JP2001319412A - Head control device in disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problem that, when head movement is controlled by an output from a linear sensor, synchronization is impossible when the state of a reference position signal is inverted exceeding ±90 degrees. SOLUTION: Detection outputs of a phase A and a phase B are obtained from a head position detecting means, and the DC level of the phase A and the DC level of the phase B at a preceding track position are utilized. In all the areas from section (1) to section (4), the combination of the phase A and the phase B differs in state. Therefore, a reference track area can surely be detected by recognizing in which section the reference position signal is inverted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head control device provided with a head driven by a linear motor or the like.
In particular, the present invention relates to a head control device that allows a head to reliably detect a track number recorded on a disk.

[0002]

2. Description of the Related Art In a conventional floppy (registered trademark) disk drive, a step drive mechanism using a stepping motor or the like as a head feeder for moving a head to a track position concentrically recorded on a recording surface of a disk. Is used, and the head is positioned at the track position by a mechanical step operation of the head feeder. In addition, instead of the step driving mechanism, a head feeder driven by a linear motor (VCM: voice coil motor) is provided, and the head is continuously moved by this head feeder.

In this type of disk drive, the head position detecting means detects that the head has returned to the origin position, and this is notified to the host computer. When the head seeks to the target track of the disk, a seek command pulse of one pulse is given to one track from the host computer side to the disk device, and based on the seek command pulse, the head is set on the disk device side. Control for moving by the number of tracks corresponding to the number of seek command pulses is performed.

Here, as in a conventional floppy disk drive, a head base is fitted to a screw shaft driven by a stepping motor, and the head is fed by rotation of the screw shaft. Since the relationship with the movement position of the stepping motor is determined by mechanical connection, only control to drive the stepping motor according to the seek command pulse from the host computer,
The head can be made to track on the target track.

On the other hand, in a device using a linear motor-driven head feeder, the head base has a degree of freedom of movement within the head feeder. It is necessary to provide head position control means based on the detection output.

As a disk device provided with such a linear motor-driven head feeder, for example, a disk for high-density recording in which a servo signal for tracking is recorded on a disk, and a floppy disk having a capacity of 2 Mbytes (FD) are both loadable. The high-density disk loaded in this type of disk device is also a flexible disk. In the following, a flexible disk having a capacity of 2 Mbytes is called a floppy disk, and is distinguished from the high-density disk. explain.

When the high-density recording disk is loaded, the head is moved by driving a linear motor.
The head reads the servo signal, and the head is positioned at each track position. On the other hand, when a floppy disk is loaded, the head feed position is controlled based on the detection output from the head position detecting means, and the head is positioned at the track position.

The head position detecting means includes a linear scale having slits formed at a constant pitch in one of a head base and a chassis, and a light source and a light receiving element opposed to each other via the slit are provided in the other. As a result, a detection output in which the polarity of the output intensity changes periodically is obtained from the light receiving element.

For example, the detection output is composed of two phases having different phases. The mounting position of the head position detecting means is determined such that the head coincides with the track center recorded on the disk at the midpoint between the maximum value and the minimum value of the detection output of one phase. Further, by obtaining detection outputs of two phases, the moving direction of the head can be recognized.

[0010]

In such a system in which the head position is controlled by the head position detecting means using a linear scale, a light source and a light receiving element as described above, the head reaches the reference track area on the inner or outer peripheral side. A reference position signal needs to be generated. For example, when the outer track side of the disk is the first track, the second track is the reference track, and the reference signal is generated when the head enters a reference track area centered on the second track.

[0011] Even when a disk is loaded into a different disk device, it is necessary that the reference position signal be obtained when the head enters the reference track area of the disk. However, since the detection output from the head position detection means is likely to fluctuate depending on the characteristics of the individual disk devices and the use environment conditions, an error occurs in the recognition of the reference track area when the reference position signal is obtained. May occur.

For example, the local maximum value of the detection output of the head position detecting means is counted, and it is determined whether or not the reference position signal is obtained before and after the track at the center between the local maximum value and the local minimum value. In the method of recognizing whether or not there is, if the detection timing of the reference position signal is delayed, the reference track area cannot be accurately grasped. That is, the allowable error range of the timing at which the reference position signal is obtained becomes very narrow.

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and it is possible to accurately recognize a reference track area even if the generation timing of a reference position signal is shifted, and to set an allowable error range of the generation timing of the reference position signal. It is an object of the present invention to provide a head control device in a disk device that can be widened.

[0014]

According to the present invention, there is provided a head control apparatus comprising: a rotation drive unit for rotating a disk; a head facing a recording surface of the disk; and a head for feeding the head in a direction crossing tracks of the disk. Feed means, head position detecting means for obtaining a detection output of a predetermined waveform when the head moves, reference position detecting means for outputting a reference position signal when the head reaches a predetermined position, and head position detection And a control unit for controlling the head feeding means based on the detection output obtained by the means, wherein a midpoint level of a maximum value and a minimum value of the detection output from the head position detection means is obtained. The relative position between the head and the head position detecting means is determined so that the head is positioned on a track of the disk when the The control unit determines whether or not the head has reached a predetermined range centered on a reference track on a disk from a change in the polarity of the detection output from the head position detection unit and the reference position signal. It is characterized by the following.

For example, the waveform of the detection output has a phase difference of 180 degrees between adjacent tracks, and the range of ± 90 degrees of the waveform of the detection output around the reference track is in the reference track area. is there.

In this case, the count number of the maximum value or the minimum value of the detection output after the reference signal is obtained is recognized, and whether the reference signal is obtained when the detection output is positive polarity or minus Depending on whether the reference signal is obtained at the time of polarity, the track area where the count number is obtained is used as the reference track area, or the reference track area is obtained by subtracting or adding a predetermined number from the count number. recognize.

In the head control device of the present invention, when the reference position signal is obtained, the reference position area (reference track area) on the disk is recognized based on the polarity of the detection output from the head position detection means at that time. are doing. Therefore,
The reference track area can be detected within the range of ± 180 degrees of the phase of the detection output, and the allowable error range when the reference signal is obtained can be widened.

Further, when the head moves in the track crossing direction of the disk and returns to the reference track side, it is possible to determine whether or not the predetermined range has been reached.

Further, when the head moves, at least one pair of a maximum value and a minimum value of the waveform of the detection output is detected, and a midpoint level of the maximum value and the minimum value is calculated. It is preferable to determine whether or not the head has reached a reference track area on a disk from the polarity of the detection output with respect to the reference position signal and the reference position signal.

As described above, the local maximum value and the local minimum value of the detection output are learned, as a result, the midpoint level is obtained, and the polarity inversion state of the detection output is known, so that the polarity change point can be detected with high precision. Can be detected.

Further, two detection outputs having different phases can be obtained from the head position detection means, and it is possible to determine whether or not the current position is within the reference track area from the polarity of the detection outputs of both phases and the reference position signal. It is. However, it is also possible to determine whether or not it is within the reference track area only from the detection output of one phase.

[0022]

FIG. 1 is a block diagram showing an example of a disk drive according to the present invention.

The disk device 10 is loaded with both a disk for high-density recording and a floppy disk (FD) having a capacity of 2M / 1M bytes as in the conventional standard.

The disk drive 10 has a turntable, that is, a rotary drive unit 1 in which the rotation centers of the two disks are loaded. The rotary drive unit 1 is provided with a spindle motor (SPM) 2 and The motor 2 is driven by the SPM driver 2a. Rotation drive unit 1
When a floppy disk (FD) is loaded into the disk, the magnetic head H0 on the side 0 contacts one recording surface of the disk and the magnetic head H1 on the side 1 contacts the other recording surface.

The magnetic head H1 is supported by a support arm 3a, and the magnetic head H0 is supported by a support arm 3b. Both support arms 3 a and 3 b are supported by a head base 4. The head base 4 can be continuously fed in the radial direction of the disk by a head feeding means having a linear motor drive (VCM) 5.

The magnetic heads H0 and H1 are connected to a floppy disk controller (FDC) 8 via a read / write amplifier (R / WAmp) 6 for 2M / 1M and a read / write channel (R / WChannel) 7. ing. The FDC 8 is a disk drive (drive) 1
It is provided on the 0 side, and controls the timing of data writing and the timing of reading. FDC8 also
It is connected to the host interface controller 11 via the disk controller 9. The host interface controller 11 is, for example, an IDE (Integrat
ed Device Electronics) and connected to the host computer 30 via an interface. As described above, the disk device 10 and the host computer 30 are connected by the single interface specification, and a control signal for controlling the disk device 10 is given from the host computer 30 via the IDE interface.

When recording or reproduction on the floppy disk (FD) is performed, the head base 4
Is detected by a linear sensor 15 as a head position detecting means, and the detection output is output from a CPU 18 serving as a control unit.
Given to. The drive of the linear motor drive unit 5 and the rotation drive unit 1 is controlled by the CPU 18.

The support arms 3a and 3b are provided with another magnetic head H0h and a magnetic head H1h used when a magnetic disk for high-density recording is loaded. When a disk is loaded in the rotary drive unit 1, recording / reproducing operations are performed using the magnetic heads H0h and H1h.

In a disk for high-density recording, a servo signal for tracking is recorded on a recording surface.
In step 8, the servo signal is detected based on the reproduced output from the magnetic heads H0h and H1h, and the linear motor drive unit 5 is controlled by the servo signal, thereby performing a seek operation and on-track control of the head.

Therefore, when a high-density recording disk is loaded, the output from the linear sensor 15 is not used for seek operation control or the like. In addition, as a circuit for performing a recording / reproducing operation of a disk for high density recording,
The magnetic heads H0h and H1h have read / write heads for high-density recording.
The disk controller 9 is connected to the disk controller 9 via a write amplifier (R / WAmp) 16 and a read / write channel (R / WChannel) 17, and the disk controller 9 is connected to the host interface controller 11 and connected to the host computer 30 via the IDE interface. Is connected to A control signal for controlling a disk drive for high-density recording is provided from the host computer 30 to the IDE interface.

The disk device 10 is provided with a data buffer 19 connected to the host interface controller 11.
In step 9, the reproduction data read from the head is temporarily stored and transferred to the host computer 30, and the recording data generated by the host computer 30 is temporarily stored and sent to the head side to be recorded on the disk. Is done.

The head position detecting means, that is, the linear sensor 15, for detecting the position of the head when a 2M floppy disk (FD) is loaded is shown in FIG.
As shown in (a) and (b), it is composed of a linear scale 12 and optical detection means 13. Linear scale 1
One of the optical detector 2 and the optical detecting means 13 is fixed to the head base 4 and the other is fixed to the chassis.

In the linear scale 12, a plurality of detection windows (slits) 12a are opened at a constant pitch in a long plate. The optical detecting means 13 is composed of a light source 13a and a light receiving / converting unit 13b which are fixedly installed facing each other with the linear scale 12 interposed therebetween. Light receiving converter 13b
Are provided with light receiving elements 14a and 14b. Assuming that the pitch of the detection windows 12a opened in the linear scale 12 is p, the arrangement distance (pitch) between the light receiving elements 14a and 14b is (3/4) · p.

Light emitted from the light source 13a passes through a detection window 12a formed in the linear scale 12, and is detected by the light receiving elements 14a and 14b. Due to the relative movement between the linear scale 12 and the optical detection means 13, the light receiving elements 14a and 14b obtain a triangular function or a two-phase detection output of an intensity change approximated to a trigonometric function according to the amount of received light. . The detection window 1 of the linear scale 12
Due to the relationship with the pitch p of 2a, the phase of the light receiving output obtained from the light receiving element 14a and the phase of the light receiving output obtained from the light receiving element 14b are shifted by ４ cycle (90 °).

FIG. 3 shows the detected output values of the light receiving elements 14a and 14b, and shows the output of the A phase and the B phase which are 90 ° out of phase with each other. In this embodiment, when the phase A reaches the zero point, that is, the midpoint of the amplitude between the maximum value and the minimum value, the recording or reproducing position of the magnetic heads H0 and H1 is positioned on the track of the floppy disk (FD). Like
The position of the linear scale 12 has been adjusted in advance. In FIG. 3, the track position (TK) of the disk is set to 1, 2, 3,... From the outer circumference to the inner circumference of the disk. The phase of the A phase between adjacent tracks is 180 degrees.

The track number of the track located at the outermost periphery of the disk is TK1, and the track number of the inner track is TK2. In this embodiment, the second track TK2 is the reference track, and the phase range of ± 90 degrees sandwiching the second track TK2 is the reference track area.

When a floppy disk (FD) is loaded in the disk device 10, the magnetic heads H0, H
1 is moved to the innermost track and then from the innermost track to the outermost track to obtain a detection output (light scale) from the linear sensor 15. At this time, 0, 1, 2, 3... Are counted from the inside with respect to the maximum value and the minimum value of the waveform of the detection output of the A phase. In FIG. 3, the count values of the local maximum value and the local minimum value are indicated by 79, 80, 81, and 82 for convenience of explanation, and the count number of the local minimum value inside the second track TK2 as the reference track is 80. The count value of the outer maximum value is set to 81, and the range from the count value of 80 to 81 is set as the reference track area.

As shown in FIG. 2, a projecting piece 12b is formed at one end of the linear scale 12 so as to project toward one side. When the edge 12b1 of the protruding piece 12b passes through the optical detecting means 13c, the optical detecting means 13
The detection output of c is inverted. This inverted signal is the reference position signal. In the optical detecting means 13c, the light source and the light receiving conversion unit face each other, and the protruding piece 12b passes between the light source and the light receiving conversion unit. In this embodiment, when the light between the light source and the light receiving / converting unit is blocked by the protruding piece 12b, the reference position signal becomes high.

As described above, in this disk device, when the midpoint level between the maximum value and the minimum value of the phase A is obtained, the magnetic heads H0 and H1 are set to be on-track on tracks on the disk. The position of the head position detecting means is determined. When the drive starts, the magnetic heads H0,
H1 is moved from the inner circumference side to the outer circumference side of the disk, a detection output from the head position detection means (linear sensor 15) is obtained, and the levels of all maximum values and minimum values of the A phase are detected. At the same time, the maximum value and the minimum value are sequentially counted from the inner circumference side. The center of the amplitude, that is, the midpoint level is detected from the maximum value and the minimum value.

In FIG. 3, the range of ± 180 ° centered on the reference track (second track TK2) on the disk is divided into equal intervals of 90 ° in sections (1) to (4). A case where the reference position signal is inverted in any of the sections (1) to (4) will be described.

When the reference position signal is inverted in the section (1) or the section (2), the polarity of the phase A at that time is minus (-). When the reference position signal is inverted in the section (3) or the section (4), the polarity of the phase A at that time is plus (+).

Therefore, when the magnetic head is moved from the inner peripheral side to the outer peripheral side of the disk, the polarity of the A-phase when the reference position signal is inverted is recognized, and when the polarity is minus (-), the polarity is recognized. When passing through the count number 80 of the phase A detected during minus, it is recognized as having entered the reference track area (the area of ± 90 degrees centered on the reference track TK2). When the polarity of the phase A when the reference position signal is inverted is plus (+), and when the count number (80) obtained by subtracting 1 from the count number 81 of the phase A obtained when the polarity is positive, Is recognized as having entered the reference track area.

Alternatively, by using the polarities of both the A-phase and the B-phase, more accurate detection is possible. Section (1)
In the figure, the A phase is minus (-) and the B phase is plus (+). Here, when the reference position signal is inverted, a case where the count number obtained at this time exceeds 80 is defined as a reference track area. In section (2), phase A is minus (-)
The phase is negative (-). Here, when the reference position signal is inverted, the time when the count number obtained at this time exceeds 80 is the reference track area.

In the section (3), the phase A is positive (+),
The phase is negative (-). Here, when the reference position signal is inverted, when the count number 80 obtained by subtracting 1 from the count number 81 obtained at this time exceeds a reference track area, the reference track area is obtained. In the section (4), the A phase is plus (+) and the B phase is plus (+). Here, when the reference position signal is inverted, when the count number 80 obtained by subtracting 1 from the count number 81 obtained at this time exceeds a reference track area, the reference track area is obtained.

Therefore, in the subsequent seek operation or recording / reproducing operation, when the magnetic head is moved to the outermost periphery, when the count number (80) is exceeded, the track area number is updated to TK2. Therefore, the reference track area can always be recognized.

The recognition of the polarity of the phase A is as follows.
When moving the magnetic heads H0 and H1 from the inner circumference side to the outer circumference side of the disk, the maximum value and the minimum value of the A phase are always detected, and the detected values are used to determine the midpoint level of the maximum value and the minimum value. Is calculated. The reference track area is determined by recognizing whether the A phase is positive or negative with respect to the calculated midpoint level. Therefore,
Even if the level of the maximum value and the minimum value of the A phase changes due to the output fluctuation of the linear sensor 15 or the like, the polarity of the A phase can be recognized with high accuracy from the midpoint level. In this regard,
The reference track area can be accurately detected.
Similarly, the maximum value and the minimum value of the B phase can be detected, and the midpoint level can be obtained.

In the method of recognizing the reference track area, as shown in FIG. 3, ± 1 with respect to the reference track TK2.
If the reference position signal is inverted within a phase range of 80 degrees, the reference track area can be known. Therefore, the allowable range of the detection error of the reference position signal can be widened. However, the actual scale output from the linear sensor 15 often includes an error. Considering that the allowable error range according to the specification is ± 30 degrees and that an amplitude fluctuation of about 15% occurs, If it is within the range of ± 120 degrees, it is possible to reliably synchronize the track of the disk with the reference position signal.

[0048]

According to the present invention described above, it is possible to widen the allowable range of the detection error of the reference position signal when recognizing the reference track area. Therefore, the reference track area can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a disk device of the present invention;

2A and 2B show an example of a configuration of detection, wherein FIG. 2A is a side view of a linear scale, FIG. 2B is a partial plan view showing a relationship between an optical detection unit and a linear scale,

FIG. 3 is a waveform chart showing a relationship between a detection output and a reference position signal.

[Explanation of symbols]

 Reference Signs List 1 rotation drive unit 2 spindle motor 3a, 3b support arm 4 head base 5 linear motor drive unit 6 read / write amplifier 8 floppy disk controller 12 linear scale 13 optical detection means 15 linear sensor 18 CPU (control unit)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Tenpaku 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo F-term in Sony Corporation (reference) 5D088 DD02 5D096 AA04 EE12 GG01 HH01

Claims (6)

[Claims] 1. A rotation drive unit for rotating a disk, a head facing a recording surface of the disk, a head feeding means for feeding the head in a direction traversing a track of the disk, and a predetermined unit when the head moves. Head position detecting means for obtaining a detection output of a waveform, reference position detecting means for outputting a reference position signal when the head reaches a predetermined position, and the head based on the detection output obtained by the head position detecting means A disk unit provided with a control unit that controls a feeding unit, wherein when the midpoint level of the maximum value and the minimum value of the detection output from the head position detection unit is obtained, the head is positioned on the track of the disk. The relative position between the head and the head position detecting means is determined so as to be located at the position. And the change in polarity of the output power, the reference from the position signal, the head is a head control unit which is characterized in that the determination of whether reaches the reference track area around the reference tracks on the disk. 2. The waveform of the detection output has a phase difference of 180 degrees between adjacent tracks, and a range of ± 90 degrees of the waveform of the detection output around the reference track is in the reference track area. The head control device according to claim 1. 3. Recognizing a count number of the maximum value or the minimum value of the detection output after a reference signal is obtained, and determining whether the reference signal is obtained when the detection output is a positive polarity or a negative polarity. Depending on whether or not the reference signal is obtained at the time, the track area where the count number is obtained is used as the reference track area, or the reference track area is recognized by subtracting or adding a predetermined number from the count number. The head control device according to claim 1 or 2, wherein: 4. The head according to claim 1, wherein when the head moves in a direction crossing the track of the disk and returns to the reference track side, it is determined whether or not the predetermined range has been reached. Control device. 5. When the head moves, at least one set of a maximum value and a minimum value of the waveform of the detection output is detected, and a midpoint level of the maximum value and the minimum value is calculated. 5. The head control device according to claim 1, wherein whether or not the head has reached a reference track area on a disk is determined from the polarity of the detection output with respect to the reference position signal and the reference position signal. 6. The head position detecting means obtains two detection outputs having different phases, and determines whether the current position is within a reference track area based on the polarity of the detection outputs of both phases and a reference position signal. 6. The head control device according to any one of items 5 to 5.