JPH06105516B2 - Tracking device - Google Patents

Description

The present invention relates to a tracking device, and more particularly to a tracking device for tracking a signal track recorded on a magnetic tape as a recording medium in a rotary head type magnetic recording / reproducing device. It relates to the device.

[Conventional technology]

In the rotary head type magnetic recording / reproducing apparatus, the input audio signal is A / D converted and recorded on a magnetic tape in the form of a digital signal, and at the time of reproduction, the digital signal recorded on the magnetic tape is D / A. A rotary head type digital audio recorder that converts and returns to the original analog audio signal for output
Tape-recorder, hereinafter R-DAT. ). R-DA
As shown in FIG. 3, T uses a small-diameter drum (1) with a diameter of 30 mm and has two rotating heads (A head (+ azimuth head) (2a) and B head (-azimuth head) with different azimuth angles. ) (2b)) are placed 180 ° opposite to each other and attached to the drum (1), and the tape (3) is attached to the drum (1).
It is wound 90 ° and the signal of the track format as shown in FIG. 4 is recorded without the guard band. In the track format of FIG. 4, (4) is a PCM area for recording a PCM audio signal, and (5a) and (5b) are ATF areas for recording a signal for tracking during reproduction. , (6a) and (6b) are sub-code areas for recording additional information such as music number and time information, which are divided into 5 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 areas (5a) and (5b), and track tracking is performed so that the tracking error signal becomes zero. Be seen. ATF area (5a)
The signal recording patterns of (5b) and (5b) are shown in FIG. Fifth
In the figure, the f1 signal (7) is called a pilot signal, and from this, a tracking error signal is generated. The f2 signal (8) and the f3 signal (9) are called sync signals, and are used as timing detection signals for generating tracking error signals. The f2 signal (8) is recorded in the A track (+ azimuth track), the f3 signal (9) is recorded in the B track (-azimuth track), and the recording length is 0.5 block length and 1 block length for every 2 tracks. It is changed and recorded, and the signal recording pattern is completed in 4 tracks. Therefore, it becomes easy to identify the tracks, and it is considered that the tracks are prevented from being slanted in a diagonal direction during normal reproduction. The f4 signal (10) is a signal for erasing the pilot signal and the sync signal by overwriting.

A method of generating a tracking error signal from the ATF signal recording pattern shown in FIG. 5 will be described with reference to FIGS. 6 and 7. FIG. 6 is a block diagram showing a configuration of a circuit for generating a tracking error signal, and FIG.
The B head (-azimuth head) (2b) is the ATF1 area (5 of the B1 track of the ATF signal recording pattern shown in FIG. 5).
FIG. 7 is a diagram showing signal waveforms of respective parts in FIG. 6 in the case of scanning (a) without a track deviation. In R-DAT, the head width is usually 1.5 times the track width, so
The head also scans adjacent tracks once. In FIG. 6, the head output signal is amplified by the head amplifier (11) and input to the low pass filter (12). The low-pass filter (12) extracts the f1 signal (pilot signal) (7) and inputs it to the envelope detection circuit (13).
An envelope signal as shown by (18) in FIG. 7 is output. F _1A2 and f in the envelope signal (18)
_1A1 is the reproduction output of the adjacent track, that is, the reverse azimuth track, but since the f1 signal has a low frequency, it is reproduced without being affected 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 (f2 signal (8) or f3 signal (9)) is detected, as shown in FIG. 7 (19). The signal shown in is output. In the sync signal detection circuit (14), the head switching signal (25) is input, and the f2 signal (8) is detected according to the polarity of the head switching signal (25), and when the head switching signal (25) is high, The f3 signal (9) is being detected. Output signal of sync signal detection circuit (14) (1
In synchronization with the rising edge of 9), the first sampling pulse (SP
1) and (20) are output, and after a fixed time (τ time) has elapsed, the second sampling pulse (SP2) (21) is output. The sampling pulse generation circuit (15) receives the head switching signal (25), divides it by a frequency dividing circuit (not shown) that incorporates the head switching signal (25), and according to the polarity of the divided signal,
The recording length of the sync signal is judged. For example, when the frequency-divided signal is at "low" level, the sync signal part of 0.5 block length is scanned, and conversely, when it is at "high" level, 1
The second sampling pulse (SP2) (21) is generated only when the sync signal portion having the block length is scanned. Therefore, when the head scans other than a predetermined track, the second sampling pulse (SP
2) Since (21) is not output, the tracking error signal is not generated, and the tracking in which a plurality of tracks are diagonally crossed is prevented. The output envelope signal (18) of the envelope detection circuit (13) is the first
To the sample hold circuit (16a) and one input terminal of the differential amplifier (17). In the first sample and hold circuit (16a), the first sampling pulse (SP1) (21)
F1 on the right adjacent track (A2 track in Fig. 7)
The signal crosstalk component (f _1A2 ) is sampled and held, and the signal shown in (22) of FIG. 7 is output. The output signal (22) of the first sample and hold circuit (16a) is input to the other input terminal of the differential amplifier (17), and the difference between the output signal (22) and the envelope signal (18) is output. The signal (23) is output. Second sampling pulse (SP
2) At the time when (21) occurs, the differential signal output (23) of the differential amplifier (17) shows the f1 signal crosstalk component ( _f1A2 ) of the right adjacent track and the left adjacent track (A1 in FIG. 7). The difference of the f1 signal crosstalk component (f _1A1 ) of the track) is output, and the signal sampled and held by the second sampling pulse (SP2) (21) in the second sample hold circuit (16b) is Tracking error signal (TE) (2
4) becomes. In the case of FIG. 7, there is no track deviation. When there is a track deviation, the level of the f1 signal crosstalk component from the adjacent track changes, so the output level of the tracking error signal (24) Changes to the positive side or the negative side depending on the direction of the track deviation. Fig. 8 shows the track shift, the f1 signal crosstalk component (26a) (L) from the left adjacent track, and the f1 signal from the right adjacent track.
The relationship between the level change of the one-signal crosstalk component (26b) (R) and the output change of the tracking error signal (24) (RL) is shown. In the figure, 180 deg corresponds to one track width. The tracking of the track is based on the tracking error signal (2
4) is performed so that it is always zero. Further, FIG. 9 shows the head switching signal (25) and the head amplifier reproduction signal waveform during normal reproduction. As shown in FIG. 3, in the R-DAT, the tape (3) is wound around the drum (1) only at 90 °,
Recording and reproduction are performed with two rotating heads mounted 180 ° opposite each other, so the reproduction signal (27) becomes an intermittent signal. Of course, the recording signal is also intermittent. Therefore, in the recording process, the sampled digital data is time-axis compressed and recorded, and in the reproduction process, the time-axis expansion is performed to restore the original data.

Up to now, the method of generating the tracking error signal at the time of normal reproduction of the R-DAT has been described, but after recording (After Record) which is one of the special functions is explained.
ing, hereinafter referred to as dubbing. The method of generating the tracking error signal at time 1) will be described. Since the R-DAT is recorded with the track format shown in FIG.
The system makes it easy to partially rewrite the PCM area (4) and subcode areas (6a) and (6b) while performing F-tracking, that is, post-recording. While generating the tracking error signal during normal playback,
After dubbing the PCM area (4), as described above, R
-In DAT, a head that is 1.5 times wider than the track width is usually used, so as shown in Fig. 10, a post-recorded portion (PCM area (4)) and a non-post-recorded portion (ATF).
Area (5a), (5b), subcode area (6a), (6b))
Therefore, in principle, the linearity of the track is impaired by the amount that the head is applied to the adjacent track (usually, 1/4 track width equivalent). In order to avoid this, as shown in FIG. 11, at the time of after-recording, it is possible to perform the off-track corresponding to the predetermined 1/4 track width and perform the tracking. The off-track method is to apply an offset voltage corresponding to a 1/4 track width to the tracking error signal (24) (RL) shown in FIG. It is difficult to uniquely determine the offset voltage due to variations in the isoelectromagnetic conversion system. Further, a method of changing the method of generating a tracking error signal at the time of after-recording and automatically off-tracking is disclosed in, for example, JP-A-61-72484. According to this method, in the ATF signal recording pattern shown in FIG. 5, the ATF1 area (5a) of the A track (+ azima track) and the ATF2 area (5b) of the B track (-azima track) are different from those in normal reproduction. Similarly, the tracking error signal (24) is generated from the difference signal of the f1 signal crosstalk components from the left and right adjacent tracks, and the ATF2 area (5b) of the A track (+ ajma track) and the ATF1 of the B track (-ajma track) are generated. In the area (5a), the tracking error signal (24a) is generated by taking the difference signal between the f1 signal crosstalk component (26b) from the right adjacent track and the f1 signal component (28) of the own track. The tracking error signal (24a) (RH) obtained by taking the difference between the f1 signal crosstalk component (26b) (R) from the right adjacent track and the f1 signal component (28) (H) of the own track Fig. 12 shows the output change with respect to the track deviation.
When the track deviation is about 90 deg (180 deg corresponds to one track width), the output level of the error signal (24a) (RH) becomes zero. As shown in (24b) of Fig. 13 (a), 90deg off track between the ATF2 area (5b) of A track (+ azima track) and the ATF2 area (5b) of B track (-azima track). Control is applied to the ATF2 of the next B track (-Ajima Struk).
AT from area (5b) to A-track (+ Ajimastrak)
During the F2 region (5b), the control works in the direction of eliminating the track shift, so the tracking is performed while causing a track shift of about 45 deg on average, that is, a track width equivalent to 1/4 track width.

However, according to the method disclosed in JP-A-61-72484, for example, as shown in FIGS. 13 (b) and (27a), for example, clogging of B head (-azimuth head) (2b), etc. As a result, if one channel's ATF signal (shown in (18a)) is missing, the tracking error signal during post-recording will have the form shown in (24c) in 16 (b), with an average of about 70deg. It causes a track shift,
There was a problem that the control that caused the track deviation of about 45deg on average could not be realized.

In order to solve the above problems, even if the ATF signal of one channel is lost due to the clogging of the head, etc., the tracking device that can automatically perform a predetermined amount of off-track is already the same. Filed by the applicants.

The tracking device, when generating a tracking error signal during after-recording, has an ATF area (5) before and after the PCM area (4).
In ATF region where the f1 signal component of the own track can be extracted without using a) and (5b), that is, in the A track (+ ajma track), in the ATF2 region (5b) and B track (− ajma track), When using the ATF1 area (5a) and scanning those ATF areas, a tracking error signal that causes a predetermined amount of off-tracking is generated from the f1 signal crosstalk component from the left and right adjacent tracks and the f1 signal component of the own track. It was created. Therefore, since the tracking error signal is generated in only one ATF region, even if the ATF signal of one channel is lost, the tracking can be realized with a predetermined amount of off-tracking.

A conventional example of the tracking device will be described below with reference to the drawings.
FIG. 14 shows a block configuration of a circuit for generating a tracking error signal at the time of dubbing, and FIG. 15 shows
The B head (-azimuth head) (2b) is the ATF1 area (5 of the B1 track of the ATF signal recording pattern shown in FIG. 5).
It shows the signal waveform of each part when scanning a). In the conventional example shown in FIG. 14, a third sample hold circuit (16c) and a summing amplifier (2) are newly added to the tracking error signal generation circuit at the time of normal reproduction shown in FIG.
9) An analog switch circuit (30) for switching the output of the tracking error signal during normal reproduction and after-recording is added, and as a signal for controlling them, an after-recording / normal reproduction switching signal (32) for switching between after-recording and normal reproduction is provided. ),
Third to operate the third sample and hold circuit (16c)
Sampling pulse (SP3) (31), A track (+
ATF2 region (5b) and B track (-
A gate signal (33) for designating the ATF1 region (5a) of Ajma Struk is added. During normal reproduction, the after-recording / normal reproduction switching signal (32) becomes, for example, "low" level, the analog switch circuit (30) is connected to the upper contact (L), and the second sample hold circuit (16) is connected.
The output signal (24) of b) is output as a tracking error signal. During after-recording, the after-recording / normal reproduction switching signal (32) becomes "high" level, is connected to the lower contact (H) of the analog switch circuit (30), and is output from the third sample-hold circuit (16c) ( 24d) is output as a tracking error signal. Further, in the sampling pulse generation circuit (15), when the after-recording mode is designated by the after-recording / normal reproduction switching signal (32), the ATF2 area (5b) of the A track (+ ajma track) and the B track (-ajma track) are specified. ) ATF1 area (5a) of the gate signal (33) is active only (when it is at "high" level, the specified area is specified and considered as active). 3 consecutive sampling pulses (SP1 ),
(SP2) and (SP3) are generated. As shown in FIG. 15, a sync signal (f3 signal (1
9)) is detected, the sampling pulse generation circuit (15) is synchronized with the rising edge of the output signal (19).
More, the first sampling pulse (SP1) (20) is output, in the first sample hold circuit (16a), the right adjacent track (in FIG. 15, A2 tracks) f1 signal crosstalk component from (f _1A2 ) Is sample-held. Next, as described above, it is determined whether or not the recording length of the sync signal is for the desired track, and if they match, a fixed time (τ time) elapses after the first sampling pulse SP1 (20) is output. After that, sampling pulse generation circuit (15)
As a result, the second sampling pulse (SP2) (21) is output, and the output signal (23) of the differential amplifier (17) is sampled and held by the second sample and hold circuit (16b).
At the time when the second sampling pulse (SP2) (21) is output, the f1 signal stroke component ( _f1A2 ) from the right adjacent track and the f1 signal crosstalk from the left adjacent track (A1 track in Fig. 15). Since the difference between the components (f _1A1 ) and the output signal (23) of the differential amplifier (17) appears, the difference between the f1 signal crosstalk components from both adjacent tracks becomes the second sample-hold circuit ( 16b) is sample-held. In addition, the second sampling pulse (SP
2) After a certain time (τ time) has passed since the output of (21), the third sampling pulse (SP3) (31) is output from the sampling pulse generation circuit (15), and the third sample hold circuit At (16c), the output signal (34) of the summing amplifier (29) is sampled and held. At the time when the third sampling pulse (SP3) (31) is output,
The second sample and hold circuit (16b) outputs the difference between the f1 signal crosstalk components from both adjacent tracks,
The difference between the f1 signal crosstalk component (f _1A2 ) from the right adjacent track and the f1 signal component (f _1B1 ) of the own track is output from the differential amplifier (17), and the signal obtained by adding them is The sample is held by the third sample hold circuit (16c). The output signal (24d) of the third sample and hold circuit (16c) is output from the analog switch circuit (30) as a tracking error signal during post-recording. The 16th operation described above
It will be described with reference to the drawings. FIG. 16 shows the signal change of each part with respect to the track shift, and (26b) is
F1 signal crosstalk level change from right adjacent track,
(26a) shows the f1 signal crosstalk level change from the left adjacent track, and (28) shows the f1 signal level change of the own track. Here, by newly rewriting (26b) as R, (26a) as L, and (28) as H, when the second sampling pulse (SP2) (21) is output, The sample-hold circuit (16b) holds the signal (24) corresponding to (RL), and outputs it as the output of the differential amplifier (17) at the time when the third sampling pulse (SP3) (31) is output. , (RH) signal (24a)
Is output and the signal (34) obtained by adding (R-L) and (R-H), that is, (24d) is sample-held by the third sample-hold circuit (16c). Looking at the change of the signal (24d) of [(RL) + (RH)] as the calculation result with respect to the track deviation, it is about 45 deg, that is, 1
Since the value becomes zero when the off-track is equivalent to the / 4 track width, it is possible to realize the off-tracking by a predetermined amount by this signal.

As shown in FIG. 17 (a), the ATF2 area (5b) is used during A-track (+ ajimastrak) reproduction, and the ATF1 area (5a) is used during B-track (-azimastrak) reproduction.
, A tracking error signal that can be off-tracked by a predetermined amount is generated, and as shown in the reproduction signal (27a) and the envelope signal (18a) of FIG. 17 (b), for example, due to clogging of the B head, etc. Even if the channel ATF signal is lost, a certain amount of off-tracking can be performed and tracking can be performed.

In FIG. 16, comparing the tracking error signal (24) (RL) during normal reproduction with the tracking error signal (24d) [(RL) + (RH)] during post-recording, the track shift Since the output level has a different slope, that is, the sensitivity is different, the loop gain is different when the servo system is configured. To prevent this, for example, the gain of the summing amplifier (29) may be reset to any value. For example, if the gain is halved, (2 in FIG.
4e) As shown in [1/2 (RL) + (RH)], the sensitivity of the track deviation to the output level can be made almost the same as in the normal reproduction.

In the above examples, the level change of the f1 signal crosstalk component from both adjacent tracks and the level change of the f1 signal component of the own track have been described with reference to FIGS. 8 and 12. However, in reality, such characteristics are not necessarily obtained due to variations in head width, head sensitivity, recording level, etc., and track differences. FIG. 19 and FIG. 20 show one example of the characteristics when the head width and the track width are equal. FIG. 19 shows the track shift, the f1 signal crosstalk component (26a ') (L) from the left adjacent track, and the f1 signal crosstalk component (26b') from the right adjacent track.
The level change of (R) and the output (24) (RL) of the second sample hold circuit (16b) at the time when the second sampling pulse (SP2) (21) is output are shown. Fig. 20 shows the track shift and the f1 signal crosstalk component (26b ') (R) from the right adjacent track, and the f1 of its own track.
The level change of the signal component (28 ') (H) and the output (24a') (RH) of the differential amplifier (17) at the time when the third sampling pulse (SP3) (31) is output are shown. . FIG. 21 shows the calculation result (24d ') [(R
-L) + (RH)] is shown. A signal (24d ') [(RL) + (RH)] which is a tracking error signal shows a change with respect to a track deviation of about 60 deg, that is, it becomes zero at an off-track equivalent to 1/3 track width. In that case, it is not possible to turn off tracking by a certain amount during post-recording (about 45deg 1/4 track width).

[Problems to be solved by the invention]

In the conventional tracking device as described above, when the characteristics of the f1 signal crosstalk component from both adjacent tracks and the f1 signal component of the own track are different from the ideal characteristics (shown in FIGS. 8 and 12), There was a problem that control that would cause a track shift of about 45 degrees on average could not be realized.

The present invention has been made to solve the above-mentioned problems, and even if the characteristics of the f1 signal crosstalk component from both adjacent tracks and the f1 signal component of its own track are different from the ideal characteristics, they can easily be about 45 An object of the present invention is to obtain a tracking device that can realize control that causes a degree of track deviation.

[Means for solving problems]

A tracking device according to the present invention includes a detecting means for detecting a pilot signal component, and a first inputting an output signal of the detecting means.
Voltage holding means, subtraction means for inputting the output signal of the detection means and the output signal of the first voltage holding means, second voltage holding means for inputting the output signal of the subtraction means,
Amplification degree changing means for inputting the output signal of the subtraction means and amplifying it by A times, addition means for inputting and adding the output signal of the second voltage holding means and the output signal of the amplification degree changing means, and the addition A third voltage holding means for inputting an output signal of the means is provided independently before and after the information signal recording area, and is detected in only one recording area of the recording areas in which the tracking pilot signals are recorded. The pilot signal level R from the adjacent track on the right, the pilot signal level L from the adjacent track on the left, and the pilot signal level H of the own track are detected based on the pilot signal component of (R−L) + A × ( R-H) is performed to generate a tracking error signal.

[Action]

In the present invention, the amplification degree changing means controls the off-track by 1/4 track by correcting the pilot signal component.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 3 is a block diagram showing the configuration of the tracking error signal generation circuit of the tracking device according to the present invention. The embodiment shown in FIG. 1 is different from the tracking error signal generation circuit shown in FIG. 14 in that a difference signal amplifier (35) having an amplification factor A is newly added to amplify the difference signal output (23) of the differential amplifier (17). Is added. In the figure, (36) is a difference signal amplified output, which is added to the summing amplifier (29).

Next, the operation will be described. As shown in FIG. 1, the differential signal output (23) is applied to the differential amplifier (17) and then the differential signal amplified output (36) is applied to the summing amplifier (29). That is, the third sampling pulse (SP
3) The differential amplifier (1
The output (RH) of 7) is A (R) by the differential signal amplifier (35).
-H) and is a tracking error signal (R-
The signal (24d ') of (L) + A (R-H) becomes zero at a place where it is off-tracked by about 45 deg. The tracking of the track is performed so that the tracking error signal (24d ') is always zero, so that it is possible to realize control that causes a track deviation of about 45 deg on average. It can be seen from FIG. 21 that the output (R-H) of the differential amplifier (17) may be reduced to about 1/2 in order to make the tracking error signal zero at a position where the tracking error is about 45 deg. Therefore, the amplification factor A of the difference signal amplifier (35) in FIG.
The tracking error signal with respect to the track deviation is shown in FIG.

Although the difference signal amplifier (35) is inserted between the differential amplifier (17) and the summing amplifier (29) in the above embodiment, it is arranged between the second sample hold circuit (16b) and the summing amplifier (29). It may be inserted, and in this case, the gain of (RL) is changed, so that the same effect as that of the above-described embodiment is obtained.

〔The invention's effect〕

As described above, the present invention is
The addition ratio of the difference component of the f1 signal crosstalk component and the difference component of the f1 signal crosstalk component from the right adjacent track is 1: 1.
Since other configurations are used, f1 signal crosstalk component from both adjacent tracks and f1 of own track due to variations in head width, head sensitivity, recording level, etc.
Even when the characteristic of the signal component is different from the ideal characteristic, the off-track amount can be set to 45 degrees.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a tracking error signal generation circuit of a tracking device according to the present invention, FIG. 2 is a diagram showing a tracking error signal S curve obtained from the tracking error signal generation circuit of the present invention, and FIG. FIG. 4 is a side view showing the relationship between the rotating head of the R-DAT and the magnetic tape, and FIG.
-DAT track format diagram, FIG. 5 is a diagram showing an ATF signal recording pattern, FIG. 6 is a block diagram showing the configuration of a tracking error signal generating circuit of a conventional tracking device, and FIG.
The figure shows the waveform of the output signal of each part of the circuit shown in Fig. 6, and Fig. 8 shows the f1 from both adjacent tracks against the conventional track shift.
Fig. 9 is a diagram showing changes in signal crosstalk level and tracking error signal output, Fig. 9 is a diagram showing a relationship between a head switching signal and a head amplifier reproducing signal at the time of normal reproduction, and Fig. 10 is a head scanning operation on a magnetic tape. Fig. 11, Fig. 11 is a diagram showing the scanning operation of the head on the magnetic tape when off-tracking, and Fig. 12 is the f1 signal crosstalk level and tracking error signal output from both adjacent tracks with respect to the track deviation when off-tracking. Diagram showing changes,
13 (a) and 13 (b) show the relationship between the conventional ATF signal and the tracking error signal, and FIG. 14 shows the configuration of the tracking error signal generation circuit of another conventional tracking device. Block diagram, FIG. 15 is an output signal waveform diagram of each part of the circuit shown in FIG. 14, and FIG. 16 is a crosstalk level of f1 signal and tracking error signal output from both adjacent tracks with respect to track deviation in the device of FIG. FIG. 17 (a) and FIG. 17 (b) are diagrams showing the changes, showing the relationship between the ATF signal and the tracking error signal in the device of FIG. 14, and FIG. 18 in the device of FIG. A diagram showing the change in the tracking error signal output with respect to the tracking deviation when the gain of the summing amplifier is arbitrarily set again. Fig. 19 shows the tracking deviation and the f1 signal crosstalk part (26a ') from the right adjacent track (26a') ( L), next to the right f1 from the track
A diagram showing the level change of the signal crosstalk component (26b ') (R) and the output (24) (RL) of the second sample hold circuit (16b) at the time when SP2 is output,
Fig. 20 shows the track shift and the level change of the f1 signal crosstalk component (26b ') (R) from the right adjacent track, the f1 signal component (28') (H) of its own track, and the difference at the time when SP3 is output. Output (24a ') (R of dynamic amplifier (17)
-H), and FIG. 21 is a calculation result sampled and held by the third sample and hold circuit (16c) (2
4d ') [(RL) + (RH)] FIG. In the figure, (11) is a head amplifier, (12) is a low-pass filter, (13) is an envelope detection circuit, (14) is a sync signal detection circuit, (15) is a sampling pulse generation circuit, and (16a) is the first sample. Hold circuit, (16b) second sample and hold circuit, (16c) third sample and hold circuit, (17) differential amplifier, (18) envelope signal, (20) sampling pulse 1 (SP1) ,
(21) is sampling pulse 2 (SP2), (24) to (24
d) is a sampling error signal, (25) is a head switching signal, (29) is a summing amplifier, (30) is an analog switch circuit, (31) is a sampling pulse 3 (SP3), and (32) is a post-recording / normal playback switching. Signal, (33) is the gate signal,
(35) is a difference signal amplifier, and (36) is a difference signal amplified output signal. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 61-72484 (JP, A) JP 63-231752 (JP, A) JP 63-292447 (JP, A)

Claims (2)

[Claims] 1. A tracking device for generating a tracking error signal by a tracking pilot signal recorded in a recording area independently provided before and after a recording area of an original information signal, the detection apparatus detecting a pilot signal component. Means, first voltage holding means for inputting the output signal of the detecting means, subtraction means for inputting the output signal of the detecting means and output signal of the first voltage holding means, inputting the output signal of the subtracting means A second voltage holding means, an amplification degree changing means for inputting the output signal of the subtracting means and amplifying it by A times, and an input signal of the second voltage holding means and the output signal of the amplification degree changing means. Adding means for adding, and a third voltage holding means for inputting an output signal of the adding means, which are provided independently before and after the recording area of the information signal, and are for tracking. Based on the pilot signal component detected in only one of the recording areas in which the pilot signal is recorded, the pilot signal level R from the right adjacent track, the pilot signal level L from the left adjacent track, and the own track Of the pilot signal level H, and a tracking error signal is generated by performing a calculation of (RL) + A * (RH). 2. When performing after recording, A =
The tracking device according to claim 1, wherein the tracking error signal is generated by performing the calculation as 0.5.