signals recorded by the two-screen recording device of FIG.

FIG. 3 is a diagram showing an operation in the case where the dual screen recording device of FIG. 1 stores a video signal in the first half of a field in a trace of a video tape.

FIG. 4 is a diagram showing an operation when the dual-screen recording device of FIG. 1 stores a video signal in the latter half of a field in a trace of a video tape.

5 is a diagram showing a screen image when a video signal is reproduced by the single screen selection reproducing device of FIG.

FIG. 6 is a block diagram showing a conventional two-screen recording device that records two systems of video signals by conventional vertical compression.

FIG. 7 is a diagram for explaining a recording operation of video signals of two systems by the dual screen recording device of FIG.

8 is a diagram showing a format of a video tape on which video signals of two systems are recorded by the dual screen recording device of FIG.

9A and 9B are views for explaining screen images in recording and reproducing of two systems of video signals by the two-screen recording device in FIG.

10 is a diagram showing details of a screen image in a state of inputting and reproducing a video signal of the dual screen recording apparatus of FIG.

FIG. 11 is a block diagram showing a conventional two-screen recording device that records two systems of video signals by conventional horizontal compression.

12 is a block diagram showing a one-screen selection reproducing device for reproducing the video signal stored in the two-screen recording device shown in FIG.

FIG. 13 is a diagram showing a format of a video tape on which video signals of two systems are recorded by the dual screen recording device of FIG. 11.

FIG. 14 is a diagram illustrating a screen image in recording / reproducing two systems of video signals by the two-screen recording device in FIG.

[Explanation of symbols]

 Reference Signs List 11 tuner 12 decoder 13 A / D conversion circuit 14 synchronization signal generation circuit 15 frame memory 16 D / A conversion circuit 17 encoder 21 write clock signal generation circuit 22 read clock signal generation circuit 30 VTR circuit

Claims (3)

[Claims] 1. A decoder for extracting a video signal from a composite video signal and for extracting horizontal and vertical synchronizing signals from the composite video signal, and performing analog / digital conversion on the video signal from the decoder to convert a digital data signal into a digital data signal. The analog / digital conversion circuit to be created and the digital data signal from this analog / digital conversion circuit are stored for one frame, and the stored digital data signal for one field is halved in the first half or second half of the one field period. A frame memory for reading the digital data signals of the odd-numbered horizontal lines and the digital data signals of the even-numbered horizontal lines in one horizontal period by sequentially reading the selected one of the periods during the horizontal line, and from this frame memory Performs digital-analog conversion of the read digital data signal A digital-to-analog conversion circuit that creates a video signal, a decoder that creates a composite video signal from the video signal from this digital-analog conversion circuit and the horizontal and vertical synchronization signals from the encoder, and a composite video signal from this decoder And a recording means for recording the image on a video tape. 2. When the decoder creates a composite video signal, a horizontal period equivalent to a period in which the video signal becomes a signal during a period in which there is no signal in the first half or the second half of one field period. 2. The dual-screen recording device according to claim 1, wherein the decoder is provided with circuit means for inserting a vertical synchronizing signal. 3. When reproducing a composite video signal recorded on a video tape by the two-screen recording device according to claim 1,
What is claimed is: 1. A single-screen selection reproducing device for reproducing a composite video signal for one screen selected from composite video signals for two screens from a composite video signal reproduced from a video tape, the composite video signal reproduced from the video tape. A decoder for taking out a video signal and taking out horizontal and vertical synchronizing signals from the composite video signal, and an analog-to-digital conversion circuit for performing an analog-to-digital conversion on the video signal from this decoder to create a digital data signal, The digital data signal from the analog-digital conversion circuit is stored for one frame, and the first half or the second half of the stored one field digital data signal is stored.
A frame memory for reading out one stored horizontal line in two horizontal periods by reading out selected one of digital data signals for two fields in one field period, and digital data read out from this frame memory. A digital-to-analog conversion circuit for performing digital-to-analog conversion of the signal to create a video signal, and a decoder for creating a composite video signal from the video signal from the digital-to-analog conversion circuit and the horizontal and vertical sync signals from the encoder A single-screen selection / playback device comprising: