JPH03230369A - Magnetic recording and reproducing device for color video signal and sound signal - Google Patents

Abstract

PURPOSE:To realize plural recording and reproducing modes by arranging six pieces of a magnetic head in specified positions on a circumference of a rotary cylinder at the recording time in three channels and changing relative positions of their individual recording tracks similarly to plural tape feed speeds. CONSTITUTION:On the rotary cylinder (SL) 15 to be rotated in the direction 16, six magnetic heads (HM) 17-22 are disposed symmetrically to a rotary center at 60 deg. respectively with the same relative height to a vertical plane to a rotary shaft. A magnetic tape (TM) is wound on the SL 15 more than 180 deg. to always be in contact with at least three pieces of HM, and recording signals as divided into three channels are supplied to the specified three pieces of HM to be in contact with the TM to be recorded on the TM. Consequently, even when the rotational speed of a capstan motor is changed and then the tape feed speed is changed, recording track widths for all the pieces of HM are the same, and at the time of reproducing, the signal is restored to its original signal in the reverse process of the recording time. By this method, the recording and reproducing can be performed in plural recording modes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic recording and reproduction of color video signals and audio signals, such as video tape recorders that record and reproduce high quality color video signals and audio signals using magnetic tape. It is related to the device.

Conventional technology Conventional commercial and broadcast video tape recorders (VTRs)
In the field of (hereinafter abbreviated as ), a method has been developed for recording and reproducing a color video signal by decomposing it into two-channel component signals, a luminance signal and a color signal. For example, it is a VTR called M format or β-CAM,
Broadcast technology magazine.

The recording method described in the October issue of 1981, pages 872-890, or the recording method called the MII format and described in the Technical Report VR70-2 of the Television Society, pages 7-12. be.

These two-channel component type VTRs have a chrominance signal track adjacent to the luminance signal track in the recording track recorded on the magnetic tape, so there is a gap between the luminance signal recording head and the chrominance signal recording head. Even if an azimuth angle is set, if overwritten recording is performed using solid writing without a guard band, unnecessary signal components will appear as interference during playback, resulting in a significant deterioration of the playback image quality. Currently, overwriting recording without guard bands is not performed. That is, a two-channel component type VTR requires a guard band, which has the problem of poor recording efficiency.

Furthermore, the tape feed amount is fixed for each method,
For example, there is a problem in that it is not possible to use different recording and playback times for the same tape, such as standard mode and long-time mode in VH3, which is a type of home VTR.

An example of the conventional two-channel component type VTR mentioned above will be described below with reference to the drawings. Second
The figure is a block diagram of main parts of a conventional two-channel component VTR. In FIG. 2, a luminance signal is input to the input terminal 36.

Further, to the input terminal 37, for example, a time-base compression multiplexed color signal is input. Here, as an example of the conventional technique, a two-channel component signal is formed by a luminance signal and a time-base compression multiplexed color signal.

The luminance signal input from the input terminal 36 is sent to the FM modulator 38.
is frequency modulated (FM) and recorded on the magnetic tape by the magnetic heads 39 and 41, and during reproduction, the reproduced brightness signal reproduced by the magnetic heads 39 and 41 is frequency modulated (FM).
The signal is demodulated by the demodulator 43 and output from the output terminal 45. On the other hand, the time-base compression multiplexed color signal input from the input terminal 37 reaches the FM modulator 47 where it is FMed and recorded on magnetic tape by the magnetic heads 40 and 42. Also, during playback, the color signal is transmitted to the FM modulator 47 and recorded on the magnetic tape by the magnetic heads 40 and 42. The reproduced time-base compressed multiplex signal is demodulated by the FM demodulator 44 and outputted from the output terminal 46.

Problems to be Solved by the Invention In the conventional 2-channel component 1-VTR,
A guard band 36 exists to suppress crosstalk interference between adjacent tracks, and there is a problem in that the recording density is lower than in solid write recording or overwrite recording. Furthermore, there is a major problem in that it is not possible to use the recording and playback time for the same tape differently, such as the standard mode and long-time mode mentioned above.

In view of the above problems, the present invention provides two recording channels for a VTR.
By increasing the amount of information that can be recorded by increasing the number of channels to 3 or 4 channels or more, it is possible to record and play back higher quality color video and audio signals, and there is no guard band that reduces tape usage efficiency. In addition, the present invention provides a multi-channel VTR capable of recording and reproducing two or more types of time for the same tape.

Means for Solving the Problems In order to solve the above problems, in the present invention, for example, when the number of recording channels is three, six magnetic heads are placed on the circumference of the rotating cylinder from the center of rotation of the rotating cylinder. They are arranged so that their center angles are 60 degrees, and the relative positional relationship of the center line or one end line of the recording track by each magnetic head changes phasewise with respect to a plurality of tape feeding speeds.

Operation The present invention has the above-described configuration, and although it is a 3-channel VTR that can record and play back high-quality color video signals and audio signals, it achieves high-density recording without guard hands, and furthermore, the recording and playback time for the same tape can be reduced to the standard mode. This makes it possible to realize a VTR that has two or more types of modes, such as a long-time mode and a long-time mode.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the main parts of an embodiment of the present invention. In this embodiment, the color video signal and audio signal to be recorded are a luminance signal and two color difference signals Cw and Cn, which are specifically high-definition signals.
, and an audio signal. In FIG. 1, for example, input terminal 1 receives a luminance signal, input terminal 2 receives a color difference signal Cw, input terminal 3 receives a color difference signal Cn, and input terminal 4 receives an audio signal. The luminance signal input from the input terminal 1 is input to the synchronization separation circuit 5,
A horizontal synchronization signal and a vertical synchronization signal are separated. The separated horizontal synchronization signal and vertical synchronization signal are input to the recording side reference clock generation circuit 6. In the recording side reference clock generation circuit 6, a well-known PLL circuit is used to generate a time axis reference for the operation of each circuit's one-rotation cylinder, capstan motor, etc. during recording from a horizontal synchronization signal and a vertical synchronization signal. A reference clock is generated.

Now, the luminance signal, two color difference signals Cw and Cn inputted from the input terminals 1, 2 and 3 are led to the recording side video signal processing circuit 7, and after being converted into digital signals, Axial compression and expansion are performed, and the signal is then stored in the memory within the recording side video signal processing circuit 7.

The audio signal input from the input terminal 4 is guided to the recording side audio signal processing circuit 8, which also adds an error correction code etc. using a well-known method and converts it into a digital P.
After being converted into a CM signal, the recording side audio signal processing circuit 8
stored in internal memory.

By the way, in this embodiment, as shown in FIG. 1, six magnetic heads 17, 18, 19, 20, 21 and 22 are placed on a rotating cylinder 15 rotating in a direction 16 with respect to the center of rotation. They are mounted in a 60 degree symmetrical arrangement. Here, the head parameters such as track width of these six magnetic heads are all the same except that the azimuth is opposite to that of the adjacent magnetic head, and each head is The relative heights of all are also the same.

Further, the magnetic tape is wound around the rotating cylinder 15 by about 180 degrees or more, and at least three heads are always in contact with the magnetic tape. In this example, the first
As shown in the figure, the recording signal is divided into three channels, and is supplied to three specific magnetic heads that are in contact with this magnetic tape, and these magnetic heads record the signal on the magnetic tape. Ru. One point of the present invention lies in the recording track pattern of the recorded signal.

That is, in the present invention, since time-axis expanded or compressed video signals, whether luminance signals or color signals, are frequency modulated (FM modulated) and recorded, the signals recorded on adjacent tracks are statistically If a signal with a strong correlation is created, even if a crosstalk signal recorded on this adjacent track is picked up during playback, this crosstalk signal will be sufficiently attenuated due to the so-called triangular noise theory during FM demodulation. As a result, crosstalk interference on the reproduced image quality becomes less noticeable. That is, the recording-side video signal processing circuit 7 uses the time reference signal of the recording reference clock generation circuit 6, which also controls the rotational phase of the rotary cylinder 150, so as to create a track pattern that records signals with strong correlation between adjacent tracks. Based on that, the output of the three channels is sent to three FM
It is transmitted to transformers 9, 10 and 11. 3 FM
The outputs of modulators 9, 1o and 11 are transmitted to the input terminals of the three switches 12, 13 and 14, respectively. There are two input terminals 12, 13 and 14 among the three switches, and the output signal of the recording side audio signal processing circuit 8 is input to the remaining terminals. The output signal of the recording-side audio signal processing circuit 8 is a PCM digital signal, and generally, unlike a video signal, there is no statistical correlation for each horizontal scanning period or one vertical scanning period, for example. Therefore, it is not necessarily necessary to record an audio signal on a track adjacent to a portion where an audio signal is recorded, but as described above, a video signal may be recorded on a track adjacent to a portion where a video signal is recorded. Therefore, an audio signal is inevitably recorded in a track portion adjacent to a portion where an audio signal is recorded. The timing at which this audio signal is recorded is changed by switches 12, 13 and 14 among the three switches.

As a result, in this embodiment, the video signal recording track and the audio signal recording track are switched while the magnetic head helically scans the magnetic tape.
The total recording track length corresponds to the period during which the magnetic head rotates 180 degrees on the rotating cylinder. A video signal is recorded in a reverse azimuth in a track portion adjacent to the portion where a video signal is recorded, and a track portion in which an audio signal is recorded in a reverse azimuth is adjacent to a track portion adjacent to a portion in which an audio signal is recorded. It's a pattern.

The recording track length of the video signal recording track is the length equivalent to the period during which the magnetic head rotates 180 degrees on the rotating cylinder, and the audio signal recording track is an area continuous to the track where the video signal is recorded. Assuming that the length of the recording track corresponds to the period during which the magnetic head rotates about 10 degrees to 30 degrees on the rotating cylinder, the magnetic tape is wound around the rotating cylinder 15 at an angle of about 2 (10 degrees).
It is also possible to consider a configuration in which the

In the present invention, six magnetic fields 17, 18, 19, 20, 21 and 22 are placed on the rotating cylinder 15.
Since the heads are mounted 60 degrees symmetrically around the center of rotation, even if the capstan motor rotation speed is changed and the magnetic tape feed speed is changed, the recording track width for all heads remains the same. Recording and playback in multiple recording modes is possible. If you want to obtain playback images with ultra-high image quality and high sound quality, you can use a recording pattern with a slight guard band, or if you want to obtain playback images with high image quality and high sound quality over a long period of time, you can use a recording pattern without guard bands. It is sufficient to use a solid recording pattern. An example of a recording track pattern is shown in FIG.

Now, during playback, the original signal is restored by the reverse process to that during recording. In FIG. 1, the signals reproduced from the three magnetic heads are input to the reproduction-side reference clock generation circuit 23, which detects synchronization signals and burst signals and determines whether a particular video signal or audio signal has been recorded. detect the timing. The reproduction side reference clock generation circuit 23 then:
The three switchers 24, 25 and 26 are respectively switched to the following. That is, when the reproduced signal is a video signal, it passes through three FM modulators 27, 28 and 29, and then leads to the reproduction side video signal processing circuit 30. Also,
If the reproduced signal is an audio signal, it is led to the reproduction side direct signal processing circuit 31.

The playback side video signal processing circuit 30 and the playback side audio signal processing circuit 31 each perform signal processing almost opposite to that on the recording side, and output a luminance signal from the output terminal 32 and a color difference signal Cw from the output terminal 33 as playback signals. , a color difference signal Cn from an output terminal 34, and an audio signal from an output terminal 35, respectively.

Furthermore, if track patterns can be detected even for recording signals recorded by rotary cylinders with different head arrangements, recording and reproduction compatibility can be ensured by controlling the timing of signal processing.

Effects of the Invention The present invention makes it possible to increase the number of recording channels of a VTR to three or more, increase the amount of recordable information, and record and play back higher quality video and audio signals, while also improving the number of recording channels of a VTR compared to conventional multichannel channels. It becomes possible to realize multiple recording and playback modes that were not possible with recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram of main parts in an embodiment of the present invention, FIG. 2 is a block diagram of main parts in a conventional embodiment, and FIG. 3 is a recording track pattern diagram according to the present invention. 1.2, 3.4... Input terminal, 5...
Synchronous separation circuit, 6... Recording side reference clock circuit, 7... Recording side video signal processing circuit, 8...
...Recording side audio signal processing circuit, 9.10.11...
...FM modulation circuit, 15...Rotating cylinder, 2
3...Reproduction side reference clock generation circuit, 27, 2
8.29...FM demodulation circuit, 30...
Reproducing side video signal processing circuit, 31... Reproducing side audio signal processing circuit, 32, 33.34.35... Output terminal.

Claims (20)

[Claims] (1) A means for inputting color video signals and audio signals and converting them into 3-channel signals that can be recorded on magnetic tape, and supplying them to the rotating cylinder by changing the rotational speed of the kip stun motor using a changeover switch. means for varying the feeding speed of the magnetic tape; and a rotating cylinder around which the magnetic tape is wound at an angle of about 180 degrees or more, and which rotates by N/2 for every field of the color video signal, where N is a positive integer. and six magnetic heads arranged 60 degrees symmetrically with respect to the central axis of the rotary cylinder and whose track ends have the same relative height with respect to a plane perpendicular to the rotation axis of the rotary cylinder. ,
Supplying the recordable signals of the three channels to at least three of the six magnetic heads that are in contact with the magnetic tape to record on the magnetic tape,
1. A magnetic recording and reproducing apparatus for color video signals and audio signals, comprising a means for reproducing the reproduced signals, and exchanging the reproduced signals with the inputted color video signals and audio signals and outputting the same. (2) The input color video signal and audio signal with a length of one field period are converted into recordable three-channel signals with a length of one field period through time axis expansion and compression processing, and each of the six magnetic heads rotates. 18 on cylinder
2. The magnetic recording and reproducing apparatus for color video signals and audio signals according to claim 1, wherein recording is performed during a period of rotation of 0 degrees. (3) The input color video signal with a length of one field period is converted into a recordable three-channel signal with a length of one field period through time axis expansion and compression processing, and six magnetic heads are placed on the rotating cylinder, respectively. An audio signal having a length of one field and inputted during a period of rotation of 180 degrees is recorded in an area adjacent to an area on the magnetic tape in which the color video signal is recorded. The magnetic recording and reproducing device for color video signals and audio signals according to item (1). (4) The magnetic heads to be driven are switched one by one in the rotational direction opposite to the rotational direction of the rotary cylinder every time the rotary cylinder rotates 60 degrees. Magnetic recording and reproducing device for color video and audio signals. (5) Magnetic recording of color video signals and audio signals according to claim (1), wherein the signal format when the color video signal is recorded is a frequency-modulated luminance signal and two color difference signals. playback device. (6) The recording track pattern is determined so that the frequency-modulated luminance signal and two color difference signals recorded on the magnetic tape have a statistically high correlation with the signals recorded on adjacent tracks. Claim (5) characterized in that
) Magnetic recording and reproducing device for color video signals and audio signals. (7) The color signal according to claim (1), wherein the signal form when the audio signal is recorded is a digital signal obtained by adding an error correction code to the digitized audio signal and modulating the signal. Magnetic recording and reproducing device for video and audio signals. (8) The magnetic recording and reproducing apparatus for color video signals and audio signals according to claim (1), wherein all six magnetic heads have the same head track width. (9) The color video signal according to claim (1), wherein the azimuth of each of the six magnetic heads is opposite to the azimuth of an adjacent magnetic head whose central angle with respect to the cylinder center is 60 degrees. and a magnetic recording and reproducing device for audio signals. (10) Magnetic recording and reproduction of color video signals and audio signals according to claim (1), wherein N, which is a positive integer, is 1, and the rotating cylinder rotates half a rotation for every one field of the color video signal. Device. (11) Means for inputting color video signals and audio signals and converting them into M-channel signals recordable on magnetic tape, where M is a positive integer greater than 3, and rotational speed of the capstan motor using a changeover switch. means for varying the feeding speed of the magnetic tape fed to the rotary cylinder by changing the speed of the magnetic tape;
It is provided with a rotating cylinder that is wound by 0 degrees or more and rotates by N/2 for each field of the color video signal, where N is a positive integer, and (180/M) with respect to the central axis of the rotating cylinder. 2M magnetic heads arranged symmetrically and having the same relative height of track ends with respect to a plane perpendicular to the rotation axis of the rotary cylinder, and recordable signals of the M channels are transmitted to the 2M magnetic heads. Among the magnetic heads, at least M magnetic heads in contact with the magnetic tape are supplied with means for recording on the magnetic tape and reproducing the reproduced signals to the inputted color video signal and audio. A magnetic recording and reproducing device for color video signals and audio signals, which is characterized by converting the signals back into signals and outputting the signals. (12) The input color video signal and audio signal with a length of 1 field period are processed by time axis expansion and compression processing.
The color image according to claim 11, wherein the color image is converted into the recordable M channel signal having a field period length, and is recorded during a period in which each of the M magnetic heads rotates 180 degrees on a rotating cylinder. Magnetic recording and reproducing device for signals and audio signals. (13) The input color video signal with a length of one field period is converted into a recordable M-channel signal with a length of one field period through time axis expansion and compression processing, and M magnetic heads are placed on each rotating cylinder. The audio signal having a length of one field and inputted during a period of rotation of 180 degrees is recorded in an area adjacent to an area on the magnetic tape in which the color video signal is recorded. A magnetic recording and reproducing apparatus for color video signals and audio signals according to claim (11). (14) A claim characterized in that the driven magnetic heads are switched one by one in a rotational direction opposite to the rotational direction of the rotational cylinder every time the rotational cylinder rotates by (180/M) degrees. The magnetic recording and reproducing device for color video signals and audio signals according to item (11). (15) The signal format when a color video signal is recorded is
12. The magnetic recording and reproducing apparatus for color video signals and audio signals according to claim 11, characterized in that the signals are a frequency-modulated luminance signal and two color difference signals. (16) The recording track pattern is determined so that the frequency-modulated luminance signal and the two color difference signals recorded on the magnetic tape have a statistically high correlation with the signals recorded on adjacent tracks. A claim characterized in that (
15) The magnetic recording and reproducing device for color video signals and audio signals as described above. (17) The signal form when an audio signal is recorded is to add an error correction code to the digitized audio signal, and
12. The magnetic recording and reproducing apparatus for color video signals and audio signals according to claim 11, wherein the signals are modulated digital signals. (18) The magnetic recording and reproducing apparatus for color video signals and audio signals according to claim (11), wherein the head track widths of the 2M magnetic heads are all the same. (19) The azimuth of each of the 2M magnetic heads is opposite to the azimuth of an adjacent magnetic head whose central angle with respect to the cylinder center is (180/M) degrees. Magnetic recording and reproducing device for color video and audio signals. (20) Magnetic recording of color video signals and audio signals according to claim (11), wherein N, which is a positive integer, is 1, and the rotating cylinder rotates half a rotation for every one field of the color video signal. playback device.