JPH06282942A - Digital signal recording device - Google Patents

Abstract

(57) [Abstract] [Objective] In a digital signal recording system for digitizing and recording a video signal and an audio signal, the movement amount of the AT head is reduced by arranging the recording area of the digital audio signal at the center of the inclined track. However, the load on the drive unit of the AT head is reduced. [Arrangement] By arranging the recording area of the digital audio signal in the central part of the inclined track, and by setting the division of the recording area of the digital video signal and the digital audio signal of the field unit at the end of the inclined track, The time required to reproduce the digital audio signal and load it into the field memory is shortened, and the movement amount of the AT head can be reduced when the cross fade editing of the digital audio is performed on the digital VTR main body, and the load on the AT head drive unit can be reduced. It can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing digital video signals and digital audio signals on a digital video tape recorder (hereinafter referred to as digital VTR).

[0002]

2. Description of the Related Art FIG. 2 shows a digital VTR D-3.
The tape format of VTR (1/2 inch digital VTR for SMPTE standard broadcasting) is shown. D-3
In a VTR, a digital video signal and a digital audio signal in one field period are divided into 3 segments in the NTSC system and 4 segments in the PAL system, and recording is performed while forming a slanted track on a tape by a pair of heads. To do. At this time, the recording areas of the digital audio signal are arranged at both ends of the inclined track as shown in FIG.
Audio channels 1 to 4 (A1 to A4 in the figure) are divided and recorded in the field. Further, the delimiter between the recording areas of the digital video signal and the digital audio signal in field units is the end of the inclined track.

FIG. 3 shows a time chart of signal processing in digital voice recording / reproducing of the D-3VTR PAL system. As shown in FIG. 3, the input sound in the 1-field period is captured 128 samples ahead of the 1-field period of the video (a1), and the time preceding the video signal is used to generate the 1-field period. Digital audio signal recording processing such as shuffling and error correction code generation is performed in units (a2), and as shown in FIG. 2, divided into 4 segments (a3 to a6) and recorded at both ends of the inclined track.

During reproduction, data for one field of four channels of reproduced digital audio signal is input to the field memory, subjected to digital audio reproduction processing such as error correction processing and deshuffling, and output.

[0005]

However, in the above-mentioned conventional digital signal recording system, when the cross-fade editing is executed by the main body of the digital VTR as an audio editing process, the reproduced digital audio signal is reproduced again as shown in FIG. It is necessary to output the reproduced audio signal at the same timing as the input timing so that it can be recorded again at the same position on the tape (b7). For this reason, as shown in FIG. 3, the reproducing head must precede the recording head by 9.5 segments, and the so-called automatic tracking head (movable head) that enables automatic tracking of the simultaneous reproducing position and the preceding reproducing position ( When this is realized by moving the AT head), there is a problem that a large load is applied to the drive unit of the AT head.

[0006]

To this end, the digital signal recording apparatus according to the present invention comprises means for recording a digital audio signal in the central portion of a tilted track, and delimitation of recording areas for digital video signals and digital audio signals in field units. Is at the end of the tilt track.

[0007]

According to the present invention, when the cross-fade editing is executed by the digital VTR main body as the editing process, the moving amount of the AT head is reduced and the load on the drive unit of the AT head is reduced by the above means.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a tape format diagram of a digital signal recording system in an embodiment of the present invention. In FIG. 1, the video signal is a component signal, and NTSC
525 mode corresponding to the system and 6 corresponding to the PAL system
The 25 modes are also shown. In the 525 mode, one field is divided into three segments S1 to S3, and in the 625 mode, one field is divided into four segments S1 to S4. And each segment is CH0-CH3
4 channels of each, and each channel goes from the lower end X on the tape to the upper end Y (or the upper end to the lower end).
Recording sectors are arranged in the order of video sector, four audio sectors, and video sector. That is, the four audio sectors are arranged in the center of each segment (that is, the center of the inclined track) so as to be sandwiched between the video sectors. As is clear from the above description, the segment S1 is composed of four segments from the lower end X1 to the upper end Y1 of the inclined track.
The segment S2 includes four channels from the lower end X2 to the upper end Y2 of the tilt track, the segment S3 includes four channels from the lower end X3 to the upper end Y3 of the tilt track, and the segment S4 includes the lower end X4 to the upper end of the tilt track. It consists of 4 channels up to Y4. Therefore, one field in the 525 mode has three segments S1 to S3 from the lower end X1 to the upper end Y3 of the inclined track.
One field in the 626 mode is 4 segments S1 from the lower end X1 to the upper end Y4 of the inclined track.
It is composed of S4. The following describes the 625 mode as an example.

As shown in FIG. 1, the video signal and the audio signal which are digitized every one field period of the video signal are divided into four segments, and the respective divided digital video signal and digital audio signal are shown in FIG. The recording head group consisting of four heads (first recording head group r0a to r3a) and (second recording head group r0b to r3b) shown in FIG. . At this time, the recording area of the digital audio signal is divided into four and recorded in the central portion of the inclined track. The digital audio signal can be recorded in four channels. As shown in FIG. 1, the four-channel digital audio signal (A1 to A4 in FIG. 1) is evenly recorded in the four divided digital audio signal recording areas. It That is, in the first segment S1, A1, A3, A2, A4
In the order of, A2, A4, A1, in the second segment S2
In the order of A3, A3, A1, A in the third segment S3
4 and A2 in this order, A4 and A in the fourth segment S4
The data is recorded evenly in one field in the order of 2, A3 and A1.

FIG. 5 shows a block diagram of a digital signal recording processing section in the embodiment of the present invention. In FIG. 5, 1 is a digital audio signal recording processing unit, 2 is a digital video signal recording processing unit, 3 is an output timing generation unit, 4
Is a digital video / audio signal processing unit.

The operation of the digital signal processing section will be described below. The input voice signal is digitized,
It is input to the digital voice recording processing unit 1. The digital voice recording processing unit 1 performs shuffling and error correction code generation. On the other hand, the input video signal is digitized and then input to the digital video signal recording processing section 2. The digital video signal recording processing unit 2 performs shuffling and generation of error correction code. In the output timing generation unit 3, a field signal synchronized with the input video signal is input, and the digital audio output timing signal and the digital video output timing signal are input to the digital audio recording processing unit 1 as shown in FIG. And output to the digital video recording processing unit 2. The digital audio recording processing unit 1 outputs the digital audio signals of four channels to the digital video / audio signal processing unit 4 in the order shown in FIG. 1 in the low section of the input digital audio output timing signal. Further, the digital video signal recording processing unit 2 outputs the digital video signal to the digital video / audio signal processing unit 4 in the low section of the input digital video output timing signal. The digital video / audio signal processing unit 4 again generates an error correction code, adds a SYNC signal and an ID signal to the input digital audio signal and digital video signal, then modulates and outputs them to the recording system, and then outputs them to the recording system. To record. At this time, the data read start timing T of each segment in FIG.
The data read at 1, T2, T3, T4 is
Recording start positions X1, X2 of the inclined track in FIG.
It is assumed that the servo control is performed so as to record from X3 and X4. As a result, the recording area of the digital video signal and the digital audio signal in units of fields is defined so as to start from the lower end X and end at the upper end Y of the inclined track as shown in FIG. 1, and the digital audio signal of each inclined track is defined. Recorded in the center.

Next, FIG. 7 shows a time chart of signal processing in digital audio recording / reproducing in the 625 mode in the embodiment of the present invention. As shown in FIG. 7, the input sound in the 1-field period is digitized and captured in accordance with the 1-field period of the video (a1). Next, by setting the recording area of the digital audio signal to the central portion of the inclined track and setting the recording start position of one field section to the lower end X1 of the inclined track, there is a time margin until the start of recording. Using this time margin, digital audio signal recording processing such as shuffling and error correction code generation is performed (a2). Then, as shown in FIG. 1, it is divided into four segments (a3 to a6), and each channel is evenly recorded in the four digital audio signal recording areas in the central portion of the inclined track.

During reproduction, data for one field of four channels of reproduced digital audio signal (b1 to b1
b4) is input to the field memory and digital voice reproduction processing such as error correction processing and deshuffling is performed (b4).
5) Output (b6). At this time, the digital audio signal 4
When the reproduced data for one field of the channel is taken into the field memory, the recording area of the digital audio signal is set at the central portion, so that one field of four channels is recorded as compared with the case where it is recorded at the end of the inclined track. The time required to reproduce the digital audio signal is 0.
It is shortened by 5 segments.

Further, by making the field delimiters of the input audio coincide with the video signal, when the reproduced audio signal is output at the same timing as the input timing (b6), 0.
5 segment time margin is created.

As a result, as shown in FIG. 7, at the position where the reproducing head precedes the recording head by 8.5 segments,
Digital VTR for crossfade editing as editing process
This can be executed by the main body, and the load on the drive unit of the AT head can be reduced.

In the digital signal recording system shown in the conventional example, when an attempt is made to execute crossfade editing as editing processing at the digital VTR main body at a position where the reproducing head precedes the recording head by 8.5 segments, the result shown in FIG.
As shown in, the time for digital audio signal reproduction processing cannot be secured (b5), and crossfade editing cannot be executed.

Further, in the case of the D-1VTR for recording a digital audio signal in the central portion of the inclined track, since the field delimiter is in the central portion of the inclined track, one AT head is inclined when performing double speed reproduction, for example. The AT must be instantaneously moved from the end point of the currently playing field in the center of the track to the start point of the next playing field in the center of the inclined track, which is a few tracks away.
It is difficult to control the head, and it is necessary to deal with it by increasing the number of reproducing heads. On the other hand, in this embodiment,
Since the field delimiter is always located at the end of the recording track, the two reproduction AT head groups p0a to p shown in FIG.
Since 3a and p0b to p3b are alternately used in segment units, when reproducing at double speed, for example, the fields to be reproduced are every other field.
Even when the reproducing head group is moved to the next field separated from the field, it is possible to move the AT head group which is not currently used for reproduction, and the AT head is easily controlled.

Further, as described in this embodiment, when the data of each channel of the digital audio signal is evenly recorded in the four digital audio signal recording areas in the central portion of the inclined track, as shown in FIG. A read address generating circuit is configured to record a digital audio signal. In FIG. 9, 5 is a read address generation unit, 6 is a segment address generation unit, 7 is a channel address generation unit, 8 is an in-channel data read address generation unit,
Reference numeral 9 is a field memory. The read address generation unit 5 is included in the digital audio signal recording processing unit 1 in FIG. 5, and includes a segment address generation unit 6 that divides a segment of data to be read, a channel address generation unit 7 that performs channel division, and 1 in one segment. It is composed of an in-channel data read address generation unit 8 for reading data in one channel. The read address generator 5 receives the digital audio signal output timing signal shown in FIG. The read address is output to the field memory 9 and the digital audio signal is read during the low period of the digital audio signal output timing signal. At this time, the read address generation unit (which includes the segment address generation unit 6, the channel address generation unit 7, and the in-channel data read address generation unit 8) 5 resets the A1 channel of the S1 segment by field reset input for each field. Initialization is performed so that the first data is read out, and an address is output respectively. After that, as described above, the intra-channel data read address generation unit 8 generates and outputs the address so that the data is read from the data of the A1 channel of the S1 segment during the low period of the digital audio signal output timing signal. After reading the data of the A1 channel of the S1 segment, the in-channel data read address generation unit 8 outputs a carry signal to the channel address generation unit 7, and the channel address generation unit 7 outputs the address indicating the A3 channel. Again, the in-channel data read address generator 8 uses the A of the S1 segment.
The data of three channels is read and a carry signal is output to the channel address generation unit 7. After that, A2, A
The 4-channel data is read and the S1 segment data is read. Then, the channel address generation unit 7 outputs a carry signal to the segment address generation unit 6, and the segment address generation unit 6 outputs the address indicating the S2 segment. Thereafter, as described above, in the S2 segment, the channels A2, A4, A1, and A3 are in this order, and in the S3 segment, A3, A1, A4, and A.
In the order of 2 channels, A4, A2 in S4 segment
It is recorded in the order of A3 and A1 channels.

As a result, the data of the A1, A2, A3, and A4 channels are evenly recorded, and errors such as tape damage can be dispersed over all channels and damage can be minimized.

[0021]

As described above, according to the present invention, the digital audio signal is recorded in the central portion of the inclined track, and the division of the recording area of the digital video signal and the digital audio signal in the field unit is the end portion of the inclined track. By doing so, when the cross-fade editing is executed by the digital VTR main body as the editing process, it is possible to reduce the advance amount of the reproducing head with respect to the recording head, and the simultaneous reproducing position and the preceding reproducing position are set to the AT head. When realized by moving, the load on the drive unit of the AT head can be reduced.

Further, by recording the n channels of the digital audio signal evenly in the n digital audio signal recording areas in the central portion of the inclined track, the error is dispersed to all the channels against tape damage and the like, and damage is caused. Can be minimized.

[Brief description of drawings]

FIG. 1 is a tape format diagram of a digital signal recording system according to an embodiment of the present invention.

FIG. 2 is a tape format diagram of a digital signal recording system in a conventional example of the present invention.

FIG. 3 is a signal processing time chart of digital audio recording / reproducing in the conventional example of the present invention.

FIG. 4 is a head layout diagram in an embodiment of the present invention.

FIG. 5 is a block diagram of a digital signal recording processing unit according to an embodiment of the present invention.

FIG. 6 is a time chart diagram of digital signal output timing in one embodiment of the present invention.

FIG. 7 is a signal processing time chart of digital audio recording / reproducing in one embodiment of the present invention.

FIG. 8 is a signal processing time chart of digital voice recording / reproducing in the conventional example of the present invention.

FIG. 9 is a block diagram of a read address generation unit according to the embodiment of the present invention.

[Explanation of symbols]

 1 Digital Audio Signal Recording Processor 2 Digital Video Signal Recording Processor 3 Output Timing Generator 4 Digital Video / Audio Signal Processor

Claims (2)

[Claims] 1. When a video signal and an audio signal are digitized and recorded, a slanted track is sequentially formed on a tape by a head group consisting of a plurality of heads arranged with a predetermined angular interval for the digitized video signal and the audio signal. In the digital signal recording device for recording as described above, the means for recording the digital audio signal in the central portion of the inclined track, and the division of the recording area of the digital video signal and the digital audio signal in field units are the end portions of the inclined track. And a digital signal recording device comprising: 2. A digital audio recording area arranged at the center of a tilted track is divided into n (n is an integer of 1 or more) and n
When recording digital audio of channels sequentially,
2. The digital signal recording apparatus according to claim 1, wherein the digital audio signals of the channels are evenly recorded in the n recording areas.