JPH08329481A - Optical disk device - Google Patents

Abstract

PURPOSE: To relieve the burden of a control circuit and to shorten the accessing time by the simple constitution of a device by returning the irradiating position of a laser beam to the original position for every tracking displacement by utilizing the rotation detecting signal of a spindle motor. CONSTITUTION: The rotation detecting signal FG of a spindle motor 4 is inputted to a controller 6 through a spindle driver 5, counted and the timing of one revolution of a magnetooptical disk 3 is detected. A control signal SC2 is outputted from the controller 6 to a servo circuit 11 for every revolution of the magnetooptical disk 3 i.e., for every revolution of the spindle motor 4 and the irradiating position of a laser beam is returned by one track, while jumping, to the side of inner periphery. Consequently, the irradiating position of the laser beam is returned to the original track independent of a system controller 12 by using the simple constitution of the device, stealing operation is enabled by relieving the burden of the system controller 12 and the access time is shortened by that of the relieved burden.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus, for example, in a magneto-optical disk apparatus, by utilizing a rotation detection signal of a spindle motor, the laser beam irradiation position is moved to the original position every one track displacement during standby. By returning to, the load on the control circuit is reduced and the access time is shortened.

[0002]

2. Description of the Related Art Conventionally, in a magneto-optical disk device,
Recording tracks are spirally formed on the magneto-optical disk to record and reproduce desired data. In such a magneto-optical disk device, the laser beam irradiation position is returned by one track for each rotation of the optical disk during standby, based on the position information obtained by reproducing the magneto-optical disk (hereinafter, this operation will be described). Is called still operation), and a method of shortening the access time has been proposed (Japanese Patent Publication No. 5-26252, Japanese Patent Laid-Open No. 58-212662).
issue).

That is, in a magneto-optical disk applied to this type of magneto-optical disk device, a pre-groove, which is a guide groove of a laser beam, is spirally formed on an information recording surface in advance, and a position is formed by meandering of the pre-groove. It is designed to record information.

In response to this, the magneto-optical disk device irradiates the information recording surface with a laser beam and receives the returned light, and generates a tracking error signal from the result of the received light. Thereby, the magneto-optical disk device forms a recording track in a spiral shape following the pre-groove based on the tracking error signal, and records / reproduces desired data.

In this series of processes, the magneto-optical disk device extracts the signal component due to the meandering of the pre-groove from the tracking error signal, and demodulates this signal component to detect the address data. As a result, the magneto-optical disk device can confirm the irradiation position of the laser beam, and controls the entire operation on the basis of this address data at the time of recording / reproducing.

On the other hand, as shown in FIG. 9, the pre-groove is formed in a spiral shape, and the laser beam irradiation position is displaced so as to follow the pre-groove, so that the magneto-optical disk device is kept in standby. When the magneto-optical disk makes one revolution on the basis of the address data obtained from the pre-groove, the laser beam irradiation position is track-jumped toward the inner circumference side by one track.

As a result, the magneto-optical disc apparatus starts the recording / reproducing operation by omitting the seek process when recording the data on the magneto-optical disc and then recording the succeeding data in the succeeding area for a certain period of time. It is retained so that access time can be shortened accordingly.

[0008]

By the way, when the still operation is performed on the basis of the address data recorded on the magneto-optical disk as described above, this address data is always used in the system controller for controlling the operation of the entire magneto-optical disk apparatus. It is necessary to check the current position.

Therefore, such a still operation has a problem that it puts a burden on the system controller. Therefore, even if an access command is input from the host computer during standby, the system controller immediately analyzes the command. Then, there is a problem that it is difficult to execute the corresponding process.

The present invention has been made in consideration of the above points. When the laser beam irradiation position is returned to the original position each time the laser beam irradiation position is displaced by one track, the load on the control means is reduced and the access time is increased. The present invention is intended to propose an optical disk device capable of shortening the time.

[0011]

In order to solve such a problem, the present invention is applied to an optical disk apparatus for accessing an optical disk having spirally formed recording tracks.
In this optical disk device, a rotation detection unit that outputs a rotation detection signal whose signal level changes in a cycle in which the spindle motor rotates at a specified angle, and the rotation detection signal is counted in the standby mode, and the spindle motor is detected based on the count result. When the optical disk drive means for returning the laser beam irradiation position by one track after one rotation and the entire operation are controlled and the access to the optical disk is completed,
And a control means for setting the optical pickup driving means to the previous standby mode.

Further, at this time, data is recorded on the previous recording track of the previous optical disc in a prescribed recording unit,
When the previous control means sets the previous optical pickup driving means to the standby mode or in the previous standby mode, the previous control unit can start the recording / reproducing process subsequent to the previously accessed recording unit. Switch the timing to return the track.

[0013]

The rotation detection means outputs a rotation detection signal whose signal level changes in a cycle in which the spindle motor rotates by a predetermined angle, and the optical pickup driving means counts the rotation detection signal in the standby mode and outputs the count result. When the spindle motor makes one revolution based on this, the laser beam irradiation position is returned by one track, the entire operation is controlled by the control means, and when the optical disk access is completed, the optical pickup driving means is set to the standby mode. The load on the control means can be reduced and the standby mode can be maintained. For example, the optical disk can be accessed immediately in response to a command input from an external device.

At this time, when the optical pickup driving means is set to the standby mode or in the previous standby mode, the laser beam irradiation position is set to 1 so that the subsequent recording / reproducing process can be started from the previous recording unit accessed immediately before.
By switching the track return timing, for example, the timing can be set so that the header accessed immediately before can be read and the standby mode can be maintained.

[0015]

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

(1) First Embodiment FIG. 1 is a block diagram showing a magneto-optical disk device according to an embodiment of the present invention. This magneto-optical disk device 1 is
The operation is switched in response to a control command output from the host computer 2, the data D1 output from the host computer 2 is recorded on the magneto-optical disk 3, and the data recorded on the magneto-optical disk 3 is reproduced. .

Here, the magneto-optical disk 3 is formed by forming a perpendicular magnetic film on a disk-shaped substrate made of polycarbonate or the like, and then arranging a protective film thereon, whereby the method of thermomagnetic recording is obtained. By applying this, desired data can be recorded and the recorded data can be reproduced by utilizing the Kerr effect. Further, in this magneto-optical disk 3, a pre-groove which is a guide groove of a laser beam is spirally formed on the information recording surface in advance, and the position information is recorded by the meandering of the pre-groove.

The magneto-optical disk device 1 chucks the magneto-optical disk 3 on the spindle motor 4 and then drives the spindle motor 4 to rotate by the spindle driver 5. At this time, the spindle motor 4 rotationally drives the magneto-optical disk 3 under the condition that the linear velocity is constant with reference to the meandering of the pre-groove of the magneto-optical disk 3. Further, the spindle motor 4 uses a built-in Hall element or the like to generate a rotation detection signal FG whose signal level switches each time it rotates by a specified angle, and outputs this rotation detection signal FG to the controller 6 via the spindle driver 5.

Thus, the magneto-optical disk device 1 can detect the rotation phase of the magneto-optical disk 3 in the controller 6 based on the rotation detection signal FG. As shown in FIG. 2, in this embodiment, the rotation detection signal FG has a duty ratio of 50.
The signal level is set to [%] so that the signal level rises 12 times during one revolution of the spindle motor 4 at equal time intervals.

As described above, in the magneto-optical disk device 1, the optical pickup 7 and the modulation coil M are arranged so as to face each other with the magneto-optical disk 3 interposed therebetween in a state where the magneto-optical disk 3 is rotationally driven.

Here, the optical pickup 7 is formed so as to be movable in the radial direction of the magneto-optical disk 3 by the sled motor 8 together with the modulation coil M, so that in the magneto-optical disk device 1, the sled motor 8 is driven. You can seek and jump again. Further, the optical pickup 7 emits a laser beam having a specified polarization plane from a built-in laser diode, and the laser beam is emitted by the objective lens 9 to the magneto-optical disk 3.
It is focused on the information recording surface of. In the optical pickup 7, the objective lens 9 is held so as to be movable vertically and horizontally, so that in the magneto-optical disk device 1, the objective lens 9 can be moved to perform tracking control and focus control.

Further, the optical pickup 7 detects the light amount of the laser beam emitted to the rear side of the laser diode and outputs the light amount detection result. As a result, the magneto-optical disk device 1 can perform so-called automatic light amount control based on the light amount detection result. Further, the optical pickup 7 receives the return light of the laser beam by a prescribed light receiving system, performs a current-voltage conversion process on the light reception result, and then outputs it to the subsequent RF amplifier 10.

The RF amplifier 10 is formed by an amplifier circuit having a matrix circuit configuration, and by adding / subtracting the output signal of the optical pickup 7, a focus error signal and a tracking error amount whose signal level changes according to the focus error amount. A tracking error signal whose signal level changes accordingly, a wobble signal whose signal level changes following the meandering of the pregroove, and a reproduction signal whose signal level changes according to the polarization plane of the return light are generated. Further, the RF amplifier 10 binarizes this reproduction signal with reference to a prescribed threshold value, and outputs a binarized signal S1 obtained as a result.

The servo circuit 11 switches its operation in response to a control signal output from the system controller 12 and under the control of the controller 6. That is, in the normal operation, the servo circuit 11 outputs a drive signal to the optical pickup 7 based on the focus error signal and the tracking error signal, so that the signal levels of the focus error signal and the tracking error signal become 0 level, respectively. The objective lens 9 is moved vertically and horizontally so that focus control and tracking control are performed.

Further, the servo circuit 11 forms a clock from the wobble signal and controls the spindle driver 5 to drive the spindle motor 4 so that the frequency of this clock becomes a prescribed frequency, thereby causing the pre-blew meandering. As a reference, the magneto-optical disk 3 is rotationally driven under the condition of constant linear velocity.

Further, the servo circuit 11 maintains the light quantity of the laser beam at a prescribed value during reproduction based on the detection result of the light quantity of the laser beam, while the servo circuit 11 reproduces the light quantity of the laser beam during recording. The light intensity at the time of recording is intermittently set to the light intensity at the time of recording.

Further, the servo circuit 11 drives the sled motor 8 by the low frequency component of the tracking error signal, so that in a normal recording / reproducing operation, the optical pickup 7 and the optical pickup 7 are tracked following the spirally formed pre-groove. The modulation coil M is sequentially displaced to the outer peripheral side of the magneto-optical disk 3.

Further, when the seek control signal SC1 is inputted from the system controller 12, the servo circuit 11 drives the sled motor 8 and the objective lens 9 by a prescribed drive signal instead of the tracking error signal, and thereby the optical signal is transmitted. The pickup 7 and the modulation coil M are sought to the target position. At this time, the servo circuit 11 generates a tracking zero cross signal whose signal level rises at the timing when the tracking error signal crosses the 0 level, and generates a drive signal based on this tracking zero cross signal.

As a result, the servo circuit 11 accelerates and decelerates the sled motor 8 while monitoring the number of tracks traversed by the laser beam, and completes the seek process in a short time.

In this seek processing, the servo circuit 1
1 indicates that when the track jumps only by one track, the signal level of the drive signal is raised or lowered according to the direction of the track jump, and then the polarity of the drive signal is switched at the timing when the signal level of the tracking zero cross signal rises. Thus, only one track is jumped on the basis of the tracking zero cross signal.

On the other hand, in the servo circuit 11, when the track jump control signal SC2 is input from the controller 6 after being set to the still mode, the sled motor 8 and the objective lens 9 are driven to drive the laser beam irradiation position. To jump one track toward the inner circumference.

That is, as shown in FIG. 3, the servo circuit 11 causes the tracking error signal TE to drive the sled motor 8 and the objective lens 9 at a specified time t0.
(FIGS. 3A and 3C) to drive signal SD
Switch to driving by. Servo circuit 11 in this state
Monitors the tracking zero-cross signal SZ (FIG. 3 (B)), switches the polarity of the drive signal SD at the timing when the tracking zero-cross signal SZ rises, and subsequently, the tracking error signal TE crosses the 0 level timing (that is, continuously). At the timing when the tracking zero cross signal SZ rises), the drive of the sled motor 8 and the objective lens 9 is switched from the drive of the drive signal SD to the drive of the tracking error signal TE.

As a result, the servo circuit 11 accelerates the sled motor 8 to the inner circumference side and then decelerates it, and when the laser beam irradiation position is displaced to the inner circumference side by one track, the tracking servo loop is turned on. set. Thus, in the track jump of one track in the still mode, the servo circuit 11 is controlled by the controller 6 instead of the system controller 12,
In the magneto-optical disk device 1, the servo circuit 11 using the servo circuit having the integrated circuit configuration applied to the conventional magneto-optical disk device is used because of the process of jumping the track by one track in the predetermined direction. Can be formed easily, and the entire structure can be simplified accordingly.

The controller 6 switches the operation based on the control signal output from the system controller 12, and when set to the still mode, controls the operation of the servo circuit 11 in place of the system controller 12.

That is, the controller 6 is formed of a ring counter, and executes a still process according to a control signal output from the system controller 12. Here, this ring counter is formed so as to count the rotation detection signal FG when a control signal is output from the system controller 12, and when the count value reaches a value corresponding to one rotation of the spindle motor 4, the servo circuit 11 is notified. The count signal is reset while the track jump control signal SC2 is output.

As a result, when the system controller 12 sets the overall operation mode to the still mode, the controller 6 sends the track jump control signal SC to the servo circuit 11 at a cycle of one rotation of the magneto-optical disk 3.
2 is output, and every time the laser beam irradiation position is displaced one track toward the inner circumference side of the magneto-optical disk 3, the laser beam irradiation position is track-jumped to the original track.

That is, as shown in FIG. 4, in this process, the controller 6 shifts from step SP1 to step SP2, is set to the still mode as the control signal is output from the system controller 12, and starts the still operation. Further, in the subsequent step SP3, the controller 6 determines the count value Nf of this counter.
Is reset to a value 0 to start counting the rotation detection signal FG, and then in a subsequent step SP4, the count value Nf corresponds to one rotation of the spindle motor 4 (in the case of this embodiment, the count value Nr is set to 12). Then, the servo circuit 11 is instructed to perform one track jump.

Further, when the control signal is output from the system controller 12, the controller 6 outputs the rotation detection signal F.
By stopping the counting operation of G and ending the still operation, it is determined in the subsequent step SP5 whether or not the still operation is completed, and if a negative result is obtained here, step S5 is performed.
While returning to P3 and continuing the counting operation again, when an affirmative result is obtained in step SP5, the process proceeds to step SP6 to end this processing procedure.

As a result, in the servo circuit 11, every time the controller 6 outputs the control signal SC2, the processing procedure shown in FIG. 5 is executed, and the laser beam irradiation position is track-jumped to the original track.

That is, the servo circuit 11 executes the step SP.
When the count value Nf reaches the count value Nr corresponding to one rotation of the spindle motor 4 from 7 in step SP8, the sled motor 8 and the objective lens 9 are accelerated toward the inner circumferential side, and then in the subsequent step SP9, The moving speeds of the sled motor 8 and the objective lens 9 are decelerated from the substantially intermediate position of (3), and the processing is ended in the subsequent step SP10.

As a result, as shown in FIG. 6, the beam spot formed on the information recording surface of the magneto-optical disk 3 by this laser beam is displaced from the reference position by a prescribed angle θ when set in the still mode. In, when one track is displaced from the original position, it is controlled so as to jump to the original track. As a result, in the magneto-optical disk device 1, even after waiting for a certain period of time, it is possible to start the recording / reproducing process subsequent to the track for which the immediately preceding recording / reproducing process has been completed, and to shorten the access time accordingly. it can.

Further, the controller 6 can set the initial value of the count value by the system controller 12 when starting the still process in this way. Thus, in the magneto-optical disk device 1, the positions of the second and subsequent track jumps can be freely set with respect to the position of the first track jump indicated by the arrow a in FIG.

In this way, this initial value is set by the system controller 12 so that the beam spot scans the position of the header accessed immediately before in the second and subsequent track jumps. Then, the subsequent recording / reproducing process can be started in a short time.

In the magneto-optical disk device 1, the address decoder 13 frequency demodulates the wobble signal in the state where the optical pickup 7 and the like are held on the magneto-optical disk 3 in this manner, and the laser beam is obtained from the demodulation result. The address data of the irradiation position is detected.

The digital signal processing circuit 14 converts the binarized signal S1 into serial data by sequentially latching the binarized signal S1 with reference to the clock generated by the servo circuit 11. Further, the digital signal processing circuit 14 encodes this serial data,
Digital signal processing such as error correction is executed, thereby reproducing the data D2 recorded on the magneto-optical disk 3 and outputting it to the host computer 2 as necessary.

On the other hand, at the time of recording, the digital signal processing circuit 14 adds an error correction code, a header, etc. to the data D1 input from the host computer 2 on the basis of the clock generated by the servo circuit 11. After the conversion into the specified data structure, the specified modulation processing is executed, and this data D1 is converted into a recording signal. Further, the digital signal processing circuit 14 outputs this recording signal to the driver 15 at a prescribed timing with reference to the address data output from the address decoder 13, and the driver 15 drives the modulation coil M.

Thus, in the magneto-optical disk device 1, a modulation magnetic field based on the data D1 is applied to the laser beam irradiation position, and the recording data D1 is thermomagnetically recorded.

The system controller 12 is a microcomputer for controlling the overall operation of the magneto-optical disk device 1, and maintains the overall operation mode in the still operation mode in the normal operation mode, and in this state, the host computer 2 When a control command is input from, the control command is analyzed, and then the entire operation is switched as necessary based on the analysis result.

That is, when an access command is input from the host computer 2, the system controller 12
Drives the servo circuit 11 and the controller 6 based on the address data output from the address decoder 13 as necessary, and thereby seeks the optical pickup 7 and the modulation coil M to the target position. At this time, the system controller 12 confirms the laser beam irradiation position based on the address data detected by the address decoder 13 and outputs a control signal such as a one-track jump as necessary to ensure the laser beam irradiation position. Seek to.

Subsequently, the system controller 12 switches the entire operation mode to the recording or reproduction operation mode,
As a result, the data D1 input from the host computer 2 is recorded on the magneto-optical disk 3, and conversely, the data recorded on the magneto-optical disk 3 is reproduced. As a result, the magneto-optical disk device 1 can record and reproduce desired data in response to a command from the host computer 2.

In this series of processes, when the system controller 12 accesses the track following the immediately preceding recording / reproducing process, the still beam irradiation position is held on the track where the immediately preceding recording / reproducing process is completed by the still operation. By doing so, the seek processing described above is omitted and the recording / reproducing processing is immediately started, thereby shortening the access time.

When the recording / reproducing process is completed in this way, the system controller 12 immediately starts the servo circuit 1.
1 and a control signal to the controller 6 to keep the overall operation mode in the still operation mode.
As a result, the system controller 12 is set so as not to execute the control of the servo circuit 11 and the confirmation processing of the address data output from the address decoder 13 in this still operation mode, and the control from the host computer 2 is performed. It is designed to wait for commands.

Therefore, in the system controller 12, the load in the still operation is reduced by that amount, and when an access command is input from the host computer 2 for the magneto-optical disk apparatus 1 as a whole, the processing in response to this command is immediately executed. Is made possible.

When switching to the still operation mode in this way, the system controller 12 sets the initial value of the controller 6 so that the beam spot scans the position of the header accessed immediately before in the second and subsequent track jumps. Is set so that the subsequent recording / reproducing process can be started quickly.

In the above configuration, the magneto-optical disk 3
Is driven to rotate at a prescribed rotation speed by the spindle motor 4, and in this state, the laser beam emitted from the optical pickup 7 is focused on the information recording surface by the objective lens 9. Further, in the magneto-optical disk 3, the returned light of the laser beam is received by the optical pickup 7, and a reproduction signal, a tracking error signal, a focus error signal, and a wobble signal are generated by the RF amplifier 10 based on the light reception result.

In the magneto-optical disk 3, the spindle motor 4 is rotationally driven by the servo circuit 11 on the basis of the clock generated from this wobble signal, whereby the spindle motor 4 is rotationally driven under the condition of constant linear velocity. Further, the objective lens 9 is moved vertically and horizontally by the servo circuit 11 on the basis of the focus error signal and the tracking error signal, whereby focus control and tracking control are performed. As a result, at the time of recording / reproducing, the laser spot formed on the magneto-optical disk 3 is sequentially displaced from the inner circumference side to the outer circumference side of the magneto-optical disk 3 along the spirally formed pre-groove.

Further, during reproduction, the reproduction signal is binarized by the RF amplifier 10, and the resulting binarized signal is converted into serial data by the digital signal processing circuit 14, and prescribed digital signal processing is executed. By doing so, the data recorded on the magneto-optical disk 3 is reproduced. At the time of recording, the address decoder 13 detects the address data of the laser beam irradiation position from the wobble signal, the light amount of the laser beam is intermittently raised based on the address data, and the modulation magnetic field is applied. The desired data is recorded.

When such recording / reproducing processing is completed,
The magneto-optical disk device 1 is set to the still mode by the system controller 12. In the still mode, the magneto-optical disk device 1 counts the rotation detection signal FG whose signal level is switched each time it rotates by the specified angle by the controller 6, and the timing of the rotation of the magneto-optical disk 3 is detected by the count result. It
Further, the magneto-optical disk device 1 outputs a control signal SC2 from the controller 6 to the servo circuit 11 every one rotation and a laser beam based on the tracking zero-cross signal SZ generated from the tracking error signal in response to this. The track jumps one track toward the inner circumference of the irradiation position.

As a result, in the magneto-optical disk device 1, in the still mode, every time the laser beam irradiation position is displaced one track toward the inner circumference side of the magneto-optical disk 3, the laser beam irradiation position jumps to the original track. , So that the subsequent recording / reproducing process can be immediately started. Also when setting to this still mode,
In the second and subsequent track jumps, the system controller 12 sets a processing value in the counter of the controller 6 so that the beam spot scans the position of the header accessed immediately before, so that subsequent recording / reproduction can be started quickly. Held in.

Further, the controller 6 executes the command for detecting the timing of one rotation of the magneto-optical disk 3 and the command for the track jump, so that the load on the system controller 12 is reduced, and the system controller 12 receives the command from the host computer 2. By being kept in the state of accepting the control command, the subsequent recording / reproducing process is quickly executed.

According to the above configuration, the spindle motor 4
Of the rotation detection signal FG of the magneto-optical disk 3 is detected by the controller 6, and the controller 6 outputs the control signal SC2 to the servo circuit 11 for each rotation of the magneto-optical disk 3. By performing a track jump of the laser beam irradiation position to the inner circumference side by one track, the laser beam irradiation position is displaced to the inner circumference side of the magneto-optical disk 3 by one track with a simple structure. Can be returned to the truck. As a result, the load on the system controller 12 can be reduced and the still operation can be performed, and the access time can be shortened accordingly.

(2) Second Embodiment FIG. 8 is a block diagram showing a magneto-optical disk device according to the second embodiment of the present invention. This magneto-optical disk device 2
0 generates a rotation detection signal FG by a dedicated sensor instead of the spindle motor 21. In the second embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the duplicated description will be omitted.

That is, the magneto-optical disk device 20 is provided with an external sensor 22 such as a hall element or an optical sensor in the vicinity of the spindle motor 21, and the external sensor 22 causes the signal level to be output every time the magneto-optical disk 3 rotates by a predetermined angle. Generates a rotation detection signal FG that switches. Further, the magneto-optical disk device 20 inputs this rotation detection signal FG to the controller 6, and detects the timing at which the magneto-optical disk 3 makes one rotation based on this rotation detection signal FG.

According to the configuration shown in FIG. 8, the external sensor 22
Therefore, even if the rotation detection signal FG whose signal level is switched each time the magneto-optical disk 3 is rotated by the specified angle is generated,
It is possible to obtain the same effect as that of the embodiment.

(3) Other Embodiments In the above embodiment, the controller 6 is initialized at the start of the still operation so that the beam spot scans the position of the header accessed immediately before in the second and subsequent track jumps. Although the case where the value is set has been described, the present invention is not limited to this, and it is only necessary to set the beam spot to scan the position of the header accessed immediately before the end of the still operation. The jump timing may be switched at any timing in the repeated track jumps.

In addition, in the above-mentioned embodiment, by adding the header and recording the data, when the data is recorded with the period of the header as a recording unit, the beam spot indicates the position of the header accessed immediately before. The case of still operation for scanning has been described, but the present invention is not limited to this, and for example, in the case of recording / reproducing in sectors, the beam spot scans the sector accessed immediately before. Set and execute the still operation.

In the above embodiment, the magneto-optical disk 3 is rotationally driven under the condition that the linear velocity is constant, and the rotational phase of the magneto-optical disk 3 is detected by the spindle motor 4 or the external sensor. The present invention is not limited to this. For example, when the magneto-optical disk 3 is rotationally driven under a constant angular velocity condition, a rotation detection signal is generated from a reproduction signal obtained from an optical pickup to generate a magneto-optical disk 3. The rotation phase may be detected.

Further, in the above-mentioned embodiments, the case where the present invention is applied to the magneto-optical disk device has been described.
The present invention is not limited to this, and can be widely applied to a write-once type optical disc device, and further to an optical disc device such as a CD-ROM drive.

[0069]

As described above, according to the present invention, a rotation detection signal whose signal level changes in a cycle in which the spindle motor rotates by a predetermined angle is counted, and when the spindle motor makes one rotation based on the count result, the laser beam By returning the irradiation position by one track, the load on the control means is reduced, and the laser beam irradiation position is reduced to 1 by a simple configuration.
When the track is displaced, it can be restored. As a result, the still operation can be executed with a simple structure and the access time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a magneto-optical disk device according to an embodiment of the present invention.

FIG. 2 is a signal waveform diagram showing a rotation detection signal of the magneto-optical disk device of FIG.

FIG. 3 is a signal waveform diagram for explaining a one-track jump.

FIG. 4 is a flow chart for explaining an operation of a controller of the magneto-optical disk device of FIG.

5 is a flowchart for explaining the operation of the servo circuit of the magneto-optical disk device shown in FIG.

FIG. 6 is a schematic diagram for explaining a still operation.

FIG. 7 is a schematic diagram for explaining the start of the still operation of FIG.

FIG. 8 is a block diagram showing a magneto-optical disk device according to a second embodiment of the present invention.

FIG. 9 is a schematic diagram for explaining a still operation in a conventional magneto-optical disk device.

[Explanation of symbols]

 1, 20 magneto-optical disk device 2 host computer 3 magneto-optical disk 4, 21 spindle motor 6 controller 11 servo circuit 12 system controller

Claims (2)

[Claims] 1. An optical disc apparatus for accessing an optical disc having spirally formed recording tracks, wherein an optical pickup for irradiating the optical disc with a laser beam, a spindle motor for rotationally driving the optical disc, and a spindle motor for rotating the spindle motor at a predetermined angle. Rotation detection means for outputting a rotation detection signal whose signal level changes in a cycle, and in the standby mode, counting the rotation detection signal,
When the spindle motor makes one rotation based on the count result, an optical pickup driving unit that drives the optical pickup to return the laser beam irradiation position by one track, and the entire operation is controlled to complete the access to the optical disc. An optical disc apparatus comprising: a control unit that sets the optical pickup driving unit to the standby mode. 2. The optical disk is a specified recording unit,
Data is recorded on the recording track, and when the control unit sets the optical pickup driving unit to the standby mode or in the standby mode, the control unit can start a recording / reproducing process that continues from the recording unit accessed immediately before. The optical disk device according to claim 1, wherein the timing for returning the one track is switched as described above.