JPH06284366A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide a magnetic recording and reproducing device for reproducing high-quality video images from a digital recording track at the time of normal reproduction and reproducing easily visible video images with less time difference on a screen from an analog recording track at the time of special reproduction. CONSTITUTION:This device is provided with first magnetic head groups 1 and 2 for analog-recording input video signals to which an analog signal processing is performed on the first track of a magnetic tape 8 and second magnetic head groups 3-6 for digital-recording the video signals to which a digital signal processing is performed on a second track adjacent to the first track. Reproducing video signals are outputted by performing a reproducing digital signal, processing to reproducing signals reproduced from the second track through the second magnetic head groups at the time of the normal reproduction and the reproducing video signals are outputted by performing a reproducing analog signal processing to the reproducing signals reproduced from the first track through the first magnetic head groups at the time of the special reproduction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for digital recording such as a digital video tape recorder.

[0002]

2. Description of the Related Art In a conventional magnetic recording / reproducing apparatus for digital recording, a video signal is shuffled before recording and divided into blocks. Also, since the amount of video data to be recorded is huge, one field video is recorded on multiple tracks by segment division or channel distribution (for details, refer to "Digital Video Recording Technology" Yoshizumi Eto,
Seiichi Mita, Shinzou Doi Published by Nikkan Kogyo Shimbun, Ltd. 133-
Page 155).

For example, in the D1 type digital VTR, three-segment division and two-channel division are adopted,
One field image is recorded on 6 tracks.

[0004]

However, in the magnetic recording / reproducing apparatus for digitally recording the one-field image data shuffled as described above over a plurality of tracks, the reproduced image at the time of special reproduction is blocked in the same field. Every time there is a time difference. This is because among the video composed of a large number of blocks, only the blocks reproduced without error from the reproduction signal are updated to be the reproduced video. As a result, the special playback video becomes a low quality image that is difficult to see. In particular, in the case of a video with a lot of movement, the image quality is significantly deteriorated.

In view of the above problems, it is an object of the present invention to provide a magnetic recording / reproducing apparatus which does not significantly deteriorate the image quality of reproduced video even during special reproduction.

[0006]

In order to achieve the above-mentioned object, a magnetic recording / reproducing apparatus of the present invention performs analog signal processing on an input video signal, and outputs it on a magnetic recording medium via a first magnetic head group. Magnetic recording the analog signal on the first track of the same, digitally processing the video signal, and digitally recording on one or more second tracks adjacent to the first track via the second magnetic head group. A recording / reproducing apparatus, which outputs a reproduction video signal by performing reproduction digital signal processing on a reproduction signal reproduced from the second track via the second magnetic head group at the time of normal reproduction, and at the time of special reproduction. It is configured to output a reproduced video signal by processing a reproduced analog signal of a reproduced signal reproduced from the first track via one magnetic head group.

[0007]

According to the present invention, since the same image is recorded on different tracks in an analog recording and a digital recording by the above-mentioned structure, it is possible to reproduce a higher quality image than a digitally recorded track during normal reproduction. Further, since the video is reproduced from the analog-recorded track during the special reproduction, the reproduced video is easy to see with little time lag on the screen.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the magnetic recording / reproducing apparatus of the present invention will be described below with reference to FIG. FIG. 1 is a block diagram showing the configuration of the magnetic recording / reproducing apparatus of the first embodiment of the present invention.

In FIG. 1, the video signal 91 input from the input terminal 9 is input to the analog video signal recording processor 10 and the digital video signal recording processor 11.

In the analog video signal recording processing section 10, the video signal 91 is processed by the Y / C separation circuit 12 and the luminance signal 12 is supplied.
1 and the carrier color signal 122. Luminance signal 121
Through the emphasis circuit 13 and the FM modulation circuit 14
Is modulated. Further, the carrier color signal 122 is the low frequency conversion circuit 1
It is converted into a low frequency by 5. Luminance FM modulation signal 1
41 and the low frequency conversion color signal 151 are added by the adder 16 to become the analog recording signal 161 whose frequency allocation is shown in FIG. The analog recording signal 161 is sent to the analog recording heads 1 and 2 on the rotary cylinder 7 via the recording amplifier 17, and is analog-recorded on the magnetic tape 8. The analog recording heads 1 and 2 have opposite azimuth angles, and are mounted at positions on the rotary cylinder that are point-symmetric with respect to the center of rotation. Further, for example, the azimuth angles of the heads 1 and 2 are +6 degrees and -6 degrees.

In the digital video signal recording processing section 11, the sync signal 1 is fed from the video signal 91 to the sync signal 1 by the sync separation circuit 18.
81 is separated, and the PLL circuit 19 generates a clock 191 having a period of 1 / N (N: integer) of the synchronization signal interval period. The video signal 91 is converted into the digital signal 201 by the AD converter 20 at the timing of the clock signal 191. When an 8-bit AD converter is used, the data amount of the digital signal 201 is 8 × N per synchronization signal interval period.
Become a bit. The data amount of the digital signal 201 is compressed by the high efficiency encoding circuit 21. DCT (discrete cosine transform), which is well known as a compression method
And so on.

An error correction adding circuit 22 adds error correction data to the digital signal whose data amount is compressed. As the error correction method, Reed Solomon error correction code, which is well known in the past, is used. The digital signal 221 to which the error correction data is added is distributed by the data distribution circuit 23 to the two systems of digital signals 231 and 232. The digital signal 231 is modulated by the modulation circuit 24. As a modulation method, scrambled NRZ modulation or 8-10 conversion, which is well known in the past, is used. The modulated signal is sent to the digital recording heads 3 and 4 on the rotary cylinder 7 via the recording amplifier 25 and recorded on the magnetic tape 8.

The digital signal 232 is similarly modulated by the modulation circuit 2.
It is sent to the digital recording heads 5 and 6 on the rotary cylinder 7 via 6 and the recording amplifier 27 and recorded on the magnetic tape 8. Digital recording heads 3, 4 and 5,
6 also has the azimuth angle reversed, and the size of the azimuth angle is set to be different from those of the analog recording heads 1 and 2.
It is attached facing 80 degrees. That is, it is attached at a position on the rotating cylinder that is point-symmetric with respect to the center of rotation. Also, for example, the azimuth angle of the heads 3 and 4 is −
20 degrees and +20 degrees, and the azimuth angles of the heads 5 and 6 are +20 degrees and -20 degrees. Although the digital signal is distributed to two systems and digitally recorded here, it may be distributed to one system or three or more systems for recording.

Next, the track shape on the tape on which the analog signal and the digital signal are recorded will be described with reference to FIG. An analog signal is recorded on the track 32 by the head 1, and an analog signal is recorded on the track 33 by the head 2. The head 3 records the digital signal on the track 34, the head 4 records the digital signal on the track 35, the head 5 records the digital signal on the track 36, and the head 6 records the digital signal on the track 37. Crosstalk interference from adjacent tracks is reduced by changing the azimuth angle between adjacent tracks.

During normal reproduction, the digital signals recorded on the digital signal recording tracks 34, 35 and 36, 37 are reproduced by the heads 3, 4 and 5, 6. The reproduced signal is input to the digital video signal reproduction processing circuit 30 via the head amplifiers 28 and 29. The digital video signal reproduction processing circuit 30 performs the reverse processing of the signal processing for recording. That is, a digital signal is detected, two systems of digital signals are integrated, errors are corrected, the compressed digital signal is expanded to the original signal, DA converted, and the reproduced digital video signal 301 is output from the output terminal 31. Is output.

At the time of special reproduction, the analog signals recorded on the analog signal recording tracks 32 and 33 are reproduced by the heads 1 and 2. The head moves across the tracks during special reproduction, but the azimuth angle of the digital recording track is different from the azimuth angle of the analog recording track, so that the reproduction signal from the digital recording track does not significantly interfere. As the analog signal reproducing head for special reproduction, another head having a wider track width than the heads 1 and 2 may be used.

The reproduced signal is input to the analog video signal reproduction processing section 27 via the head amplifier 26. The analog video signal reproduction processing unit 27 performs the reverse process of the signal process for recording. That is, the reproduced signal is FM demodulated to be a reproduction luminance signal, the reproduction color signal is converted into a reproduction carrier color signal, the reproduction luminance signal and the reproduction carrier color signal are added, and the reproduction analog video signal 271 is output as a reproduction signal. It is output from 31.

Next, a second embodiment of the magnetic recording / reproducing apparatus of the present invention will be described with reference to FIG. In FIG. 4, the video signal 91 input from the input terminal 9 is input to the analog video signal recording processing unit 10 and the digital video signal recording processing unit 38.

In the analog video signal recording processing section 10, the video signal 91 is processed by the Y / C separation circuit 12 and the luminance signal 12 is outputted.
1 and the carrier color signal 122. Luminance signal 121
Through the emphasis circuit 13 and the FM modulation circuit 14
Is modulated. Further, the carrier color signal 122 is the low frequency conversion circuit 1
It is converted into a low frequency by 5. Luminance FM modulation signal 1
41 and the low frequency conversion color signal 151 are added by the adder 16 to become the analog recording signal 161 whose frequency allocation is shown in FIG. The analog recording signal 161 is sent to the analog recording heads 1 and 2 on the rotary cylinder 7 via the recording amplifier 17, and is analog-recorded on the magnetic tape 8. The analog recording heads 1 and 2 have the same azimuth angle, and are mounted on the rotating cylinder so as to face each other by 180 degrees. For example, the azimuth angles of the heads 1 and 2 are both +6 degrees.

In the digital video signal recording processing unit 38, the sync signal 1 is fed from the video signal 91 to the sync signal 1 by the sync separation circuit 18.
81 is separated, and the PLL circuit 19 generates a clock 191 having a period of 1 / N (N: integer) of the synchronization signal interval period. The video signal 91 is converted into the digital signal 201 by the AD converter 20 at the timing of the clock signal 191. When the 8-bit AD converter is used, the data amount of the digital signal 201 is 8 × N bits per synchronization signal interval period. The data amount of the digital signal 201 is compressed by the high efficiency encoding circuit 21.

An error correction data is added to the digital signal whose data amount is compressed by an error correction addition circuit 22. The digital signal 221 to which the error correction data is added is modulated by the modulation circuit 24. The modulated signal is sent to the digital recording heads 39 and 40 on the rotary cylinder 7 via the recording amplifier 25 and recorded on the magnetic tape 8. The heads 39 and 40 for digital recording have the same azimuth angle, and the size of the azimuth angle is set to be different from that of the heads 1 and 2 for analog recording, and they are mounted 180 degrees opposite to each other. For example, the azimuth angle of the heads 39 and 40 is -20 degrees. Although the digital signal is digitally recorded in one system here, it may be recorded in two or more systems.

Next, the track shape on the tape on which the analog signal and the digital signal are recorded will be described with reference to FIG. An analog signal is recorded on the track 41 by the head 1, and an analog signal is recorded on the track 42 by the head 2. The head 39 records the digital signal on the track 43, and the head 40 records the digital signal on the track 44. Crosstalk interference from adjacent tracks is reduced by changing the azimuth angle between adjacent tracks.

During normal reproduction, the digital signals recorded on the digital signal recording tracks 43 and 44 are reproduced by the heads 39 and 40. The reproduced signal is input to the digital video signal reproduction processing circuit 45 via the head amplifier 28. Digital video signal reproduction processing circuit 4
In 5, the reverse process of the signal process for recording is performed.
That is, digital signals are detected, errors are corrected,
The compressed digital signal is expanded to the original signal,
The DA conversion is performed and the reproduced digital video signal 451 is output from the output terminal 31.

During special reproduction, the analog signals recorded on the analog signal recording tracks 41 and 42 are reproduced by the heads 1 and 2. The head moves across the tracks during special reproduction, but the azimuth angle of the digital recording track is different from the azimuth angle of the analog recording track, so that the reproduction signal from the digital recording track does not significantly interfere. As the analog signal reproducing head for special reproduction, another head having a wider track width than the heads 1 and 2 may be used.

The reproduced signal is input to the analog video signal reproduction processing section 27 via the head amplifier 26. The analog video signal reproduction processing unit 27 performs the reverse process of the signal process for recording. That is, the reproduced signal is FM demodulated into a reproduction luminance signal, the reproduction color signal is converted into a reproduction carrier color signal, the reproduction luminance signal and the reproduction carrier color signal are added, and the reproduction analog video signal 271 is output as a reproduction signal. It is output from 31.

In the first and second embodiments, the case where one video signal is input has been described. However, even in simulcast broadcasting in which one program is broadcast with both current video and high definition video, If the video is analog-recorded and the high-definition video is digitally recorded, the reproduced video and the specially reproduced video are also high-quality images.

[0027]

As described above, according to the present invention, since the digitally recorded video signal is reproduced during the normal reproduction, it is possible to reproduce a high resolution, low noise and high quality image. In addition, since the analog-recorded video signal is reproduced during special reproduction, an easy-to-see video with a low SN ratio but a small time difference on the screen can be reproduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing frequency allocation of a recorded analog signal in the first and second embodiments of the present invention.

FIG. 3 is a schematic diagram showing the shape of a recording track on a magnetic tape in the first embodiment.

FIG. 4 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram showing the shape of a recording track on a magnetic tape in a second embodiment.

[Explanation of symbols]

1, 2 Analog recording head 3, 4, 5, 6, 39, 40 Digital recording head 10 Analog video signal recording processing unit 11, 38 Digital video signal recording processing unit 27 Analog video signal reproduction processing unit 30, 45 Digital video Signal reproduction processing section 32, 33, 41, 42 Analog recording track 34, 35, 36, 37, 43, 44 Digital recording track

Claims (3)

[Claims] 1. An analog video signal processing is applied to an input video signal, the analog recording is performed on a first track on a magnetic recording medium via a first magnetic head group, and the video signal is digital signal processed, A magnetic recording / reproducing apparatus for digitally recording on one or more second tracks adjacent to the first track via a second magnetic head group, and at the time of normal reproduction, a second magnetic head group via the second magnetic head group. A reproduced video signal is output by processing the reproduced signal reproduced from the second track by a reproduced digital signal. During special reproduction, the reproduced signal reproduced from the first track through the first magnetic head group is reproduced. A magnetic recording / reproducing apparatus which outputs a reproduced video signal by signal processing. 2. The first magnetic head group is a pair of heads having opposite azimuth angles, and is mounted at a position on a rotary cylinder that is point-symmetrical with respect to the center of rotation. 2. The group is a pair or a plurality of pairs of heads having opposite azimuth angles, and the paired heads are mounted at positions on the rotary cylinder that are point-symmetrical with respect to the center of rotation. Magnetic recording and reproducing device. 3. A first magnetic head group is a pair of heads having the same azimuth angle, and is mounted at a position on a rotary cylinder that is point-symmetrical with respect to the center of rotation. 2. The group is a pair or a plurality of pairs of heads having the same azimuth angle, and the paired heads are mounted at positions on the rotary cylinder that are point-symmetrical with respect to the center of rotation. Magnetic recording and reproducing device.