JPS62246184A - Disk and disk driving device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a disk driving device and to perform accurate speed control and position control by recording a tracking servo signal in a prescribed position and calculating the distance between the current position of a recording and reproducing element and a target position based on the servo signal to supply a control signal to a mobile means. CONSTITUTION:A microprocessor 14 compares the level data of respective servo signals with one another to detect the zone where a magnetic head 11 exists. Each time the zone is changed twice, it is discriminated that the magnetic head 11 advances by one track, and a counter, which indicates the track number of the current position of the magnetic head 11 incorporated in the microprocessor 14 is counted up or down to detect the current position. The difference between the value of this counter and the track number of the target position is obtained to calculate the number of tracks to the track of the target position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a disk drive device, and in particular, to an apparatus that can improve the accuracy of tracking servo.

(Prior Art) Disk drive devices have been known that record various information signals as concentric or spiral tracks on a rigid disk housed in the main body of the device. The information is recorded and reproduced by a recording/reproducing element such as a magnetic head which is moved in the radial direction of the disk surface which is rotated at high speed.

Incidentally, in this type of apparatus, tracking servo consisting of speed control and position control is performed so that the magnetic head can accurately track on a predetermined track formed on the disk surface.

As this tracking servo, there is one as described in Patent Application No. 82212 filed in 1985 by the applicant of the present invention.

That is, as shown in FIG. 8, the rotating shaft 4 of the access motor 3 for moving the magnetic head 1 in the radial direction of the disk 2 is magnetized with N poles and S- poles alternately at a predetermined pitch on the outer periphery. A disk-shaped scale 5 is integrally attached, and a detector 6 using an MR element (11 resistance effect element) is arranged near the outer periphery of the scale 5.
Based on the output of the magnetic head 1, the position of the magnetic head 1 in the disk radial direction, the distance (number of tracks) between the current position track and the target position track of the magnetic head 1, or the moving speed of the magnetic head 1 are sequentially detected. There is. Based on these detection results, the speed control and position control of the magnetic head 1 is performed.

(Problems to be Solved by the Invention) The detection output of the detector 6 using the MR element as described above has a substantially sinusoidal waveform as shown in FIG.

In order to cause the magnetic head 1 to on-track on the target position track based on such a detection output, the access motor 3 is operated so as to converge this detection output to a predetermined position P corresponding to the target position track. Just control it.

However, in the case of such a tracking servo, since the portion H of the detection output that can be regarded as a straight line is short, it is difficult to control the detection output to converge on the predetermined position. There was a risk that the vehicle could end up on track with the truck in front or behind it.

In addition, in the case of a tracking servo using an MR element as described above, a track center based on the detection output,
There is a possibility that thermal off-track occurs in which the actual track center of the disk 2 deviates due to temperature change, and as a result, various signals cannot be read or written correctly.

(Means for solving the problems) The present invention has been made in view of the above-mentioned circumstances,
It is an object of the present invention to provide a disk capable of improving tracking servo and a disk drive device for transmitting and receiving signals of the disk.

In order to achieve this object, the present invention provides a disk drive apparatus, as shown in FIG. A recording and reproducing element 11 for recording and reproducing signals, and this recording and reproducing element 1
1 in the radial direction (in the direction of the arrow) of the disk 10; a detection means 13 for detecting the servo signal from the reproduction output signal of the recording/reproduction element 11; The distance between the current position of the recording/reproducing element 11 and the target position is calculated based on the servo signal, and based on this result, a control signal is supplied to the moving means 12 to cause the recording/reproducing element 11 to converge to the target position. The control means 14 is also provided.

Further, as shown in FIG. 2, the disk 10 is a disk on which various signals are recorded as concentric or spiral tracks Tn, and two tracks are adjacent in the radial direction (in the direction of the arrow) of the disk Across Tn and Tn+1,
and 41 areas AA that are offset from each other in the circumferential direction (arrow 8 directions).

Servo signals of single cycle liquid numbers are recorded in As, Ac, and Ao, respectively.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7.

FIG. 2 is a diagram schematically showing the recording pattern of the disk 10 according to this embodiment, and as shown in the figure, a plurality of sectors SE are sequentially formed on concentric tracks 7n.

In addition, in front of sector SE, that is, on the left side in the figure, two tracks Tn adjacent in the radial direction of this disk 10 are located.
, Tn +1%, and four areas AA, As, Ac, and A that are offset from each other in the circumferential direction.

Single frequency servo signals SA, Spa, 'So, S
0 is recorded in each. That is, in this embodiment, two areas AA and AC located on both sides of the center position 10 of this track Tn are formed in the n-th track 7n, and servo signals SA, AC are applied to each of these areas AA and Ac.
So is recorded respectively. Further, in the n+1-th track Tn+1 or the n-1-th track Tn-1 adjacent to the track Tn in the radial direction, each of these tracks Tn+1. Two areas As and Ao are formed on both sides of each center position Tc of Tn-1, and a servo signal S is sent to each of these areas Aa and Ao.

So is recorded respectively.

Thereby, in order to cause the magnetic head 11, which is a recording/reproducing element, to on-track, for example, the n-th track Tn, it is only necessary to control the servo signals SA and Sc during reproduction output so that they are at the same level.

Further, in this embodiment, each of the above areas AA.

Day A, Ac, and Ao are positioned offset from each other in the radial direction of the disk 10, so that the servo signals recorded in these areas AA, As, Ac, and Ao are , So are played back with a shift in the time axis direction.

In this embodiment, each sector SE consists of a generally well-known index field ID, data field □ ata, etc., and each of these fields I
An index signal, a synchronization signal, and data are recorded in D and Data, respectively.

On the other hand, the disk 1o as described above is installed in a disk drive device equipped with a tracking servo system as shown in FIG. 1, with the disk 10 attached to a spindle motor 15 that rotates the disk 10 at high speed.

This disk drive device includes a magnetic head 11 that sends and receives signals to and from the disk 10, and a magnetic head 11 that sends and receives signals to and from the disk 10.
1 in the radial direction of the disk 10, and the servo signal S from the reproduction output of the magnetic head 11.
A, Sa, Sc.

It is equipped with a detection means 13 for detecting So, and a microprocessor 14 which is a control means for supplying a control signal to the movement means 12 for causing the magnetic helad 11 to be on-track to the target position track on the disk 10. .

In this embodiment, the detection means 13 detects the servo signals SA and S, which are pulse signals as shown in FIG. 3A, from the reproduction output outputted from the magnetic head 11 via the recording and reproduction circuit 131.

A pulse detector 132 extracts Sc and SD, and FQ (F
(requency Qenerator) circuit 13
3, a burst gate circuit 134 that outputs a burst gate signal as shown in the figure C based on the pulse signal output from the FG circuit 133, and a servo signal gate-controlled as shown in the figure C using this burst gate signal. SA,
S8. A servo signal generation circuit 135 that generates a servo signal as shown in E in the same figure based on Sc and So, and an AD (analog-digital) converter 136 that digitizes the level of this servo signal at the timing shown in F in the same figure.
It is composed of.

In this embodiment, the FG circuit 133 is provided to generate the burst gate signal as described above, but for example, as shown in FIG. 2, fρ1 and fρ2 having different frequencies are alternately recorded in the radial direction. By reproducing this, a pulse signal as described above can be obtained. According to this method, since the pulse signal can be directly extracted from the disk 10, an extremely accurate burst gate signal can be obtained.

After the output level of the AD converter 136 has elapsed, the signal is sequentially taken into the microprocessor 14.

Further, the microprocessor 14 in this embodiment receives each servo signal SA supplied from the detection means 13,
8F! , Sc, So level data LA, La, L
It is configured to calculate the moving speed of the magnetic head 11 and the distance (number of tracks) between the current position and the target position based on c and Lo, and output a control signal based on the results.

Note that this microprocessor 14 has a built-in speed control program for the magnetic head 11 according to the number of tracks to be sought, and the magnetic head 11 is controlled at a speed programmed according to the distance between the current position and the target position as described above. 11 is designed to output a control signal to move.

Further, the moving means 12 includes the microprocessor 1
OA (
a voice coil motor (VCM) that linearly moves the magnetic head 11 in the radial direction of the disk 10; ) 124, and this moving means 12 moves the magnetic head 11 at a predetermined speed based on the control signal.

Next, the operation of the tracking servo in the disk drive device configured as described above will be explained.

Consisting of two operations, speed control accelerates and decelerates the moving speed of the magnetic head 11 as shown in the figure to seek close to the target position, and position control causes the magnetic head to accurately track the target position. .

That is, at the speed 11111, the microprocessor 14 first outputs the servo signals SA, Ss.
, Sc, So level data LA+Le, Lc, L
o as shown in FIG. 5 to determine whether the magnetic head 11 is in the AD zone (zAo) of each track or in the CA zone (zAo).
oA), BC zone (Zsc), or DB zone (Zoe).

Then, each time the zone changes twice, it is assumed that the magnetic head 11 has advanced by one track, and a counter that indicates the track number of the current position of the magnetic head 11 built in the microprocessor 14 is sequentially counted up or down. This allows the current position to be detected.

Next, the number of tracks up to the target position is calculated by calculating the difference between the value of this counter and the track number of the target position.

Furthermore, when the difference in the level data when the magnetic head 11 moves is calculated, it changes as shown in a straight line as shown in FIG.

Therefore, the equation for this straight line 1 is determined in advance, and the microprocessor 14 substitutes the difference in level data as described above into the equation to calculate the radial position of the magnetic head 11 in each zone. be able to.

That is, as shown in Figure 6, if the width of each zone is set to 1
00, and the distance from this center position in each zone of the magnetic head 11 is X (-50≦X≦50), it can be determined by the formula x=-X50.

In this equation, b is the maximum absolute value in each zone, and a is the maximum absolute value in each zone, and a is the maximum absolute value in each zone.
zAO).

As a result, according to this embodiment, the distance to the target position track can be calculated extremely accurately with shoulder resolution, for example, 100,200 Tp.

Then, in accordance with the distance to the track at the target position calculated in this way, the moving speed of the magnetic head 11 is determined as shown in FIG. 4 based on a preset speed control program.

On the other hand, in this microprocessor-4, the change in the distance to the target position track calculated as described above is calculated as the time required to move this distance, that is, the above-mentioned A
By dividing by the sampling period of the D converter 136, the moving speed of the magnetic head 11 is accurately detected in real time.

Then, the microprocessor 14 detects the difference between the moving speed of the magnetic head 11 detected in this way and the speed determined based on the speed control program, and generates a control signal to make these respective speeds match. and supplies this control signal to the moving means 12.

As a result, according to this embodiment, extremely accurate speed control can be achieved.

Next, when the magnetic head 11 approaches the target position by a predetermined distance, that is, the distance to the target position is Tp/2, for example.
When this happens, the control mode of this disk drive device becomes position control.

In this position control, the microprocessor 14 uses the equation representing the straight line 1 to control the magnetic head 11.
The distance X between the magnetic head 11 and the target position is sequentially detected as a positional error, and a control signal is outputted so that the magnetic head 11 can converge at the target position, that is, the positional error can be reduced to zero.

In this embodiment, the position error is determined as shown in the table below by comparing the zone to which the magnetic head 11 belongs and the zone to which the target position belongs when switching from speed control to position control.

That is, if the target position is in the CA zone (ZcA) and the position control is switched, the magnetic head 11 is in the A zone.
D zone (2A+)), the above position error is determined by X calculated using the above formula, the distance 100 from the center position of the AD zone (ZAD) to the target position, that is, the center position of the CA zone (ZcA). Corresponds to the sum of

Furthermore, if the zone to which the target position belongs is the same as the zone to which the magnetic head 11 belongs when switching to position control, it is assumed that the magnetic head 11 has already reached the zone where it follows the target position. The positional error is defined as the value X determined by the above formula.

In addition, if the target position belongs to the OA zone (zcA)≠Niji,
If the magnetic head 11 belongs to the DB zone (70 days), it is outside the pull-in range and cannot be controlled.

Therefore, in this embodiment, position control is possible when the magnetic head 11 is located in a zone adjacent to the zone to which the target position belongs, and as a result, the pull-in range in this embodiment is ±3Tp/4.

Further, as described above, the distance to the target position can be detected with extremely high accuracy in position control as well.

As a result, even if the moving speed of the magnetic head 11 when switching from speed control to position control is too high and the target position is significantly passed, or if the moving speed at this time is too small, the above-mentioned By such position control, the magnetic head 11 can be accurately focused on the target position.

Note that in position control as well, the pull-in range can be set to ±3Tρ/4 or more by counting tracks.

As described above, according to this embodiment, extremely accurate speed control and position control can be realized, and the accuracy of tracking servo can be improved.

Note that the servo signal SA to the disk 10 according to the present invention,
The recording patterns of Se, Sc, and So are not limited to the embodiments described above, and may be recorded as shown in FIG.

(Effects of the Invention) As is clear from the above description, the disk according to the present invention enables a disk drive to transmit and receive signals to and from the disk by recording a single-frequency tracking servo signal at a predetermined position on the disk. The configuration of the device can be simplified.

Further, according to the disk drive device according to the present invention, accurate speed control and position control can be realized.

As a result, according to the present invention, the accuracy of tracking servo can be improved.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram showing the configuration of a disk drive device according to the present invention, FIG. 2 is a diagram schematically showing a recording pattern of a disk according to the present invention, and FIG. 3 is a disk drive device shown in FIG. 1. A time chart showing the operating status of
FIG. 4 is a flow chart of the magnetic head in the disk drive device shown in FIG. 1, FIG. 6 is a diagram schematically showing the relationship between the detection results and each zone for speed control and position control, and FIG. A>, (B), and (C) are diagrams schematically showing the recording pattern of the disc according to the present invention, FIG. 8 is a diagram showing the main parts of a conventional disc drive device, and FIG. 9 is similar to FIG. It is an MR ratio output waveform diagram of the disk drive device shown. 10... Disk, 11... Magnetic head (recording/reproducing element), 12... Moving means, 13... Detecting means, 1
4...Microprocessor (control means), AA,
As, Ac, Ao-area. Patent applicant: Victor Japan Co., Ltd. Representative Odori Part 2 Figure 4 Flash No. 8rj! I Figure 5 Figure 7 (A) Figure 7 CB) Figure 7 (C) Figure 8 M S N 5 N
4.Drinking Bina→Figure 9

Claims (2)

[Claims] (1) On a disk where various signals are recorded as concentric or spiral tracks, a single frequency is recorded in four areas circumferentially offset from each other across two radially adjacent tracks of the disk. A disc characterized in that each tracking servo signal is recorded thereon. (2) A disk in which a tracking servo signal of a single frequency is recorded in four areas circumferentially offset from each other across two tracks adjacent in the radial direction, and recording and reproduction of various signals on this disk. a recording/reproducing element for performing a recording/reproducing element; a moving means for moving the recording/reproducing element in the radial direction of the disk; a detecting means for detecting the tracking servo signal from a reproduction output signal of the recording/reproducing element; The distance between the current position of the recording/reproducing element and the target position is calculated based on the tracking servo signal, and based on this result, a control signal is supplied to the moving means to cause the recording/reproducing element to converge to the target position. A disk drive device comprising a control means.