JPH10112039A - Optical disk device and optical disk driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the random access stability of data and the speed in optical disk memory devices such as a CD-ROM drive. SOLUTION: In an optical disk track servo mechanism, the device is provided with an eccentricity detecting circuit 8 which discriminates the direction of the eccentricity of a disk and acceleration from the conditions of track error signals when a track jump command is generated and a track jump enable signal generating circuit 9 which determines the track jump start timing from the obtained eccentricity condition, the track jump direction, the number of jumps and the relationship with the present disk number of revolutions. Having these circuits 8 and 9, a jump is executed with an optimum timing against the disk eccentricity. Note that the stability and the sureness of a track jump are improved because the track jump is conducted by observing the conditions of the optical disk eccentricity (the acceleration and the direction) and waiting for the execution of the jump till the size and the direction of the optimum eccentricity acceleration are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random access method for an optical disk memory device, and to a tracking servo mechanism, in particular, to minimize the influence of disk eccentricity at the start of a jump and to stably and surely jump an optical pickup to a target track. It is about the method of making it.

[0002]

2. Description of the Related Art A track jump method of a conventional optical disk memory device will be described with reference to FIGS.
FIG. 1 shows a CD-RO which is a read-only optical disk memory device.
3 shows a schematic configuration of an M drive. Numeral 1 denotes an optical disk, on which digital information is spirally recorded from the inner circumference to the outer circumference of the disk as a sequence of pits having minute lengths different from each other, and an optical pickup 2 uses a laser diode to reflect light reflected from the disk. The data is received by a photodiode and amplified by an amplifier to reproduce the data. The RF amplifier 10 amplifies the output of the photodiode of the optical pickup and passes it to the data slice / error correction block 11. The CD-ROM performs a rotation speed control called a CLV servo that keeps the linear velocity of the disk constant in order to read data at a constant data rate regardless of the inner and outer circumferences of the disk. The CLV servo 14 receives signals from the data slice and the error correction block, and outputs a signal C4 for controlling the spindle motor to the spindle motor so that the read data cycle is constant. The data after error correction in the data slice and error correction block enters the interface block 12 with the host, and outputs the data to the host computer 13 according to a specific format.

However, in the CD-ROM, as a manufacturing error of the disk and the drive, the axis of rotation of the disk is not strictly at the center of the disk, and has an eccentricity equal to or less than a value determined by the standard. The data tracks engraved on the disk are actually engraved spirally from the innermost circumference to the outer circumference, but because the distance between adjacent tracks is extremely small,
The description will be made assuming that the shape is approximately concentric around the rotation axis. When an arbitrary data track is observed from a stationary viewpoint with respect to the ground, if the disk rotates at high speed, the track is viewed from the optical pickup as shown in FIG. Will not be seen as a single stationary line but will be observed to oscillate radially with a period of rotation.

In a CD-ROM, the track spacing in the disk radial direction is 1.6 μm, and the maximum eccentricity defined by the standard is ± 70 μm or less. I will cross. Therefore, in order to reproduce data while rotating a disk and tracing one track, a track servo for causing an optical pickup to follow a target track is required.

The amplifier 3 calculates the reflected light of the disk to generate a track error signal S1 indicating how much error the laser spot has from a target track, and generates an error signal S1.
To the phase compensation filter of. Regarding the transfer characteristics of the actuator 6 that moves the optical pickup, the phase at the point where the loop gain becomes 0 dB is delayed by more than 180 °, and the system is not stabilized as it is. Therefore, the system is kept stable by advancing the phase at the frequency at which the gain becomes 0 dB by the phase compensation filter 4. Also, it plays a role of increasing the loop gain of a band in which a track error signal is desired to be suppressed.
The actuator driver 5 receives the output of the phase compensation filter 4 and generates a drive signal S5 for moving the actuator 6 of the optical pickup.

The actuator 6 is moved by the drive signal S5 in the radial direction of the disk so as to suppress the track error signal, and performs the operation of always following the target track by continuing the above operation.

In this CD-ROM device, a mechanism for jumping a track by moving an optical pickup in a radial direction of a disk in accordance with a command from a control means (not shown) in order to access target data. Is provided. In general, in a CD-ROM device, an actuator for moving an optical pickup in a disk radial direction includes a fine actuator (movable range of about 100 μm) for following eccentricity and reproducing data recorded in a spiral shape. There are two systems of a coarse actuator (movable range of about 30 mm) that slides the optical pickup in the radial direction of the disk. However, in the description of the present invention, the actuator is simply referred to as an actuator without distinction.

A track jump is generally performed by the following operation. The actuator driver generates a kick signal for temporarily suspending the track servo operation in response to a track jump command from the control means and moving the actuator of the optical pickup in the inner or outer peripheral direction of the disk. When the actuator operates to move the optical pickup in the radial direction of the disk, the number of tracks crossed from the waveforms of the track error signal and the data signal during the movement of the pickup is counted. If it is determined that the target track has been reached from the counted number of tracks, the track servo operation is resumed and data reading is started.

[0009]

However, in the conventional track jump method, the increase in the disk eccentricity due to the increase in the disk rotation speed causes the disk eccentricity rather than the moving speed of the optical pickup depending on the timing of the start of the track jump. Since the track traversing speed is higher, the optical pickup moves apparently in a direction opposite to the track jump direction, and there is a possibility that a phenomenon in which the optical pickup does not reach the target track may occur. In this case, it is necessary to read the disk data again and perform the jump again, resulting in a problem that it takes time to reach the target track.

Taking a CD (compact disk) as an example, in recent years, as the CD has evolved from digital audio reproduction to use as a data recording medium for multimedia, the rotation speed of the disk is twice that of digital audio reproduction. The speed has been increased four times and eight times. C
D performs a rotation speed control called CLV servo that maintains a constant linear velocity of the disk in order to read data at a constant data rate regardless of the inner and outer circumferences of the disk. When a track near the innermost circumference is being traced, the rotation speed of the disk becomes the highest. When data is reproduced at a data transfer rate eight times that of a normal digital audio data transfer rate, the maximum eccentricity is constant independently of the angular velocity of the disk rotation, but the maximum eccentric acceleration is the angular frequency of rotation. Depends on. That is, the eccentricity and the eccentric acceleration are expressed by the following equations. xo indicates the maximum eccentric displacement.

Displacement x = xo · sinωt (1) Eccentric acceleration d ² x / dt ² = −xo · ω ² sinωt = −ω ² x (2) From the above equation, the phase between the eccentric displacement and the eccentric acceleration is 180.
It can be seen that the sine waves have different degrees. Here, assuming that the maximum eccentricity is 140 μm and the disk linear velocity during normal digital audio reproduction is 1.4 m / s, the rotational angular frequency at the innermost circumference of the disk is as follows.

Ω = 2πf = linear velocity / innermost radius = 1.4
/0.025=56 Therefore, the maximum eccentric acceleration is d ² x / dt ² = 562 ² 140e-6 = 0.44 m / s ² .

If data is read out at an eight-fold linear velocity, ω = 2πf = 11.2 / 0.025 = 448 at the innermost circumference of the disk. Maximum eccentric acceleration = 448 ² · 140e−6 = 28.1m
/ S ² , which is 8 × 8 = 6 of ordinary digital audio.
It will have four times the eccentric acceleration.

As described above, when the rotation speed of the disk is increased to increase the data transfer rate, the eccentric acceleration increases with the square of the disk. Therefore, depending on the eccentric acceleration and the timing at the start of the jump, there is a possibility that the optical pickup may move in a direction opposite to the direction in which the track jump is desired to be performed. In addition, when the track servo is pulled in at the time of jump convergence, there is a possibility that the servo cannot be drawn because the relative speed of the optical pickup and the track in the disk radial direction is too large.

In view of the above background, the present invention describes a method of performing a stable track jump while minimizing the influence of the eccentricity of the optical disc in the conventional track jump method.

[0016]

In order to solve the above problems, an optical disk apparatus and an optical disk driving method according to the present invention include: (means 1) a track error signal generating circuit for generating a track error signal; In an optical disc device having a phase compensation filter for performing phase compensation and a means for driving an actuator so that the track error signal becomes 0 based on the output of the filter, a track jump command is received, Eccentricity detection means for detecting the direction and acceleration of the eccentricity of the disk based on the eccentricity information and outputting the eccentricity information, and a track jump enable signal indicating a track jump start timing based on the eccentricity information, the track jump direction and the current disk rotation cycle Generate track jump enable signal An optical disc device comprising: a generating unit; and a jump signal generating circuit that receives the track jump enable signal and generates a jump signal that moves the actuator.

(2) The optical disk apparatus according to (1), wherein the jump command includes jump number information, and generates a track jump enable signal indicating the track jump start timing based on the jump number information.

(Means 3) The track error signal is compared with the signal level when the beam spot of the optical pickup is on the track to generate a binary signal, and a track zero cross comparator is received. A gain-down signal generating circuit for lowering the gain of the servo band of the phase compensation filter to increase the amplitude of the track error signal. 2. The optical disk apparatus according to claim 1, further comprising: an eccentricity detection circuit that obtains the eccentricity information of the disk from a level and an edge of the track zero cross signal after the comparison and binarization by a comparator.

(Means 4) In response to the track jump command, the frequency response characteristic of the phase compensation filter is varied to hold a control signal to the track actuator, and to hold the optical pickup. A sampling circuit for sampling the value of the track error signal generated at a constant time interval, calculating the eccentric state from the change amount of the sampled track error signal and the sample time, and outputting the eccentricity information. An optical disk device according to claim 1, further comprising an eccentricity detection circuit.

(Means 5) The range data of the magnitude of the eccentric acceleration suitable for the track jump and the range data of the eccentric direction determined based on the jump direction, the jump track number information and the spindle rotation period information are displayed in a window. And a track jump enable signal generating circuit for generating a track jump enable signal when the eccentric acceleration and the eccentric direction output by the eccentricity detecting circuit are within a predetermined window. The optical disc device according to the means 1 or 3, wherein:

(Means 6) A track error signal generating circuit for generating a track error signal, a phase compensation filter for compensating the phase of the track error signal, and the track error signal becomes zero based on the output of the filter. A method for driving an actuator, the method comprising: receiving an instruction to jump a track; detecting an eccentric direction and acceleration of the disk based on a track error signal; outputting the eccentricity information; A track jump enable signal indicating a track jump start timing is generated based on the track jump direction and the current disk rotation cycle, and the track jump enable signal is received to generate a jump signal for moving the actuator. Method of driving optical disk

[0022]

The optical disk device according to the means 1 and 2 first takes in the track error signal immediately before the jump into the eccentricity detecting section and observes the state of the eccentricity (acceleration and direction). By executing the track jump only after waiting for the eccentric speed and the direction which is considered to be the most optimal determined from the current spindle rotation speed, the stability and reliability of the track jump are improved.

In the case of a track jump mechanism of an optical disk drive, the optimum eccentric acceleration range and direction with respect to the track jump direction, the number of jump tracks, and the number of spindle rotations are previously stored in storage means (such as a table). ) Can increase the reliability of track jump in various types of optical disk devices.

In particular, the invention described in Means 1 is based on a track error signal used for tracking servo of an optical disk.
An eccentricity detection circuit for detecting the eccentric acceleration of the disk, and a track jump enable circuit for generating a timing for executing a track jump based on the detected eccentric acceleration and information on the jump direction, the number of jumps, and the spindle speed. The eccentricity detection circuit detects the magnitude and direction of the eccentric acceleration from the track error signal and outputs the detected eccentricity to the next-stage track jump enable circuit. The track jump enable circuit includes an eccentric acceleration and the number of jumps,
A jump enable signal is output so as to perform a jump at a timing that is least affected by eccentricity determined by the jump direction and the spindle rotation speed.

Next, the eccentricity detecting circuit in the optical disk device described in Means 3 intentionally lowers the gain of the track servo system immediately before the track jump and generates a track error signal. Thereafter, the track error signal is compared with the on-track level to generate a track zero cross signal. This track zero cross signal indicates whether the laser spot of the optical pickup is on the inner circumference side or the outer circumference side of the disk with respect to the track being traced when the servo operation is performed with the gain lowered. . The edge at which the level changes from 1 to 0 or from 0 to 1 indicates that the laser spot of the optical pickup has traversed the track being traced. That is, the direction of the eccentric acceleration can be determined based on the level of the track zero cross signal. The point at which the eccentric acceleration is maximum is the middle point of the track zero cross edge, and the point at which the eccentric acceleration is zero is the edge of the track zero cross signal.

The eccentricity detection circuit in the optical disk device described in the means 4 is another embodiment of the eccentricity detection circuit. That is, the characteristics of the track phase compensation filter are switched so that the optical pickup is held immediately before the track jump. When the optical pickup is held, a track error signal is output. A track error signal is taken in according to a predetermined sampling rate. First, assuming that the track error signal captured at time t (n-1) is TE (n-1) and the track error signal captured at time t (n) is TE (n), the eccentric speed is TV ( n) = {TE (n) -TE (n-1)} / {t (n) -t (n-1)} (3)

Similarly, assuming that the track error signal taken in at the next time t (n + 1) is TE (n + 1), the eccentric speed is TV (n + 1) = {TE (n + 1) − TE (n)} / {t (n + 1) −t (n)} (4)

That is, the sampling time interval is fixed = Δ
Assuming that t, TV = ΔTE / Δt (5) Therefore, the eccentric acceleration is proportional to the amount of change in the eccentric speed, and ΔTV = TV (n + 1) −TV (n) (6) Eccentric acceleration AC∝ΔTV

As described above, information on the direction and magnitude of the eccentric acceleration can be obtained by sampling the track error signal at regular time intervals.

When the track jump enable signal generating circuit in the optical disk device according to the means 5 receives a track jump command from the control means, the track jump direction, the number of track jumps and the output signal from the disk rotation control circuit to the spindle motor. And sets a window for the direction and magnitude of the eccentric acceleration when jumping is permitted according to a predetermined table. Further, the direction and magnitude of the eccentric acceleration are input from the eccentricity detection circuit, and the track jump enable signal is output only when the value enters the set window. The driver that drives the actuator of the optical pickup outputs the drive signal of the optical pickup actuator only after receiving the enable signal, the jump command and the signal of the jump direction. When the driven optical pickup jumps a predetermined number of jumps, the track servo is pulled in again and the jump sequence ends.

Further, according to the optical disk driving method described in the means 6, the track jump can be surely performed.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The track jump system of an optical disk memory device according to a first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. In FIG. 2, 1 indicates an optical disk, for example, a CD-ROM, and 2 indicates an optical pickup. First, a description will be given of a data reproducing system. Reference numeral 10 denotes an RF amplifier for amplifying a data signal having a small amplitude output from an optical pickup for data processing, and reference numeral 11 denotes a data slicer for binarizing data output from the RF amplifier. Indicates a block for correcting a data error. Reference numeral 12 denotes an output of the data slice / error correction block to the host computer 1.
Reference numeral 13 denotes an interface for converting the data into an input / output format for output to the output unit 3, and reference numeral 13 denotes a host computer. Reference numeral 14 denotes a CLV servo block for changing the rotation speed of the spindle motor between the inner and outer circumferences of the disk in order to read data at a constant linear velocity.
Indicates a rotation speed control signal to the spindle motor.

Next, the control system will be described. Reference numeral 3 denotes an amplifier (hereinafter referred to as an amplifier) which calculates a reflection signal from the optical pickup and generates a track error signal indicating how much error the laser spot has from the track being traced. Here, for convenience of explanation, the track error signal is 0 when the optical pickup is on the track, negative when the optical pickup is shifted to the inner circumference of the disk from the track being traced, and is positive when the optical pickup is shifted to the outer circumference. It is assumed that the track error signal S1 has been generated. A track error signal generation circuit generates a signal indicating how much the laser spot of the optical pickup has an error from the target track in the inner or outer circumference of the disk by calculating the reflection signal of the disk.
Reference numeral 4 denotes a phase compensation filter which performs an operation on the track error signal so that the track servo loop has a desired transfer function. Based on the filter output, the actuator drive signal generation circuit drives the actuator via the pickup actuator driver 5 so that the track error signal becomes zero. Reference numeral 8 denotes an eccentricity detection circuit for detecting eccentricity from the track error signal S1, and a jump enable signal generation circuit 9 includes eccentricity information S3 and a jump direction C output from control means (not shown).
2, receives the jump number C3 and the spindle rotation control signal C4, and generates a jump enable signal S4.

Next, the configurations of the eccentricity detection circuit 8 and the jump enable generation circuit 9 in the first embodiment will be described with reference to FIGS. First, in the eccentricity detection circuit 8, reference numeral 81 denotes a low-pass filter for removing high-frequency components from the track error signal S1. The track error signal from which the high-frequency component has been removed is compared by an on-track track error signal level, that is, 0 by a track zero cross comparator 82 to generate a track zero cross signal S31.

Before the jump command C1 is output from the control means, the optical pickup traces a certain track on the optical disk. In this state, the track error signal S1 is almost zero. In this state, even if the signal passes through the filter 81, the track error signal S1 is considered to frequently cross zero due to noise components and the like.

Next, when the jump command signal C1 is output from the control means, the gain down signal generation circuit 83
, A gain down command S2 is issued to the track phase compensation filter 4 for a certain period. When receiving the gain down command S2, the track phase compensation filter 4 lowers the low band gain of the filter to a preset value. It is desirable that the value of the gain be determined in advance so that the servo does not come off.

Since the servo gain decreases, the track error suppression ratio decreases, and the amplitude of the track error signal S1 increases. Therefore, the track error signal S86 after passing through the filter 81 does not frequently cross zero due to the influence of noise. In this state, the output S31 of the track zero cross comparator 82 is output as a binary signal synchronized with the disk eccentric period as shown in FIG.

Next, the jump enable signal generation circuit 9
Receives the track zero cross signal S31 and determines the direction of the eccentric acceleration and the maximum point. That is, when the track zero-cross signal S31 is at level 0, it indicates that the optical pickup is located on the inner peripheral side of the disk with respect to the track. It is located on the side. Further, as shown in FIG. 4, the eccentric acceleration at the edge portion of the zero cross signal S31 is zero. In the first embodiment, the magnitude of the eccentric acceleration is not detected, and only the information on the maximum point, the minimum point, and the direction of the acceleration is extracted. The track jump enable signal generating circuit 9 according to the present embodiment receives the zero cross signal S31 from the eccentric speed detecting circuit 8, controls the jump direction C2 and the number of jump tracks C3 from the control means, and controls the rotation of the spindle motor from the CLV servo block. Receive the signal C4. This is a command signal to a driver of a spindle motor having a certain size.

First, it is assumed that the jump direction setting signal C2 from the control means instructs a jump in the jump direction from the inner circumference to the outer circumference.

In this embodiment, in order to eliminate the phenomenon of jump reverse running due to eccentricity as much as possible, the jump is executed when the eccentric acceleration is directed inward, that is, when the eccentric acceleration is in the opposite direction to the jump direction. Is good. From the equations (1) and (2), it is known that the eccentric phase, that is, the phase of the track error signal and the phase of the eccentric acceleration are shifted by 180 degrees, so that the jump is executed at the positive portion of the track zero cross signal. . The appropriate timing for starting the jump is considered to be near the rising edge of the track zero cross signal.However, the rising edge of the track zero cross cannot be predicted in advance immediately after the jump command is issued from the control means. Wait or output the jump enable when a certain time has elapsed from the falling edge. That is,
In this case, the track jump enable generation circuit 9 generates the window signal S94 in accordance with the data stored in the internal ROM 93 so as to generate the jump enable S4 when a certain delay time has elapsed from the rise or fall of the track zero cross S31. Generate. Here, the example of the CD-ROM is shown, but this window is appropriately set based on the characteristics of the drive device and the characteristics of the optical disk.

FIG. 4 shows signal timings in the present embodiment. After the jump command C1 becomes 1 level, a jump delay S4 is output after waiting for a certain delay time set by the window setting circuit 92 for the first fall of the track zero cross S31. Further, when the rise of the track zero cross is detected before the fall of the track zero cross, a window is generated so as to output a jump enable at that time. As a result, the magnitude of the eccentric acceleration at the start of the jump is close to zero, and the probability that the eccentric acceleration is opposite to the jump direction during the jump increases, so that the possibility of being overtaken by the eccentricity can be reduced.

Upon receiving the jump enable signal S4, the actuator driver 5 generates a drive signal for moving the actuator 6 according to a jump command from the control means, and executes a track jump.

Next, a second embodiment of the present invention will be described with reference to FIGS. 2, 5 and 6. As in the first embodiment, FIG. 2 shows an optical disk 1 and an optical pickup 2 in FIG. Reference numeral 10 denotes an RF amplifier for amplifying a data signal having a small amplitude output from the optical pickup for data processing. Reference numeral 11 denotes a data slicer for binarizing data output from the RF amplifier, and a block for correcting data errors. Is shown. Reference numeral 12 denotes an interface for converting the output of the data slice / error correction block into a data input / output format for output to a host computer, and reference numeral 13 denotes a host computer. Reference numeral 14 denotes a CLV for changing the number of revolutions of the spindle motor between the inner and outer circumferences of the disk in order to read data at a constant linear velocity.
A servo block is shown, and C4 shows a rotation speed control signal to the spindle motor. Reference numeral 3 denotes an amplifier for generating a track error signal S1 that indicates the amount of error from the track being traced by the laser spot by calculating the reflection signal from the optical pickup. Here, for convenience of explanation, the track error signal is 0 when the optical pickup is on the track, negative when the optical pickup is shifted to the inner circumference of the disk from the track being traced, and positive when the optical pickup is shifted to the outer circumference. It is assumed that the error signal S1 has been generated. 4 is a phase compensation filter,
5, a pickup actuator driver; and 6, a pickup actuator.

Reference numeral 8 denotes an eccentricity detection circuit for detecting eccentricity from the track error signal S1, and reference numeral 9 denotes a jump enable signal generation circuit which includes eccentricity information S3 and a jump direction C2,
It receives the jump number C3 and the spindle rotation control signal C4 and generates a jump enable signal.

Next, an eccentricity detecting circuit 8 and a jump enable generating circuit 9 according to a second embodiment of the present invention will be described with reference to FIGS.

First, when the track servo is applied and the optical pickup is following the track, the amount of change in the minute time interval of the track error signal S1 represents an eccentric acceleration due to the influence of high frequency noise even through the filter. It is hard to say that there is. Then, when the jump command signal C1 is output from the control means, the hold signal generation circuit 84 outputs a hold signal S2 to the track phase compensation filter 4. Upon receiving the hold signal S2, the track phase compensation filter 4 changes its characteristic to a low-pass characteristic, that is, a characteristic that cuts off a high-frequency component of the input signal and cannot follow a steep change.

As a result, the operation of the optical pickup to follow the track eccentricity is held, so that the eccentricity itself appears in the track error signal S1.

The eccentric acceleration calculation circuit 85 converts the filtered track error signal S86 into a predetermined time interval Δ
The sampling is performed at t, and the eccentric acceleration is calculated. That is, as shown in FIG. 6, the track error signal S1 is held at regular time intervals Δt, and the eccentric velocity V = ΔTE / Δt;
The magnitude and direction of the acceleration are obtained by performing the calculation of acceleration = ΔV / Δt.

Referring to FIG. 5 as an example, the track error signal S1 output by the pickup hold is described.
Is the track error value sampled at intervals of Δt,
It is assumed that TE (n-1), TE (n), and TE (n + 1), respectively. The eccentric velocity at each sampling time is expressed as TV (n) = TE (n) -TE (n-1) (7) TV (n + 1) = TE (n + 1) -TE (n) (8) Is done.

Since the acceleration is represented by the amount of change in the eccentric speed, acceleration = ΔTV = TV (n + 1) −TV (n) (9)

The sign of ΔTV indicates the direction of acceleration. FIG.
Since TV (n)> TV (n + 1) in the example of, ΔTV
Is negative, and the acceleration goes from the outer circumference to the inner circumference of the disk. The magnitude of the eccentric acceleration is obtained by | TV (n + 1) −TV (n) |. As described above, the eccentric acceleration is calculated from the track error signal,
The eccentric acceleration direction signal indicated by 32 and the eccentric acceleration amount signal indicated by S33 in FIG.

Next, the jump enable signal generating circuit 9
Detects the jump direction C2 and jump number C3 from the control means, and also detects the spindle rotation control signal C3 from the spindle control unit, and sets a window for the enable signal S4.

In the present embodiment, if the track jump is made to jump from the inner circumference to the outer circumference, the eccentric acceleration is close to 0 in order to minimize the possibility of reverse running in the pickup jump direction due to eccentricity. It is appropriate to execute the jump at the timing. Also, by setting the window to start jumping some time before the eccentric acceleration is opposite to the jump direction, to start the jump in a wider range than when starting the jump after the eccentric acceleration is opposite to the jump direction. Can be done. Using the above concept, the jump enable signal generating circuit 9 allows the track jump from the jump direction C2, the jump number C3, and the control signal C4 of the spindle motor according to the contents of the table ROM 93 shown in FIG. The direction and magnitude range of the eccentric acceleration are determined and set as a window as shown in FIG. When the value of the direction signal S32 of the eccentric acceleration and the value of the signal S33 indicating the magnitude of the acceleration from the eccentricity detection circuit fall within this window, a track jump enable signal S4 is generated.

Upon receiving the jump enable signal S4, the actuator driver 5 generates a drive signal for moving the actuator 6 in accordance with a jump command from the control means, and kicks the pickup actuator 6 to execute a track jump.

[0055]

As described above, the track jump mechanism of the optical disk memory device according to the present invention executes the track jump at the optimum timing by monitoring the state of the disk eccentricity. As much as possible, a stable and reliable track jump is executed, and the probability that the optical pickup reaches the target track is improved. That is, the access time for accessing the target data is shortened, and the reading or writing operation is sped up. The track jump method of the present invention is considered to have a great effect particularly in a drive having a large media eccentricity and a high rotational speed when the frequency of short-range random access is high.

[Brief description of the drawings]

FIG. 1 is a block diagram of a track control unit of a conventional optical disk memory device.

FIG. 2 is a block diagram of a track control unit of the optical disk memory device according to the present invention.

FIG. 3 is a block diagram of an eccentricity detection circuit and an enable signal generation circuit according to the first embodiment of the present invention.

FIG. 4 is a signal timing chart according to the first embodiment of the present invention.

FIG. 5 is a block diagram of an eccentricity detection circuit and an enable signal generation circuit according to a second embodiment of the present invention.

FIG. 6 is a track error signal diagram according to the second embodiment of the present invention.

FIG. 7 is a conceptual diagram of eccentricity in the optical disk device.

[Explanation of symbols]

Reference Signs List 1 optical disk memory 2 optical pickup 3 track error amplifier 4 phase compensation filter 5 actuator driver S5 drive signal 6 pickup actuator 7 spindle motor 8 eccentricity detection circuit 81 low-pass filter 82 track zero cross comparator 83 gain down signal generation circuit 84 hold signal generation circuit 85 eccentricity Acceleration calculation circuit S86 Track error signal output from low-pass filter 81 9 Jump enable generation circuit 91 Jump enable determination circuit 92 Window setting circuit 93 Read-only memory S94 Window signal 10 RF amplifier 11 Data slice and error correction 12 Interface 13 Host computer 14 CLV servo S1 Track error signal S2 Phase compensation fill Gain up or hold signal S3 Eccentric acceleration signal S31 Track zero cross signal (eccentric acceleration phase signal) S32 Eccentric acceleration direction signal S33 Eccentric acceleration amount signal S4 Track jump enable signal C1 Jump command signal C2 Jump direction signal C3 Jump number signal C4 Spindle Control signal

Claims (6)

[Claims] A track error signal generating circuit for generating a track error signal, a phase compensation filter for compensating a phase of the track error signal, and an actuator based on an output of the filter so that the track error signal becomes zero. An optical disk device having a driving unit;
An eccentricity detecting means for receiving a command to jump a track, detecting the eccentric direction and acceleration of the disc based on a track error signal and outputting the eccentricity information, and the eccentricity information, the track jumping direction and the current disc rotation cycle. Track jump enable signal generation means for generating a track jump enable signal indicating a track jump start timing based on the above, and a jump signal generation circuit for receiving the track jump enable signal and generating a jump signal for moving the actuator. An optical disc device characterized by the above-mentioned. 2. The optical disk apparatus according to claim 1, wherein the jump command includes jump number information, and generates a track jump enable signal indicating the track jump start timing based on the jump number information. 3. A track zero-cross comparator for generating a binary signal by comparing the track error signal with a signal level when a beam spot of an optical pickup is on a track, and receiving the track jump command. A gain-down signal generation circuit for lowering the gain of the servo band of the phase compensation filter to increase the amplitude of the track error signal. 2. The optical disk device according to claim 1, further comprising: an eccentricity detection circuit that obtains the eccentricity information of the disk from a level and an edge of the track zero cross signal after the comparison and binarization. 4. A holding signal generating circuit for receiving the track jump command, changing a frequency response characteristic of the phase compensation filter to hold a control signal to the track actuator, and holding the optical pickup. A sampling circuit for sampling the value of the track error signal at a fixed time interval, and calculating the eccentric state from the amount of change in the sampled track error signal and the sample time to output the eccentricity information. The optical disk device according to claim 1, further comprising a circuit. 5. A window stores eccentric acceleration range data and eccentric direction range data, which are determined based on the jump direction, the jump track number information, and the spindle rotation period information, and are suitable for a track jump. And a track jump enable signal generation circuit that generates a track jump enable signal when the eccentric acceleration and the eccentric direction output by the eccentricity detection circuit enter a predetermined window. 4. The optical disk device according to claim 1, wherein: 6. A track error signal generating circuit for generating a track error signal, a phase compensating filter for compensating a phase of the track error signal, and an actuator so that the track error signal becomes 0 based on an output of the filter. A driving method for an optical disc having a means for driving the disc, receiving a command to jump a track, detecting an eccentric direction and an acceleration of the disc based on a track error signal, outputting the eccentricity information, and outputting the eccentricity information and the track jump. An optical disk, which generates a track jump enable signal indicating a track jump start timing based on a direction and a current disk rotation period, receives the track jump enable signal, and generates a jump signal for moving the actuator. Drive method.