JPH01138647A - Tracking control system for r-dat - Google Patents

Abstract

PURPOSE:To accurately control a tracking by providing a head for detecting a pilot and detecting other signal even when a signal is not recorded to one side of a plus or minus azimuth track. CONSTITUTION:When a plus azimuth head (+H) detects an ATF synchronizing signal 342, a head (PH) 13 for detecting a pilot is provided on a position to detect an ATF synchronizing signal 331. When the minus of H becomes defective and a signal cannot be recorded into minus azimuth tracks (-T) 31, 33 and 35 at the time of recording, first, +H11 to move on +T34 detects an ATF synchronizing signal 342, and then, the PH13 detects ATF pilot signals 321 and 341 of the +T32. The intensity of the leakage magnetic field from the signals 321 and 341 is compared, and the travelling speed of the tape is changed so as to make the intensity of the detecting signal from the signals 321 and 341 coincident. Thus, the +H11 is tracking-controlled so as to trace correctly on the +T34 and the reproducing can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tracking control method for R-DAT, and is particularly applicable to a tape in which no signal is recorded on one of the plus azimuth track or the minus azimuth track. The present invention also relates to an R-DAT tracking control method that allows accurate tracking control.

R-DAT is a rotary head.
) type D A T (Digital Audio T
ape recorder), and has superior performance in terms of SZN ratio 1 frequency characteristics, distortion rate, dubbing characteristics, random access, etc., compared to conventional analog tape radars.

[Conventional technology]

In recent years, research and development of DAT has progressed, and in particular, R-DAT, which can be applied to VTR technology, has already been put into practical use.

This R-DAT is, for example, approximately 6°23 with respect to the tape.
Data signals such as stereo music are digitized and time-compressed and recorded on tracks having a width of 13.6 .mu.m and having an angle of . When reproducing recorded signals, it is necessary for the head to accurately trace the track, and for this reason, as part of the R-DAT standard, the part where data signals such as stereo music are recorded (PCM A T F (Automatic Track Fi) that performs tracking control on both sides of the
nding) signal is recorded. This ATF signal is composed of a sync signal and a pilot signal, and tracking control is performed by detecting the ATF signal recorded on each track during playback and changing the running speed of the tape.

FIG. 5 is a diagram for explaining the tracking control system of the conventional R-DAT, and FIG. 5(a) shows the structure of the head provided on the rotating drum, and FIG. This figure shows the tape format and the relative relationship between moving heads to explain tracking control using ATF signals. As shown in FIG. 2A, the conventional R-DAT head includes a positive azimuth head 111 and a negative azimuth head 112 arranged at an angle of 1800 degrees around the outer periphery of a rotating drum 101.

Here, reference number 102 indicates a fixed drum, and a rotary drum lot provided with two heads 11L112 is configured to rotate on the fixed drum 102.

The positive azimuth head 111 is arranged so that its azimuth angle is plus 20 degrees with respect to the direction perpendicular to the tracing direction of the head, and the negative azimuth head 111 is
12 has an azimuth angle of -20° with respect to a direction perpendicular to the tracing direction of the head. As a result, each azimuth head 11L112
When reproducing the signals recorded on each azimuth track, the azimuth track is hardly influenced by the signals recorded on adjacent tracks.

By the way, in the R-DAT, various signals to be recorded and played back on the tape 103 are defined by a predetermined format, and tracking control is performed by the ATF on both sides of the PCM part.
and ATF2. That is, as shown in FIG. 5(b), for example,
When the plus azimuth head 111 is tracing the plus azimuth track 134, when the plus azimuth head 111 detects the ATF sync signal 1342 of the plus azimuth track 134 at A T F +,
The ATF pilot signal 1332 of the next adjacent negative azimuth track 133 to that track 134 is detected, and furthermore, the ATF pilot signal 1352 of the negative azimuth track 135 adjacent to the front of the track 134 is detected. That is, the positive azimuth head 111 moving on the positive azimuth track 134 moves on the negative azimuth tracks 133 and 135 adjacent on both sides.
ATF pilot signals 1332 and 1352 at
Compare the strength of the leakage magnetic field from both pilot signals 13
The running speed of the tape is changed so that the intensities of the detection signals from 32 and 1352 are matched.

As a result, the positive azimuth head 111 is tracking-controlled so as to accurately trace the positive azimuth track 134. Such an ATF signal is applied to the AT on both sides of the PCM portion for each track.
It is recorded in two locations: F+ and ATFZ. Here, the ATF pilot signal is specifically 130.67
A KHz signal is used, which has a frequency that is not easily affected by azimuth loss.

[Problem that the invention seeks to solve]

As described above, the conventional R-DAT is configured to perform recording and reproduction using two heads, a plus and a minus azimuth head.

Tracking control is performed using the PCM of each track.
This is done by detecting the sync signal and pilot signal of the ATFs provided on both sides of the section and ATF2.

Incidentally, R-DAT has a small tape output, and recorded signals may not be completely readable due to the thinness of the tape, contact with the head, adhesion of dust, clogging of the head, etc.

To this end, the R-DAT has various functions for correcting and supplementing errors during playback. For example, during playback, if the signal of one of the positive azimuth tracks or the negative azimuth track cannot be read, the recorded signal can be restored by interpolating the signal of the other readable azimuth track (average value interpolation). Can be played. However, conventional R-DA
In the T, unless a signal is recorded on either the positive azimuth track or the negative azimuth track, tracking control using the ATF signal cannot be performed, and therefore the recorded signal cannot be reproduced. In other words, in the conventional R-DAT, if one azimuth head becomes defective during playback and the signal can only be read from the other azimuth head, the signal from the other azimuth track that could be read is averaged by interpolation. It was possible to reproduce the recorded signal. but,
If one azimuth head becomes defective during recording and a signal cannot be recorded on one azimuth track, tracking control using the ATF signal cannot be performed even if both azimuth heads can read the recorded signal during playback. Therefore, it was impossible to reproduce the recorded signal.

That is, as shown in FIG. 5(b), for example, if the negative azimuth radar 112 becomes defective during recording and no signal is recorded on the negative azimuth track 13L 133,135, the positive azimuth Radar 111
is the ATF sync signal 1 of the positive azimuth track 134
342 is detected, the ATF pilot signal 1332 of the next adjacent minus azimuth track 133 after that track 134 and the ATF pilot signal 1352 of the minus azimuth track 135 adjacent before the track 134 are not recorded and cannot be tracked. cannot be controlled.

For example, even if the minus azimuth head 112 is normal (reading recorded signals is possible) during playback, the minus azimuth head 112 moving on the minus azimuth track 133 will
ATF of the next adjacent positive azimuth track 132
Although it is possible to detect the pilot signal 1321 and the ATF pilot signal 1341 of the positive azimuth track 134 adjacent to the front of the track 133, the ATF sync signal 13 of the negative azimuth track 133
31 is not recorded, tracking control cannot be performed.

In this way, in the conventional R-DAT, if a signal is not recorded on either the positive azimuth track or the negative azimuth track, both the positive azimuth head and the negative azimuth head are normal during playback. However, the recorded signals could not be reproduced because tracking control could not be performed.

In view of the problems of the tracking control method of the conventional R-DAT described above, an object of the present invention is to perform tracking control even for tapes in which no signal is recorded on either the positive azimuth track or the negative azimuth track. The purpose of this method is to read the signal of the other track accurately and to reproduce the recorded signal.

[Means for solving problems]

According to the present invention, there is provided a tracking control method for an R-DAT that detects ATF signals recorded by first and second azimuth heads during recording and controls tracking during playback. If no signal is recorded, an ATF sync signal of a second azimuth track is detected by the second azimuth head, and in response to the detection, an ATF pilot signal of the second azimuth track is transferred to the first azimuth track. A tracking control method for an R-DAT is provided, which is characterized in that tracking control is performed by detecting a pilot with a pilot detection head that moves on a track.

[For production]

According to the tracking control method of the R-DAT of the present invention having the above-described configuration, when no signal is recorded on the first azimuth track, the ATF sync signal of the second azimuth track where the signal is recorded is A of the second azimuth track is detected by the second azimuth head.
The TF pilot signal will be detected by the pilot detection head.

As a result, even for tapes where no signals are recorded on the first azimuth track, tracking control can be performed accurately and playback can be performed from the signals on the second azimuth track where signals are recorded. .

〔Example〕

Hereinafter, the R-DAT tracking control method according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining the tracking control method of the R-DAT of the present invention, in which (a) shows the relative relationship between the tape format and the moving head, and (b) This shows the detected signal waveform.

As shown in FIG. 1(a), a case will be described in which, for example, the minus azimuth head becomes defective due to clogging or the like during recording and no signal can be recorded on the minus azimuth tracks 3L33, 35. First, in ATF,
The positive azimuth head 11 moving on the positive azimuth track 34 is the AT of the positive azimuth track 34.
When the F sync signal 342 is detected, the pilot detection head 13 provided on the rotating drum moves to the track 3 so as to have a predetermined positional relationship with the positive azimuth head 11.
The ATF pilot signal 321 of the next positive azimuth track 32 after 4 is detected, and the ATF pilot signal 321 of the track 34 is further detected.
Detect pilot signal 341.

That is, in the ATF, the plus azimuth head 11 moving on the plus azimuth track 34 receives the ATF sync signal 34 of the plus azimuth track 34.
2, the pilot detection head 13 moving on the minus azimuth track 33 comes to a position where it detects the ATF sync signal 331 under normal conditions. As a result, the positive azimuth head 11 receives the ATF sync signal 342 of the positive azimuth track 34.
, the pilot detection head 13 detects the ATF pilot signal 321 and the ATF pilot signal 341 in the positive azimuth tracks 32 and 34 adjacent to both sides of the negative azimuth track 33, and detects the leakage magnetic field from these ATF pilot signals 321 and 341. The running speed of the tape is changed so that the intensities of the detection signals from both pilot signals 321 and 341 match. As a result, the positive azimuth radar 11 is controlled to accurately trace the positive azimuth track 34, and the signal recorded on the positive azimuth track 34 can be reproduced. The signal (PCM signal) recorded on this plus azimuth track 34 will be interpolated and reproduced. Here, the azimuth angle of the pilot detection head 13 is perpendicular to the tracing direction of the head.

The positional relationship between the positive azimuth head 11 and the pilot detection head 13 in the case of FIG. 1(a) is as shown in FIG. 2(a).
As shown in FIG. 1 and (b), the pilot detection head 13 is located above the positive azimuth head 11 by a distance (d) of one track (approximately 13.6 μm) in the height direction, and is located above the rotating drum 1. They are spaced apart from each other by a distance of four blocks (approximately 153 μm) d2 in the direction of rotation. As a result, as shown in FIG. 1(b), in the ATFI, the positive azimuth rad 11 is changed to the ATF sync signal 342 (of the positive azimuth track 34).
When the signal Sl) is detected, the pilot detection radar 13
detects the ATF pilot signal 321 (signal P11) and ATF pilot signal 341 (signal P, □) in the positive azimuth tracks 32 and 34 adjacent to both sides of the negative azimuth track 33, and detects the leakage from these ATF pilot signals 321 and 341. By comparing the strength of the magnetic field (for example, comparing the sample hold timing of 2 blocks), both pilot signals 321 and 34 are determined.
The running speed of the tape is changed so that the intensities of the detection signals Pl+ and P1□ from No. 1 are made equal to each other.

When ATF2 is detected by the head having the configuration shown in FIG.
Detection signals PH1 and P22 of the pilot detection head 13 are compared six blocks after the detection of the pilot detection head 13 at a sample hold timing of two blocks.

In the above, tracking control in each track may be performed by detecting either ATF or ATF2 in each track;
This can also be done by detecting both FI and ATF. Further, the positional relationship between the pilot detection head 14 and the negative azimuth head 12 is the same as the positional relationship between the pilot detection head 13 and the positive azimuth head 11, and the positive azimuth tracks 32 and 34
It is designed to be able to handle tapes on which no signals are recorded. Therefore, rotating drum 1 has 4
Two heads will be provided. Here, reference number 2 indicates a fixed drum, and a rotary drum 1 provided with four heads 11 to 14 is configured to rotate on a fixed drum 2.

FIG. 3 is a diagram showing another example of the head configuration for realizing the R-DAT tracking control method of the present invention. The same figure (a
) and (b), the R-DAT of the present invention
Another example of a head configuration that realizes the tracking control method is that the pilot detection head 13 is set at a distance of one track in the height direction (approximately 13
．． 6 μm) d, and are spaced apart from each other by a distance of two blocks (approximately 76.5 μm) d2 in the rotational direction of the rotating drum 1. As a result, for example, the positive azimuth head 11 is connected to the positive azimuth track 34.
When the ATF sync signal 343 is detected, the pilot detection head 13 comes to the position where the ATF sync signal 334 should be detected in the normal state of the negative azimuth track 33 adjacent to the track 34. Further, the positional relationship between the pilot detection head 14 and the minus azimuth head 12 is the same as the positional relationship between the mohirosoto detection head 13 and the plus azimuth head 11. It has also been designed to be able to handle this.

FIG. 4 is a diagram showing still another example of the head configuration for realizing the R-DAT tracking control method of the present invention. The head configuration shown in FIGS. 4(a) and 4(b) is as follows:
Both of the pilot detection heads described with reference to FIGS. 2 and 3 are provided, and the rotary drum 1 has six
There will be several heads. That is, the positional relationship between the positive azimuth head 11 and the pilot detection heads 13a and 13b is as follows:
3a and 13b are at a distance of one track in the height direction from the positive azimuth head 11 (approximately 13.6 μm) d,
It is separated from the top. In addition, the pilot detection head 13a is spaced apart so as to be delayed by a distance d2m corresponding to four blocks in the rotational direction of the rotary drum l, and
The pilot detecting rods 13b are provided so as to be spaced apart from each other by a distance azb corresponding to two blocks in the rotational direction of the rotary drum 1. And the pilot detection head 13
A detects the pilot signals 321 and 341 of the ATF, and the pilot detection head 13b performs tracking control by detecting the pilot signal L324°344 of the ATF2. The same applies to the positional relationship between the pilot detection heads 14a and 14b and the minus azimuth head 12.

In the head configuration for realizing the R-DAT tracking control system of the present invention shown in FIGS. 2 to 4 described above, the pilot detection head is configured to trace over the next negative azimuth head adjacent to the positive azimuth head. However, the pilot detection head can also be provided at a position where it traces over the negative azimuth head in front of and adjacent to the positive azimuth head. Further, it goes without saying that the positional relationship between the positive azimuth head, the negative azimuth head, and the pilot detection head is not limited to that shown in FIGS. 2 to 4.

〔Effect of the invention〕

As described above in detail, in the R-DAT tracking control method according to the present invention, when a signal is not recorded on either the positive azimuth track or the negative azimuth track, the ATF of the other track where the signal is recorded is
By detecting the sync signal and detecting the ATF pilot signal of the other track where the signal is recorded with the pilot detection head, tracking control is performed accurately and the signal recorded on the other track is complemented. can be played.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the tracking control method of the R-DAT according to the present invention, FIG. 2 is a diagram showing an example of a head configuration for realizing the tracking control method of the R-DAT according to the present invention, and FIG. 4 is a diagram showing another example of the head configuration for realizing the R,-DAT tracking control method of the present invention, and FIG.
FIG. 5 is a diagram illustrating a conventional R-DAT tracking control method. (Explanation of symbols) ■... Rotating drum, 2... Fixed drum, 3... Tape, 11... Plus azimuth head, l2... Minus azimuth head, 13, 13a, 13b, 14.14a , 14b-pilot detection head, 31.33.35... minus azimuth track, 3
2.34...Plus azimuth track, 321.32
4,341.344...ATF pilot signal, 32
2.323,342,343...ATF sink signal.

Claims (1)

[Claims] 1. An R-DAT tracking control method that detects ATF signals recorded by first and second azimuth heads during recording and controls tracking during playback, comprising:
If no signal is recorded on the first azimuth track, the second azimuth head detects the ATF sync signal on the second azimuth track, and in response to the detection, the ATF pilot signal on the second azimuth track is detected. A tracking control method for an R-DAT, characterized in that tracking control is performed by detecting a pilot detection head that moves on the first azimuth track. 2. The method according to claim 1, wherein the pilot detection head performs tracking control by detecting one of two ATF signals recorded on the second azimuth track. 3. The method according to claim 1, wherein the pilot detection head detects both of the two ATF signals recorded on the second azimuth track to perform tracking control. 4. The pilot detection head is provided adjacent to the second azimuth head, and when the second azimuth head detects the ATF sync signal of the second azimuth track, the pilot detection head 2. The system of claim 1, wherein the system is adapted to detect an ATF pilot signal of the second azimuth track. 5. The method according to claim 1, wherein one pilot detection head is provided adjacent to each of the first and second azimuth heads. 6. The pilot detection head is provided at a distance of one track in the height direction and a distance of four blocks in the rotational direction from the second azimuth head, and When the head detects the ATF sync signal on the second azimuth track, the pilot detection head detects the position where the ATF sync signal should be detected in the normal state of the first azimuth track adjacent to the second azimuth track. The method according to claim 5, wherein the method is adapted to: 7. The pilot detection head is provided at a distance of one track in the height direction and a distance of two blocks in the rotational direction from the second azimuth head, and When the head detects the ATF sync signal on the second azimuth track, the pilot detection head detects the position where the ATF sync signal should be detected in the normal state of the first azimuth track adjacent to the second azimuth track. The method according to claim 5, wherein the method is adapted to: 8. The method according to claim 1, wherein two pilot detection heads are provided adjacent to each of the first and second azimuth heads. 9. One of the pilot detection heads is spaced apart from the second azimuth head by a distance of one track in the height direction and a distance of four blocks in the rotational direction, and one of the pilot detection heads The other of the pilot detection heads is spaced apart from the second azimuth head by a distance of one track in the height direction and a distance of two blocks in the rotational direction, and each of the pilot detection heads Said second
when the azimuth head detects the first or second ATF sync signal in the second azimuth track,
The first or second AT in the normal state of the first azimuth track adjacent to the second azimuth track, respectively.
9. The method according to claim 8, wherein the F sync signal is located at a position where it is to be detected.