JPH1079160A - Optical disk apparatus and method for correcting eccentricity of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk apparatus and an eccentricity correction method whereby eccentricity of an optical disk can be corrected at high speed in a simple structure. SOLUTION: A spindle structure body 10 loading a loaded optical disk 4 and a spindle motor 5 driving the optical disk 4 is moved from a data read position 11 to an eccentricity correction position 12 when an eccentricity of the optical disk 4 is to be corrected. An impact force is impressed by an eccentricity correction impact hammer 1 to the optical disk 4 at the position, thereby to correct the eccentricity. The eccentricity can be corrected while the optical disk 4 is rotated at high speed.

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 using an exchangeable optical disk such as a CD-ROM or a DVD ROM / RAM, and a method of correcting eccentricity of such an optical disk. The present invention relates to an eccentricity correction method.

[0002]

2. Description of the Related Art In an optical disk apparatus, an optical disk is mounted on a turntable directly connected to a spindle motor, and the optical disk is clamped and rotated by a clamper and a turntable mounted separately from the spindle motor. Data is read by a pickup using a semiconductor laser. In order to be able to use various types of optical discs, the disc clamp section for performing the above-mentioned clamping cannot improve the fitting accuracy of the turntable and the disc hole part so much, and the precision of the press working of the optical disc is not so high. For this reason, it often occurs that the optical disk is eccentric from the center of the turntable by several tens μm to 100 μm while the optical disk is mounted on the turntable.

The eccentricity of a data track of an optical disk is C
It is standardized to 140 μm or less according to the D standard (Red Book). At this eccentric amount, high-speed rotation, for example, 1
When a high-speed rotation at twice the speed (corresponding to 15.6 m / s) or more is performed, the maximum eccentric acceleration is 55.3 m / s ² . on the other hand,
Since the maximum following acceleration in the track direction of the actuator equipped with the laser pickup is about 20 m / s ² ,
It is impossible to follow the maximum eccentric acceleration of the optical disk.

As a method of correcting such eccentricity of an optical disk, for example, in the invention disclosed in Japanese Patent Application Laid-Open No. 4-241261, a side surface of the optical disk is pressed by a pinch roller while a clamping force on the optical disk is kept low, and A method for correcting eccentricity has been proposed.

[0005]

According to this correction method, a disk clamp drive circuit is required, which complicates the configuration of the optical disk apparatus, and the eccentricity correction must be performed by rotating the optical disk at a low speed, which takes time. There were drawbacks.

An object of the present invention is to provide an optical disk apparatus and an optical disk eccentricity correction method capable of performing eccentricity correction while rotating an optical disk at a high speed with a simple configuration.

[0007]

An optical disk apparatus according to the present invention has an optical disk having a data track for recording data, a driving device for driving the optical disk, data reading means for reading data recorded on the data track, In an optical disc device including an eccentricity detecting means for detecting an eccentricity when the data track is rotated, and an eccentricity correcting means for correcting the eccentricity detected by the eccentricity detecting means, the data is recorded on the data track by the data reading means. And a second position for correcting the eccentricity by the eccentricity correcting means with a position moving means for integrally moving the optical disk and the driving device. Thus, eccentricity correction can be performed with a simple configuration while rotating the optical disc at high speed.

Further, a comparing means for comparing the eccentric amount detected by the eccentric amount detecting means with a predetermined eccentric amount is further provided. Thus, a slight amount of eccentricity not related to high-speed reading of data can be ignored.

In addition, when the eccentric amount is detected by the eccentric amount detecting means, an inquiry means for inquiring the user whether or not to perform the eccentricity correction by the eccentric amount correcting means is provided. This makes it possible to perform eccentricity correction in consideration of the user's intention.

The eccentricity correcting means is an impact force applying means for applying an impact force to the optical disc to correct the eccentricity. This makes it possible to easily perform high-speed eccentricity correction with a simple configuration.

Further, the impact force applying means applies the impact force using an electromagnetic force. This makes it possible to easily perform high-speed eccentricity correction with a simple configuration.

The eccentricity correcting means is a pressing force applying means for correcting the eccentricity by applying a pressing force to the driving device or the optical disk. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

The pressing force applying means applies a pressing force using a piezoelectric element. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

Further, the pressing force applying means applies the pressing force using an electromagnetic force. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

According to the eccentricity correction method for an optical disk of the present invention, an optical disk having a data track for recording data is mounted on a drive device for driving the optical disk, and the optical disk mounted on the drive device is mounted on the data track. Moving the drive unit integrally with the driving device to an eccentricity correction position for correcting the eccentricity during rotation, detecting the eccentricity at the eccentricity correction position, and detecting the eccentricity at the eccentricity detecting step. The method includes a step of correcting at an eccentricity correction position, and a step of moving the driving device and the optical disc to a data reading position for reading data integrally after the correcting step. Thus, eccentricity correction can be performed by a simple method while rotating the optical disk at a high speed.

After the step of detecting the amount of eccentricity,
The method further includes a step of comparing the eccentric amount detected in this step with a predetermined eccentric amount. Thus, a slight amount of eccentricity not related to high-speed reading of data can be ignored.

Further, a step of inquiring the user whether or not to perform the correction step before performing the step of correcting the eccentric amount is provided. This makes it possible to perform eccentricity correction in consideration of the user's intention.

After performing a step of inquiring the user as to whether or not to perform a correction step, if the user instructs not to perform the correction step in this step, the data recorded on the data track is read. And a step of reading data by driving the optical disc at the maximum rotational speed that can be performed. Thereby, high-speed data reading can be performed within a possible range without being affected by the eccentricity of the optical disk.

In the step of correcting the amount of eccentricity, an impact force is applied to the optical disk to correct the amount of eccentricity. This makes it possible to easily perform high-speed eccentricity correction with a simple configuration.

Further, in the step of correcting the amount of eccentricity, an impact force is applied using an electromagnetic force. This makes it possible to easily perform high-speed eccentricity correction with a simple configuration.

In the step of correcting the amount of eccentricity, a pressing force is applied to the driving device or the optical disk to correct the amount of eccentricity. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

In the step of correcting the amount of eccentricity, a pressing force is applied using a piezoelectric element. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

In the step of correcting the amount of eccentricity, a pressing force is applied using an electromagnetic force. As a result, eccentricity correction can be performed quickly without being restricted by the rotation speed of the optical disk at the time of correction, and the data transfer speed can be improved.

[0024]

FIG. 1 is a perspective view showing an essential part of a first embodiment of an optical disk apparatus according to the present invention.
FIG. 2 is a side view showing a main part of the present embodiment.

In FIG. 1 and FIG.
The optical disc 4 having the above is mounted on the rotation axis of the spindle motor 5 and is driven to rotate by the spindle motor 5. A clamper support 13 is provided on the optical disc 4.
A clamper 6 fixed to the optical disk 4 is vertically movably supported. When the clamper 6 comes into close contact with the optical disk 4, the optical disk 4 is fixed and held.

The spindle motor 5 is pivotally supported at one end by a shaft 14 and is rotatable about the shaft 14 between a data reading position 11 and an eccentricity correction position 12.
A pickup actuator 2 for reading data on the data track 3 of the optical disc 4 is fixed in the spindle structure 10. Note that the eccentricity correction position 12 corresponds to the spindle structure 1
The leading end of 0 is, for example, approximately 2
This is a displacement position within a range in which the optical disc 4 can be clamped with a clamping force smaller than the rated value at the time of data reading by the clamper 6, which is about a mm away.

When the optical disk 4 is at the eccentricity correction position 12, the spindle motor 5 is positioned near the optical disk 4.
An eccentricity correction is performed by an electromagnetic force for correcting an eccentricity amount by applying an impact force to the optical disk 4 in the direction of the rotation center position of the optical disk 4 so as to match the rotation center of the data track 3 of the optical disk 4 with the rotation center of the spindle motor 5. The impact hammer 1 is held by a holding member (not shown). In FIG. 2, the impact hammer 1 for eccentricity correction is drawn shifted to the right side for easy understanding.

An output terminal of the pickup actuator 2 is connected to a data track 3 of the optical disk 4 based on a tracking signal detected by the pickup actuator 2.
The input terminal of the eccentricity detection circuit 16a for detecting the eccentricity is connected to the output terminal of the eccentricity detection circuit 16a, and the eccentricity detected by the eccentricity detection circuit 16a is within a predetermined reference value. The input terminal of the judgment circuit 16b for judging whether or not is connected is connected. The output terminal of the judgment circuit 16b is connected to the input terminal of the drive circuit 16c for driving the eccentricity correction hammer 1, and the output terminal of the drive circuit 16c is connected to the input terminal of the eccentricity correction hammer 1. I have.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, the operator of the optical disc apparatus of the present embodiment places the optical disc 4 on the spindle motor 5 to load the optical disc 4 (step S1), and then places the disc 4 as shown in FIG. The spindle structure 10 moves circularly about the shaft 14 and moves from the data reading position 11 to the eccentricity correction position 12. At this position, the clamper 6 fixed to the clamper support 13 descends and clamps the optical disc 4 with a clamping force smaller than the rated value at the time of data reading (step S2).

Thereafter, the focus of a laser device (not shown) for irradiating the optical disk 4 is adjusted (step S3), and the optical disk 4 is rotated at a standard speed (about 1.3 m / s). At the same time as the rotation of the optical disk 4, the pickup actuator 2 measures a tracking signal indicating the number of trackings (step S4), and inputs the tracking signal to the eccentricity detection circuit 16a. The eccentricity detection circuit 16a detects the eccentricity of the data track 3 from the input tracking signal and inputs it to the determination circuit 16b (Step S).
5). The determining circuit 16b determines whether or not the eccentricity detected by the eccentricity detecting circuit 16a is within a predetermined reference value (step S5). The body 10 is moved to the data reading position 11, and the clamping force is set to the rated value (Step S
6) Read out the data recorded on the data track 3 by increasing the rotation speed of the optical disk 4 (step S7).

If the eccentricity is larger than the reference value, a message to correct the eccentricity is output to a display device (not shown) (step S8), the correction amount is calculated by the drive circuit 16c, and the eccentricity correction hammer 1 is used. Then, a drive signal corresponding to the correction amount is output, and the eccentricity is corrected by applying an impact force to the optical disk 4 from the eccentricity correcting impact hammer 1 (step S9).

Thereafter, the tracking signal is measured again (step S4), the eccentric amount is calculated, and it is determined whether or not the eccentric amount is within a predetermined reference value (step S5). Then, the spindle motor structure 10 is moved to the reading position 11, the clamping force is set to the rated value (step S6), and the rotation speed is increased to read the data (step S7). The eccentricity correction routine may be executed a plurality of times.

Since the rotation speed during the measurement of the eccentricity is determined by the time constant of the impact hammer 1 for eccentricity correction, if the speed corresponds to the time constant of the impact hammer 1 for eccentricity correction. It may be other than the standard speed.

As described above, the eccentricity is corrected at the eccentricity correction position 12 by using the eccentricity correction impact hammer 1 to correct the eccentricity of the data track 3 while rotating the optical disk 4 at a high speed with a simple configuration. Data transfer speed can be improved.

FIG. 4 shows a second embodiment of the optical disk apparatus according to the present invention.
9 is a flowchart showing the operation of the embodiment. The hardware configuration of the optical disk device according to the present embodiment is shown in FIG.
4 is the same as that of the first embodiment shown in FIG. 2, and the operation is also the same as that of the first embodiment shown in FIG. In FIG. 7, only the steps different from those in the flowchart of FIG. 3 are assigned different numbers, and the description of the steps of the same operation is omitted.

In this embodiment, when the eccentricity of the data track 3 of the optical disk 4 is larger than the reference value,
The eccentricity correction message is output to the display device (step S8), and at the same time, a message asking the user whether to correct the eccentricity is displayed on the display device (step S1).
0). When the user inputs an instruction not to perform the correction through an input device (not shown), the eccentricity correction is not performed, and the optical disk 4 is rotated at the maximum rotational speed at which the data track 3 of the optical disk 4 can be read with the eccentricity. Rotate
The data on the data track 3 is read (step S1)
1). Note that the maximum readable rotation speed at this time is naturally lower than the high-speed rotation speed in step S7 when there is no eccentricity. For example, if the high-speed rotation speed in step S7 is 12-times speed, the eccentric amount is Although it depends, the speed is about 6 to 8 times.

On the other hand, when the user inputs an instruction to perform correction via the input device and when the user does not input any instruction for a certain period of time, as in the first embodiment,
The eccentricity of the optical disc 4 is corrected (step S9), and it is again determined whether or not the eccentricity is within a predetermined reference value (step S5). Data is read out at high speed (step S
7).

With the above operation, the eccentricity of the data track 3 of the optical disk 4 can be corrected while respecting the opinion of the user, and the data transfer speed can be improved.

FIG. 5 is a perspective view showing the structure of an optical disk device according to a third embodiment of the present invention. In the figure,
The same components as those of the optical disc device of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, an actuator 7 having a triangular prism-shaped piezoelectric element having three support rods on three surfaces abutting on three points on the inner wall at the rotation center position of the spindle motor 5 is used as the spindle motor 5. And a slip ring 15 is connected to the actuator 7. The output terminal of the power supply 17 whose input terminal is connected to the output terminal of the determination circuit 16 b is connected to the slip ring 15, and a voltage corresponding to the correction amount is supplied from the power supply 17 to the actuator 7 via the slip ring 15. Is done. That is, in the present embodiment, the eccentricity correction of the data track 3 of the optical disk 4 at the eccentricity correction position 12 is performed by shifting the position of the spindle motor 5, and the voltage corresponding to the correction amount is supplied from the power supply 17 to the slip ring 15. Is supplied to the actuator 7 via
The three support rods move in accordance with the expansion and contraction of the piezoelectric element of the actuator 7, and the rotation center position of the spindle motor 5 moves, and the rotation center of the data track 3 of the optical disk 4 and the rotation center of the spindle motor 5 move. Match.

As described above, in the present embodiment,
By using the eccentricity correction mechanism by the actuator 7, there is no limitation on the number of rotations of the optical disc 4 at the time of eccentricity correction, so that the eccentricity of the data track 3 can be corrected quickly and the data transfer speed can be improved. .

FIG. 6 is a perspective view showing the configuration of an optical disk device according to a fourth embodiment of the present invention. In the figure,
The same components as those of the optical disc device of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the eccentricity correction position 1
2, a roller supporting member, one end of which is pivotally supported and the other end of which is rotatable, is installed at a position in contact with the side surface of the optical disk 4, and moves back and forth so as to press the side surface of the roller supporting member. An actuator 9 driven by an electromagnetic force having a central axis is provided. The input terminal of the actuator 9 is connected to the output terminal of the drive circuit 16c, and is driven by a drive signal output from the drive circuit 16 in accordance with the correction amount of the position of the optical disc 4, and presses the roller 8 against the side surface of the optical disc 4. The roller support member on which the roller 8 is mounted and the actuator 9 are provided at three positions on the peripheral surface of the optical disk 4 so that the center position of the optical disk 4 can be moved to an arbitrary position.

In this embodiment, when correcting the eccentricity of the data track 3 of the optical disk 4, a drive signal corresponding to the amount of eccentricity of the data track 3 is output from the drive circuit 16c to the actuator 9, and the drive signal is supplied to the actuator 9 at three locations. Actuator 9 expands and contracts the respective central axes according to the respective correction amounts and presses the side surfaces of the three roller support members, and presses the side surfaces of the optical disc 4 by the three rollers 8 to thereby obtain data. The rotation center of the track 3 and the rotation center of the spindle motor 5 are matched. When the eccentricity correction is completed,
The roller 8 retreats from the peripheral surface position of the optical disc 4.

As described above, in the present embodiment, the eccentricity correction can be completed by one operation by using the eccentricity correction mechanism using the roller 8, so that the correction time can be shortened and the data can be reduced. Transfer speed can be improved.

[0046]

According to the optical disk apparatus and the optical disk eccentricity correction method of the present invention, the optical disk is moved to the eccentricity correction position dedicated to the eccentricity correction and the eccentricity correction is performed, so that the clamping force at the eccentricity correction position is reduced. With a simple configuration, eccentricity correction can be performed while rotating the optical disc at high speed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of an optical disk device according to a first embodiment of the present invention.

FIG. 2 is a side view of a main part of the optical disk device of FIG.

FIG. 3 is a flowchart showing an operation of the optical disk device of FIG. 1;

FIG. 4 is a flowchart showing an operation of the optical disc device according to the second embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of an optical disc device according to a third embodiment of the present invention.

FIG. 6 is a perspective view illustrating a main part of an optical disc device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 Impact hammer for eccentricity correction 3 Data track 4 Optical disc 5 Spindle motor 6 Clamper 7 Piezoelectric element 8 Roller 9 Actuator 10 Spindle structure 11 Data reading position 12 Eccentricity correction position 13 Clamper support 14 Axis 15 Slip ring 16a Eccentricity detection circuit 16b Judgment circuit 16c Drive circuit 17 Power supply

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiaki Yamauchi 502 Kandachicho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratories, Hitachi, Ltd. (72) Seiichi Kato 502-Kindachi-cho, Tsuchiura-shi, Ibaraki Hitachi, Ltd. Inside the Machinery Research Laboratory (72) Inventor Shigeki Mori 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref.

Claims (17)

[Claims] An optical disk having a data track for recording data, a driving device for driving the optical disk,
Data reading means for reading data recorded on the data track, eccentricity detecting means for detecting an eccentricity when the data track is rotated, and eccentricity correcting means for correcting the eccentricity detected by the eccentricity detecting means An optical disk device comprising: an optical disk; a first position at which data recorded on the data track is read by the data reading means; and a second position at which the eccentricity is corrected by the eccentricity correcting means. An optical disc device comprising a position moving means for integrally moving the driving device. 2. The optical disk device according to claim 1, further comprising a comparing unit that compares the eccentric amount detected by the eccentric amount detecting unit with a predetermined eccentric amount. 3. An inquiring means for inquiring a user whether or not to perform eccentricity correction by said eccentricity correcting means when said eccentricity detecting means detects said eccentricity. An optical disk device as described in the above. 4. The optical disc according to claim 1, wherein the eccentricity correction means is an impact force applying means for applying an impact force to the optical disc to correct the eccentricity. apparatus. 5. The optical disk device according to claim 4, wherein the impact force applying means applies the impact force using an electromagnetic force. 6. The eccentricity correcting means is a pressing force applying means for applying a pressing force to the driving device or the optical disk to correct the eccentricity. An optical disk device according to the item. 7. The optical disk device according to claim 6, wherein said pressing force applying means applies said pressing force using a piezoelectric element. 8. The optical disk device according to claim 6, wherein said pressing force applying means applies said pressing force using an electromagnetic force. 9. An optical disk having a data track for recording data on a drive device for driving the optical disk, and an eccentricity of the data track on the drive device when the data track is rotated. Moving the drive unit integrally with the driving device to an eccentric amount correction position for correcting the eccentric amount; detecting the eccentric amount at the eccentric amount correcting position; and detecting the eccentric amount detected in the eccentric amount detecting step. Eccentricity correction of an optical disk, comprising: a step of correcting at an amount correction position; and a step of integrally moving the drive device and the optical disk to a data reading position for reading the data after the correcting step. Method. 10. The eccentricity correction method for an optical disk according to claim 1, further comprising, after the step of detecting the amount of eccentricity, a step of comparing the amount of eccentricity detected in the step with a predetermined amount of eccentricity. . 11. The eccentricity correction method for an optical disk according to claim 9, further comprising a step of inquiring a user whether or not to perform the correction step before performing the step of correcting the eccentricity amount. 12. After performing a step of inquiring the user as to whether or not to perform the correction step, if the user instructs not to perform the correction step in the step, the data recorded on the data track is recorded. 12. The eccentricity correction method for an optical disk according to claim 11, further comprising a step of reading the data by driving the optical disk at a maximum rotational speed at which the data can be read. 13. The eccentricity correction method for an optical disk according to claim 9, wherein in the step of correcting the eccentricity amount, an eccentricity amount is corrected by applying an impact force to the optical disk. . 14. The eccentricity correction method for an optical disk according to claim 13, wherein in the step of correcting the amount of eccentricity, the impact force is applied using an electromagnetic force. 15. The eccentric amount is corrected by applying a pressing force to the drive device or the optical disk in the step of correcting the eccentric amount.
3. The eccentricity correction method for an optical disc according to any one of 2. 16. The eccentricity correcting method for an optical disk according to claim 15, wherein in the step of correcting the amount of eccentricity, the pressing force is applied using a piezoelectric element. 17. The eccentricity correction method for an optical disk according to claim 15, wherein in the step of correcting the amount of eccentricity, the pressing force is applied using an electromagnetic force.