JPH06111215A - Magnetic recording/reproducing apparatus - Google Patents

Abstract

PURPOSE:To prevent the deterioration of video signals even on the occasion of instantaneous clogging of a head by deleting not only audio tracks, but video tracks by twice M pairs of necessary minimum deleting heads. CONSTITUTION:4ch audio signals of one field are sampled by a processing part 16 and sent to a processing part 20 with a predetermined timing along with the previous inputs. The signals are converted into a predetermined format and fed to an amplifying part 24 or 28. Then, the signals are recorded to a tape by heads 30-37 through amplifiers 21-28 and a rotary transformer 29. When the signals are to be deleted, signals of a track to be recorded are first deleted in accordance with signals of control circuits 42-45 by amplifying parts 46-49, the transformer 29 and deleting heads 38-41. When video and audio signals are to be recorded simultaneously, all the tracks are deleted. Meanwhile, when audio signals are to be recorded, the recorded part alone is deleted by the head 39 or 41. If video signals are to be rewritten, four heads are driven in parallel. A drum is rotated with a frequency of a multiple of an odd number of the frame frequency and the adjacent audio track is scanned by a different head. As a result of this, even when one head is used at the reproducing time, audio signals of two consecutive fields can be obtained, and no deterioration is brought about.

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 having a function of recording a video signal and an audio signal on a magnetic tape. In particular, the present invention relates to an apparatus for recording video signals and multi-channel audio signals by dividing them into a plurality of helical tracks for recording.

[0002]

2. Description of the Related Art Video signals and multi-channel audio signals are
As a magnetic recording / reproducing apparatus for recording by dividing into helical tracks, SMPTE (Society of US) is used.
Motion Picture and Televi
The so-called D- of the Engineers standards)
1 and D-2 digital VTRs are well known.
In these VTRs, video signals and audio signals are recorded on each track of the helical. Therefore, in the case of rewriting the audio signal, the erasing heads are required by the number of rotary heads for recording each track. This causes a drawback that the number of erasing heads increases when recording a large amount of high-definition video signals in a large number of tracks in a divided recording.

As a proposal for solving this problem, there is a technique described in JP-A-4-188978.

By dividing the track for recording the audio signal and the track for recording the video signal and providing an erasing head dedicated to the audio, this is an excellent method for erasing prior to recording with the minimum erasing head.

[0005]

However, in the above invention, the erasing method for improving the reliability at the time of rewriting the video signal is not mentioned, and when the recording head is instantaneously clogged at the time of recording. Has the drawback that the previously recorded data remains unerased and is reproduced and mixed with newly recorded data, resulting in deterioration of image quality. A first object of the present invention is to provide means for erasing not only an audio signal but also a video signal with the smallest number of heads.

Further, in the above invention, since clogging of the reproducing head is not taken into consideration, there is a drawback that when the reproducing head of the audio track is clogged, the reproduced audio signal is deteriorated. A second object of the present invention is to provide a means for reproducing an audio signal evenly when one of the reproducing heads for an audio track is destroyed.

[0007]

In order to solve the above problems, the magnetic recording / reproducing apparatus of the present invention provides the following means for solving.

In order to solve the first problem, a video signal and an audio signal of the L channel (L = 1, 2, 3, ...) Are N tracks (N) at regular time intervals (for example, 1 field).
= 4, 5, 6, ...) in a magnetic recording / reproducing apparatus for recording in a divided manner, first means for recording the video signal on the (N-1) track and recording the audio signal on the one track. And a continuous (N / M-1) track (M
, 1, 2, 3, ...), a fourth means for erasing one track, a fifth means for processing a signal in (N / M) track units, and M A sixth means for recording the (N / M) tracks of the set at substantially the same time is provided, and a third means for erasing when the tracks recorded at the substantially same time by the sixth means do not include an audio signal. A means for operating the fourth means and erasing the track to be recorded by the sixth means prior to recording is provided.

In order to solve the second problem, a video signal and an audio signal of the L channel (L = 1, 2, 3, ...) Are N tracks (N) at regular time intervals (for example, 1 field).
= 4, 5, 6, ...) in a magnetic recording / reproducing apparatus for recording in a divided manner, first means for recording the video signal on the (N-1) track and recording the audio signal on the one track. And a seventh means for recording an L-channel audio signal within a fixed time and an L-channel audio signal within a time corresponding to that time in the same track in which the audio signal is recorded. Further, a recording head or a reproducing head is arranged so that the same head does not scan adjacent tracks for recording the audio signal during normal recording / reproducing.

[0010]

According to the above-mentioned means, it becomes possible to erase not only the audio track but also the video track with the necessary minimum number of erasing heads which is twice as many as M sets. As a result, even if the recording head is momentarily clogged as described above, the unerased data does not occur and the deterioration of the video signal can be prevented.

Further, since another head scans an adjacent audio track, even if one head scanning the audio track is clogged during reproduction, a continuous audio signal is output from the output of another head. Can be reproduced, and deterioration of the audio signal can be prevented.

[0012]

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a recording pattern on a magnetic tape recorded by the magnetic recording / reproducing apparatus of the present invention. There are three linear tracks on the magnetic tape 1. There are a control track 2 used for tracking the magnetic head, a time code track 3 showing the address of the magnetic tape, and an analog audio track 4 for analog voice. The video signal and the L channel audio signal are recorded in the helical track area 5.
In the helical track area 5, there are a video track 6 which mainly records a video signal and an audio track 7 which mainly records an audio signal. On the video signal track 6, a digitized video signal 12 as shown in FIG. 3 is recorded together with the preamble 8. The preamble is a signal used for clock synchronization during reproduction. On the audio track 7, user data 9 as shown in FIG.
And the audio data 10 are recorded together with the preamble 8 and the gap 11. The user data 9 contains useful information for the user such as a time code indicating the position on the tape, information on the recorded date and time, and the name of the user.
There are 8 blocks of audio data 10 per track. The contents of 8 blocks are the input audio signals of 4 channels.
The voice data 12, 22, 32, 42 created from the voice signal input in the field section and the preceding fields.
Voice data 11, 21, 31, 4 input to the black section
It is 1. Among the numbers after the voice data, the preceding numbers show the channel number of the voice and the latter numbers show which field the data is. Therefore, in this embodiment,
The number of channels L of the audio signal is four. The preamble is used for clock reproduction at the time of reproduction, and the gap is used for absorbing a timing shift when rewriting a certain channel of the audio track. When rewriting the user data 10 or the voice data 12,
Rewrite the block and the preamble immediately before it that should be rewritten.

A 1-field video signal is divided into 11 video tracks and recorded. Therefore, of the 12 tracks, 11 tracks are tracks for video signals, and 1 track is a track for audio signals.

FIG. 4 shows a block diagram of the recording system of the magnetic recording / reproducing apparatus for realizing the recording pattern shown in FIG. Before describing the operation, the structure of the head of the drum used in the magnetic recording / reproducing apparatus will be described. FIG. 5 is a view showing the head arrangement of the drum. In the drum 50, REC BLK1, REC BLK2 which is an assembly of recording heads and PB BLK1, PB BLK2 which is an assembly of reproducing heads.
And FE BLK1, FE which is an assembly of erase heads
BLK2 is installed.

The assembly of the recording head and the reproducing head is shown in FIG.
4, four heads 58, 59, 60, 61 are mounted on the head base 57, and each head is configured to scan each track as shown in FIG.

As shown in FIG. 7, the erasing head assembly has two heads 63 and 64 mounted on a head base 62. As shown in FIG. 9, the head 63 simultaneously moves on three adjacent tracks. When scanning, the head 64 is configured to scan its adjacent track. When recording, first the erasing head assembly FE BLK1, 2 erased 4
On the track of the book, a set of recording heads REC BLK
Data is recorded on 4 tracks by 1 and 2.

The operation of the recording system of the recording / reproducing apparatus shown in FIG. 4 will be described.

Data to be recorded is extracted by the video signal processing unit 15 from the video signal input to the input terminal 13, and further divided into 11 tracks of data per field, and the signal processing unit 17, Sent to 18, 19, 20. The signal processing units 17, 18, 19 and 20 add additional data such as error correction code, track number and field number of video signal to the sent data and record it on the magnetic tape. To the recording amplifiers 21 to 28 for modulation for
1 through S4. The switch circuits S1 to S4 are switched to the side where the head aggregate on the drum is in contact with the tape. Since the drum is rotating at a frequency three times the frame frequency, 12 tracks are formed per field as shown in FIG. For example, X-fi
The video signals of the field and the (X + 1) field are recorded on 11 tracks each except the tracks 67 and 68.

The 4-channel audio signal input to the input terminal 14 is sampled in the audio processing section 16 for one field section, and the audio signal input to the previous field is described with reference to FIG. The signal is sent to the signal processing unit 20 at the timing of such a recording pattern. Signal processing unit 2
In the case of 0, an error correction code is added to a voice signal input as user data, converted into a format as shown in FIG. 2 and sent to the amplifying section 24 or 28.

The signals amplified by the amplifiers 21 to 28 pass through the rotary transformer 29 and the heads 30 to 37.
And recorded on a magnetic tape.

The erase operation will be described. Erase control circuits 42, 43, 44 and 45 generate signals for erasing and should be recorded by amplifiers 46, 47, 48 and 49, rotary transformer 29 and erase heads 38, 39, 40 and 41. Erase a track first. The erase heads 38 and 40 erase with a width of three tracks, and the erase heads 39 and 41 erase with a width of one track, as described above.

The operation of the erase control circuit differs depending on the recording mode. First, when a video signal and an audio signal are simultaneously recorded, the erasing head operates all and erases all tracks before recording. When re-recording only the audio signal, erase only where the channel of the audio to be recorded is recorded. Therefore, in this case, the head 3
9 or 41 operates. The operation is a little more complicated when only the video signal is rewritten. In the embodiment of the present invention, as described above, four heads are operated substantially in parallel and four tracks are recorded almost simultaneously. As shown in FIG. 11, the data of each field is Y,
Recording is performed as Y + 1 and Y + 2, but since the track 67 does not include a video signal, rewriting is not performed. Therefore, erasing is not performed on the track 67 either. The erasing is performed when the erasing head scans the other tracks (tracks including the video signal).

In the embodiment described above, the drum is used as a frame.
Since it is rotated at an odd multiple of the audio frequency, different heads scan different audio tracks as shown in FIG. As a result, at the time of reproduction, even if one of the heads is clogged, two consecutive audio signals of the field are obtained, so that the reproduced audio signal is not deteriorated. When the drum is rotated at an even multiple of the frame frequency, the same head scans, so it is necessary to change the position of the audio track in each field as shown in FIG. There is.
In FIG. 10, the audio tracks are changed from the head of the field to the tracks 65 and 66, and 8th and 4th, respectively.

[0025]

As described above, the video signal track and the audio signal track are separated from each other, and not only the audio track but also the video track can be erased by the required minimum erasing head which is twice as many as M sets. It will be possible. As a result, even if the recording head is momentarily clogged as described above, the unerased data does not occur and the deterioration of the video signal can be prevented.

In addition, an audio signal input to the section and an audio signal input to the previous section are simultaneously recorded on the audio track, and reproduction is performed because another head scans an adjacent audio track. At times, even if one head scanning an audio track is clogged, it is possible to reproduce a continuous audio signal from the output of the other head, and it is possible to prevent deterioration of the audio signal.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a recording pattern created by a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is an explanatory diagram of a recording pattern of an audio track created by the magnetic recording / reproducing apparatus of the present invention.

FIG. 3 is an explanatory diagram of a recording pattern of a video track created by the magnetic recording / reproducing apparatus of the present invention.

FIG. 4 is a block diagram of a recording system of the magnetic recording / reproducing apparatus of the present invention.

FIG. 5 is an explanatory diagram of a head arrangement of a drum of the magnetic recording / reproducing apparatus of the present invention.

FIG. 6 is a diagram showing a configuration example of an assembly of recording and reproducing heads of the magnetic recording / reproducing apparatus of the present invention.

FIG. 7 is a diagram showing a configuration example of an aggregate of erasing heads of the magnetic recording / reproducing apparatus of the present invention.

FIG. 8 is a diagram for explaining how a set of recording and reproducing heads of a magnetic recording / reproducing apparatus of the present invention scans a track.

FIG. 9 is a diagram for explaining how an aggregate of erasing heads of the magnetic recording / reproducing apparatus of the present invention scans a track.

FIG. 10 is a diagram illustrating a state of a track formed over two fields in the magnetic recording / reproducing apparatus of the present invention.

FIG. 11 is a diagram for explaining a state of another track formed over two fields in the magnetic recording / reproducing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic tape 15 ... Video signal processor 16 ... Audio signal processor 17-20 ... Signal processor 29 ... Rotary transformer 30-37 ... Recording head 38-41 ... Erase head 42-45 ... Erase controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G11B 5/53 101 C 2106-5D H04N 5/92 H 4227-5C (72) Inventor Toshiro Aizawa Kanagawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Ltd.

Claims (4)

[Claims] 1. A video signal and an L channel (L = 1, 2,
In a magnetic recording / reproducing apparatus for recording an audio signal of (3, ...) By dividing it into N tracks (N = 4, 5, 6, ...) At regular time intervals (for example, one field), -1) A first means for recording the video signal on a track, a second means for recording the audio signal on a track, and a continuous (N / M-1) track (M = 1, 2, 3).・ ・ ・
The magnetic recording / reproducing apparatus is provided with a third means for erasing ..) and a fourth means for erasing one track. 2. A magnetic recording / reproducing apparatus according to claim 1, wherein a fifth means for processing a signal in units of (N / M) tracks and a sixth means for recording M sets of (N / M) tracks at substantially the same time. The third means and the fourth means for erasing when the tracks recorded by the sixth means at the same time do not include an audio signal.
6. A magnetic recording / reproducing apparatus characterized in that the means for operating is operated to erase the track to be recorded by the sixth means prior to recording. 3. A video signal and an L channel (L = 1, 2,
In a magnetic recording / reproducing apparatus for recording an audio signal of (3, ...) By dividing it into N tracks (N = 4, 5, 6, ...) At regular time intervals (for example, one field), -1) First means for recording the video signal on a track, Second means for recording the audio signal on a track, L channel audio signal within a fixed time, and within a time period that corresponds to that time 7. A magnetic recording / reproducing apparatus comprising: a seventh means for recording the L channel audio signal in the same track for recording the audio signal. 4. The magnetic device according to any one of claims 1 to 3, wherein adjacent tracks for recording the audio signals are configured so that the same head does not scan during normal recording and reproduction. Recording / playback device.