JPH04211596A - Video signal recorder - Google Patents

Abstract

PURPOSE:To satisfactorily record and reproduce HDTV signals by distributing the time divided multiplexed signals of brightness signals and chroma signals to two channels and defining the chroma signals of each of the respective channels to one. CONSTITUTION:Line memories 6r, 6b extract the 1st and 2nd chroma signals alternately in one horizontal period each from the video signals consisting of the brightness signals and the 1st and 2nd chroma signals and subject the extracted chroma signal to time base compression. The brightness signals are subjected to time base expansion in line memories 3A, 3B. Adders 10A, 10B time divided multiplex the brightness signals subjected to the time base expansion and the chroma signals. The time divided multiplexed signals are distributed to the two channels in such a manner that the kinds of the chroma signals of the respective channels are made single in a frame memory 11. The distributed signals are sequentially recorded with two times of scanning for one field by two channel heads 17A, 17B having the azimuth angles varying from each other by each of the two channels.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention is applicable to HD such as high-definition.
The present invention relates to a video signal recording device for recording TV signals.

0002

2. Description of the Related Art Video signal recording devices for recording and reproducing HDTV signals, such as high-definition signals, especially for consumer devices, convert chroma signals into line-sequential lines, expand and contract the time axis, and time-division multiplex them with luminance signals. It has been considered to record and reproduce so-called TCI signals by dividing them into a plurality of channels using a multi-channel head (see Japanese Patent Laid-Open Publication No. 194494/1984, etc.).

[0003] However, in the above literature, for example, 2
One field is scanned twice using a channel head (4
The recording pattern of the luminance signal and chroma signal in the case of recording and reproducing in the channel) is shown in FIG. In the figure, Y indicates a luminance signal, CN and CW each indicate a chroma signal, and the suffix indicates the number of the horizontal period to which the signal belongs (corresponding to FIG. 6 in the above-mentioned document).

That is, in this example, for example, FIG.
The TCI signal formed as shown in A of FIG.
The chroma signal CW of the (n+2)th horizontal period is exchanged, and the time axis is expanded by a factor of two to create a first channel based on the signal from the even-numbered horizontal period and a second channel based on the signal from the odd-numbered horizontal period. It is divided into For example, the signals of the 40th and 41st horizontal periods at the beginning of the effective screen are recorded in the first scan (first segment), and the signals of the subsequent 42nd, 43rd, 44th, and 45th horizontal periods are recorded in the second scan ( The signals of the next 46th to 49th horizontal periods are recorded in the first segment, and the signals of the following four horizontal periods are alternately distributed to the first and second segments. recorded.

[0005] As a result, the signal of the effective screen of the first field of the 40th to 557th horizontal period is recorded in the first and second segments. Furthermore, the signal of the effective screen in the second field of the 603rd to 1120th horizontal periods is obtained in substantially the same way as above by reversing the correspondence between the odd and even horizontal periods and the first and second channels. For example, 0 is distributed between the third and fourth segments.
．． By performing recording with an offset of 5 horizontal periods, recording is performed using 2 channels and 4 segments as shown in the above-mentioned recording pattern diagram.

[0006] In this way, so-called high-vision signals can be recorded. When reproducing a signal recorded in this manner, normal reproduction can be performed satisfactorily by reversing the above-described recording process using, for example, one field's worth of memory.

However, when attempting to perform variable speed playback of the above-mentioned recording pattern using the scanning trajectory of the head as shown by the broken line in the diagram, for example, due to the azimuth angle of the head, diagonal lines are added from the head of each channel. Only part of the signal will be reproduced. Therefore, this reproduced signal becomes as shown in A and B in FIG. 22, for example.

[0008] When considering this reproduced signal, a disturbance occurs in the continuity of the chroma signal at the time of a track jump (TJ) from the first segment to the second segment or from the third segment to the fourth segment. Therefore, even if this reproduction signal is processed, a correct chroma signal cannot be restored, and normal reproduction cannot be performed.

On the other hand, it is conceivable to align the recording positions of the chroma signals by alternating the offset between segments by 1.5 horizontal periods and 0.5 horizontal periods, but increasing the offset is not possible due to the characteristics of the recording medium. There may be limitations in terms of usage efficiency.

[0010] Furthermore, even if the recording positions of the chroma signals are aligned, in the above example, the chroma signal at the start end is changed for each segment, and in variable speed playback, it is unclear which segment the start end of the scanning locus matches. Therefore, it has become extremely difficult to distinguish the chroma signal and perform restoration processing.

[0011]

SUMMARY OF THE INVENTION This application has been made in view of the above points, and it is an object of the present invention to provide a video signal recording device that has a simple configuration and can perform variable speed playback satisfactorily.

0012

[Means for Solving the Problems] The present invention extracts the first and second chroma signals alternately for one horizontal period from a video signal consisting of a luminance signal and first and second chroma signals, The extracted chroma signal is time-axis compressed (line memories 6r, 6b), the luminance signal is time-axis expanded (line memories 3A, 3B), and the time-axis expanded luminance signal and the time-axis compressed chroma signals are time-division multiplexed (adders 10A, 10B), and the time-division multiplexed signals are distributed to two channels so that each channel has a single type of chroma signal (frame memory 1
1) Using a rotary head device, the distributed signals are sequentially recorded for two channels by two-channel heads 17A and 17B having mutually different azimuth angles by scanning one field twice (spindle motor 20). This is a video signal recording device that sequentially records images on inclined tracks.

[0013]

[Operation] According to this, a time division multiplexed signal of a luminance signal and a chroma signal is distributed to two channels, and
Since the chroma signal for each channel is determined to be one, the continuity of the chroma signal is not disturbed even if a track jump occurs during variable speed playback, etc., and good HDTV signal recording and playback can be achieved with a simple configuration. It can be carried out.

[0014]

[Embodiment] In FIG. 1, 1 is an input terminal for a luminance signal Y demodulated from an HDTV signal, and the signal from this terminal 1 is supplied to line memories 3A and 3B via an A/D converter 2. . 4r and 4b are chroma signals demodulated from HDTV signals (color difference signals R-Y:PR, B-Y:PB)
Signals from these terminals 4r and 4b are supplied to line memories 6r and 6b via A/D converters 5r and 5b, respectively.

Furthermore, 7 is an input terminal for a synchronization signal (Sync) separated from the HDTV signal, and the signal from this terminal 7 is supplied to a control circuit 8. In this control circuit 8, various control signals and clock signals, which will be described later, are generated in accordance with a reference clock signal supplied from a predetermined reference oscillator 9 and the above-mentioned synchronization signal.

As a result, the signal taken out from the memory 3A and the signal taken out from the memory 6r are combined by the adder 10A and supplied to the frame memory 11. Further, the signal taken out from the memory 3B and the signal taken out from the memory 6b are combined by an adder 10B and supplied to the frame memory 11.

The signal taken out from this memory 11 is supplied to emphasis and FM modulation circuits 14A, 14B via D/A converters 13A, 13B, and the emphasis and FM modulated signal is sent to recording amplifiers 15A, 1.
5B, is supplied to the heads 17A, 17B on the head drum via the recording/playback switch 16A, 16B,
It is recorded on tape 18. Further, a reference signal from the control circuit 8 is supplied to a servo circuit 19, and a spindle motor 20 of the head drum is driven by the signal from the servo circuit 19. Furthermore, a signal from the servo circuit 19 is supplied to a capstan motor 21, and this motor 21 drives a capstan 22 for transporting the tape 18.

Furthermore, the signals recorded on the tape 18 are reproduced by the heads 17A and 17B, and this signal is transmitted to the switch 16.
The signal is supplied to the servo circuit 19 via A and 16B, and is further supplied to de-emphasis and FM demodulation circuits 24A and 24B via reproduction amplifiers 23A and 23B. The de-emphasized and FM demodulated signals are sent to TBC circuits 26A and 26B via A/D converters 25A and 25B.
At the same time, signals from circuits 24A and 24B are supplied to clock generation circuits 27A and 27B, and the generated clock signals are supplied to A/D converters 25A and 25B and TB.
It is supplied to C circuits 26A and 26B.

Signals from the TBC circuits 26A and 26B are supplied to a frame memory 28. The signal taken out from this frame memory 28 is transmitted to the line memories 30A and 30.
The signals taken out from the memories 30A and 30B are combined by an adder 31 and output to an output terminal 33 for the luminance signal Y via a D/A converter 32.

Furthermore, the signals taken out from the frame memory 28 are supplied to line memories 34r and 34b, and the signals taken out from these memories 34r and 34b are supplied to an interpolation circuit 35.
r, 35b. And interpolation circuits 35r, 35
The signal from b is sent to output terminals 37r and 37b of chroma signals (PR, PB) via D/A converters 36r and 36b.
is output to. In addition, a synchronization signal (Syn
c) is output to the output terminal 38.

[0021] In this apparatus, when recording a high-definition signal, for example, first, A, B, and C in FIG.
The luminance signal Y and chroma signal (RY:PR
, BY:PB) are sampled by clock signals of frequencies fA and fB from the control circuit 8, respectively, and A
/D converted and written to memories 3A, 3B, 6r, and 6b.

Here, the frequency fA is, for example, an integer ratio as simple as possible of 74.25 MHz, which is the basic clock of high-definition, and the horizontal frequency of high-definition (fH1
= 33.75kHz), for example,

[Math 1] It is said that Also, fB is selected to be 1/4 of fA.

That is, by providing the reference oscillator 9 with a frequency of 44.55 MHz and supplying the clock signal from the oscillator 9 to the control circuit 8, the clock signal with the frequency fA is directly outputted. At the same time, the clock signal having the frequency fB can be outputted by dividing the supplied signal into 1/4.

As a result, the luminance signal Y and the chroma signal (
PR, PB) are respectively shown in the above figure,
One horizontal scan line is sampled at 1320 and 330 samples and written to memories 3A, 3B, 6r, 6b. Note that writing is performed using each horizontal synchronizing signal as a start signal, and data is written into the memories 3A and 3B alternately every horizontal period.

Furthermore, this written signal has a frequency fC
The time axis is expanded/contracted by being read out using the clock signal, and these signals are combined by adders 10A and 10B.
For example, so-called TCI signals as shown in D and E in the above diagram are formed.

Here, the clock frequency f of this TCI signal
C, the number L of horizontal scanning lines per frame, and the number S of samples per horizontal scanning line are selected as follows. In other words, when forming a TCI signal from the above-mentioned high-definition signal, since the above-mentioned device records two channels simultaneously,

[Formula 2] must hold, and the values of L and S are selected according to the characteristics of the video signal recording device, for example, L = 1332.
, S=1500 recording format,

[
Equation 3] becomes.

Therefore, the clock signal of this frequency fC is supplied to the memories 3A, 3B, 6r, 6b, and the line memory 6 is supplied, for example, from 50 clocks after the horizontal synchronizing signal.
280 samples of the effective screen period of the chroma signal (PR, PB) written to r, 6b are read out, and then synchronized with 1120 samples of the effective screen period of the luminance signal Y written to the line memories 3A, 3B. 100 samples of the period are read.

As a result, two-channel (A, B) TCI signals as shown in the above diagram are formed. Note that reading is performed using every other horizontal synchronizing signal as a start signal. Also, since the frequency fC is greater than 1/2fA,
The length of one horizontal period of an actual TCI signal is somewhat shorter than twice that of a high-definition signal. TCI thus formed
Signals are sequentially written into frame memory 11.

The signal written in this frame memory 11 is then read out using a clock signal of frequency fC. Here, from the frame memory 11, signals of every other horizontal period written in the memory 11 during the first scan (first segment) of the tape 18 by the heads 17A and 17B are sequentially transmitted at a frequency fC. Reading is performed such that signals of every other horizontal period are read out in sequence during the second scan (second segment). This read signal is D/A converted, subjected to emphasis and FM modulation, and recorded on tape 18 by heads 17A and 17B. At this time, a reference signal with a frequency fD = 60 Hz is supplied from the control circuit 8 to the servo circuit 19, and the heads 17A and 17B are rotated at a cycle of the frequency fD. will be transferred. As a result, recording is performed on the tape 18 in a recording pattern in which one frame has two channels and four segments as shown in FIG. 3, for example.

That is, in this device, the TCI signal has two channels, each including a chroma signal PB of an even-numbered horizontal period, as shown in FIGS. 4A and 4B, and
and a second channel containing the chroma signal PR of odd-numbered horizontal periods. Note that this T
The CI signal is time-division multiplexed with luminance signals and chroma signals belonging to the same horizontal period.

Note that the formation of the TCI signal is not limited to the method described above, and the formation of the TCI signal is not limited to the method described above.
, PR (red and blue difference signals), the chroma signals PB and PR of the color video signal are line-sequentialized and time-base compressed, and then the luminance signal (its horizontal blanking period) is
The multiplexed signal [color-line sequential TCI (time compressed integration) signal] may be multiplexed into a color line and the time axis expanded. Alternatively, the luminance signal may be time-axis expanded, the chroma signals PB and PR may be line-sequentialized and then time-axis compressed, and the time-axis expanded luminance signal and the time-axis compressed chroma signal may be time-division multiplexed. good.

[0032] For example, the first 42, 43 of the effective screen
The signal of the th horizontal period is recorded in the first scan (first segment), the signal of the following 44th and 45th horizontal period is recorded in the second scan (second segment), and the following two horizontal periods are recorded. signals are alternately distributed to the first and second segments and recorded.

As a result, the signals of the effective screen of the first field of the 42nd to 557th horizontal periods are recorded in the first and second segments. Furthermore, the signals of the effective screen of the second field of the 604th to 1119th horizontal periods are recorded in the third and fourth segments in substantially the same manner as described above. In this way, the signal of one frame is distributed into the first to fourth segments, and by recording with an offset of, for example, 0.5 horizontal period between each segment, two segments as shown in the above recording pattern diagram are obtained. Recording is performed using channel 4 segments.

In the above recording pattern diagram, a digital audio signal recording range is provided in the front side in the head scanning direction from the video signal recording range, as shown in the diagram. Here, each track has a wrapping angle of 180 degrees.
This corresponds to 66.5 horizontal periods, of which 23 horizontal periods (2
4.86 degrees) is the recording range of audio signals. Approximately 1.2 degrees at the front end is used as a margin, the next 2.0 degrees is used as a preamble portion, and the digital audio signals of the third and fourth channels are recorded in the following 8.0 degrees. Further next 1
．． 2 degrees is a postamble part, and the following 1.2 degrees is a guard part between audio signals. Further, the next 2.0 degrees is a preamble section, the next 8.0 degrees are recorded with the digital audio signals of the first and second channels, and the next 1.26 degrees is a postamble section.

Further, following this audio signal recording range, a guard section between the audio signal and the video signal for two horizontal periods is provided, and in the subsequent 11 or 11.5 horizontal periods, vertical synchronizing signals V1, V2, Information signals such as AGC reference level and clamp level are provided, followed by 13
The TCI signal of 0 horizontal period is recorded as shown according to the distribution described above. Note that a margin of 0.5 or 1 horizontal period is provided after the recording range of this TCI signal.

In the above-mentioned apparatus, during normal reproduction, the head 17 is sent along with the reference signal of the above-mentioned frequency fD.
A part of the reproduction signal from A and 17B is supplied to the servo circuit 19, and the head 1 is supplied so as to match the recording pattern described above.
Servo of 7A, 17B and tape 18 is performed. Then, processing that substantially reverses the above-described recording is performed on this reproduced signal, including the TBC and interpolation operations necessary for reproduction, and the luminance signal Y and chroma signals PR and PB are reproduced. In this way, recording and normal playback of high-definition signals can be performed.

On the other hand, when variable speed reproduction is performed, the scanning locus of the head is, for example, as shown in FIG. 3 of the above-mentioned recording pattern. Then, only the signals of the shaded portions are reproduced from the head of each channel, and reproduced signals such as those shown in A and B of FIG. 4, for example, are formed. Note that the reproduced signal is shown only for the range of the video signal.

Therefore, when examining this reproduced signal, it is found that the chroma signal is There is no disturbance in continuity,
It is possible to always perform good chroma signal restoration.

Furthermore, the horizontal period distributed to each channel is restored as follows. That is, Figure 6
shows the relationship between the recording pattern and the scanning locus in the case of, for example, 5x speed playback, where the head for the first segment scans each segment in the order of (1 → 2 → 3 → 4 → 1),
The head for the corresponding second segment separates each segment from (
Scan in the order of 2 → 3 → 4 → 1 → 2).

[0040] Considering the relationship between the signal reproduced and the restoration for each combination, the head for the first segment reproduces the first segment, and the head for the second segment reproduces the second segment. Figure 7 in case
As shown in A, the original playback is performed and the restoration is performed as is.

On the other hand, if the head for the first segment is reproducing the second segment, and the head for the second segment is reproducing the third segment, the ● and X marks on the left side of FIG. The signal indicated by is played back, but the signal marked with an x mark is actually the one on the right due to the offset between the segments.
The marked signal is played. Then, each of these signals is regarded as a signal marked with an ○, and restoration is performed.
Here, in the signals marked with ●, the signals on the right side are shifted only by one horizontal scanning line, and the relative positional relationship is approximately equal to the original signal.

Furthermore, when the head for the first segment is reproducing the third segment and the head for the second segment is reproducing the fourth segment, the signals shown by the × and the ● mark on the right side in C of the same figure. is reproduced, but here, due to the offset between the segments, the signal marked with an x mark is actually reproduced as the signal marked with a circle mark on the left. Each of these signals is regarded as a signal marked with a circle, and restoration is performed, but here, the relative positional relationship of the signal marked with a circle is the same as the original signal.

In addition, if the head for the first segment is reproducing the fourth segment and the head for the second segment is reproducing the first segment, the ● and × on the left side of FIG.
The signal indicated by the mark is reproduced, but due to the offset between the segments, the signal indicated by the × mark is actually reproduced by the signal indicated by the circle mark on the right side. Then, each of these signals is regarded as a signal marked with a circle, and restoration is performed.
In the marked signal, the signal on the right side is only shifted down by one horizontal scanning line, and the relative positional relationship is approximately equal to the original signal. Furthermore, the reproduction of the second field is similar to that of the first field in the above explanation.
, the second, third, and fourth can be interchanged to perform substantially the same procedure.

Therefore, according to this device, the horizontal period distributed to each channel can be restored satisfactorily even during variable speed reproduction. In the above description, when the speed ratio is set to an even number, the head for the second segment reproduces the same segment as the head for the first segment, so there is a possibility that restoration cannot be performed satisfactorily. Furthermore, if the starting end of the scanning trajectory of the head for the first segment is set to the second segment, there is a possibility that the positional relationship between the segments may be reversed. In other words, in this device, as long as the speed ratio is an odd number and the head for the first segment maintains the scanning trajectory that reproduces from the start of the first segment, regardless of whether the rotation is normal or reverse, Any variable speed playback can be performed in the same manner as described above.

[0045] According to the above-mentioned device, the time-division multiplexed signal of the luminance signal and the chroma signal is sequentially distributed to two channels, so that the chroma signal for each channel, in other words, for each azimuth angle of the head is Since it is defined as one, the continuity of the chroma signal is not disturbed even if a track jump occurs during variable speed playback, etc., and it is possible to record and play back HDTV signals in good quality with a simple configuration. .

Moreover, in the above-mentioned apparatus, consecutive 4
The luminance signals of the horizontal scanning period constitute one field.
Since the information is recorded in two tracks, even if a track jump occurs, luminance signals for almost continuous horizontal scanning periods can be output. Furthermore, since time-division multiplexing is performed on luminance signals and chroma signals belonging to the same horizontal scanning period, signal processing is relatively simple, and memory and hardware can be made small.

In the above-described apparatus, the effective lines of one field are shown as from the 42nd line to the 1119th line, but the range of the effective lines is not limited to this. As a second example, FIG. 8 shows a recording pattern when the effective lines are set from the 40th line to the 1120th line.

FIG. 10 shows recording signals S1 (T1, T2) for each 1/2 field supplied to the four rotating magnetic heads when forming the track pattern of the third embodiment.
, S2 (T3, T4), S3 (T5, T6), S4 (T
7, T8), the luminance signal Y and color signals Pr, Pb
They are indicated by line numbers. However, the effective lines are from the 41st line to the 1120th line.

In this case, each line signal of the luminance signal Y is
Segment inclined track recording signals T1, T3, T2,
T4, T1, T3, T2, T4, ... and T5, T
7, T6, T8, T5, T7, T6, T8, . . . are distributed in this order. Moreover, the color signals Pb and Pr are T in the recording signals T1 to T8 of each segment inclined track.
Recording signals with odd numbers of subscripts are unified as color signals Pb, and recording signals with even numbers are unified with color signals Pr.

FIG. 9 shows a recording pattern when the recording signal shown in FIG. 10 is supplied to the above-mentioned rotating magnetic head device and recorded on a magnetic tape.
CH and BCH indicate two segment inclined tracks on which signals are simultaneously recorded, the numbers indicate the line numbers of the luminance signal, and the line numbers of the chrominance signal are omitted. Note that recording signals T1, T3, T5, and T7 for 1/2 field of recording signals in FIG. 10 are recorded in sequential ACH from bottom to top in FIG. 9, and recording signals T2, T4, T6,
T8 is similarly recorded in sequential BCHs from bottom to top. Note that the recording signal S1 of each pair of segment inclined tracks is
The positions of ~S4 on the magnetic tape are sequentially shifted by 0.5H (H is the length on the magnetic tape corresponding to the horizontal period).

As can be easily seen from the recording pattern of the embodiment shown in FIG. 9, in this color video signal recording apparatus, each channel, in other words, the color signal of each azimuth angle recording signal is one type of color signal Pr or Pb. It is distinctive in that it is unified. Another feature is that each segment is recorded so that the BCH includes a luminance signal two lines after the ACH that is recorded at the same time.

Therefore, even if the rotating magnetic head jumps the segment inclined track on the magnetic tape during variable speed playback, the color signal can be accurately restored, and especially the N
When performing +0.5x speed playback, an almost natural image can be output by rearranging the signals in the same manner as during standard playback.

Next, variable speed reproduction,
For example, during double speed and triple speed playback, the scanning locus of the rotating magnetic head with respect to the segmented inclined track on the magnetic tape and the playback signal based on the discrepancy between the azimuth angle of the gap of the rotating magnetic head and the recording azimuth angle of the segmented inclined track. FIGS. 12 and 13 show the portion where the noise becomes noise (indicated by diagonal lines). Furthermore, Figure 12 and Figure 1
3, + and - indicate the difference in the recording azimuth angle of the segment inclined track.

According to FIGS. 12 and 13, if the multiple speed number is an integer, the position of the noise bar will overlap every 1/2 field on the screen during playback, regardless of whether it is an even number or an odd number. It means.

Therefore, by using the above-described rotating magnetic head device used in the conventional example and the embodiment of the present invention, the scanning locus of the rotating magnetic head with respect to the segment inclined track on the magnetic tape and the rotating magnetic FIG. 11 shows a portion (indicated by diagonal lines) in which the reproduced signal becomes noise due to the mismatch between the azimuth angle of the head gap and the recording azimuth angle of the segment inclined track.

According to FIG. 11, the speed number is N+0.5.
(N is 0 or a positive or negative integer) means that the position of the noise bar on the playback screen differs every 1/2 field and does not overlap. This is true for both the color video signal recording system of the embodiment of the present invention and the conventional example.

Next, with reference to FIG. 14, an example of the configuration of a reproduction system in consideration of variable speed reproduction of the video signal recording apparatus will be described. 4
Reference numerals 1 and 42 indicate a pair of ACH and BCH rotary magnetic heads that simultaneously reproduce signals for two tracks, and each reproduced signal is transmitted to an FM demodulator (including a de-emphasis circuit) 42 and 52 and a dropout detector. 47,57. The outputs of the demodulators 42, 52 are supplied to A/D converters 44, 54 through low-pass filters 43, 53, where they are converted into digital signals, and then subjected to time axis error correction,
The signals are supplied and written to frame memories 46 and 56 for dropout correction, deshuffling, and time axis compression/expansion. 45 and 55 are write clock signal generation circuits equipped with a PLL, and FM demodulation circuits 42 and 52.
A write clock signal of three times or four times the color subcarrier frequency synchronized with the horizontal synchronization signal and the color burst signal (each having jitter) separated from the output of the , and supply clock signals to the A/D converters 44 and 54. Also, 47,5
7 is a dropout detection circuit, which connects each rotary magnetic head 4
1 and 51, and when the amplitude of its envelope is below a predetermined level, it outputs a dropout detection signal and supplies it to frame memories 46 and 56.

69 is a read clock signal generation circuit;
A jitter-free write clock signal is generated at the same frequency as the write clock signal, and the frame memory 4
6 and 56, respectively. From the frame memories 46 and 56, time axis error corrected, deshuffled, and time axis expanded/compressed TCI signals are obtained, and a two-channel luminance signal synthesis circuit 58 and a two-channel chroma signal synthesis circuit/interpolation circuit are obtained. The signals are supplied to a filter 64 and combined. The output of the synthesis circuit 58 is the luminance signal vertical filter 5
After the outputs of the synthesis circuit 58 and filter 59 are switched by a changeover switch 60, the signal is supplied to a D/A converter 61, where it is converted into an analog luminance signal Y, and output from an output terminal 62. This changeover switch 60
is switched to the synthesis circuit 58 side during normal playback and to the vertical filter 59 side during shuttle playback by a normal/shuttle switching control signal from the input terminal 63. Two types of chroma signals from the synthesis circuit/interpolation filter 64 are supplied to D/A converters 65 and 66, respectively, and converted into analog chroma signals Pb and Pr, respectively, and output terminals 67,
68.

FIG. 15 shows a specific example of the configuration of the luminance signal vertical filter 59 in the reproduction system of FIG. 14. A luminance signal from an input terminal 71 is supplied to a cascade circuit of delay devices 72 and 73 having a delay time of 1H for one horizontal period. Input terminal 7
1 and 1H from delayers 72 and 73, respectively.
, 2H delayed luminance signals have their levels reduced to 1/4, respectively.
, 1/2 and 1/4 coefficient multipliers 74, 75, 76
The signals are supplied to the adder 77 through the adder 77 and added, and the added output is outputted from the output terminal 78. According to the vertical filter 59, it is possible to limit the band of the reproduced signal and obtain a reproduced signal that is close to natural.

Next, standard reproduction and 2
．． 5x variable speed playback will be explained with reference to FIG. 16. A in FIG. 16 shows the reproduced output signal of the A/D converter 44, and the number indicates at which scan the signal was obtained. That is, it is shown that the first field is composed of signals obtained in the first scan and the second scan. Figure 1
6B is a memory timing chart for standard playback. Here, ■ and ■ are the first positions of the frame memory 16, respectively.
This represents a write reset/enable signal supplied to the field memory section and the second field memory section. The signal of the scan is written into the second field memory section. In the case of standard playback, the signals of the 1st scan, 2nd scan, 3rd scan, and 4th scan correspond to the signals of the 1st segment, 2nd segment, 3rd segment, and 4th segment, respectively, so the 1st segment The first field is restored using the second segment signal, and the second field is restored using the third and fourth segment signals.
The field will be restored, and the original one frame signal will be output from the frame memory. Note that 1/2 in the figure indicates that restoration was performed using the first scan signal and the second scan signal. FIG. 16C is a memory timing chart for 2.5x playback. In this case, write reset is performed twice in one field,
The period of the noise bar is controlled so that no writing is performed, as indicated by diagonal lines in ■ and ■. Therefore, in the first field memory section, the signal of the first scan is stored as is during the noise bar period of the second scan, and the signal of the second scan is written in the other period, and the signal of the second scan is stored as is. In the memory section, the signal of the third scan is stored as is during the noise bar period of the fourth scan, and the signal of the fourth scan is written in the other periods. Then, the same line is read out twice and restored, and an output signal from the frame memory is obtained in which the noise bar portion is interpolated with the odd-numbered scanning signal in both the first and second fields.

FIGS. 17A and 17B are diagrams showing the screen configuration of the playback screen based on the head trajectory at 2.5 times the speed of FIG. 11. The numbers indicate field numbers of the original video signal. Here, the numbers enclosed in parentheses represent the fields that have been interpolated. For example, if N=1, the first field during variable speed playback is the first field of the original screen, the second field
field and a third field, and the second field is composed of the third field, fourth field, and fifth field of the original screen.

Furthermore, A, B, and C in FIG. 18 are diagrams showing the restoration process of the reproduced signal in the third embodiment at 2.5 times the speed, and the reproduced signals of ACH, BCH, and both channels are shown. It shows the combined output of the combined signal of the reproduced signal. However, this diagram conceptually shows the restoration process, and Figure 1
It does not directly correspond to the playback system in 4. Here, the numbers indicate line numbers of luminance signals, and line numbers for color differences are omitted. For example, if a signal including a luminance signal of 42 horizontal scanning periods is reproduced in the first scan of ACH as shown in A in FIG. The signal is taken as a reproduction signal. In the case of this embodiment, regarding the luminance signal, BC
Recording is performed so that H includes the signal two lines after ACH, and the chroma signal is recorded so that the type is unified for each channel, so regarding the luminance signal, 44 horizontal lines are recorded in the first scan of BCH. A signal containing the luminance signal of the scanning period is reproduced, and a signal containing the luminance signal of 44 horizontal scanning periods is made into a reproduced signal by interpolation in the same manner as in the case of ACH in the second scanning of BCH. Regarding the chroma signal, ACH reproduces Pb and BCH reproduces only Pr. In this way, the reproduced signals shown in A and B of FIG. 18 are obtained. Next, if you perform the same restoration as standard playback, the luminance signal will alternately repeat the signals of the same channel twice like ACH, ACH, BCH, BCH, and the chroma signal will repeat like ACH, BCH, ACH, BCH. The signals of each channel are taken out alternately and combined, and as shown in FIG. 18C, an output is obtained in which a luminance signal in which the same signal is repeated twice and a chroma signal in which Pb and Pr are alternated are combined. When viewing this on a monitor, the resolution is half that of a standard screen, but the hue is normal and the screen looks natural.

A, B, C in FIG. 19 are A, B, C in FIG.
This is a diagram of a reproduction signal of a conventional example for comparison with the conventional reproduction signal.If the ACH, BCH signals are restored in the same manner as the standard reproduction in the same manner as in the above case, the luminance signals will be ACH, BCH,
Each channel signal is alternately extracted like ACH and BCH, and for the chroma signal, signals of the same channel are alternately extracted twice and combined like ACH, ACH, BCH, BCH, as shown in FIG. 19C. , the output is a composite of a luminance signal in which the same signal appears at intervals of one line and a chroma signal in which the same type continues. When viewed on a monitor, the screen appears mosaic-like and has an abnormal hue.

[0064]

According to the present invention, a time-division multiplexed signal of a luminance signal and a chroma signal is distributed to two channels, and one chroma signal is determined for each channel. Even if a track jump occurs, the continuity of the chroma signal is not disturbed, and it has become possible to record and reproduce good HDTV signals with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an example of a video signal recording device according to the present invention.

FIG. 2 is a waveform diagram for explaining signals.

FIG. 3 is a diagram for explaining a recording pattern.

FIG. 4 is an explanatory diagram of a recording signal.

FIG. 5 is an explanatory diagram of a reproduced signal.

FIG. 6 is a diagram showing a scanning locus during variable speed scanning.

FIG. 7 is an explanatory diagram of restoration processing during variable speed playback.

FIG. 8 is a diagram showing another example of a recording pattern.

FIG. 9 is a diagram showing another example of a recording pattern.

FIG. 10 is an explanatory diagram of a recording signal.

FIG. 11 is a diagram showing a head trajectory at 2.5 times speed.

FIG. 12 is a diagram showing a head trajectory at double speed.

FIG. 13 is a diagram showing the head trajectory at triple speed.

FIG. 14 is a configuration diagram during playback.

FIG. 15 is a configuration diagram of a vertical filter for luminance signals.

FIG. 16 is a timing chart diagram of a frame memory.

FIG. 17 is a diagram showing monitor output during variable speed playback (2.5x speed).

FIG. 18 is a diagram showing a reproduced signal in a third embodiment.

FIG. 19 is a diagram showing a reproduction signal of a conventional example.

FIG. 20 is a diagram for explaining a conventional recording pattern.

FIG. 21 is an explanatory diagram of a recording signal.

FIG. 22 is an explanatory diagram of a reproduced signal.

[Explanation of symbols]

1, 4r, 4b, 7 Input terminal 2, 5r, 5b, 25A, 25B A/D converter 3A
, 3B, 6r, 6b, 30A, 30B, 34r, 34b
Line memory 8 Control circuit 9 Reference oscillator 10A, 10B, 31 Adder 11, 28 Frame memory 13A, 13B, 32, 36r, 36b D/A converter 14A, 14B Emphasis and FM modulation circuit 1
5A, 15B, 23A, 23B Amplifier 16A, 16
B Switches 17A, 17B Head 18 Tape 19 Servo circuits 20, 21 Motor 22 Capstans 24A, 24B De-emphasis and FM demodulation circuit 2
6A, 26B TBC circuit 27A, 27B Clock generation circuit 33, 37r, 37b, 38 Output terminal 35r, 35
b Interpolation circuit

Claims (3)

[Claims] [Claim 1] Video signals for one field are divided into two different
In a video signal recording device that divides into two channels corresponding to two azimuth angles A and B, and records two tracks simultaneously on a recording tape by two scans, one horizontal period obtained by expanding the time axis with the head of the above azimuth angle A is used. A first time-division multiplexed signal is recorded by time-division multiplexing a luminance signal and a first type of chroma signal for one time-axis compressed horizontal scanning period. A second time-division multiplexed signal obtained by time-division multiplexing a luminance signal for one horizontal scanning period and a second type of chroma signal for one horizontal scanning period compressed in the time axis is recorded. Device. 2. The video signal recording apparatus according to claim 1, wherein the time division multiplexing is performed so as to include the luminance signal and the chroma signal belonging to the same horizontal scanning period. 3. The head having an azimuth angle B receives the second time division multiplexed signal including a luminance signal two horizontal scanning periods later than the horizontal scanning period of the luminance signal included in the first time division multiplexed signal. The video signal recording device according to claim 1, wherein the video signal recording device records video signals.