JP2001216667A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical disk and an optical disk device capable of correcting an eccentric quantity of a track in the clamped state to a minimum in a short time and the optical disk and the optical disk device capable of setting the intensity of light to an optimal value. SOLUTION: Vector information showing the direction and distance of a deviation between the central point of a central hole 21 of the disk 20 and the central point of the track is recorded in the optical disk. Vector information is read out by the optical disk device 1 and it is utilized for the purpose of correcting the eccentricity of the track. Or it is utilized as bias information preliminarily shifting the optical head in the case of tracking. Also, optimal light intensity information used in recording, reproducing and erasing is recorded in the optical disk 20. Optical intensity information thereof is read by the optical disk device to be utilized for recording, reproducing and erasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk and an optical disk apparatus, and more particularly to an optical disk and an optical disk apparatus that perform at least one of recording, reproducing, and erasing of information using light.

[0002]

2. Description of the Related Art In general, an optical disk represented by a CD is manufactured by forming pits containing track information by press working or the like, and thereafter working a center hole for clamping.
For this reason, the center of the track and the center of the center hole do not completely coincide with each other, which causes eccentricity when clamping the optical disc.

[0003] If the eccentricity is large, the amount of movement of the track due to the rotation increases, and the tracking performance decreases.
That is, it is difficult to increase the number of rotations of the optical disc or to reduce the track pitch.

In order to solve such a problem, the first method is to re-clamp the track until the amount of track blurring falls below a specified value (Japanese Patent Laid-Open No. 6-176478), and the second method is as follows. A method of detecting the amount and direction of the track blurring in a state where the disk is clamped, releasing the clamp once, moving the disk in parallel so as to adjust the blurring direction, and re-clamping the disk (Japanese Patent Laid-Open No. 5-314642). As a third method, the amount and direction of the track in the state where the disk is clamped is detected, the clamp is released once, the spindle motor is rotated by a fixed angle and the clamp is re-clamped, and the amount and direction of the shake are detected again. (Japanese Patent Application Laid-Open No. 6-4989) has been proposed in which the operation of repeating the operation is repeated to adjust the disc in a direction in which the amount of blur is minimized.

[0005]

The causes of eccentricity when the disk is clamped include eccentricity of the rotating shaft of the spindle motor, eccentricity of the center hole of the disk, and eccentricity of the clamping mechanism. The eccentricity in the clamp state is represented by the sum of these vectors. However, the conventional method is basically a trial and error method,
There is a problem that the correction is incomplete or the correction takes time.

For example, in the first method, only the eccentricity due to the clamp is considered, and the amount of track blurring is not always less than a specified value. It requires many times of clamping and takes time. This will be described with reference to FIG. In FIG. 4, the mark x is an ideal center point of the track, M is the eccentric vector of the spindle motor, D is the eccentric vector of the disk,
C is an eccentricity vector due to the clamp. S is the sum of the vectors M, D, and C. In the adjustment by the re-clamp, the vector C is dispersed in a circle A which is a region where the eccentric vector locus drawn by the clamp adjustment is drawn. It takes time to find a point where the amount of blur is minimum from this area, and that point does not match the best point when the three vectors M, D, and C are independently adjusted.

In the second method, the eccentricity is merely improved by adjusting the clamp. Specifically, in FIG. 5, the vector S, which is the sum of three vectors, is merely adjusted to the maximum vector C1 that is antiparallel in the circle A. Even if this operation is repeated, the vector C is adjusted to the vector Cn. It is only done. That is, the adjustment point here does not coincide with the best point when the three vectors M, D, and C are independently adjusted.

A third method is to find the direction in which the amount of eccentricity is minimized while changing the relative direction between the eccentricity vector D of the disk and the eccentricity vector M of the motor.
It takes time to correct. Referring to FIG. 6, the third
In the method of the above, while changing the direction of the vector D, the vector S
In order to find the direction of the vector D in which is minimized, the condition is adjusted to be the minimum in the orbicular zone in FIG. Not only does this take time, but it does not always coincide with the best point Sn because the vectors D and C are not distinguished.

[0009] On the other hand, the intensity of light to be used for recording, reproducing, and erasing information may change due to a change over time in an optical disk. In such a case, even if irradiation of light for recording or erasing information is performed, a change in the recording state cannot be induced, and as a result, there is a possibility that information cannot be recorded or erased. there were. In addition, when light irradiation is performed to reproduce information, there is a possibility that a change in the recording state is induced, and consequently, the recorded information is erased.

Accordingly, a first object of the present invention is to provide an optical disk and an optical disk apparatus capable of correcting the eccentricity of a track in a clamped state to a minimum in a short time.

A second object of the present invention is to provide an optical disk and an optical disk apparatus that can set the intensity of light, which may differ from disk to disk, to an optimum value.

Further, a third object of the present invention is to provide the above-described second embodiment.
Another object of the present invention is to provide an optical disk device capable of correcting the light intensity to an optimum value in response to the aging of the disk.

[0013]

In order to achieve the above objects, the optical disk according to the first aspect of the present invention has a vector information indicating a direction and a distance between a center point of a center hole of a disk and a center point of a track. It is characterized by being recorded.

According to a second aspect of the present invention, there is provided an optical disk apparatus comprising: a removable optical disk in which vector information indicating a direction and a distance between a center point of a center hole of a disk and a center point of a track is recorded; Control means for using the recorded vector information for track eccentricity correction.

According to the optical disk and the optical disk apparatus, the eccentricity of the track of the clamped optical disk can be reduced by using the vector information indicating the direction and the distance between the center hole of the disk and the center point of the track. The calculation can be performed based on time, and the eccentric amount can be corrected to the minimum. Therefore, high-speed tracking is possible, and recording, reproduction, and erasing with high accuracy can be realized.

In particular, in the optical disk device according to the second aspect of the invention, more accurate tracking can be realized by using vector information recorded on the optical disk as bias information for shifting the optical head during tracking.

In this optical disk apparatus, there is further provided a clamp means for automatically fixing and releasing the optical disk to the rotating member of the spindle motor, and the control means releases the clamp on the optical disk once and sets the relative position between the optical disk and the rotating member. Preferably, the position is corrected based on the vector information. More preferably, the control means holds eccentric vector information of the rotating member and eccentric vector information by a clamp.

The control means is a rotating member (spindle motor)
By obtaining the eccentricity vector information of the optical disc and the eccentricity vector information by the clamp, and obtaining the eccentricity vector information of the optical disc, the eccentricity state of the track of the optical disc further clamped is measured based on the information. Thus, the eccentricity vector of the optical disk and the eccentricity vector by the clamp can be separated, and the eccentricity of the track can be corrected more accurately and in a shorter time.

In this optical disk device, if the eccentricity vector information of the optical disk is measured and the measured information is added to the optical disk, the track eccentricity can be corrected more efficiently. .

An optical disc according to a third aspect of the present invention is characterized in that optimal light intensity information used for at least one of recording, reproduction, and erasing is recorded.

According to a fourth aspect of the present invention, there is provided an optical disk apparatus comprising: a removable optical disk on which optimum light intensity information used for at least one of recording, reproduction, and erasing is recorded; and a light intensity information recorded on the optical disk. And control means for reading and using at least one of recording, reproduction, and erasure.

By using the optical disk and the optical disk device, it is possible to set the recording light, the reproducing light, and the erasing light to optimal intensity by using the light intensity information recorded on the optical disk, thereby improving the reliability. I do.

In particular, in the optical disk apparatus according to the fourth invention, if at least one of the optimum light intensity of recording, reproduction and erasure on the optical disk is measured, and the measured information is additionally recorded on the optical disk, Reliability is improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an optical disk and an optical disk device according to the present invention will be described with reference to the accompanying drawings.

(First Embodiment) FIG. 1 schematically shows an optical disk apparatus (recording / reproducing apparatus) according to a first embodiment of the present invention. The optical disk 20 used here is a well-known one having a recording layer capable of recording, reproducing and erasing with a light beam of a predetermined wavelength, and has a center hole 21 for clamping, and the information recording is performed. In the area (control track), vector information indicating the direction and distance of the shift between the center point of the center hole 21 and the center point of the track is recorded in advance.

The optical disk device 1 includes a spindle motor 2 having a rotary table 3, a clamp mechanism 5, and an optical head 6, and further includes a controller 11, an actuator drive circuit 12, and an eccentricity measurement circuit 13. .

The clamp mechanism 5 is a well-known mechanism for automatically fixing and releasing the optical disk 20 in which the center hole 21 is engaged with the turntable 3. The optical head 6 records, reproduces, and erases information on the optical disc 20 by irradiating a light beam of a predetermined wavelength, and is movable in a tracking direction by an actuator (not shown).

The controller 11 controls the rotation of the spindle motor 2 and also controls the actuator drive circuit 12. The optical head 6 is operated while rotating the optical disk 20 clamped on the turntable 3, and the eccentricity measurement circuit 13 detects the eccentricity of the track (eccentricity direction and eccentricity amount) based on a signal from the drive circuit 12. Is measured. This measured value is transferred to the controller 11, and the eccentricity correction described below is performed.

Here, the eccentricity of the track of the optical disk 20 in the optical disk apparatus 1 and the correction thereof will be described by exemplifying numerical values.

It is assumed that an optical disk 20 having an eccentricity of 20 μm between the center point of the center hole 21 and the center point of the track is clamped on the rotary table 3 of the motor 2 having an eccentricity of 5 μm. As shown in FIG. 2, the eccentricity vector of the motor 2 is M,
The eccentricity vector of the optical disk 20 is D, and the angle between these vectors M and D is θ. The amount of eccentricity caused by the clamp mechanism 5 is 10 μm, and the eccentricity vector is indicated by C.

Under the above conditions, the eccentricity vector D is recorded in advance in the information recording area of the optical disc 20,
The controller 11 reads and acquires this information. The controller 11 stores information on the eccentricity vector M of the motor 2 and rotates the motor 2 so that the sum of the vectors D and M is minimized, that is, the angle between the vectors D and M is 180 °. Adjust the angle.

More specifically, the clamp of the optical disk 20 by the clamp mechanism 5 is released, and the motor 2 (table 3) is released.
Is rotated clockwise by (180 ° -θ) and re-clamped. Note that the motor 2 and the optical disk 2
0 may be relatively rotated.

Next, it is preferable that the eccentricity vector C is adjusted by the clamp mechanism 5 in addition to the above operation.
Specifically, the clamp is released, and the optical disk 20 is moved in the direction opposite to the vector of the sum of the vectors D and M adjusted as described above.
Press to translate and reclamp.

By the above two operations, the eccentricity correction of the track is completed in a short time and with high accuracy. That is, eccentricity of 5 μm can be suppressed by one re-clamping process. The re-clamping process will be performed several times.
The clamp may be re-clamped several times without moving the 0 in parallel.

In the first embodiment, the eccentricity vector D recorded on the optical disc 20 may be used as bias information for shifting the optical head 6 in accordance with the vector D during tracking. Tracking can be realized.

Specifically, the amount of deviation from the ideal position is calculated from the track of the track calculated from the eccentricity vector D in advance, and a table of the amount of deviation according to the rotation angle of the motor is created. At the time of tracking, a control signal is generated by multiplying the table by an amount corresponding to the radius of the track, and by adding this signal as a bias signal for track control, tracking can be performed in accordance with the deviation amount.

Further, the eccentricity vector information of the optical disc 20 may be measured, and the measured information may be added to the information recording area of the optical disc 20, so that the track eccentricity correction can be performed more efficiently.

More specifically, tracking is performed while slowly rotating the optical disk 20, and signals for the actuator for one round are stored. The eccentric direction (phase) and eccentric amount (amplitude) are obtained from the AC component of the signal, and the information is recorded on the optical disc 20. By using the eccentricity information added at the time of reproduction, eccentricity correction can be performed.

(Second Embodiment) Next, an optical disc device according to a second embodiment of the present invention will be described. This optical disk device is designed to set the light intensity of a laser used for recording, reproduction and erasing to an optimum value. Therefore, on the optical disc, information of the optimum light intensity for recording, reproduction and erasing is recorded in the information recording area (control track).

The optical intensity of the laser used for recording, reproducing and erasing differs depending on the type of the recording layer and the like of the optical disk. Therefore, information of the optimum light intensity is recorded on the disk itself, and the optical disk device reads and uses the information.

For example, it is assumed that the standard light intensity of the device is 1 mW during reproduction, 10 mW during recording, and 15 mW during erasing, and each is variable. The optimum light intensity of the optical disk used is 1 mW during reproduction, 7 mW during recording, and 10 mW during erasing, and these information are recorded in advance in the information recording area of the optical disk. In this case, the optical disk device reads the information from the optical disk, and records,
The light intensity is set to an optimum value during each of the reproduction and erasing processes.

As described above, in the second embodiment,
Recording, reproduction, and erasing can be processed with the optimum light intensity, and there is no possibility of erroneous operation such as erroneous erasing during recording.

On the other hand, in an optical disk, the light intensity used for recording, reproduction, and erasure may change due to deterioration of the recording layer. Therefore, in the optical disk device according to the second embodiment, the changed optimum light intensity is measured, the measured data is written in the information recording area of the optical disk, and the measured data is read out and used during the recording, reproducing, and erasing processes. I made it.

For example, it is assumed that the standard light intensity of the apparatus is 1 mW during reproduction, 10 mW during recording, and 15 mW during erasing, and each is variable. When the optical disk to be used requires a light intensity of 17 mW for erasing due to a state change, the light intensity at the time of erasing is changed from 15 mW to 17 mW. As a result, erasure omission does not occur.

Assuming such a change in the optimum light intensity, when the optical disk is used, the optimum light intensity is measured and added to the information recording area of the optical disk. FIG. 3 shows an example of such a control procedure.

First, when it is confirmed that the optical disk is mounted (step S1), the light intensity used for recording, reproducing and erasing is read from the information recording area which is a part of the track of the optical disk (step S2). The light intensity is set to the value read in step S2 (step S3).

Next, the information of the recording area to be tested is read and stored as needed (step S4), and all the data in the test area is erased by the erasing light having the intensity set in step S3 (step S5). . Then, all the data in the test area is read to check whether the data has been erased (step S6). If it is not erased, the intensity of the erasing light is increased (step S7), and steps S5 and S6 are executed. If erased, all data in the test area is erased as necessary (step S
8).

Next, predetermined data is recorded in the test area with the recording light having the intensity set in step S3 (step S9). Then, it is checked whether all data in the test area is read out and recorded (step S1).
0). If not recorded, the intensity of the recording light is increased (step S11), and steps S8, 9,
Execute Step 10. If it has been recorded, the light intensity used for recording, reproduction, and erasure set in the information recording area is written (step S12). Further, information is written back to the test area as needed (step S13).

In the above control, the optimum light intensity that changes with time is measured, and the light intensity is set to the optimum value and is additionally recorded on the optical disk. Recording, reproduction, and erasing can always be performed under optimal conditions.

(Other Embodiments) The optical disk and the optical disk apparatus according to the present invention are not limited to the above-described embodiments, but can be variously modified within the scope of the invention.

In particular, in the second embodiment, the information recorded on the optical disk has been described as the light intensity.
The present invention is not limited to this, and information such as a current value for driving a laser diode as a light source and a modulation pulse width may be used.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an optical disk device according to a first embodiment of the present invention.

FIG. 2 is a chart for explaining eccentricity correction in the optical disk device.

FIG. 3 is a flowchart illustrating a light intensity correction procedure in an optical disc device according to a second embodiment of the present invention.

FIG. 4 is a chart for explaining a first example of conventional eccentricity correction.

FIG. 5 is a chart for explaining a second example of conventional eccentricity correction.

FIG. 6 is a chart for explaining a third example of conventional eccentricity correction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus 2 ... Spindle motor 3 ... Rotary table 5 ... Clamp mechanism 6 ... Optical head 11 ... Controller 12 ... Actuator drive circuit 13 ... Eccentricity measurement circuit 20 ... Optical disk 21 ... Center hole

Claims (9)

[Claims] 1. An optical disk which is detachable from an optical disk device and in which at least one of recording, reproducing and erasing of information is performed using light, a deviation between a center point of a center hole of the disk and a center point of a track. An optical disc characterized by recording vector information indicating a direction and a distance of the optical disc. 2. An optical disk apparatus which performs at least one of recording, reproducing, and erasing of information by using light, wherein vector information indicating a direction and a distance of a shift between a center point of a center hole of the disk and a center point of a track is provided. An optical disk device comprising: a removable optical disk on which is recorded; and control means for using vector information recorded on the optical disk for eccentricity correction of tracks. 3. The optical disc apparatus according to claim 2, wherein the control means uses vector information recorded on the optical disc as bias information for shifting an optical head during tracking. 4. A clamping means for automatically fixing and releasing the optical disk to and from a rotating member of a spindle motor, wherein the control means temporarily releases the clamp on the optical disk and sets the relative position between the optical disk and the rotating member to the vector information. The optical disk device according to claim 2, wherein the correction is performed based on: 5. The optical disk device according to claim 4, wherein said control means holds eccentric vector information of said rotating member and eccentric vector information by clamping. 6. The optical disk device according to claim 2, wherein the eccentricity vector information of the optical disk is measured, and the measured information is additionally written on the optical disk. 7. An optimum optical intensity used for at least one of recording, reproduction, and erasing in an optical disk that is detachable from an optical disk device and performs at least one of recording, reproducing, and erasing of information using light. An optical disc characterized by having information recorded thereon. 8. An optical disk device that performs at least one of recording, reproducing, and erasing of information by using light, wherein a removable optical recording device stores optimal light intensity information used for at least one of recording, reproducing, and erasing. An optical disc device comprising: an optical disc; and control means for reading light intensity information recorded on the optical disc and using the information for at least one of recording, reproducing, and erasing. 9. The optical disk apparatus according to claim 8, wherein an optimum light intensity of at least one of recording, reproducing, and erasing on the optical disk is measured, and the measured information is additionally recorded on the optical disk.