JPS5933674A - Tracking controller - Google Patents

Abstract

PURPOSE:To shift stably the tracking phase with a simple constitution for a follow-up system in which pilot signals having frequencies different by tracks are recorded cyclically, by having a time division phase comparison among a reproduced pilot signal, a reference signal and a reference signal of a prescribed phase, respectively. CONSTITUTION:The switching of a switch 58 is controlled via a time division signal generating circuit 57, in response to a lock point control element 59 of a lock control circuit 52. As a result, a reference signal and a 1-track phase advanced reference signal given from a phase advance switch circuit 54, etc. are applied in different time division periods to a multiplier 14 of an error signal producing circuit 51 to which the reproduced pilot signal is applied. Then the circuit 51 produces error signals having different output times from a comparison carried out between both reference signals and a pilot detecting signal. A phase is shifted as desired for the lock point in response to the time division ratio. In such a way, it is possible to shift stably the tracking phase by a desired amount with a simple constitution for a follow-up system in which pilot signals having different frequencies for each track are recorded cyclically.

Description

[Detailed Description of the Invention] [Industrial Application Field] Regarding the present invention, the t-side racking 1ilJ side 1 unit W-1,
In particular, a plurality of A pilot signals with different frequencies are cyclically recorded on the recording medium for each information recording trunk 7, and then re-recorded 41
1id(j/(7) is applied to the information recording head 4, which tracks the information recording track with the reproducing head using the /e pilot signal reproduced by the head.

[Background technology and its problems]

This type of information recording/reproducing device is used, for example, in a tracking servo device in an RJ video tape recorder (VTR). In other words, as one of the phase laser systems in the capstan system of a VTR, a plurality of signals with different frequencies are recorded on a tape in a circular manner for each video track, and when the video signal is played back, the signals of adjacent tracks are A tracking error signal is obtained by reproducing the pilot signal 7 and detecting the difference between each pilot signal,
Based on this tracking error signal, the tracking servo device, so-called automatic track following system (A, TF)
method) is used.

This ATF type tracking control device can perform tracking servo Y using the information recording track and its reproducing head, so it has the advantage of reducing the lifespan of the tracking-specific components. However, there was a problem that the tracking lock point could not be set at an arbitrary position t11 between the tracks.

As a second tracking method to reduce this inconvenience, a control dedicated track (C timing signal is written as Q+-), and its reproduction timing signal is provided on the tape by a control signal head (CTL head) as a tracking phase detection signal. A so-called control signal method (CTL method) is used in a capstan tracking servo device as a difference signal from a reference signal.

In such a tracking control device, when you want to shift the rotating video head from its tracking point on a predetermined track to another track during post-recording, or when you want to measure tracking shift and crosstalk. It is desirable to be able to shift the tracking lock point by a predetermined amount as necessary, such as when you want to quickly track the tracking.

Regarding this point, in the CTL method, conventionally, an absolutely adjustable reference signal (for example, It: J,' 3(l [11
z'] by a predetermined amount as necessary, the tracking lock point can be shifted at an arbitrary phase. Incidentally, in order to actually shift the tracking, the phase of the reference signal can be shifted independently by adjusting the tracking control volume (commonly abbreviated as NitraConvolume).

2 or 1. In the case of the ATF method, the tracking detection signal cannot be compared with an absolutely adjustable reference signal in principle, so a simple method such as the CTL method can be used to detect an arbitrary phase or tracking lock point. However, in the past, no one has been proposed that can shift tracking only to a sufficiently large phase shift for practical purposes. [Objective of the Invention] The present invention takes the above points The above A
In the TF type tracking control device k, an attempt is made to realize a tracking control device that can stably shift an arbitrary amount h1'' depending on the necessity of the tracking phase by using a simple configuration as possible.

[Summary of the invention υ]

In order to achieve such an objective, the present invention provides the following features: The first reference/e Irot signal is in phase one track ahead of the Irotsu HH, and the second reference ξ・i is in phase with the J and b racks.
(Created Knee No. 1 and reproduced it with these first and second reference pilot signals)? The first and second tracking phase error signals are obtained at a time division ratio of p) and the tracking error signal based on the result.

〔Example〕

The following drawings describe the present invention as a two-head helical scanning type V
Let us explain in detail one embodiment of the case where TR is changed. First, the tracking control device according to the present invention is constructed based on the following operating principle.

That is, as shown in FIG. 1, the tracking control device detects a pilot signal of a part of the reproduction output of a video head as a reproduction head S1 and a pilot signal detection circuit 1 of a one-pass filter structure.
11 [5 (, t), the recording medium and (7) generate a reproduced/zealot signal s2 consisting of the reproduced output of the pilot signal recorded on the magnetic tape, and this reproduced pilot No. 82 is applied to the first and second error signal forming circuits (2) and (3).The first and second error signal forming circuits (2) and (3) are connected to the lock point control circuit (4).
) The error signals 831 and s:32 formed under the control of the control signal are given to the error phase calculation circuit (5), and the tracking error signal S4 is sent to its output terminal - thus, the error signal forming circuit (2), (3) and four error phase generator circuits (5) constitute an error detection circuit.

First and second errors (li shadow forming circuit 2) and (3
) have the same configuration as each other, as indicated by the same reference numerals 7, and have the configuration shown in FIG. 2 in which the KATF operates in principle. In other words, on the tape (]1), as shown in Figure 3, there are ! of each frequency! Is there 4 types of number analogy? Four video tracks TI, T2 on which the pilot signals f1 r'2 T f3+f4 are recorded.

The pairs of T3 and T4 extend closely and diagonally so as to repeat in a circular manner. Here, the head (12)
)'? :What is the effective width of the video head? ', 1 are selected to be equal to the width of the tracks T1 to T4, and thereby the playback head (12
) is correctly tracking the track currently being reproduced and scanned (referred to as the mutual track).By reproducing only the pilot signal recorded on the relevant track, the pilot frequency component included in the reproduced output is On the other hand, when the playback head (12) is shifted to the right or to the left with respect to the track as shown by the broken line, the playback head (12) moves to the track adjacent to the right or left side of the playback track. By reproducing the recorded pilot signal, the number of pilot frequency components contained in the reproduced output becomes two types, and the thick 8 of each pilot frequency component corresponds to the corresponding 1-track. The button is sized to match the opposing length of the opposing reproducing head.

However, the frequency f of the four types of pilot signals f1 to f4
1 to f4 are low frequencies (600 to 700 (kHy, ))
For example, in the four circulating tracks T1 to T4, the center of the odd-numbered track 'rl, T3'r (2) is selected in the lower band of the color component converted to The difference is 31 people, and the frequency 6 with the pilot signal of the left truck is ΔfB, and the pilot signal of the right truck, pilot H, No. 4, is centered on even-numbered trucks T2 and T4. The frequency difference with the pilot signal of the left track is ΔfB, and the frequency difference with the pilot signal of the left track is ΔfA.
The awn is shaped like this.

Therefore, the head (12) is an odd-numbered track TI.

When reproducing T3g, the frequency component of the pilot signal included in the 6 raw signals is (N
If there is a signal component of the difference frequency ΔfB, it is known that the head (12) is shifted to the right, and if there is a signal component of the difference frequency ΔfB, it is known that the head (12) is shifted to the left. It can be seen that when there is no signal component of 7 fB, the tracking is performed correctly.

Similarly, the head (]2) is on even-numbered track T2.
When reproducing T4, if there is a signal component of the difference frequency ΔfB as a frequency component of the pilot signal included in the reproduced number Ff, it can be seen that the head (12) is shifted to the right, and also the difference frequency ΔfA (1) If there is a component, it can be seen that the head (12) is shifted to the left.

In this example, the station building is: 1. Second. Third. 1 for the fourth track TI, T2, T3, T4
Applied frequencies f1, f2, f3,
f4 t:1f1=102 [kHz], f2=l]
6[kHy,:] , f3==l(in(kHy,:
).

f 4'''146 (kHz), thus the difference frequencies Δf· and ΔfBvU:.

ΔfA-'If1 f21=lf3 f41=11[
k, 1. Iz:]・・・・・・-・(J) Δfu=Ifz fal=Ifz f4t =44
(kHz)......(2) is selected.

The reproduced signal 81 with such content obtained from the head (12) is given to a pilot signal detection circuit (1) having a low-pass filter configuration, and the pilot signals f1 to f4 included in the reproduced signal S1 are extracted. (playback) The e-lot signal S2 is applied to the multiplication device (14) as a first multiplication input. Hanging H! The reference pilot signal S of the lock point control circuit (15) is input to Er (14) as a second multiplication input.
ll is given.

The lock point control circuit (15) has a frequency of f1 to f4 (7)4.
Is the pilot frequency output f1 to f4 generated? A head switching pulse RF-SW that changes the logic level when the head that scans the tape among the two video heads associated with the rotating drum (not shown) is switched. (FIG. 4A).

In the +i example, the switch circuit (17) has a quaternary counter circuit 11'iI- which counts 1 (1) when the level of the head switching pulse RF-8W changes. ~Fourth track T1~
Gate signal corresponding to T4
"J," respectively, open the gates according to the gate signal of this trunk TI - T = 1, and the 41st "2"
1 B shows "4-as < , kl Ilot frequency 1;!1 occurrence times F8 (lCi), Ilot frequency output "1~
The design is such that f4 is sent out as the first semi-pilot E SIJ.

Note that A4i, 1.
During recording, the reference pilot output 811 sent to the video head is sent to the video as a pilot signal via the signal line 2/(1t3)2, thus the video head outputs 1t-JJ, 4
(Corresponding to tracks T1 to T4 '5 during scanning), pilot signals of -1 wave numbers f1 to f4 are sequentially recorded on each track T1 to 'F4 in addition to the video head. There is.

In this way 1. While the head (12) is scanning the first to fourth tracks Tl=T'47<? By multiplying the reproduction signal S2 outputted to the output terminal of the output signal detection circuit (1) by the reference, At some point (l), a multiplication output 812 is obtained that includes a difference frequency component having a frequency that is the difference between the frequency component included in the raw pilot signal S2 and the frequency of the reference pilot signal 811 (actually, the summation output 812 is This multiplication output S12 also contains other signals such as frequency components of the horizontal phase).
The first and second difference frequency detection circuits (2(υ) and (21) are configured with filters. First difference frequency detection circuit 1ai'+ (2tJ) k + output S12
In the above 2-ho (via 2 frequency ΔfA based on formula 11 (7
) When the No. 8 component is included, extract the current and convert it to DC using the rectifier circuit 471 and flow converter circuit (22) to obtain the first error detection signal 813 at the DC level. . Similarly, the second difference frequency detection circuit (21) It,1
Difference based on the above (2) 2 in the calculation power S12: Ji
When the fractional component of J wave %ΔfII is included, it is extracted and the second error detection example +3St-+ is obtained from the DC conversion circuit (23).

Here -\rad''2) is the first. Department 1.2. 3rd, 8th I
+, 4 tracks TI, T2, T3,
1'4 (therefore the switch circuit 17 scans each trunk TI, T2, T as shown in FIG. 4B).
3. Frequency fl at the timing corresponding to T4,
Reference pilot No. 45 Sll of f2, f3, f,
When the head (1) is on the right
(IJ, raw) v obtained based on the reproduced signal Sl of 2)
It0 ItiT Q S 2 K? 41.4 Figure C
As shown in I, the circumference ρJ, 3. (f and f, f
and f3.

1 2 2 f and f, f and fl)ξiron)(;i
The multiplication output 812 and (7te 2a 4
As shown in Figure DJ, the difference frequency Δf A, (= f
1 to f2).

Δf B (= f 2 ~ f 3 ), Δf A (=
f3-f4).

On the other hand, if the head (12) is shifted to the left, the reproduction pylon L [S2] generates a signal sequentially containing ΔfB (=f4~f, ) as shown in Fig. 4.02. Frequencies af and f, f and f2, f2 and 4
11 f3, f3, and f4) (Iron) (The trap is set to include the M number, and accordingly, the multiplication output 812 is sequentially 41Y)
As shown in D2, the difference frequency ΔfB (=f4 to f1).

Δf A (= f 1 to f 2), Δf B (= f 2 to f 3
), ΔfA (=f3 to f4) are sequentially included.

Thus, as shown in Fig. 4 E and F, the DC level rises from 0 every time the spatula F (12) switches the scan path. And the second error detection signal 813 and Sl/l can be obtained from the DC conversion circuits (22) and (23).

The first and second error detection counters Q813 and S14 are input to the subtraction circuit (24) as an addition input and a reduction input, respectively. Every time the two error detection signals S13 and 814 are obtained alternately, a subtraction output S15 that changes AC-wise is obtained. This subtraction output 815 is applied to the first input terminal a1 of the interview changeover switch circuit (25), and is also applied to the inverting circuit (26).
It is given to 1 Ma2. Changeover switch times! i'; (
25) #: For example, head (12) is set to odd-numbered track TI by l head switching and 9th RJ-SW.
, during T3'4 scanning, the first input terminal a l 1i
Switch to li [-) 1 operation 1-1 On the other hand, even numbered tracks T2, T4 Q-When running uphill, switch to the second input terminal a2 Figure I
As shown in I, the head (12) is off to the right! 2(), the DC level output 816 of the thick stop 19. corresponding to the amount of rightward deviation is missing () (on the other hand, when the leftward deviation state σ
) is the target, and the flow level output 5lfi is 1t to the left.
When fA is large enough to correspond to tX, it becomes negative 1〆"r-characteristic", and this is the DC amplifier (27) Y, y ・5"l", which sends out the error signal S of the error detection circuit (28) as 7. Hatakeru. r'i, the head (1z) is placed on the right, for example, J:, the playback trunk is the note number TI,
0 difference frequency Δ at the output terminal of the a circuit (]/l) when T3
By the appearance of the turtle (tj component), the first difference frequency (f (frost) is switched to the J-th human power yjM a l side, so it sends out an error number 817 of the positive 111-stream level.On the other hand, the yjM a l side of the yjM a l side sends out an error number 817 of the positive 111-stream level.
When , the output terminal of the multiplication circuit M+1 (14) has a difference frequency Δ
iB σ) A h component is 111. By doing 1, the output from the second frequency detection circuit (21) is given to the Makoto 34-circuit (24), and is turned off at this time] tI switch circuit (2Fr) t:i-th 2 input terminal a2
Since the output is switched to the side, the polarity is reversed by the output reversal circuit (2Li) of the voice reduction circuit (21), and the output is switched to the 2nd and stop direct b11.
It is sent as a level error signal 817.

Therefore, this error signal S1.7y! l - For example, gearbustan length - Volup σ), i, 7.441 - Use as a correction signal to the Riese circuit.

When using ``r-p'' to stop, the speed of the ``r-p'' is increased, and when it is negative; 'Sleeve stop [
7. In this way, correct tracking to blur can be achieved.

Tracking control 11a fCr t in Fig. 1 1st and 2nd errors (F<-bow) with principle structure like this
) and (3), the phase becomes one track't)ll, the standard? Count Ilot S33 and 8
Error No. 48 831 and Hi S: 32
"I F (1/f 41")
), the tracking error signal S4 Y is created by Dr.
4 allows the playback head to be tracked to a desired position # between two adjacent tracks.

° That is, the first and second signal forming circuits IM (21
and error-1a No. 361 and S3 borrowed from (3);
, the voltage values E1 and E2 are calculated by the coefficients α and β in the coefficient circuits (31) and (32) of the error phase calculation circuit (5), and then added in the addition↓・Y1 circuit (33). The resulting voltage value E3 is E3=αE1+βE2. (3) is sent out as a tracking error signal S4 via the amplifier circuit (34). Here, 44・numbers α and β are α+β= l
-----°°-゛(41) Thus, by selecting the values of the coefficients α and β to arbitrary values as necessary, the tracking lock point of the tracking error signal S4 can be changed.

First, the first error signal forming circuit (2) has the first and second signals.
．． Third. Fourth track TI, T2, T3゜T
4, the e-lotted signals of the frequencies f1, f2, f3, and f4 assigned to the track are given to the multiplication circuit (14) as a reference pilot signal 833. In this way, when the reference pilot signal S3:3 synchronized with the reproduced pilot signal S2 is given, the error signal S:3 of the first error signal forming circuit (2) is generated.
A pressure value E1 of 1 exhibits a triangular wave-like response characteristic as shown in FIG. 5 with respect to track deviation of the cutting head (12) in the left or right direction.

That is, for example, considering the first track TI as the center, when the M main head (12) coincides with the track TI (that is, when there is no track misalignment), the white E1 is 0 and shifts to the right from this state. If you go to the play head (12
) and l! Since the opposing length with the second track 1-2 of i'i increases and goes to 7, the detection circuit (20
) According to the output of each of the iFt E l & J, it goes up in a straight line, and every track is equal to the 1st - erl, 2
It becomes maximum when it matches track T2 (that is, when it deviates by l track). If you shift further, 1041
The own head (12) begins to face the third track T3, and the length of the head (12) facing the third track T3 becomes shorter (-j <
Therefore, the value E1 decreases linearly, and becomes 0 when it coincides with the third track T3 (that is, when it is shifted by two tracks). If you move further by 1, the playback head (]2)
is opposite to the fourth track T4, and the value IC1 becomes negative due to the output from the detection circuit (21) j of the −C difference frequency ΔfB and further decreases linearly.
(i.e., when it is shifted by three tracks), it has a minimum lifespan. As it shifts towards the end, the opposing length between the P) conversion head (12) and the fourth track T4 becomes shorter, so the value E11 increases linearly and matches the first track T1. (that is, shifted by 4 tracks @) becomes 0.

On the other hand, if the head (12) moves to the left from the first track T1, the sense of opposing length with the adjacent fourth track T4 becomes longer, so the detection circuit for the frequency difference Δ'+3 (21) The value E1ic is determined by the output from 11111.
t linearly downward by 11, 1, and in this way, the point (0 point) when the playback head (■2) coincides with the track Tl (1-, that is, when there is no track deviation) is the center point. The characteristic curve will be shown.

The error signal forming circuit (3) of 21 to 2 has a reference signal ? The timing of the pilot signal 834 is shifted by one track in the leading phase direction (or the slowing direction). Second. 3rd゜4th track TI, 2nd, 3rd, 4th wP
Frequency f2, 3rd, 4th,
No of fl (or 4th.f□, 2nd, 3rd)? The reference pilot signal 8 is applied to the multiplication circuit (14)
Give as 34. In this way, when the reference pilot signal 834' which is synchronized with the reproduction pilot number a S2 by one track is applied, the '1M1x value of the error column S32 of the second error signal forming circuit (3) is obtained. The characteristic curve of 2 is the error 1? of the first error sign formation cycle iR'+ (2) as shown in No. 61 A (or Figure 6 B). No. S: 3 (the characteristic curve of the voltage value El of i + - rank C) is a curve similar to 4 and 2.

Therefore, the error obtained at the output end of the adder circuit (33) expressed by the above equation (3) (the characteristic curve of the voltage E3 of the Fli number S4 is shifted in the advancing direction and α= /" ==
-H, as shown in Figure 7, the electric moon and
It corresponds to the value obtained by adding the values χ of each track position 16 of the characteristic curves of El and E2.

However, in the characteristic curves shown in Figs. 5 to 7, the tracking lock position of the reproducing head ([2) is the point where the curve crosses the voltage 0 from the negative side to the positive side in the upper right corner, and therefore the reproducing -\rad The tracking lock position in (12) is the position of the first track TI, which is the tracking lock position of the voltage E1 of the first error signal 831, and the position of the first track TI, which is the tracking lock position of the voltage E1 of the first error signal 831.
The moving field can be set at a position (in this case, a position shifted by i track) between the locked position of voltage E2 of 2 and a position shifted by one track. And the deviation of this lock position is α
By changing the ratio of and β, it can be determined accordingly.

In this way, so as to satisfy the above equation (3),
The playback head (
12) The tracking lock position can be moved by a predetermined distance as necessary. However, 4 in Figure 1. II
If the configuration is used, E7 must be added to the error signal forming circuits (2) and (3) for the two series.

The present invention is based on the above operating principle, and moreover, only one series of error signal forming circuits is required, and the tracking control device according to the present invention uses two error signals in a time-divided manner. One error signal forming circuit (5
1) Has 7r. Then, the lock point control circuit (52) outputs a 79 pilot signal f-f44 head switching pulse RF-8W (Fig. 9A) of the pilot frequency generation circuit (45).
) The reference switch circuit (53) sends out the reference pilot signal 851 (FIG. 9B) which switches in synchronization with the playback head (12) according to the phase of the reference A pilot signal S51. (advanced by 900) phase-advanced no? Irottoi signal number 552 (Fig. 9C) Phase advance switch circuit (54) that sends out intermittently and reference pilot signal 85
1, and a slow phase switch circuit (55) that sends out a slow phase pilot signal 553 (FIG. 9D) having a phase delayed by one track (delayed by 90) relative to 1.

Leading phase switch circuit (54) and slowing phase switch circuit (55)
)'s advanced pilot Iha No. 852 and slow phase pilot No. 852? The pilot signal 853 is the first and second switching input terminal b1 and b2 of the tracking advance/lag switching circuit (56).
and is selected by the lead/lag switching signal 854 generated in the time division signal generation circuit (57) to the second input terminal d2 of the time division operation switch circuit (58).
will be sent to. The first of the time division operation switch circuit (58)
The output 851 of the reference switch circuit (53) is applied to the input QW dl of Grt, and the output 851 of the reference switch circuit (53) is selected by the time division control signal 855 generated in the time division signal generation circuit (57). Multiplication circuit (1
4) is inputted by multiplication human power S56 and 17.

As shown in FIG. 9 EtIC, the time division signal generation circuit (57) generates a time division jlil signal 8 whose switching level changes at a frequency sufficiently higher than the frequency of the head switching pulse RF-8W.
55 cases occur. In addition, FIG. 9E shows the time scale of each of the 48 issues shown in FIGS. 9A to 9D as enlarged L7.

When advancing the phase of the tracking lock point, 114-division control control 55 is used, as shown in FIG. 1, and a second section W2 of logic level "L" which selects the output of the tracking advance/slow II changeover switch circuit (56). The tracking lock point h14 formed by the tracking volume can be changed by the adjusting element (59) as a time division ratio. boundary position (i.e. time division control signal S!; 5 falls from logic "H" to rLJ;
Point j) The time division ratio is changed before and after failure.

In the above configuration, when tracking is performed so as to match the birth hexagon (Iz) y reference track, the 11-separation control signal S55 of the time division signal generation circuit (57) is used.
is continuously maintained at a logic 1'-HJ level.

At this time, 11.7 minutes? 11 operation switch circuit (58)
is connected to the first input terminal di side and the reference switch circuit (
The reference A pilot signal 851 from 53) is input to the multiplication circuit (14) of the error signal forming circuit (51) (FIG. 9 F1).

In this way, the Pl raw head (12) deviates from the reference tracking position and the output from the pilot signal output circuit (1) explodes.During the P1 raw head (12), the output from the pilot signal output circuit (1) suddenly matches the reference pilot signal 851 at a frequency IJ (! When the 411th number of minutes is included, this difference frequency vI detection circuit (2
0) or (2J) is detected and the error signal S47 corresponding to the direction of the deviation is sent from the output amplification circuit (60) of the Fj number forming circuit (51). Is there a signal other than the reference track's slot signal in the slot signal S2 for playback?
Reference point tracking state that does not include pilot signal (5th
(a state equivalent to the characteristic curve shown in the figure).

If you want to shift the tracking point of the playback head (12) to the right from this reference point tracking state, use the lead/delay switching signal 554Yf from the time division signal generation circuit (57).
iiffl signal is raised to "H" to switch the tracking advance/delay changeover switch circuit (56) to the first input terminal BL side, thereby causing the advance phase pilot signal from the advance phase switch circuit (54) to be switched to the first input terminal BL side. 852 is sent out. Along with this, the adjustment element (59)'! 'Adjust the time division ratio by the value V corresponding to the tracking position that you want to shift. At this time, the time division control signal 855 is as shown in FIG. 9 F2.
The reference pilot signal 851 which is given to the first input terminal d1 of the open time division operation switch circuit (58) in the section W1 of the logic rHJ for each period is converted to the error signal forming circuit (51).
), the lead-phase pilot signal 852 which is sent to the second input end d2 of the open time division operation switch circuit (58) in the section W2 of the logic rLJ is sent to the tracking advance/delay switching circuit (56). Y error write) number formation circuit (51).

Therefore, the error signal forming circuit (51) uses the time-division control signal 855 as the quantity standard for the period v'1 of the logic rHJ.
The error signal S4 based on the pilot signal 851 is generated and the tracking state to the reference position reaches 11j3 (a state equivalent to the characteristic curve in FIG. 5), and then the time division control signal S55 is cut off during the period W1 of the logic rLJ. When the phase advance pilot signal 852
A state is reached in which the signal is tracked to position C (a state equivalent to the characteristic curve shown in FIG. 6B). As a result, the entire tracking control device has a section W
After performing a tracking operation for l to the quantity reference position for that time, 1 from the quantity reference position for that time for section W2.
A tracking operation is performed to move the camera to a position that is a track ahead, and these two tracking operations are performed alternately.

In the end, the tracking position of the playback head (12) is between the 8'$ position and the position advanced by one track, and the ratio of the logical "H" and "L" sections of the time division control signal S55 is
Therefore, the distance from the base 1 (zero position) is equal to the time division ratio.Such a time division control signal S55
The operation in one cycle of is repeated for each cycle, and in effect it is a double series of equations (3)? When satisfied, a tracking state equivalent to the characteristic curve shown in FIG. 7 is reached.

On the other hand, if you want to shift the tracking point of the playback head (12) to the left from the reference point tracking state,
The lead/lag switching signal S54 from the time-division signal generation circuit (57) is lowered to logic 1-tJ, and the tracking lead/lag switching circuit (56) is switched to the second input terminal b2.
Switch to the side and explode, this causes the slow phase switch circuit (55)
Slow phase from? The pilot signal 853 is sent out. At the same time, the time division ratio is adjusted to a value corresponding to the tracking position to be shifted by -4 by operating the adjustment element (59).

At this time, the time division control unit No. 1 S55 is the 9th h<+r
As shown in FIG. 3, the reference voltage given to the first input tha1 of the open time division operation switch circuit (58) in the section Wl of the logic rHJ for each station 31111 is shown in FIG. Ilot signal S51
'After sending it to the J error g formation circuit (51), logic 1
-L” section W2 open time division operation switch circuit (52)
The lagging phase signal which is applied from the tracking lead/lag switching circuit (56) to the second input terminal d2 of the tracking lead/lag switching circuit (56). The error signal forming circuit (51) sends the time division control signal 8 to the error signal forming circuit (51) to
55 is logic [quantity standard of period W1 of Hj)? An error signal S4 based on the pilot signal 851 is generated to enter a tracking state to the reference position (a state equivalent to the characteristic curve in FIG. 5), and then the 1-division control signal 855 switches to a period W2 in which the logic is "L". When the delay pilot signal 853
84 error signals were generated based on 16. This results in a state equivalent to the characteristic curve of the tracking state (FIG. 6B). As a result, the tracking control device as a whole performs a tracking operation for section W1 to the quantity reference position for that hour, and then performs a tracking operation for section W2 to a position delayed by one track from the quantity reference position for that hour. The playback head (12
)'s tracking position is one track behind the reference position i? t, and the ratio of the sections of the logic "I(" and rLJ of the time division control signal 855, therefore, the distance corresponding to the time division ratio will be shifted from the reference position. In the end, the characteristic shown in FIG. 7 We end up in a -rucking state which is equivalent to the curve.

Note that the frequency of the Jr division control signal 855 is a constant of the tracking servo system. : All you have to do is take it into account and adjust it quickly according to the necessity, and if you improve the frequency, you can sufficiently suppress the shock given to the servo system.

Figure 1O is an example of a capsule shape for the configuration in Figure 8. In Figure 8, the time division ratio was changed to adjust the tracking position, but instead, in Figure 10, the reference tracking Section wl and lead/lag tracking section W
The error signal forming circuit (
51), the gain of the output S4 is changed. In other words, the output amplifier circuit (65) of the error signal forming circuit (51) is not a variable gain amplifier, and the gain in the reference tracking section W1 of the y-divided control signal S!, i,', + is The gain in the lead/lag tracking section W2 is switched to a value arranged by si'4 by a gain adjustment element (66)i.

In this way, the first
The tracking servo mechanism is driven with a gain G1 of
It can be determined by the ratio of G2 and G2.

〔Effect of the invention〕

As described above, according to the present invention, one system is used as an error signal forming circuit to perform time-division operation, and as a result, the reference tracking error (, tracking operation by No. and tracking operation based on lead or lag tracking error signal, and 2.
Tracking position fif can be made by
Adjustment for shifting t'aj can be easily realized. If this adjustment is made during variable speed playback, the noise band can be shifted to any position as required.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the operating principle of the tracking flj control device according to the present invention, Fig. 2 is a block diagram showing its error signal forming circuit, and Fig. 3 is...? Route map showing the recording pattern of the pilot signal, Fig. 4d. Fig. 2 is a signal waveform diagram of each part, Figs. 9 are signal diagrams for explaining its operation, and FIG. 10 is a block diagram showing another embodiment of the present invention. (1)... V pilot signal detection circuit, (21, (31
...1st゜second error signal forming circuit, (4)...
Lock point control circuit, (5)...error phase calculation circuit,
(11)...tape, (12)...playback head,
(13)...Rizoirot signal detection circuit, (14)...
... Multiplier, (15) ... Lock point control circuit, (16
)...Pilot frequency generation circuit, (17)...Switch circuit, (20), (2])...First. Second
difference frequency detection circuit, (22), (23)...DC conversion circuit, (2A)...subtraction circuit, (25)...changeover switch circuit, (26)...inversion circuit, (31)... )
. (32)... Coefficient circuit, (45)... Pilot frequency generation circuit, (51)... Error signal forming circuit, (
52)... Lock point control circuit, (53)... Reference switch circuit, (54)... Phase advance switch circuit, (55)...
)...Lagging phase switch circuit, (56)...Tracking lead/lag switching switch circuit, (57)...Time division signal generation circuit, (!58)...Time division operation switch circuit, (59)... )...Tracking lock point adjustment element, (
60), (65)...output amplification circuit, (66)...
・Gain adjustment element. =41: Figure 4/-10

Claims (1)

[Claims] 1. Multiple noises with different frequencies? A recording medium in which a pilot signal is recorded cyclically on each track is reproduced by the above-mentioned piezoelectric no. χ playback head. In the tracking control device which obtains a difference frequency component and obtains an error signal for the tracking position of the endogenous head according to the difference frequency component, The first reference signal that generates the reference pilot signal? A second reference signal generation circuit and a second reference signal whose phase is shifted by one track with respect to the reference signal ξ of &λl. The second one that generates the pilot signal.
a reference pilot signal generation circuit, a time division switch circuit that sequentially outputs the first and second reference par lot No. 15 at a predetermined time division ratio, and an output of the time division switch circuit and the reproduction pilot. The tracking control device shall be equipped with an error detection circuit capable of transmitting an error signal to the above-mentioned tracking position in addition to the signal. The patent h? has a time division ratio adjustment element that changes the ratio of the output sections of the reference and a pilot signals. ! ;The tracking control device described in the first part of the requested scope @. 3. The upper error detection circuit outputs the error signal through the gain control amplifier circuit, and the upper Rc gain control circuit outputs the error signal through the first and second base 4fi, .
A tracking control device according to claim 1, which is capable of changing the ratio of the eleventh gain in the section in which the j+ilot signal is outputted, and