JPH0221450A - Controller for reproducing device - Google Patents

Abstract

PURPOSE:To stably perform control even when stuffing is generated in a head on one side by finding a tracking error signal independently without averaging by using the computed result of an arithmetic means which performs a specific arithmetic operation. CONSTITUTION:The H, R, and L of a pilot signal level reproduced from a selected track and pilot signal levels cross-talked from a right adjacent track and a left adjacent track are found, respectively, and the arithmetic operation of S=(H-R)+A(L-R) is performed at a (2i+1)th track, and the arithmetic operation of S=(H-L)+A(R-L) is performed at a 2i-th track, and a driving means to attach fluctuation on the relative position of an information recording medium and a read-out means is controlled based on an obtained signal S. In such a way, it is possible to obtain the value of the tracking error signal 24 without averaging even in a long time of reproduction, and to perform the tracking control stably even when the stuffing is generated in the head on one side.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tracking device, particularly a playback device for tracking signal tracks recorded on a magnetic tape as a recording medium in a rotary head type magnetic recording and playback device. The present invention relates to a control device.

[Conventional technology]

Some rotary head magnetic recording and reproducing devices convert input audio signals into digital signals and record them on a magnetic tape in the form of digital signals. During playback, the digital signals recorded on the magnetic tape are converted into D/A converters. A rotary head digital audio recorder that converts the signal back to the original analog audio signal and outputs it.
ype Digital Audio Tape-re
coder (hereinafter referred to as R-DAT).

As shown in Fig. 3, R-DAT uses a small diameter drum 1 with a diameter of 301 m, and has two rotating heads (A head (+azimuth head) 2a (!:
B head (-azimuth head) 2b) is attached to drum 1 facing 180 degrees, and tape 3 is attached to drum 1 at 90 degrees.
The track formant signal shown in FIG. 4 is recorded without a guard band.

In the track format shown in Figure 4, 4 is PCM
The PCM sub-regions 5a and 5b which record encoded audio signals are ATF? where signals for tracking during playback are recorded. The iI area, 6a, and 6b are subcode areas for recording additional information such as song number and time information, and are divided into five blocks. During playback, a tracking error signal, which is a signal for tracking the signal track, is generated from the signals recorded in the ATF 95 areas 5a and 5b, and track tracking is performed so that the tracking error signal becomes zero. . ATF
FIG. 5 shows the signal recording pattern in the fiI areas 5a and 5b.

In FIG. 5, r, signal 7 is called pylon Hg%, which generates the tracking error signal e f
11 times 8, f, and signal 9 are called sync signals and are used as timing detection signals for generating tracking error signals. f22 times 8 is on A track (+azimuth track), f.

Signal 9 is recorded on the B track (-azimuth track), and its recording length is 0.5 block length every two tracks.
■The signal recording pattern is recorded by changing the block length and can be completed in 4 tracks. This makes it easy to identify the tracks, and is designed to prevent tracking across multiple tracks in a diagonal direction during normal playback. f44 times 10 is a signal for erasing the biloft signal and sync signal by overwriting.

A method of generating the ATF call signal recording pattern tracking error signal shown in FIG. 5 will be described with reference to FIGS. 6 and 7. FIG. 6 is a block diagram showing the configuration of a circuit that generates a tracking error signal, and FIG.
The head (-azimuth head) 2b is A shown in FIG.
TF call signal recording pattern 11-Rack ATFIS
6 shows signal waveforms of each block in FIG. 6 when the Jj area 5a is scanned without track deviation. R-DA
In T, the head width is usually 1.5 times the track width, so the head scans over adjacent tracks as well.

In FIG. 6, the head output signal is amplified by the head amplifier 11 and input to the low-pass filter 12. In the low-pass filter 12, r11 times (pilot signal) 7 is extracted, and further input to the envelope detection circuit 13.
An envelope signal as shown at 18 in FIG. 7 is output. In the envelope signal 18, f IAZ and f
IAI is the reproduction output of the adjacent track, that is, the reverse azimuth track, and since the f signal has a low frequency, it is reproduced without being affected much by the azimuth effect of the head.

The output signal 27 of the head amplifier 11 is also input to the sync signal detection circuit 14, and the sync signal (rz signal 8 or f,
The signal 9) is detected and outputs a signal as shown at 19 in FIG. The sync signal detection circuit 14 inputs the head switching signal 25, and depending on its polarity, for example, when it is at a "low" level, it detects f22 times 8, and when it is at a "high" level, it detects f3 times 9. ing. The first sampling pulse SPI (20) is output from the sampling pulse generation circuit 15 in synchronization with the rising edge of the output signal 19 of the sync signal detection circuit 14, and then the first sampling pulse SPI (20) is output for a certain period of time (
τ time), the second sampling pulse/s 5p2
(21) is output. Sampling pulse generation circuit 1
5 inputs the head switching signal 25, divides it by a built-in frequency divider circuit (not shown), and determines the recording length of the sync signal according to the polarity of the divided signal. . For example, only if a 0.5 block length sync signal portion is scanned when the frequency-divided signal is at a “low” level, and a 1 block length sync signal portion is scanned when the frequency-divided signal is at a “high” level. A second sampling pulse 5P2 (21) is generated. Therefore, when the head scans a track other than the predetermined track, the second sampling pulse SP2 (21) is not output, so a tracking error signal is not generated, and tracking that crosses multiple tracks diagonally is prevented. There is.

Output envelope signal 18 of envelope detection circuit 13
is input to the input of the first sample and hold circuit 16a and one input terminal of the differential amplifier 17. In the first sample hold circuit 16a, the first sampling pulse SPI
(21), the right adjacent track (A2 in Fig. 7)
1-rack) is sampled and held, and a signal shown at 22 in FIG. 7 is output. Output signal 22 of first sample and hold circuit 16a
is input to the other input terminal of the differential amplifier 17, and a difference signal 23 with the envelope signal 18 is output as the output of the differential amplifier 17. Second sampling pulse SP2
At the time when (21) occurs, the difference signal output 23 of the differential amplifier 17 is f of the right adjacent track, the signal crosstalk component +Az, and the left adjacent track (A, I in FIG. 7).
- rack), and the difference between the signal crosstalk component IAI is output, and the signal sampled and held by the second sampling pulse 5P2 (21') in the second sample and hold circuit 16b is converted into the tracking error signal T. ,
It becomes B24.

In the case of FIG. 7, the case is shown when there is no track deviation, and when there is a track deviation, the level of f from the adjacent track and the signal crosstalk component changes, so the output level of the tracking error signal 24 is the same as the track deviation. It changes to the positive side or negative side depending on the direction of deviation. FIG. 8 shows the level changes of track misalignment, f11 times crosstalk component 26a from the left adjacent track, f from the right adjacent track, signal crosstalk component 26b (R), and tracking error signal 24 (R- In figure 0 showing the relationship between the output changes of L), 180 degrees corresponds to one track width. Track tracking is performed so that the tracking error signal 24 is always zero.

Further, FIG. 9 shows waveforms of the head switching signal 25 and the head amplifier reproduction signal during normal reproduction. As shown in Fig. 3, in the R-DAT, the tape 3 is wound around the drum 1 only at 90 degrees, and recording and playback is performed using two rotating heads mounted 180 inches opposite each other, so the playback signal 27 is intermittently generated. Naturally, the recorded signal will also be intermittent.

Therefore, digital data sampled during the recording process is compressed on the time axis and recorded, and during the playback process, the digital data is expanded on the time axis and restored to its original state.

Now, the method for generating the tracking error signal during normal playback has been described so far, but the method for generating the tracking error signal during playback in the long-time mode, which is a special function, will now be described. In the long-time mode, the drum rotation speed and tape feed speed are reduced to half of normal recording and playback speeds.
This mode allows recording and playback to be performed twice as long on the same tape as in normal recording and playback. Theoretically, both the drum rotation and tape feed speed can be reduced to half of the normal speed during playback, but then the relative speed between the tape and the head during playback will also be reduced to half of the normal speed, and the playback signal will be reduced. level will decrease.

Therefore, when playing in long-time mode, the tape advance speed is 2 times the normal speed.
The drum rotation will remain at the normal rotation rate, although the rotation will be reduced to 1/2. At this time, as shown in FIG. 10, the trajectory of the head has a different inclination from the recording pattern, and the head passes through the same track twice, resulting in incomplete tracking for all patterns.

When trying to enlarge two of the four envelopes,
The playback signal is determined from the tracking trajectory of the head by 2 in Figure 11.
7 output, and the one that can properly take the sync signal is A.
2. Only the output of the ATF area of Bl is available.

In the case of long-time playback, ATF sampling pulses must be generated only at these two locations.

However, if the ATF error output is extracted using the configuration shown in Figure 6, the ATF error will be as shown in 24 in Figure 11.
The error sampled by B1 contributes for a longer time than the error in A2, A2. In order to equalize the contribution rates of the error outputs of Bl, it is necessary to treat the error outputs of A2.81 equally. Therefore, for long-time playback, a circuit configuration as shown in FIG. 13 is required.

In the figure, 21a is the second sampling pulse SP2
However, it is output only when the head switching signal 25 is, for example, "low" level, and 21b is also the second sampling pulse SP2, but this is when the state of the head switching signal 25 is different from 21a, for example, "high". ” Output only when level. 16c is the second second sample hold circuit, 24b is the output obtained from the second second sample hold circuit 16c, and 2a is the output 24 of the first second sample hold circuit 16b. A summing amplifier 32 adds and amplifies the output 24b of the second sample-hold circuit 16c, and 32 is a long-time playback/normal playback switching signal, which, when indicating a long-time playback state, becomes, for example, a "heil bell." Also, a sampling pulse is generated. The two types of second sampling pulses 21a and 21 shown above output by the circuit 15
b is limited to when the long-time playback/normal playback switching signal 32 indicates long-time playback at the "high" level, and if the signal 32 is at the "low 2" level, it is normal playback, so 21a and 21b correspond to 21 in FIG. 30 is the tracking error signal 24 during normal playback.
This is a switch for selecting the tracking error signal 24c during long-time playback.

The output of the tracking error signal 24c during long-time playback will be explained using FIGS. 13 and 12. As shown in FIG. 12, the second sampling pulse 21a is output at a point A2, and the output 23 of the differential amplifier 17 at this moment is held in the first second sample and hold circuit 16b. Also, the second sampling pulse 21b
is also output at the location Bl as shown in FIG.
The output 23 of the differential amplifier 17 at this moment is shown in bold in the second second sample and hold circuit 16c. Each second sample and hold circuit 16b. The outputs 24 and 24b obtained from the 16C are added together by a summing amplifier 29 to form a tracking error signal 24c during long-time playback. l Ruffing error signal 2 obtained in this way
In 4C, since the generation interval of the second sampling pulse 21b is the same as the generation interval of the second sampling pulse 21a, the error signal 24 obtained at the point A2 and the error signal 24b obtained at the point 81 are the same. exist as the same contribution rate, and the averaged result is obtained as the correct tracking error signal 24c.

[Problem to be solved by the invention]

Conventional control devices are configured as described above, so during normal playback, tracking errors are sampled at two locations in one track scan, but during long playback, tracking errors are sampled at two locations out of four scans, and the average of the two is sampled. is used as the correct tracking error signal. Therefore, if one head becomes clogged and data is read using only one head, the values cannot be averaged, so a correct tracking error signal cannot be obtained, making it impossible to perform accurate tracking. There was a point.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a control device for a playback device that can stably perform tracking control even when one head is clogged.

[Means to solve the problem]

A control device for a playback device according to the present invention is a control device for use in a playback device that plays back a recording medium in which a tracking signal (Viloft signal) is recorded multiplexed with information on a plurality of mutually adjacent information tracks. reading means for reproducing signals from the information track; level detection means for separating and extracting the pilot signal level reproduced from the selected track and the pilot signal levels H, R, and L crosstalked from the right adjacent track and the left adjacent track, respectively; If the selected track is the 21st+1st track, S- (H
-R)+A (L-R), and in the case of the 21st track, S=(H-L)+A (R-L); an information recording medium in accordance with the signal S; and a driving means for varying the relative position between the reading means and the reading means.

[Effect]

In the control device according to the present invention, H, R, and L of the pilot signal level reproduced from the selected track and the pilot signal level crosstalked from the right adjacent track and the left adjacent track are determined respectively.In the 21st+1st track, S= ( H-R)+A (L-R), or in the 21st track, S= (
Since the calculation HL)+A(R-L) is performed and the driving means that changes the relative position between the information recording medium and the reading means is controlled based on the signal S obtained, it is possible to Also, the tracking error signal can be obtained without averaging the values.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained using FIGS.

FIG. 1 fat shows the configuration of an embodiment of the present invention in which the 2i+1th track is the selected track, and FIG. 1(b) shows the configuration in which the 21st track is selected.

When long-time playback is specified by the long-time playback/normal playback switching signal 32, the sampling pulse generation circuit 15
Gate signal 33a specifying the ATF2jl area 5b of the track or ATFISI of the B track
Only when the gate signal 33b specifying the area 5a is active (output at 6 high level), three consecutive sampling pulses SPI.

SF3. Generate SF3. The timing at which SF3 (31) is output is after the output of SF3 (21) for a time τ, which is the same as the time between 5P1eSP2 (see Figure 2).
a), (bl), 34 is an amplifier that varies the gain of the output 24 of the second sample and hold circuit 16b, and 35 is the output of the amplifier 34 and the second sample and hold circuit 16c.
A differential amplifier 36 obtains the difference between the outputs 24d of the amplifier 34.
and the output 22 of the first sample and hold circuit 16a.
37 is a summing amplifier that adds the calculation result of the differential amplifier 35 or subtraction amplifier 36 and the envelope signal 18. 16d is a summing amplifier that holds the calculation result of the summing amplifier 37 at the timing of 5P3 (31) and outputs it. 38 is a gate signal 33
When a or 33b is at a "high" level and long-time playback is specified, this is an AND gate that outputs a switching signal to select the output of the third sample-and-hold circuit 16d as a tracking control signal.

Next, the operation will be explained using FIG. 1 (al) and FIG. 2 (a). In order to perform long-time playback, the tracking error signal is During scanning, Bl can be obtained only at two locations, A2 (5b) and Bl (5a).
In (5a), the output of the second sample and hold circuit 16b similar to that in normal reproduction is used as the tracking error signal 24, and signal generation in A2 (5b) is as described below.

That is, the second sample hold circuit 16b calculates the difference 24 (R-) between f, signal crosstalk component (R) of the right adjacent track and r, signal crosstalk component (L) of the left adjacent track
L), and the first sample hold circuit 1
6a is f of the right adjacent track, signal crosstalk component 22
is outputting.

After the output 24 is varied by the amplifier 34, the output 22
is input as is to the subtraction amplifier 36, and the calculation result (
-R+A (L-R)) is added to the envelope signal 18 by a summing amplifier 37.

In A2, that is, the A-track ATF2 area 5b, the gate signal 33a is at the "high" level, and the sampling pulse generation circuit 15 generates the sampling pulse 5P3 (31
) is generated, and the calculation result of the summing amplifier 37 is (H-R)+A
(LR) is held in the third sample hold circuit 16d. Is the output 24C of the third sample hold circuit 16d A2 (5b)? It becomes a tracking error signal in the iU range, and becomes A2. The tracking error signal for each region of Bl is switched by an analog switch 30, and the switching is performed based on the result of logical product (AND gate 38) of the gate signal 33a and the long-time playback/normal playback switching signal 32. According to the configuration of FIG. 1 (al) shown above, track A is recognized as the selected track, and S=
(H-R)+A (L-R) is used to control the phase by delaying the phase by 45@, and the result is 81? In the il area 5a, tracking control is applied by calculation 5-LR for normal reproduction.

Next, the operation will be explained using FIG. 1(b) and FIG. 2(bl). In the case of the configuration shown in FIG. 16
The output of b is the tracking error 24, and B
Signal generation in l (5a) is as described below.

That is, the second sample hold circuit 1 used for normal playback
6b and another second sample hold circuit 16c convert the envelope signal 18 into a sampling pulse SP2 (21)
Hold. The value and the output of the amplifier 34 are input to a differential amplifier 35, and the output and the envelope signal 18 are added together by a summing amplifier 37. B1, i.e. B track AT
In the FI region 5a, the gate signal 33b is at a "high" level, and the sampling pulse generation circuit 15 generates a sampling pulse 5P3 (31), and the summing amplifier 3
The calculation result (H-L)+A (R-L) of step 7 is held in the third sample hold circuit 16d. The output 24C of the third sample and hold circuit 16d becomes a tracking error signal in the Bl (5b) region, and A2. The tracking error signal for each region of Bl is switched by an analog switch 30, and the switching is performed based on the result of logical product (AND gate 3B) of the gate signal 33b and the long-time playback/normal playback switching signal 32. Figure 1(b) as above
According to the configuration, track B is recognized as the selected track, and track A is recognized as the selected track.
2? In the fl region 5b, B 1 ? In lI region 5a, S-(HL)+A
Control is performed to advance the phase by 45 degrees by the calculation (R-L), and tracking control is performed.

〔Effect of the invention〕

As described above, according to the present invention, when the selected track is track A, the calculation result is S - (HR) + A (LR) in the ATF2 area of track A,
In the B track ATF16i area, the calculation result is 5=L-R, and if the selected track is the B track, in the B track ATF1jW area, the calculation result is S - (H-L).
With the calculation result of +A (R-L), A-track ATF
In the 26N region, the tracking error signal is calculated independently without being averaged using the calculation result of 5-LR, so that stable control can be performed even if one head is clogged.

[Brief explanation of the drawing]

FIGS. 1(b) and 2(a) are diagrams showing the configuration of a control device of a playback device according to an embodiment of the present invention, respectively.
(bl is an operating waveform diagram of the above embodiment, FIG. 3 is a plan view showing the configuration of the conventional device, FIG. 4 is a diagram showing the track format on the tape of the conventional device, and FIG. 5 is a diagram of the conventional device. Figure 6 shows the ATF signal recording pattern, Figure 6 shows the configuration of the circuit that generates the tracking error signal, Figure 7 shows the configuration of the circuit that generates the tracking error signal.
The figure shows the B head and the ATF14ff of the B1 track in Figure 5.
Figure 8 shows signal waveforms for scanning the area without track deviation. FIG. 9 is a diagram showing the relationship between the output change of the tracking error signal, and FIG. 9 is a diagram showing the head switching signal and head amplifier reproduction signal waveform during normal playback.
0 is a diagram showing a head tracking pattern during long-time mode playback, FIG. 11 is a waveform diagram showing a tracking error signal during long-time mode playback with the configuration of FIG. 6, and 12
13 is a waveform diagram showing a tracking error signal during long-time mode playback with the configuration shown in FIG. 13, and FIG. 13 is a diagram showing a circuit configuration required during long-time mode playback. 11 is a head amplifier, 12 is a low-pass filter, 13 is an envelope detection circuit, 14 is a sink detection circuit, 15 is a sampling pulse generation circuit, 16a is a first sample hold circuit, 16b and 16C are second sample hold circuits, 16d 3 is a third sample and hold circuit, 17 is a differential amplifier, 34 is a variable amplifier, 35 is a differential amplifier, 3
6 is a subtraction amplifier, 37 is a summing amplifier, 30 is an analog switch, 20 is a sampling pulse SP1.21 is a sampling pulse SP2.31 is a sampling pulse SP
3.32 is a long-time playback/normal playback switching signal, 33a, 3
3b is a gate signal, 25 is a head switching signal, 24-24
d is a tracking error signal, and 38 is an AND gate. Figure Figure 3: Boots Figure-7'';T'/? Me2 Horns 3: f2 = 522.67 Hz 9: 13 = 784.0 OKH210: f4
= 1.568 MHz Figure Figure Ichigaku Imeji/2 A1 Sun 2 B1 Mela/2 A2 Person U, 72 82/'/'72 Figure 11 Figure 12 Figure 4c

Claims (1)

[Claims] (1) In a control device used in a reproducing device that reproduces a recording medium in which a pilot signal is recorded multiplexed with information on a plurality of mutually adjacent information tracks, the control device comprises: a reading means for reproducing signals from the information tracks; and a selected track. a level detecting means for separating and extracting the pilot signal level reproduced from the track and the pilot signal level crosstalked from the right adjacent track and the left adjacent track, respectively, H, R, and L, and when the selected track is the 2i+1 track; The calculation S=(H-R)+A(L-R) is calculated as S=(H-L)+ in the case of the 2nd i track.
A calculation means for performing the calculation A(R-L); and a drive means for varying the relative position of the information recording medium and the reading means in accordance with the signal S when the playback area is the ATF area of the selected track. A control device for a playback device, characterized in that: