JPH0326079A - Video signal recording device - Google Patents

Abstract

PURPOSE:To easily attain excellent speed change reproduction by recording a video signal while the phase or time width of a horizontal synchronizing signal of video signals of adjacent segments is varied. CONSTITUTION:A horizontal synchronizing signal variable circuit 10 of a video signal recorder in which rotary heads 11A1, 11A2, 11B1, 11B2 are used for segment recording to record a broad band video signal varies a phase or a time width of horizontal synchronizing signals 5A, 5B of video signals recorded on adjacent segments. Thus, the difference between 1st and 2nd segments is detected by detecting the horizontal synchronizing signal with a different phase or time width at reproduction, and a normal pattern is displayed without applying shuffling even with speed change reproduction or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal recording device for recording wideband signals such as high-definition television video signals.

[Summary of the invention]

The present invention relates to a video signal recording device suitable for use in high-definition television and the like.The present invention relates to a video signal recording device suitable for use in high-definition television, etc., and is capable of recording video signals of adjacent segments recorded by a segment recording method by changing the phase or time width of a horizontal synchronization signal. This makes it possible to easily perform good variable speed reproduction by detecting segment differences based on differences in phase or time width recorded in each horizontal synchronizing signal during reproduction.

[Conventional technology]

MtlSE (Multiple Sub-Ny), which broadcasts high definition television signals by satellite, has recently been proposed.
quist-SamPIing Encoding) etc., the video signal is converted to 8. Although it is compressed to 1MI{z, if you want to record l fields of such MIISE signals or even wideband high-definition television signals on one track like a conventional VTR, the head drum diameter will be Segment recording or multi-channel recording has been proposed since it is several times as large as the current level and is not practical. This segment recording method will be explained with reference to FIG.

That is, FIG. 1l is a schematic diagram of the rotary head device,
This is the same as the conventional rotating head (l^HIB> is 180
They are spaced at angular intervals and the tape (2) is wrapped around the guide drum over an angular range of 180 degrees. The number of rotations of the rotary head is increased to twice that of the conventional one, that is, the number of rotations of the rotary head is increased to twice the number of rotations per one frame.

When the video signal is recorded using this rotary head device and the drum phase servo is applied so that the vertical synchronization signal of the video signal is recorded at the part where it starts to come into contact with the tape (2), the video signal is Rotating head (IA) every 2 fields
and (IB), and a track pattern T is formed on the tape (2) by a rotary head (IA) as shown in FIG.
A is formed into a track pattern T by a rotating head (IB).
B is sequentially formatted and a video signal is recorded.

A pair of track pattern TA and track pattern TB is called one segment.

Therefore, video signals for 1/2 field are recorded in each of the track patterns TA and TB,
One field's worth of signals will be recorded with these two track patterns, and compared to the conventional case where one field's worth of signals was recorded on one track pattern, the recording wavelength will be reduced by one field at a time. If you look at the track pattern, it will be the same as growing twice as long. Therefore, the baseband band that can be recorded as each track pattern becomes wider, making it possible to record a wideband signal.

However, when recording in this way, the track pattern T
A will be the information for the upper half of the screen, and track pattern TB will record the information for the lower half of the screen.
During playback, the signals from these track patterns TA and TB are switched every 1/2 field and taken out from the two rotating heads, so the playback screen is the upper half of the screen from the track pattern TA, as shown in Figure 13. (3^) and the screen <3B> is the lower half of the track pattern TB.

With this configuration, when performing variable speed playback on a VTR with guard band recording, the upper and lower screens (3
There was a problem that A>(3B>) would be mixed.Furthermore, multi-channel recording systems use multiple heads to perform simultaneous recording, but generally a rotating drum records multiple track patterns for one field. It is recorded over a period of time.

The applicant previously developed the multi-channel recording method described above in Japanese Unexamined Patent Publication No. 6
1-196407. FIG. 14 shows an example of a rotary drum device using this multi-channel recording method. In this example, there are two pairs of rotary heads (IIA.) (IIA2) (IIB.) (I
IB2) is used. A pair of rotating heads <IIA. ) (
11B. ) are arranged at angular intervals of 180 degrees and have equal azimuth angles. Further, a pair of rotating heads (11A2) (IIB.) are also arranged at an angular interval of 180 degrees and have the same azimuth angle. And in this example, head (IIA.) (11B,) and head (
IIA2) (1182) is made to have a different azimuth angle from each other. However, when recording so as to form a guard band between adjacent tracks, the azimuth angles do not need to be different.

Further, in this case, the heads (11^1> and (11^2) and the heads (11B,) and (1182) are arranged close to each other and at positions shifted by one rotation angle in the rotation direction.

The rotary head arranged in this manner is rotated at a rotational speed such that one rotation is made for one frame of a video signal, similar to a conventional home VTR. Then, tape (2) is attached to the 14th rgJ.
As shown in the figure, the tape is wound obliquely over a 180° angle range on the guide drum (4) and run at a constant speed in the direction of the arrow in the figure, and the tape is rotated almost simultaneously at 1/2 rotation by two rotating heads with different azimuth angles. Two tracks are formed during the contact period, and this is sequentially repeated every 1/2 rotation to perform recording.

[Problems to be Solved by the Invention] In the case of the conventional segment recording method described above having a guard band or the segment recording method and multi-channel recording, the track pattern TA. It is necessary to determine which track pattern of the TB is being scanned. For example, the head (IIA.
) (IIA2> and (IIB,><1182) have a 1-base 2-chip structure, rotate the drum (4) at 2V, twice the rotation speed of 1 frame, and generate a video signal as shown in Fig. 15. Time Compressed I
Consider the case where the signal is recorded as a signal (integration).

This TCI signal is obtained by time-compressing the luminance signal to 3/4 and the chrominance signal to 1/4, time-division multiplexing in one scanning line period, and the chrominance signal is transmitted line-sequentially. That is, in FIG. 15, (5) is the horizontal synchronizing signal, (6) is the burst, and (7) is the R-Y. B-
A color signal such as Y, and (8) a luminance signal are shown.

When such TCI signals are recorded in segments, a track pattern as shown in FIG. 16 is obtained on the tape (2). The figure shows a TCI signal of 1100 H per frame, and the track pattern T A + is the head (IIA,)
The track pattern TA2 shows an even line track pattern recorded by the head (11^2>).

Similarly, the track pattern TA. , TA2 are recorded. From the track patterns TA, TA'2 at this time, a certain first segment and the track pattern TB. , the second one from TB2
The segments project completely different parts on the playback screen shown in FIG.
A 1 and track pattern TA2 are different, and if we consider the first segment based on track patterns TA, TA2 and the second segment consisting of track pattern T B l + T B2 , the azimuth will be the same. For this purpose, track patterns T A + , T
At the beginning of Az, the same segment synchronization signal S+. S+
The same segment synchronization signals S2, S2 were added to the beginning of the track patterns TB, TB2.

However, when variable-speed playback is performed across these track patterns, each horizontal line is randomly arranged up and down on the screen, so there is a problem that the playback screen will not be a normal screen if only the segment synchronization signal mentioned above is used. was there.

The present invention was developed in view of the above-mentioned drawbacks, and its object is to provide a video signal recording device that can perform good variable speed reproduction with a simple structure.

[Means to solve the problem]

Examples of the video signal recording device of the present invention are shown in FIGS.
As shown in the figure, the rotating head (IIA, >(li
A, ) (IIB.) In a video signal recording device that records a wideband video signal by segment recording according to (11B.), the horizontal synchronization signal (5^ > (5B) is recorded by changing the phase or time width.

[Effect]

The video signal recording device of the present invention records the horizontal synchronizing signals of each segment recorded on the tape (2) with different phases or time widths, so that the horizontal synchronizing signals with different phases or time widths are recorded on the tape (2). By detecting this, the difference between the first and second segments can be detected during playback, and even if variable speed playback or the like is performed, a normal screen can be displayed without shuffling or the like.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video signal recording apparatus of the present invention will be described below with reference to the drawings.

In FIG. 1, a wideband video signal input through an input terminal (20) is converted into a digital signal in an A/D converter (21) and supplied to a channel division circuit (22). ), the input digital video signal DV (FIG. 3A) is divided into two channels for each horizontal line.Then, the odd-numbered line information Do (
Figure 3 B) is the time axis expansion episode! 8 (23^>) and the time axis is doubled. Also, the dividing circuit (22)
Information DE of even-numbered horizontal lines from (Fig. 3C)
is supplied to the time axis expansion circuit (23B), which is also 2
Expanded to double the time axis. This time axis expansion circuit (23A
) and (23B) have a memory, and can be expanded by reading with a read clock having a frequency 1/2 of the write clock. Note that when reading this, 2
The positions of the heads of one field of the channel signals are aligned.

Output signal DE from this time axis expansion circuit (23A)
O (Fig. 3D) is connected to the adder circuit (24) through the delay circuit (24).
9A>. This delay circuit (24) connects the head (11^1) (11B1) and the head (11A2) (
This is for compensating for the phase difference with IIL). or,
The output signal EDE (FIG. 3E) of the time axis expansion circuit (23B) is supplied to the addition circuit <9B>. These addition times! 8 (9^) (9B) has a horizontal synchronizing signal variable circuit (1
0) to a horizontal synchronization signal (5A> or (5B) in which the time width of the horizontal synchronization period is different by, for example, twice as shown in FIG. 2A and B).
is switched and supplied according to the first and second segments, thereby adding a synchronization signal to the video signal and converting it into a composite video signal.

As a result, the time axis has been expanded! (23A>) and the output signal EDO obtained through the delay circuit (24) (Fig. 3D)
A horizontal synchronizing signal (5A) shown in FIG. 2A is added to each of the 1st to 275th horizontal lines and the 551st to 825th horizontal lines. That is, each horizontal line of the segment showing the upper side on the screen has a horizontal synchronization signal (5A).
is added. Similarly, the 27th line of the output signal EDE (Fig. 3E) obtained through the time axis expansion circuit (23B)
6th to 550th horizontal lines as well as 826th to 1100th horizontal lines
A horizontal synchronizing signal (2B) shown in FIG. 2B is added to the horizontal line. That is, a horizontal synchronizing signal (5B) is added to each horizontal line of the segment showing the lower side on the screen.

The composite video signals from the ml circuits (9A) (9B) are supplied to D/A converters (25A) (25B) and converted back into analog signals, respectively. Addition circuit (9A) (
9B) is D/A (25A) (2
5B), and the synchronizing signal may be mixed in the adder circuit (9A') (9B') after analog conversion.

The analogized composite video signal is sent to an FM modulation circuit (26A
) and (26B) and after being FM modulated,
It is supplied to switch circuits (28A) and (28B) through amplifiers (27A) and (27B>).

And the switch circuit (28A) is connected to the head (IIA,
) and the head (11B,) are alternately switched by the switching signal RFSW, during each tape contact period, and the signal through the amplifier (27A) is switched during the tape contact period of the head (11^.) (118), respectively. These heads (IIA.) (11B.) are supplied. Similarly, the switching signal RFSW. Switch circuit (28B)
is switched, and signals are alternately supplied to the heads (IIA.) (1182) through the amplifier (27B) during the tape contact period of the heads (IIA.) and (11B2).

Therefore, in this case, the switching signals RFSII, and RFSen2 are the head (IIA,) (11B,) and (
The phase is made to differ by an amount corresponding to the angular interval from IIA2) (11B2).

In terms of signals, the output signal of the time axis expansion circuit (23^) is sent to the head (11^+) (
11A2) and the head (11B, ) and (28B) are different in time, but when viewed from the input broadband signal, they are the same switching point,
The signals of one field divided into two channels are divided into tracks T A + and T A 2 in just the right amount.
, T B + , T B 2 .

In the recording track pattern, as shown in FIG. 16, a signal in which one horizontal line is expanded over two horizontal line sections is applied to tracks T A + and TA2 or TB. For example, two segments are formed as TB2 and TB2. And in this case head (
IIA. ) (11B,) and (11^2) (11B2
> by multiplying the interval of 1 degree by an integer H', the tape (2
) are simultaneously recorded on tracks TA, and TA2,
T.B. and TB2, the horizontal synchronizing signal recording positions HT are lined up along the width direction of the track as shown in FIG.

At the time of recording, tracking control signals may be recorded at the ends of the tape in the width direction using a fixed head, as in the conventional method, or they may be superimposed on the video signal as in the case of 8 mm video. Pilot signals of four frequencies may be recorded cyclically and tracking may be performed using these four-frequency pilot signals during reproduction.

FIG. 4 shows a reproduction system for signals recorded in this manner.

That is, by simultaneously scanning the tracks TA, TA and TA2 by the heads (11A,) and (11^2), and by scanning the tracks TA and TA2 in the same way by the heads (11B.) and (11B2), two channels are At the same time, a reproduced signal can be obtained. Then, these four heads (1180 and (IIB.) and (11A2) and (11B.)
The two tracks T AI+ are switched by the switching signals RFSW and RFSL at
Signals are sequentially obtained from T A2+ T BIT B2 through switch circuits (31A) and (31B). In this case, the tracking servo is applied using the aforementioned control signal or four-frequency pilot signal, and at the same time, the switching signal RFS is applied.
I1. and RFSW. A phase servo is applied so that when each head enters the table contact period, the switch circuit (3 1A < 3 18) selects the output of that head.

In this way, the signals obtained from the switch circuits (31A) and (31B) are sent to the amplifier (32^) and (32B).
Through the FM demodulation circuit (33A) and (33B) and the dropout detection circuit (43A) and (43B)
FM demodulation is performed. Then, each demodulated output is supplied to A/D converters (34A) and (34B) to be converted into digital signals, and then sent to a time base error correction circuit (TBC) (not shown) and defective switches (45A) and (45).
B) Memory (35A) and (35B) through
supplied to Memory <35^) and (35B)
is a memo for upper and lower screens that has a memory capacity of at least one field.
5B. ) and (35B2), switch (45A
) (45B) forces you to choose. Switch (45A)
and <458) is the ID detection circuit (36A) and (3
6B) The switching is performed by the output. ID detection circuit (
36A) and (36B) are FM demodulation circuits (33^)
For example, the difference in time width (2W or W) between the horizontal synchronizing signals (5A) and (5B) shown in No. 21!I is detected from the outputs of the switch (45) and (33B>). ^) and (45B) are switched to distribute and store the reproduced signal into the upper and lower screen memories (35A.) (35B.) and (35A.) (3582).

Writing and reading to this memory (35^) (35B) is performed by the timing controller (37A) and (37
Do this with the output of B). It will be done. That is, the switch (45
A) and (45B) If the contact piece a is turned towards the fixed contact b side, the composite video signal from the head (IIA,) ('IIA.) side will be stored, and if the contact piece a is turned towards the fixed contact C side, the composite video signal from the head (IIB) will be stored.
．． ) The writing on the (1182) side is omitted. memory
The signals written in (35^) and (35B) are respectively supplied to the time axis compression circuits (39^) and (39B), and the signals that were expanded by 2 times are compressed in time to 1/2, respectively. The signal for the horizontal period is returned to the original signal for the time length of one horizontal period. In this case, the memory (3
Among the signals from the head (11A2) and (5B),
The signal from the head (IIA,') (11B2) is delayed through the delay circuit (38) and supplied to the time axis compression circuit (<39A), where it is aligned in time with the signal from the head (IIA,') (11B2).

The signals restored to their original time length by the time axis compression circuits (39A) and (39B) are supplied to the combination circuit (40).

In this combining circuit (40), signals from the time axis compression circuits (39A) and (39B) are obtained and combined alternately for each horizontal line, and the combined output is sent to a D/A converter (4l). ) for conversion into the original analog broadband video signal, which is then delivered to the output terminal (42).

As described above, video signals for l fields can be recorded on two tracks each with time axis expansion, so the recording wavelength of the signal per track becomes long, and wideband signal recording and playback is possible. This makes it possible to easily write and read a composite video signal for each horizontal line depending on the difference between the first and second segments. In the above embodiment, ID detection was performed at the analog stage, but as shown in FIG.
34B) and then the digital ID detection circuit <36A') or (36B') may detect an ID signal for identifying the difference in horizontal synchronization signals.

FIG. 6 shows a specific example of the ID detection circuit (36A) (36B), and FIG. 7 is a circuit diagram for detecting the difference in time width between the horizontal synchronizing signals (5A) and (5B) shown in FIG. 7B, and FIG. 7 is an operation waveform diagram thereof. The input terminal (46) in FIG. 6 has a horizontal synchronizing signal (5A) or 5B) shown in FIG.
A composite video signal including a horizontal synchronizing signal (5^) shown in FIG. 7 or a horizontal synchronizing signal (5B) shown in FIG. 7F is supplied. This composite video signal is passed through a low pass filter (LPF) (47) to detect a horizontal synchronizing signal (5A) or (5B) and supply it to one input terminal of a comparator (48). The other human input terminal of this comparator (48) is '! J7 diagram A
, F is supplied from a reference voltage source (49). In the converter (48), the horizontal synchronizing signal <5
The level of A) or (5B) and the reference voltage Es are compared, and the horizontal synchronizing signal (48A) or (48A) shown in FIG.
8B> is obtained, and this horizontal synchronizing signal (48＾冫 or (48B)) is supplied to the output terminal (54), and from then on V
It is used as a reference horizontal synchronization signal in the TR, and
1st Mono 7 Multi-by-Break (MM.) (50〉 and D
It is supplied to the clock terminal CK of the type flip-flop circuit (DFF) (52). In the first mono-multi-by-break (50), a delay waveform (50) or (50B) shown in FIG. 7C is obtained by triggering at the edge of the horizontal synchronizing signal and obtaining a pulse of a predetermined width. The output of the first mono multivibrator (50) is fed to a second mono multivibrator (MM!) (51), which generates pulses of a predetermined width triggered by the edges of the first mono multivibrator (50). As a result, a wind waveform (51A) or <518) shown in FIG. 7D is obtained. By supplying the output of this second mono multivibrator (5l) to the D terminal of the D-type flip-flop circuit (52), the horizontal synchronizing signal (5l) has a horizontal synchronizing signal amplitude of 2W, which is twice the normal frequency.
In case A), a high "1" signal (52A) as shown in Figure 7 is obtained at the Q output of the D-type flip-flop circuit (52), and the horizontal synchronization signal width is the normal width W. (5B), as shown in Figure 7H, the Q output of the D-type flip-flop circuit (52) is supplied with a low “0” signal (5B).
213) is obtained, the switch (45A>(45B) may be switched based on the identification (ID) signal of "0" and "1" obtained at the output terminal (53).

In the above embodiment, the ID signal detection circuit was explained in the case where the horizontal synchronization signal was recorded by changing its time width W.
As shown in the figure, in the case of a positive synchronization signal (5C) that falls within the amplitude range of the video signal, it can be identified by a horizontal synchronization signal (5D) whose polarity is inverted as shown by the broken line.

I of the reproduction system when horizontal synchronization signals with different phases as shown in Fig. 8 are recorded as ID signals for segment identification.
An example of the D detection circuit (313A) or (36B) will be explained with reference to FIGS. 9 and 10.

In FIG. 9, the human input terminal (46) is connected to the positive horizontal synchronizing signal (5C) (50) having a different phase as explained in FIG. )
A composite video signal containing L P F (47) is supplied.
Only these horizontal synchronizing signals are classified and supplied to a delay circuit (55) and an adder circuit (56). The output of the delay circuit (55) is as shown in FIG. 10B. Delayed waveform (55C) or (55D) delayed by τ period as shown in I
is output and supplied to the adder circuit (56). Figure 10 A, H of the output of the adder circuit (56〉, L P F < 47)
Delay circuit (55) from the waveform (5C) or (5D)
Waveforms of output B and I in Figure 1O (55C) or (550
) differential output waveform (56C) or (56D) (first
Figure 0C, J) is obtained. The output of the adder circuit (56) is supplied to one of the input terminals of the first and second converters (57) or (58), respectively. The first comparator (5
The other input terminal of the second converter (59) is supplied with the reference voltage Es from the reference voltage source (58), and the other input terminal of the second converter (59) is supplied with the reference voltage E from the reference voltage source (60).
S/ is supplied. First and second converters (57
) and (59), these reference voltages and the differential output are compared, and the output waveform (57C) of the l-th comparator (57) is
The horizontal synchronizing signal (57C) in FIG. 10D is obtained in the second converter (59), and the horizontal synchronizing signal (590) in FIG. 10K is obtained in the second converter (59), which is output via the OR circuit (62). The horizontal synchronizing signals shown in FIG. 10D and K are outputted to the terminal (54) and used as the reference horizontal synchronizing signal for the VTR.

The output of the OR circuit (62) is also supplied to the second mono multi-by-break (63). In addition, the first converter (
57) horizontal synchronization signal (57C) Ha! The signal is supplied to the No. 1 mono multivibrator (61), and the rising edge thereof triggers the No. 1 mono multivibrator (61) to obtain the wind waveform (61C) shown in Fig. 10. The latch clock waveform (63C) in FIG. 10 F obtained by the second mono-multi-bi-break (63) is supplied to the clock terminal CK of the D-type flip-flop circuit (52>). Therefore, the positive output Q has "l" shown in Fig. 10G and L.
Since the signal (52C) or "0" signal (520) is obtained, it is supplied to the ID output terminal -j゛・(53), and then the fourth
It is sufficient to supply the signal to the switch (45A) or (45B) shown in the figure to identify whether it is the horizontal synchronizing signal waveform of FIG. 10A or FIG. 10B. According to the above-mentioned feature, it is possible to prevent the image from being disturbed even during variable speed playback where track jumps and the like are performed.

Further, although the above example describes a head having an azimuth, a similar structure can be used in the case of guard band recording with two heads. Further, the number of pairs of rotating heads is not limited to two pairs, but may be n pairs of three or more pairs.Furthermore, the number of rotations of the drum may be n times faster (in this case, the number of discrimination types of the waveform of the horizontal synchronization signal is increased). It is obvious that various changes may be made without departing from the spirit of the present invention.

〔Effect of the invention〕

In the present invention, since an ID signal for identifying a segment is recorded for each horizontal line, video signals that have been mixed can be easily restored to their original order even during playback at variable speeds such as double speed without using methods such as shuffling. This has the advantage of providing a video signal recording device that can be restored.

[Brief Description of the Drawings] Fig. 1 is a block diagram of a recording system showing an embodiment of the video signal recording device of the present invention, and Fig. 2 is a horizontal synchronization signal recorded in the video signal of the video signal recording device of the present invention. FIG. 3 is a waveform diagram showing an example of a waveform, FIG. 3 is a timing chart during recording of the video signal recording device of the present invention, and FIG. 4 is a block diagram showing an embodiment of the reproduction system of the video signal recording device of the present invention. Fig. 5 is another block diagram of the ID detection circuit used in the present invention, Fig. 6 is a diagram of the horizontal synchronization signal radiation detection circuit used in the present invention, Fig. 7 is a waveform explanation diagram of Fig. 6, and Fig. 8 is a horizontal synchronization signal diagram. Other waveform diagrams of the signals, FIG. 9 is a diagram of a horizontal signal phase detection circuit used in the present invention, FIG. 1O is a waveform explanatory diagram of FIG. 9, and FIG. 12 is a recording track pattern diagram by the rotary head shown in FIG. 1L, FIG. 13 is a diagram showing its playback screen, FIG. 14 is an explanatory diagram of another conventional rotary head device, and FIG. 15 is a diagram showing the rotation of FIG. 14. A TCI waveform diagram recorded by the head, and FIG. 16 is a recording track pattern diagram thereof. 〈11^,) (11A2) (11B,) (IIB
．． ) is a rotating head, (36A) (36B) is an ID detection circuit, (35A) (35B> is a memory, (35A.
) (35B,) is the memory for the upper screen, (35A2) (
35aa) is a memo for the bottom screen! J, (45A) (45
B) is a switch. Deputy Hide Mori Hitomatsu Kuma-441- 7th Flash

Claims (1)

[Claims] In a video signal recording device that records a broadband video signal by performing segment recording using a plurality of rotary heads, the phase of a horizontal synchronization signal of a video signal recorded in adjacent segments is provided. Or a video signal recording device characterized by recording with varying time widths.