JPH0896535A - Disk device - Google Patents

Abstract

PURPOSE: To prevent deviation when a head is sent to a target position by converting address information corresponding to the present position of the head read from a disk recording medium into a count value, loading it to a count means and eliminating deviation between a head position and the count value. CONSTITUTION: An optical pickup 4 is moved to the innermost periphery of a disk 2 by a stepping motor 10 as re-calibration, and a counter 17 is reset when a read-in switch 18 is turned on. When a command for turning off a tracking servo and moving the pickup 4 is issued, the number of steps of the motor calculated from an address showing the present position of the pickup 4 for the disk 2 is compared with the present value of the counter 17 before the pickup 4 is sent by the motor 10, and when they deviate, the value corresponding to the number of steps is loaded to the counter 17. The stepping motor is switched to an FG motor, and the pickup 4 is jumped to the target position. The tracking servo is turned on, and the servo of a spindle motor 9 is switched to a servo mode synchronizing with the data read from the disk 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device which handles a disk-shaped recording medium on which at least address information indicating a radial position is recorded.

[0002]

2. Description of the Related Art Conventionally, as disc-shaped recording media, there are optical discs such as so-called compact discs (CD) and mini discs (MD: Mini Disc, trademark of Sony Corporation). Here, of the disc-shaped recording media, for example, the MD is a recordable / reproducible disc (recordable disc), a replay-only disc (pre-master disc), and a recordable region in advance in the disc. There is a disc (hybrid disc) provided with a pre-master area in which pits are carved. In these various MDs as well, the basic parameters and recording density in optical recording are the same as those of CDs.

FIG. 4 shows an outline of the disc formats of the above three types of MDs. The premaster disc is shown in FIG. 4A and the recordable disc is shown in FIG. 4B. 4C schematically shows a cross section of the hybrid disc.

In these discs, the innermost peripheral portion of the information area is a lead-in area, which is used to handle information for setting laser power called TOC (Table Of Contents) and the disc. Basic information is recorded as pit information. The information areas other than the lead-in area on the innermost circumference of each of these discs are pit areas or recordable grooves depending on the characteristics of the disc, such as the above-mentioned read-only and recordable / reproducible discs.

Further, referring to FIG. 5, the recordable disc shown in FIG. 4B will be described in more detail. The radius of the disc is 30.5 mm, and the recordable area is divided into the lead-in area and the recordable area. The boundary is 16.0 mm from the center of disk rotation,
Further, the recordable area is 14.5 mm from the lead-in area to the outer peripheral side.

In the above recordable disc,
The recording groove on the entire circumference of the recordable area is AD when the disc is molded.
Cluster and sector address information called IP (ADdress In Pregroove) is formed by wobbling. Using this, not only the tracking and control of the CLV (constant linear velocity) spindle servo but also the system control including the access operation at the time of recording and reproduction is performed.
The ADIP signal is obtained by modulating a 22.05 kHz carrier with address information, and the recording groove meanders by about 30 nm with this carrier. The optical pickup can read the address information by the wobbling groove independently of the recording signal, and at the time of recording, recording is performed in cluster units based on the address information.

FIG. 6 shows the data structure of about one cluster of the recordable disc. In FIG. 6, one cluster is composed of a link area having a link center LS of 3 sectors, a sub data sector SS of 1 sector, and a data area having a data sector DS of 32 sectors.

Since the data is continuously recorded on the read-only disc, the three sectors in the link area are unnecessary, and in addition to these three sectors, the first four sectors are all allocated to the sub-data sector SS.

[0009]

By the way, in the optical disk device handling the above-mentioned optical disk, for example, a spindle motor is provided as a structure for rotating the optical disk, and a thread feed for moving an optical pickup or the like is provided. It has a mechanism.

Here, in the above optical disk device,
First, at the beginning of the drive operation, the optical pickup is moved to, for example, the innermost circumference of the optical disc by the sled feed mechanism. At this time, a lead-in switch is arranged at a position (reference position) corresponding to the innermost circumference of the optical disk, and when the optical pickup is moved to the innermost circumference position by the sled feed mechanism, the lead-in switch is turned on. Turn on. As the lead-in switch, a mechanical switch that mechanically turns on / off, a photo interrupter that optically turns on / off, or the like is used.

The ON signal of the lead-in switch is a reset signal of the counter whose count value increases / decreases with the movement of the optical pickup by the sled feeding mechanism.
The current position of the optical pickup moved by the sled feed mechanism (the position in the radial direction from the innermost circumference of the disc) can be known from the count value of the counter after the reset. The counter often obtains the count value by counting, for example, an FG pulse of a sled motor as a drive source of the sled feed mechanism.

However, when the optical pickup is accessing the optical disk by the thread feeding mechanism, the actual position of the optical pickup (to be exact, the position of the objective lens of the optical pickup) and the counter of the above-mentioned counter due to the step-out of the mechanism or the like. There may be a deviation from the count value.

When the deviation between the actual position of the optical pickup and the count value occurs in this way, when the optical pickup is sent to the target position on the disk, it cannot be accurately sent to the target position. .

Further, a limit value is usually defined for the feed amount of the sled feed mechanism so that the optical pickup does not move over a predetermined range. However, if the count value deviates, the limit value is increased. The value may exceed the value, and in such a case, it may cause a failure of the thread feeding mechanism.

Therefore, it is not preferable that the position of the optical pickup and the count value are deviated by the thread feeding mechanism.

Further, in the case where the count value is deviated due to the step-out or the like, if the optical pickup is moved to the position of the lead-in switch by the thread feeding mechanism and the counter is reset again, it takes time to access. It is not preferable because it causes a problem.

Therefore, the present invention has been proposed in view of the above situation, and eliminates the deviation between the position of the head (for example, an optical pickup) and the count value, and shifts the head to the target position. In other words, it is an object of the present invention to provide a disk device that can prevent movement of the thread feeding mechanism that exceeds the limit value and can prevent access from taking a long time.

[0018]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and in a disk device handling a disk-shaped recording medium in which at least address information indicating a radial position is recorded, Corresponding to the thread feeding means for moving the head in the radial direction of the disk-shaped recording medium, the counting means for outputting a count value corresponding to the feed amount of the thread feeding means, and the current position of the head read from the disk-shaped recording medium. And a counter loading means for converting the address information into a count value and loading the count value on the counting means.

Here, the counter loading means loads the count value in response to a seek start instruction.

In addition to the above structure, the device of the present invention is
Rotation speed control means for controlling the rotation speed of a motor for rotating the optical disk having a different linear velocity or recording density in the circumferential direction based on the count value of the counting means is also provided.

[0021]

According to the present invention, the address information corresponding to the current position of the head read from the disk-shaped recording medium is converted into a count value and loaded into the count means, so that, for example, step out is performed and the thread feed position is determined. Even if the count value deviates, the count value can be calibrated.

Further, by loading the count value for each seek start instruction, an accurate seek operation becomes possible. Further, when the disk-shaped recording medium at this time has different linear velocities or recording densities in the circumferential direction, when performing a seek, the rotational speed of the motor for disk rotation is controlled based on the count value of the counting means. However, by calibrating the count value for each seek start command, it is possible to reduce the deviation of the target value of the motor rotation speed (that is, the linear velocity of the disk) after the seek.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a schematic structure of a disk device of the present invention.

As shown in FIG. 1, the disk apparatus of the embodiment of the present invention handles a magneto-optical disk 2 as an example of a disk-shaped recording medium in which at least address information indicating a radial position is recorded. , A stepping motor 10 as a drive source of a thread feeding means for moving the optical pickup 4 as a head in the radial direction of the magneto-optical disk 2 and a count value corresponding to the feed amount (step number) of the stepping motor 10 are output. And a motor control circuit 14 which also has a function as a counter loading means for converting the address information corresponding to the current position of the optical pickup 4 read from the magneto-optical disk 2 into a count value and loading it into the counter 17, It is characterized by having a system controller 15.

Here, the motor control circuit 14 loads the count value in response to a seek start command supplied via the system controller 15.
At this time, the motor control circuit 14 and the system controller 15 of the apparatus of the present embodiment rotate the magneto-optical disk 2 having different linear velocities or recording densities in the circumferential direction based on the count value of the counter 17. It also has a function as a rotation speed control means for controlling the rotation speed of 9.

In the optical disk device 100 shown in FIG. 1, first, as a recording medium, a magneto-optical disk 2 such as the above-mentioned recordable MD which is rotationally driven by a spindle motor 9 is used.

The optical pickup 4 is composed of, for example, a laser light source such as a laser diode, a collimator lens, an objective lens 3, optical components such as a polarization beam splitter and a cylindrical lens, and a photodetector having a light receiving portion of a predetermined pattern.

The optical pickup 4 is provided at a position facing the recording magnetic head 1 with the magneto-optical disk 2 interposed therebetween. When data is recorded on the magneto-optical disk 2, the recording magnetic head 1 is driven by an OWH (overwrite head) driver (write driver) 5 which is a head driving circuit of a recording system, and a modulation magnetic field according to the recording data is generated by the optical signal. While applying to the recording surface of the magnetic disk 2,
By irradiating the target track of the magneto-optical disk 2 with a laser beam of a predetermined power by the optical pickup 4 through the objective lens 3, thermomagnetic recording by a so-called magnetic field modulation method is performed.

At the time of this recording, for example, the data to be recorded supplied from the host computer 101 or the outside is sent to the encoder of the signal processing circuit 6, where the addition of the error correction code and the 8-14 modulation (EFM) are performed. It is converted into the applied recording signal. This recording signal is the above-mentioned OWH driver 5
Then, the driver 5 drives the recording magnetic head 1 according to the recording signal. At the same time, the optical pickup 4 is operated by the PWM (pulse width modulation) driver 1
The laser light is controlled by 2 so as to have a recording power, which raises the temperature of the recording surface of the recording track to the so-called Curie point.

At the time of reproduction, the recording track of the magneto-optical disk 2 is traced by the laser light by the optical pickup 4 to perform magneto-optical reproduction utilizing the so-called Kerr effect.

The optical pickup 4 detects the reflected light of the laser light applied to the target track and sends this detection signal to the RF amplifier 8. This detection signal includes a reproduction signal corresponding to the difference in the polarization angle (Kerr rotation angle) of the reflected light of the laser beam from the target track during reproduction, and a focus error signal during recording and reproduction, for example, by the so-called astigmatism method. And a tracking error signal by a so-called push-pull method, and address information by the wobbling groove used at the time of recording.

When reproducing data from the magneto-optical disk 2, the RF amplifier 8 extracts the reproduction signal from the output signal of the optical pickup 4 and sends it to the signal processing circuit 6. At this time, the signal processing circuit 6 obtains reproduced data by performing demodulation of the EFM and error correction processing on the reproduced signal by the decoder section. This reproduction data is then sent to, for example, the host computer 101 or the like.

Further, the RF amplifier 8 extracts the focus error signal and the tracking error signal from the output signal of the optical pickup 4 at the time of recording and reproducing, and sends these error signals to the servo circuit 13.

The servo circuit 13 uses the focus error signal and the tracking error signal read by the optical pickup 4 to generate a focus servo signal and a tracking servo signal, and these servo signals are passed through the PWM driver 12. Optical pickup 4
Send to. As a result, focus servo and tracking servo are performed in the optical pickup 4. That is,
For the focus servo, focus control of the optical system of the optical pickup 4 is performed so that the focus error signal becomes zero. Further, for the tracking servo, tracking control of the optical system of the optical pickup 4 is performed so that the tracking error signal becomes zero.

Further, the servo circuit 13 has a structure for the rotation servo of the spindle motor 9 for rotating the magneto-optical disk 2 in addition to the structure for the focus servo and the structure for the tracking servo described above. are doing. That is, the servo circuit 13 of the spindle motor 9 drives the spindle motor 9 so as to rotate the magneto-optical disk 2 at a predetermined rotation speed (for example, a constant linear velocity: CLV). Servo.

The rough servo of this spindle motor 9 is
The motor control circuit 14 performs this based on the FG signal from the spindle driver 11. Further, the motor control circuit 14 and the system controller 15 are adapted to perform rotation speed control (CLV control) of the magneto-optical disk 2 according to the position of the optical pickup 4 with respect to the magneto-optical disk 2. The CLV control in the motor control circuit 14 and the system controller 15 is performed based on the count value from the counter 17 for the feed amount of the stepping motor 10.

In the optical disc device 100, the optical pickup 4 and the recording magnetic head 1 are moved to the target track position of the magneto-optical disc 2 designated by the system controller 15. These movements are performed by the system controller 15 described above.
It is realized by the motor control circuit 14 controlling the stepping motor 10 as a drive source of the thread feeding mechanism based on the designation from In other words, the system controller 15 can know the radial position of the optical pickup 4 on the magneto-optical disk 2 from the count value obtained by counting the number of steps of the stepping motor 10. Further, the system controller 15 can know the position of the optical pickup 4 in the radial direction on the magneto-optical disk 2 from the address information corresponding to the wobbling groove read by the optical pickup 4.

The address decoder 7 is used only for writing, for example, and generates an address signal and an FM carrier signal according to a signal corresponding to the wobbling groove on the magneto-optical disk 2 extracted through the RF amplifier 8. , And sends it to the encoder section of the signal processing circuit 6.

At this time, the signal processing circuit 6 sends the address signal to the OWH driver 5 and compares the FM carrier signal with a predetermined reference clock signal, and the spindle of the motor control circuit 14 according to the comparison result. Controls the motor control unit.

The system controller 15 is, for example, a CPU
(Central processing unit), it controls each part and also controls data transmission / reception with the host computer 101.

By the way, as described above, the optical disc apparatus 100 of this embodiment has the stepping motor 10 as a drive source of the sled feed mechanism for moving the optical pickup 4 and the like.

Also in the apparatus 100 of the present embodiment, first, at the beginning of the drive operation, the optical pickup 4 is moved to the innermost circumference of the magneto-optical disk 2 by the sled feeding mechanism, and the innermost part of the magneto-optical disk 2 is moved. The counter 17 is reset by an ON signal of a lead-in switch 18 provided at a position (reference position) corresponding to the circumference. The counter 17 counts up / down in synchronization with the excitation of the stepping motor 10 as a drive source of the sled feed mechanism, and is used to know the position of the optical pickup 4 fed by the sled feed mechanism. Is.

Here, in the apparatus 100 of the present embodiment, for example, a step out of the mechanism occurs due to access such as seek, and the actual position of the optical pickup (correctly, the position of the objective lens of the optical pickup) and the above-mentioned In order to prevent deviation from the count value of the counter 17, an address (acluster number, sector number) read from the magneto-optical disk 2 is moved before the optical pickup 4 is moved by seek. , A count value is generated and loaded into the counter 17.

After the count value is loaded into the counter 17, a seek operation for moving the optical pickup 4 to a target position on the magneto-optical disk 2 is performed. Also,
During the seek operation, the rotation speed of the spindle motor 9 for rotating the magneto-optical disk 2 is set to the magneto-optical disk 2
Linear velocity at the upper target position (linear velocity corresponding to the radial position on the disc 2 from the center of the disc 2 to the target position)
Control so that. As a result, when the rotation control of the spindle motor 9 is performed based on the count value from the counter 17, it is possible to reduce the deviation of the target linear velocity caused by the deviation of the count value.

FIG. 2 shows a flowchart of the load operation of the counter 17 and the processing up to the spindle servo.

In the flowchart of FIG. 2, first, in step S2, as a recalibration operation (recalibration), the stepping motor 10 moves the optical pickup 4 to the innermost circumference of the magneto-optical disk 2, and the lead-in switch 18 operates. When turned on, the counter 17 is reset. The reset value of the counter 17 at the innermost peripheral position (reference position) of the magneto-optical disk 2 is set to a value other than 0000 _(h) such as 15FF _(h) . This is to prevent the count value from taking a negative value depending on the stepping direction of the stepping motor 10 when the reset value is set to 0000 _(h), for example. Note that (h) indicates that it is expressed in hexadecimal.

In the next step S2, when an instruction to turn off the tracking servo and move the optical pickup 4 is received as in the seek operation, before the stepping motor 10 feeds the optical pickup 4,
When the number of steps of the stepping motor 10 calculated from the address indicating the current position of the optical pickup 4 with respect to the magneto-optical disk 2 (the position of the objective lens with respect to the disk 2) is compared with the current count value of the counter 17, there is a deviation. The counter 17 is loaded with a value corresponding to the number of steps calculated from the above address. When the deviation amount is small, the optical pickup 4 can be sent to a position very close to the target position at the time of seeking. Therefore, the count value should be loaded only when the deviation amount is large. It is also possible to load the count value before the seek even if there is no deviation. In this embodiment, in order to ensure the accuracy of the seek operation, the above-mentioned count value is loaded for each seek (before each seek).

In step S3, the current count value of the counter 17 is the number of steps to the stepping motor 10 required to move the optical pickup 3 to a target position (track) when the optical pickup 4 seeks. Ask from. In other words, the count value for moving the optical pickup 4 to the target track is calculated (the count value corresponding to the step number is added to or subtracted from the current count value), and the step number corresponding to this count value is calculated. Only by driving the stepping motor 10, the optical pickup 4 is moved to the target position.

If the number of steps is determined in step S3, the spindle motor 9 is switched to the FG servo in the next step S4, and the optical pickup 4 is jumped to the target position by the stepping motor 10 in the next step S5.

After that, in step S6, when the jump of the optical pickup 4 by the stepping motor 10 is completed, the tracking servo is turned on to enter the servo mode in which the servo of the spindle motor 9 is synchronized with the data read from the magneto-optical disk 2. Switch.

Next, the number of tracks to be jumped from the current position of the optical pickup 4 on the magneto-optical disk 2 to the target position when performing the above-described seek operation is calculated as follows.
For example, the system controller 15 is configured to do the following.

First, in order to seek from a track of the magneto-optical disk 2 currently being traced by the optical pickup 4 of FIG. 1 to a track having a designated address, it is necessary to find out how many tracks should be moved. . In the magneto-optical disk 2 having different linear velocities or recording densities in the circumferential direction, the relationship between the address and the number of tracks changes, so it is necessary to change the formula or the conversion table for converting the address to the number of tracks.

Therefore, in this embodiment, the following is done.

Here, as shown in FIG. 3, the addresses of the cluster and sector at the reference position on the magneto-optical disk 2 are the address cluster 0000 _(h) and the sector FC _(h), and this address cluster 0000 _{(h )} , Sector FC
The radius position (distance from the rotation center of the magneto-optical disk 2 ₎ in _(h) is r ₀ [m], and the sector frequency is f [Hz].
Note that (h) of the above address cluster and sector is expressed in hexadecimal notation.

First, the system controller (CP
U) 15 takes in the address at the position traced by the optical pickup 4 (the position at the time of the drive orbit), and further determines the disk rotation speed there from the FG from the spindle driver 11 that drives the spindle motor 9.
Obtained by monitoring the signal.

Here, the cluster corresponding to the read address is a, the sector is b, and the obtained rotation speed is N _r [rps]. At this time, address cluster 0
000 _(h) , sector FC _(h) to cluster a, sector b
The number of sectors N _{ts up to} is 1 cluster is 3 as described above.
In the case of 6 sectors, _Nts = 36 × a + b + 4 (in the case of the outer circumference from the TOC area), and the linear velocity V (m / s) of the disk is calculated by the following equation. That is, the linear velocity V of the disk is V = 1/2 {dw (1-p) + √ (d ² w ² (1-p) ² + 4r ₀ ² w ² -4dr ₀ w ² ) in the TOC area. } In the outer circumference from the TOC area, V = 1/2 {-dw (1-p) + √ (d ² w ² (1-p) ² + 4r ₀ ² w ² -4dr ₀ w ² )}. However, p = wN _ts / πf, w = 2πN _r [ra
d / s], d is a track pitch [m] of 1.6 μm (=
1.6 × 10 ⁻³ m), r ₀ = 16 mm = 16 × 10 ⁻³ m
Is.

Address cluster 0000 _(h) , sector F
When seeking to a location (address) away from C _(h) by the number of sectors N _{s, the} number of tracks N _trk to be moved is obtained as follows. However, N _trk is negative inside the address cluster 0000 _(h) and sector FC _(h) and positive outside.

As shown in FIG. 3, a position at a distance r ₀ from the center of the disk (center of the motor) is set as a reference position (origin), and when the address cluster 0000 _(h) and sector FC _(h) are set at the above reference position. , R ₀ = 16 mm. When counting the number of tracks from this position as 0, the number of tracks N _trk in the address cluster Adc _(h) and the sector Ads _(h) to seek is (1) Adc _(h) = FF ×× _(h) , N _trk = −1 / 2d {−√ ((d-2r ₀ ) ² −4dNt _ts V / πf) −d +
2r ₀ } N _ts = (FFFF _(h) −Adc _(h) ) × 24 _(h) ＋24 _(h) − (Ad
s _(h) +4 _(h) ) (2) When Adc _(h) ≠ FF × × _(h) , N _trk = 1 / 2d {√ ((d-2r ₀ ) ² −4dNt _ts V / πf) − d-2
r ₀ } N _ts = Adc _(h) × 24 _(h) + Ads _(h) +4 _(h) . In the above equation, d = 1.
6 μm (track pitch), r ₀ = 16 mm, V = 1.
2 m / s to 1.4 m / s, f = 75 Hz (sector frequency), N _ts = total number of sectors. The addition of 4 _(h) is for the purpose of a 1-byte operation.

Further, the calculation of the conversion from the address to the track number is performed as follows.

The track number and the track number N _trk when the linear velocity is V = 1.2 m / s are calculated as follows.

[0062] ₍₁₎ Adc (h) = when FF ×× of _(h) (TOC _{region) N trk = -1 / 2d {} -√ ((d-2r 0) 2 - 4dN ts V / πf) -d +
2r ₀ } = −312.5 × (−√ (1023.898-0.03259 × N _ts ) ＋31.9
984) N _ts is the address cluster 0000 _(h) , sector F
It is the number of sectors from C _(h) .

Here, for example, Adc _(h) = FF2
The track numbers of C _(h) and Ads _(h) = 13 _{(h) and} the number of tracks N _trk are: N _ts = (FFFF _(h) −FFC2 _(h) ) × 24 _(h) +24 _(h) − ( 13
_(h) +4 _(h) ) = 61 _(d) x 36 _(d) +36 _(d) -23 _(d) = 2209 [sectors], so N _trk = -312.5 x (-√ (1023.898 -0.03259 × 220
9) +31.9984) = -357.94. That is, when address cluster 0000 _(h) and sector FC _(h) are moved to the inner circumference by 357.9 tracks, address cluster FFC2 _(h) and sector 13 _(h) are formed.

(2) When Adc _(h) ≠ FF ×× _(h) (outer periphery from address cluster 0000 _(h) ) N _trk = 1 / 2d {√ ((d-2r ₀ ) ² + 4dN _ts V / πf) -d-2
r ₀ } = −312.5 × (√ (1024.10 + 0.03259 × N _ts ) −32.001
6) Here, for example, Adc _(h) = 0400 _(h) , Ads _(h)
= Track number of FD _(h) and number of tracks N _trk are N _ts = 0400 _(h) × 24 _(h) ＋ FD _(h) ＋4 _(h) ＝ 36864 _(d) ＋2 _(d) ＝ 36866 [sector] Therefore, N _trk = 312.5 × (√ (1024.10 + 0.03259 × 36866) −3
2.0016) = 4471.96. That is, the address cluster 0400 _(h) and the sector FD _(h) are located 4741.9 tracks away from the address cluster 0000 _(h) and the sector FC _(h) to the outer circumference.

In the above-mentioned embodiment, the address is converted into the number of tracks by calculation.
~ It is also possible to use a conversion table as shown in Table 5. In this case, the conversion table is stored in the ROM in the system controller 15 of FIG. Therefore, by using the conversion table in the ROM, the system controller 15 can convert the address into the number of tracks without performing the above calculation. Tables 1 and 2 are divided conversion tables when the linear velocity V = 1.20 m / s. Tables 3 to 5 show the linear velocity V.
The conversion table when = 1.40 m / s is divided and shown. Also, dTrack in the table indicates how many tracks are in one cluster (that is, tracks / clusters).

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

[0070]

[Table 5]

Here, a case where the track numbers of the address cluster 100 _(h) and the sector 02 _(h) are obtained from the above table will be described.

For example, the linear velocity V = 1.2 shown in Tables 1 and 2
When it is 0 m / s, the range including the address cluster 100 _(h) is searched in the table. At this time, ED _(h) <100 _(h)
Since <108 _(h) , the address cluster ED _(h) ,
How many clusters the address cluster 100 _(h) and the sector 02 _(h) are apart from the sector FC _(h) are calculated. That is, 100 _(h) -ED _(h) = 13 _(h) (1) 02 _(h) -FC _(h) = 6 _(h) (2) From these formulas (1) and (2), 13 _{(h )} +6 _(h) / 24 _(h) = 19.25 (decimal), which means that the distance is 19.25 clusters.

Therefore, the number of tracks is 1296.50 +5.16 (the number of tracks per cluster) x 1
9.25 = 1395.83 (decimal) ≈ 1395.

As described above, according to the apparatus of this embodiment, the linear velocity of the magneto-optical disk 2 is determined by the number of revolutions of the spindle motor 9 for rotating the magneto-optical disk 2 and the radial position of the magneto-optical disk 2. The target position address,
The address of this target position is converted into the number of tracks from the current position to the target position, and at the time of this conversion, correction is made according to the linear velocity of the magneto-optical disk 2 so that the track from the current position to the target position is changed. It is possible to accurately obtain the distance or the number of tracks to be moved, and therefore, it is possible to optimize the seek operation for a disk having any linear velocity, and as a result, it is possible to realize high-speed access.

In the above-mentioned embodiments, a magneto-optical disk such as MD is taken as an example of the disk-shaped recording medium, but a CD, a rewritable phase change type optical disk,
It goes without saying that the same effect can be obtained even with a magnetic disk or the like.

[0076]

As described above, according to the present invention, by converting the address information corresponding to the current position of the head read from the disk-shaped recording medium into a count value and loading the count value into the count means, for example, a mechanical step-out occurs. Even if the thread feed position and the count value are misaligned, the count value can be calibrated. Therefore, the misalignment between the head position and the count value can be eliminated, and the head is sent to the target position. It is possible to prevent an error in movement, a movement that exceeds the limit value of the thread feed mechanism, and a long access time.

Further, by loading the count value for each seek start instruction, an accurate seek operation becomes possible. Further, when the disk-shaped recording medium at this time has different linear velocities or recording densities in the circumferential direction, when performing a seek, the rotational speed of the motor for disk rotation is controlled based on the count value of the counting means. However, by calibrating the count value for each seek start command, it is possible to reduce the deviation of the target value of the motor rotation speed (that is, the linear velocity of the disk) after the seek.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a schematic configuration of an optical disk device of an embodiment of the present invention.

FIG. 2 is a flowchart showing a load operation of a counter and processing up to a spindle servo in the apparatus of this embodiment.

FIG. 3 is a diagram showing a reference radial position r ₀ on a disk and a movement amount of a stepping motor.

FIG. 4 is a diagram showing an MD disc type and a recording layout.

FIG. 5 is a diagram showing an outline of a recordable disc format.

FIG. 6 is a diagram showing a data structure of about one cluster of a recording disc.

[Explanation of symbols]

 1 Recording Magnetic Head 2 Optical Disk 4 Optical Pickup 5 OWH Driver 6 Signal Processing Circuit 7 Address Decoder 8 RF Amplifier 9 Spindle Motor 10 Stepping Motor 11 Spindle Driver 13 Servo Circuit 14 Motor Control Circuit 15 System Controller 17 Counter 100 Optical Disk Device

Claims (3)

[Claims] 1. In a disk device handling a disk-shaped recording medium on which at least address information indicating a radial position is recorded, a thread feeding means for moving a head in the radial direction of the disk-shaped recording medium, and a thread feeding means of the thread feeding means. It has a counting means for outputting a count value corresponding to the feed amount, and a counter loading means for converting the address information corresponding to the current position of the head read from the disk-shaped recording medium into a count value and loading it on the counting means. Disk device characterized by. 2. The disk device according to claim 1, wherein the counter loading means loads the count value in response to a seek start instruction. 3. A rotation speed control means for controlling the rotation speed of a motor for rotating the disk-shaped recording medium having a different linear velocity or circumferential recording density based on the count value of the counting means. The disk device according to claim 1 or 2.