JP2002117552A - Optical disk device and optical disk device control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that errors are produced in the number of accesses by shifting of an objective lens during the stoppage of a tracking follow-up operation in access processing accompanied by the movement of an optical pickup. SOLUTION: A correction section 52 receives the position quantity of the objective lens 12 in the optical pickup 11 and traverse moving quantity that a target position moving quantity calculating section 102 calculates from the present position of the light spot on the optical disk 1 and the target position. The correction section 52 calculates the quantity at which the objective lens 12 shifts during the stoppage of the tracking follow-up operation from the position quantity and subjects the traverse moving quantity to correction. As a result, there are no more errors in the number of the accesses produced by shifting of the objective lens during the stoppage of the tracking follow-up operation.

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 recording or reproducing information on or from an optical disk having concentric or spiral information tracks.
In particular, the present invention relates to an optical disk device having a so-called access function of traversing the information track in a radial direction and searching for necessary information.

[0002]

2. Description of the Related Art In recent years, CDs (Compact Disks) and MDs (Mi
2. Description of the Related Art An optical disk device that records or reproduces information on an optical disk having concentric or spiral information tracks, such as a ni disk) and a DVD (Digital Video Disk), has been developed. One of the important functions of these optical disk devices is the so-called high-speed random access, in which the information tracks are arranged in the same plane, and the light spot is moved in the radial direction to search for desired information. ing. When performing high-speed random access, the number of information tracks that light spots traverse,
If the number of so-called accesses is about several tens, it is possible to access only by moving the objective lens in the optical pickup. However, for example, when the number is several hundred or more, it is necessary to move the light spot beyond the range in which the objective lens can move in the optical pickup, and it is necessary to perform a traverse movement for moving the optical pickup itself.

A conventional optical disk device will be described below with reference to the drawings. FIG. 10 shows a block diagram of a conventional optical disk device. In FIG. 10, reference numeral 1 denotes an optical disc having concentric or spiral information tracks;
Is an optical pickup, and this optical pickup 11
Is an objective lens 12 which is a condensing means, and the objective lens 12
Tracking actuator 13 for moving
And a photodetector 14 for converting light reflected from the optical disc 1 into an electric signal. Reference numeral 21 denotes a tracking error detection circuit which is a means for generating a tracking error signal indicating a positional shift between a light spot irradiated on the optical disc 1 and an information track in the optical disc 1, and 22 denotes a phase compensation for the tracking error signal. A tracking loop filter for performing a calculation process such as a tracking control signal; 23, a switch for turning on / off a tracking following operation; and 24, a tracking for driving the tracking actuator 13 by the tracking control signal generated by the tracking loop filter 22. It is an actuator drive circuit. Reference numeral 31 denotes a current position detection circuit for detecting the position of a light spot on the optical disk 1. Reference numeral 41 denotes a traverse movement circuit that moves the optical pickup 11 in the radial direction of the optical disc 1, and reference numeral 42 denotes a traverse movement control unit that controls the traverse movement circuit 41 and moves the optical pickup 11 by a desired distance. Reference numeral 100 denotes a system controller, which includes an access processing unit 101 and a target position movement amount calculation unit 102.
The access processing unit 101 is an access control unit that controls the timing of starting and stopping the tracking following operation and the timing of starting the traverse movement. The target position movement amount calculation unit 102 calculates a traverse movement amount to a desired target position using the position of the light spot on the optical disk 1 obtained by the current position detection circuit 31.

FIG. 11 shows a flowchart of an access process involving a traverse movement in a conventional optical disk device. When normal access processing is started, switch 23
Is in the ON state, and the tracking error detection circuit 21
The tracking actuator drive circuit 24 drives the tracking actuator 13 to perform the tracking following operation so that the tracking error signal generated by the above becomes zero.

At the time of access processing, first, step S21 is performed. In step S21, the target position movement amount calculation unit 102 calculates a traverse movement amount corresponding to a distance from the current position to a desired target position based on the current position obtained by the current position detection circuit 31.

[0006] The photodetector 14 converts the reflected light of the light beam applied to the optical disc 1 into an electric signal. The current position detection circuit 31 detects the address information corresponding to the position of the light spot on the optical disc 1 as the current position from the electric signal. As shown in FIG. 12, the target position movement amount calculation unit 102 includes a target position instruction unit 201 and a traverse movement amount instruction unit 202, for example. The target position indicating unit 201
The traverse movement amount instructing unit 202 is instructed to set an address on the optical disk 1 having necessary information as a target position. The traverse movement amount instruction unit 202 receives the current position and the target position obtained by the current position detection circuit 31, and converts the traverse movement distance into, for example, the number of tracks.

Next, in step S22, the access control unit 101
Turns off the switch 23 and stops the tracking following operation. As a result, the tracking actuator 13 stops the driving operation for the objective lens 12, and only the force from the elastic support such as a spring supporting the objective lens 12 is applied. For this reason, the objective lens 12 shifts to the vicinity of the center in the optical pickup 11, which is the mechanical midpoint of the elastic support, and stops.

In step S23, the access control unit 101
The traverse movement control unit 42 is instructed to start traverse movement. The traverse movement control unit 42 controls the traverse movement circuit 41 so that the optical pickup 11 moves by the movement amount calculated by the target position movement amount calculation unit 102 in step S21.

After the traverse movement is completed, in step S24, the access control unit 101 turns on the switch 23, restarts the tracking following operation, and ends the access processing.

[0010]

Normally, when a tracking following operation is performed, the tracking actuator 13 drives the objective lens 12 so that the light spot follows the information track on the optical disk 1, and the optical disk 1 Each time the light spot rotates, the light spot moves outward by one track. Accordingly, the position of the objective lens 12 in the optical pickup 11 also moves from the inner circumference to the outer circumference in accordance with the rotation of the optical disc 1. Therefore, when the access processing is started, the position of the objective lens 12 is often shifted from the center in the optical pickup 11. In such a case, when the tracking following operation is stopped, the objective lens 12 is moved by the force from an elastic support such as a spring supporting the objective lens 12 into the optical pickup 11 which is the mechanical midpoint of the elastic support. Is shifted to the center.
After the traverse movement of the access process is completed,
Is located at the center of the optical pickup 11,
The tracking following operation starts. At this time, the movement amount of the traverse is calculated from the position on the optical disc 1 of the light spot detected at the time of the tracking following operation and the target position. For this reason, the movement amount of the light spot becomes an error with respect to a desired movement amount by an amount shifted by the objective lens 12 when the tracking following operation is stopped.

An object of the present invention is to propose an optical disk device that improves the accuracy in access processing by eliminating the above-mentioned error, and thereby shortens the time required for access.

[0012]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object. In an optical disk apparatus for recording and reproducing data on and from an optical disk, an objective lens for focusing a light source on a light spot is provided. An optical pickup including a lens moving unit that moves the optical pickup in a radial direction; a lens position detecting unit that detects a radial position of the objective lens in the optical pickup; and a traverse moving unit that moves the optical pickup in the radial direction When,
Current position detecting means for detecting the position of the light spot on the optical disc; target position indicating means for indicating a target position of the light spot on the optical disc; target position indicated by the target position indicating means; Traverse movement control means for calculating the amount of movement of the optical pickup from the current position detected by the position detection means and the position of the objective lens detected by the lens position detection means, and moving the optical pickup using the traverse movement means An optical disc device characterized by having:

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Hereinafter, an optical disc device according to a first embodiment will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the optical disk apparatus of the present invention. In FIG. 1, reference numeral 1 denotes an optical disk having concentric or spiral information tracks, 11 denotes an optical pickup, and the optical pickup 11 moves an objective lens 12 as a condensing means and moves the objective lens 12 in a radial direction. And a photodetector 14 for converting light reflected from the optical disc 1 into an electric signal. 21 is a tracking error detection circuit which is a means for generating a tracking error signal indicating a positional shift between the light beam irradiated on the optical disc 1 and the information track in the optical disc 1, and 22 is a phase compensation circuit for the tracking error signal. Performing arithmetic processing such as
A tracking loop filter that generates a tracking control signal, 23 is a switch that turns on and off a tracking follow-up operation, and 24 is a tracking actuator drive circuit that drives the tracking actuator 13 by the tracking control signal generated by the tracking loop filter 22. Reference numeral 31 denotes a current position detection circuit for detecting the position of a light spot on the optical disk 1. Reference numeral 41 denotes a traverse movement circuit that moves the optical pickup 11 in the radial direction of the optical disc 1, and reference numeral 42 denotes a traverse movement control unit that controls the traverse movement circuit 41 and moves the optical pickup 11 by a desired distance. The traverse movement circuit 41 includes a circuit configured by a lead screw, a gear, and a motor, and a circuit configured by combining a flat gear. In this embodiment, a traverse mechanism using a stepping motor that can easily control the movement amount by the number of pulses is used. 100 is a system controller, and the access processing unit 101
And a target position movement amount calculation unit 102. Access processing unit 1
01 is an access control means for controlling the timing of starting and stopping the tracking following operation and the timing of starting the traverse movement. Target position movement amount calculation unit 102
Calculates the traverse movement amount to the desired target position using the position of the light spot on the optical disk 1 obtained by the current position detection circuit 31. Reference numeral 51 denotes a lens position detection circuit that detects the position of the objective lens 12 in the optical pickup 11. Reference numeral 52 denotes a correction unit that corrects the traverse movement amount received from the target position movement amount calculation unit 102 using the position amount of the objective lens 12 in the optical pickup 11 obtained from the lens position detection circuit 51. The correction unit 52 sends the corrected traverse movement amount to the traverse movement control unit 42.

Next, the operation will be described. FIG. 2 shows a flowchart in the case of performing access processing to a certain target position for searching for desired information.

First, in step S11, based on the current position obtained by the current position detecting means 31, the target position movement amount calculating section 102 calculates the traverse movement amount corresponding to the distance from the current position to the desired target position. Is calculated.

The photodetector 14 converts the reflected light of the light beam applied to the optical disk 1 into an electric signal. The current position detection circuit 31 detects the address information corresponding to the position of the light spot on the optical disc 1 as the current position from the electric signal. As shown in FIG. 12, the target position movement amount calculation unit 102 includes a target position instruction unit 201 and a traverse movement amount instruction unit 202, for example. The target position indicating unit 201
The traverse movement amount instructing unit 202 is instructed to set an address on the optical disk 1 having necessary information as a target position. The traverse movement amount instruction unit 202 receives the current position obtained by the current position detection circuit 31 and the target position obtained from the target position instruction unit 201, and converts the traverse movement distance into, for example, the number of tracks. For example, this traverse movement amount is set to a.

Next, in step 12, the objective lens in the optical pickup 11 obtained by the lens position detection circuit 51
From the position 12, the amount by which the objective lens 12 is shifted by the force of the elastic support when the tracking following operation is stopped is calculated, and the traverse movement amount is corrected.

The lens position detection circuit 51 receives the reflected light of the light beam from the photodetector 14 to the optical pickup 11.
The lens position signal corresponding to the position of the objective lens 12 is detected. The detected lens position amount is set to LN1. Assuming that the lens position amount at the mechanical midpoint of the elastic support is 0, the amount b by which the objective lens 12 shifts when the tracking following operation is stopped is expressed by b = LN1 × SEN [track book]. Is done. Here, the lens position amount LN1 is a digital signal value, and corresponds to, for example, a distance from the mechanical midpoint of the elastic support as a starting point. The amount of lens position at the mechanical midpoint of the elastic support is set to, for example, 0, the case on the inner peripheral side in the radial direction is represented by a positive value, for example, and the case where the objective lens 12 is located on the outer peripheral side is represented by Is expressed as the value of. The constant SEN is an amount corresponding to, for example, the number of tracks per unit amount of the lens position amount. The constant SEN can take a desired value by configuring the lens position detecting means 51 with a lens position signal generation circuit 511 and a gain amplifier 512 as shown in FIG. 3, for example. For example, the tracking actuator 13 is driven by using the tracking actuator drive circuit 24 to shift the objective lens 12 by a distance corresponding to, for example, n tracks. When the lens is located at that position, the lens position signal generation circuit 511 detects the amount of lens position from the photodetector 14 and adjusts the value using the gain amplifier 512 to a desired value. For example, when this value is LNN, the constant SEN
Can be expressed by SEN = n / LNN [tracks / unit lens position]. By storing and storing this constant SEN in a RAM or the like, it is possible to convert the amount of lens position into, for example, the number of tracks.

The correction section 52 receives the lens movement amount LN1 detected by the lens position detection means 51, and calculates the amount b by which the objective lens 12 shifts when the tracking following operation is stopped, for example, by the above method. Further, the correction unit 52 receives the traverse movement amount a calculated by the target position movement amount calculation unit 102 in step S11, and calculates the corrected traverse movement amount from the traverse movement amount a and the shift amount b. The correction of the traverse movement amount is performed by the traverse movement amount a before correction and the shift amount
Is performed by adding or subtracting. When the lens position amount is represented by a positive value on the inner circumference side, for example, when the access movement direction is the inner circumference direction, the correction is addition, that is, (a +
Perform the calculation in b). When the access direction is the outer peripheral direction, subtraction, that is, calculation of (ab) is performed as correction.

Next, in step S13, the access control unit 101
Turns off the switch 23 and stops the tracking following operation. As a result, the tracking actuator 13 stops the driving operation for the objective lens 12, and only the force from the elastic support such as a spring supporting the objective lens 12 is applied. For this reason, the objective lens 12 shifts to the vicinity of the center in the optical pickup 11, which is the mechanical midpoint of the elastic support, and stops.

In step S14, the access control unit 101
The traverse movement control unit 42 is instructed to start traverse movement. The traverse movement control unit 42 controls the traverse movement circuit 41 such that the optical pickup 11 moves by the movement amount calculated by the correction unit 52 in step S12.

Finally, in step S15, the switch 23 is turned on by the access control means 100, the tracking following operation is resumed, and the access processing is completed.

As described above, in this embodiment,
The moving amount by which the objective lens 12 shifts when the tracking following operation is stopped in the access processing can be corrected with respect to the traverse moving amount, thereby improving access accuracy.

(Embodiment 2) Next, an optical disk device according to a second embodiment will be described in detail with reference to the drawings.

Normally, when the tracking following operation is not performed, only the force from an elastic support such as a spring supporting the objective lens is applied to the objective lens. At this time, when a force due to an external impact or a radial gravity due to the attitude of the optical pickup is applied to the objective lens, the objective lens vibrates, and the optical pickup, which is a mechanical center point of the elastic support, is moved. Does not necessarily stop near the center. In the optical disc device according to the first embodiment,
If the objective lens is deviated from the center when the tracking operation is stopped for the above-described reason, an error occurs when the traverse movement amount is corrected.

In the second embodiment, lens position control is performed to control the lens driving means so that the objective lens coincides with a predetermined target position in the optical pickup. Has been resolved.

FIG. 4 is a block diagram showing a configuration of an optical disk device according to Embodiment 2 of the present invention. In FIG. 4, 1 to 52 and 100 to 102 are the same as those in FIG. 1 described above. Reference numeral 53 denotes a lens position loop filter that performs arithmetic processing such as phase compensation on the position amount of the objective lens 12 in the optical pickup 11 detected by the lens position detection circuit 51, and generates a lens position control signal. Reference numeral 54 denotes a switch for turning on / off lens position control for moving the objective lens 12 to a desired radial position in the optical pickup 11.

When the switch 54 is turned on, a lens position control signal generated by the lens position loop filter 53 is input to the tracking actuator drive circuit 24, and the objective lens 12 is moved to a desired radial position in the optical pickup 11. Then, the tracking actuator 13 is driven so as to be fixed at that position. Thereby, the optical pickup 11
It is possible to prevent the objective lens 12 from inadvertently vibrating in the tracking direction due to gravity applied to the objective lens 12 generated according to the posture of the object, or vibration applied from the outside,
Access processing can be performed more stably.

Next, the operation will be described. FIG. 5 shows a flowchart in the case of performing access processing to a certain target position for searching for desired information. In FIG. 5, steps S11, S13 to S15 are the same as those in FIG. 2 described above.

First, in step S11, based on the current position obtained by the current position detection means 31, the target position movement amount calculating section 102 calculates the traverse movement amount corresponding to the distance from the current position to the desired target position. Calculate a.

Next, in step 161, a correction amount is obtained from the position of the objective lens 12 in the optical pickup 11 obtained by the lens position detection circuit 51 and the position of the objective lens 12 during the lens position control operation, and Correct the amount of movement. This correction amount is determined by stopping the tracking operation in step S13 and immediately before performing the tracking operation in step S15.
Within the range.

The lens position detecting circuit 51 receives the reflected light of the light beam from the photodetector 14 to the optical pickup 11.
The lens position signal corresponding to the position of the objective lens 12 is detected. The detected lens position amount is set to LN1. Further, the lens position amount when performing the lens position control while the traverse is moving in step S14 is LN2.
The correction unit 52 includes, for example, a correction calculation unit 521 as shown in FIG.
And a lens position control unit 522 for lens position control.
The correction calculation unit 521 includes a lens movement amount LN1 detected by the lens position detection unit 51 and a lens position control time lens position instruction unit 522.
Receives the lens position amount LN2 indicated by, and calculates a correction amount. This correction amount is defined as b1. The correction amount b1 is expressed as b1 = (LN1−LN2) × SEN [track book] using the above-described constant SEN when expressed in track books, for example. Here, the lens position amount LN2 is a digital signal value similarly to the above-described lens position amount LN1, and corresponds to, for example, a distance from the mechanical midpoint of the elastic support as a starting point.

The correction calculating unit 521 calculates the traverse movement amount a calculated by the target position movement amount calculating unit 102 in step S11.
Then, the corrected traverse movement amount is calculated from the traverse movement amount a and the correction amount b1. The correction of the traverse movement amount is performed by adding or subtracting the traverse movement amount a before correction and the correction amount b1 according to the access direction, that is, the moving direction of the traverse. When the lens position amount is represented by a positive value on the inner circumference side, for example, when the access movement direction is the inner circumference direction, addition, that is, calculation of (a + b1) is performed as the correction. When the access direction is the outer peripheral direction, subtraction, that is, calculation of (a-b1) is performed as correction.

Next, in step S13, the access control unit 101
Turns off the switch 23 and stops the tracking following operation.

Next, in step S162, the access control unit 10
1 turns on the switch 54 to start lens position control. The access control unit 101 turns on the switch 54 almost simultaneously with turning off the switch 23 in step S13. Thus, the lens position control is started almost simultaneously with stopping the tracking following operation. The tracking actuator driving circuit 24 receives the lens position control signal generated by the lens position loop filter 53, and fixes the objective lens 12 at a desired position.
Drive 13

In step S14, the access control unit 101
The traverse movement control unit 42 is instructed to start traverse movement. The traverse movement control unit 42 controls the traverse movement circuit 41 such that the optical pickup 11 moves by the movement amount calculated by the correction unit 52 in step S161.

Finally, in step S15, the switch 23 is turned on by the access control means 100, the tracking follow-up operation is resumed, and the access processing ends.

As described above, in the present embodiment,
By performing lens position control, even when external impact or radial gravity due to the attitude of the optical pickup 11 is applied to the objective lens 12, the amount of movement of the objective lens 12 shifted during the access processing is Correction can be made for the traverse movement amount, thereby improving access accuracy.

(Embodiment 3) Next, an optical disk device according to a third embodiment will be described in detail with reference to the drawings.

In the second embodiment, a lens position loop filter or the like needs to be newly provided in the first embodiment in order to control the lens position.

The optical disk device according to the third embodiment described here has the same configuration as that of the first embodiment, and is not affected by an external impact or a traverse movement amount caused by radial gravity due to the attitude of the optical pickup. All of the correction errors.

FIG. 7 is a block diagram showing a configuration of an optical disk device according to Embodiment 3 of the present invention. 7, 1 to 52 and 100 to 102 are the same as those in FIG. 1 described above. However, the target position movement amount calculation unit 10
The traverse movement amount calculated by 2 is sent to the traverse movement control unit 42. The correction unit 52 is a correction unit that performs correction using the information from the traverse movement control unit 42 and the amount of position of the objective lens 12 in the optical pickup 11 obtained from the lens position detection circuit 51.

Next, the operation will be described.

When the tracking following operation is not performed,
If the above-described lens position control is not performed, the objective lens 12 receives only a force from an elastic support such as a spring supporting the objective lens 12. At this time, depending on the attitude of the optical pickup 11, gravity may be applied to the objective lens 12 in the radial direction. In such a case, the objective lens 12 does not always stop near the center in the optical pickup 11, which is the mechanical midpoint of the elastic support, but stops at a position shifted from the center.

When the attitude of the optical pickup 11 changes during the access process, the radial gravity applied to the objective lens 12 changes, and the position of the objective lens 12 in the optical pickup 11 is not constant. In such a case, the most appropriate correction amount for the traverse movement amount is the difference between the lens position immediately before the stop of the tracking operation and the lens position immediately before restarting the tracking operation at the end of the access. However, the detection of the lens position immediately before restarting the tracking following operation is performed after the traverse movement is performed, and the traverse movement amount cannot be corrected. Therefore, here, the lens position detected immediately before the end of the traverse movement capable of correcting the traverse movement amount is used when calculating the correction amount.

FIG. 8 shows a flowchart in the case of performing access processing to a certain target position for searching for desired information. 8, steps S11, S13 to S15 are the same as those in FIG. 2 described above.

First, in step S11, based on the current position obtained by the current position detecting means 31, the target position movement amount calculating section 102 calculates the traverse movement amount corresponding to the distance from the current position to the desired target position. Calculate a.

Next, in step S171, the lens position detection circuit 51 receives the reflected light of the light beam from the photodetector 14
, A lens position signal corresponding to the position of the objective lens 12 in the optical pickup 11 is detected. The detected lens position amount is set to LN1. The correction unit 52 includes, for example, a correction amount calculation unit 521, a lens position amount storage unit 523, and a remaining movement amount monitoring unit 524 as shown in FIG. The correction unit 52 stores the lens position amount LN1 in a lens position storage unit 523 such as a RAM, for example, and temporarily stores the same.

In step 13, the access control unit 101 turns off the switch 23 to stop the tracking following operation.

In step S14, the access control unit 101
The traverse movement control unit 42 is instructed to start traverse movement. The traverse movement control unit 42 receives the notification and controls the traverse movement circuit 41 so that the optical pickup 11 moves by the traverse movement amount a calculated by the target position movement amount calculation unit 102 in step S11. The traverse movement control unit 42 controls the optical pickup by a desired movement amount.
In order to control the traverse movement circuit 41 so as to move the optical pickup 11, the remaining amount of movement of the optical pickup 11 is monitored, for example. The remaining movement amount is initially the same as the traverse movement amount, and decreases as the optical pickup 11 moves. The traverse movement control unit 42 performs a stop process such as a brake when the remaining movement amount becomes, for example, near 0, and controls the traverse movement circuit 41 so that the movement of the optical pickup 11 stops when the remaining movement amount becomes 0.

In step S172, the correction section 52 monitors, for example, the above-mentioned remaining movement amount, and confirms that the remaining movement amount has reached a certain amount.
The correction amount is calculated from the detected lens position amount and the lens position amount LN1 stored in the lens position storage unit 523 in step S171, and the remaining movement amount is corrected.

As described above, the correction unit 52 includes, for example, a correction amount calculation unit 521, a lens position amount storage unit 523, and a remaining movement amount monitoring unit 524 as shown in FIG. When the traverse movement is started in step S14, the remaining movement amount monitoring unit 524
Receives, for example, the above-mentioned remaining movement amount from the traverse movement control unit 42. The remaining movement amount decreases with the movement of the optical pickup 11, and when a certain amount is reached,
The remaining movement amount monitoring unit 524 instructs the correction calculation unit 521 to make a correction. Here, the certain amount is, for example, an amount capable of correcting the traverse movement amount a. The largest correction amount for the traverse movement amount a can be said to be the largest amount that the objective lens 12 can shift in the radial direction in the optical pickup 11. That is, the amount from the innermost circumference to the outermost circumference, or the amount from the outermost circumference to the innermost circumference, at which the objective lens 12 can move within the optical pickup 11, can be said to be the largest amount of correction. That is, if the maximum amount of the correction remains as the remaining amount of the traverse movement, the correction can be performed on the remaining movement amount, thereby making it possible to correct the traverse movement amount a.

The correction calculation unit 521, which has received the instruction to start the correction from the remaining movement amount monitoring unit 524, sets the lens position amount detected by the lens position detection circuit 51 at the time of receiving the instruction (this value is referred to as LN3).
) And the lens position amount LN1 stored in the lens position storage unit 523 to calculate the correction amount b2. The correction amount b2 is expressed as b2 = (LN1−LN3) × SEN [track book] using, for example, the above-described constant SEN when expressed in track books. Here, the lens position amount LN3 is a digital signal value similarly to the above-described lens position amounts LN1 and LN2, and corresponds to, for example, a distance from the mechanical middle point of the elastic support as a starting point.

The correction calculating section 521 receives, for example, the remaining movement amount a 'from the traverse movement control section 42, and calculates the corrected remaining traverse movement amount from the remaining movement amount a' and the correction amount b2. The remaining movement amount is corrected by adding or subtracting the before-correction remaining movement amount a 'and the correction amount b2 according to the access direction, that is, the moving direction of the traverse.
When the lens position amount is represented by a positive value on the inner circumference side, for example,
When the access movement direction is the inner circumferential direction, addition, that is, calculation of (a '+ b2) is performed as a correction. When the access direction is the outer peripheral direction, subtraction, that is, calculation of (a'-b2) is performed as correction.

Finally, after the end of the traverse movement,
In S15, the switch 23 is turned on by the access control means 100, the tracking following operation is restarted, and the access processing is terminated.

As described above, in the present embodiment,
By detecting the lens position twice before the start of the traverse movement and twice immediately before the end of the traverse movement, and correcting the traverse movement amount based on the detected lens position, the configuration is easier than in the second embodiment. Almost the same effects as in the second embodiment can be realized.

In the above description, an example has been described in which the lens position is obtained from the output signal of the photodetector 14. However, the optical pickup 11 of the objective lens 12 is separately provided.
A lens position sensor for detecting a radial position in the inside may be provided.

[0059]

As described above, according to the present invention,
The moving amount by which the objective lens shifts when the tracking following operation is stopped in the access processing can be corrected to the traverse moving amount, thereby improving access accuracy. This also reduces the number of accesses required for the light spot to reach the target position on the optical disk, thereby reducing the time required for access.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing an access processing operation of the optical disc device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing an internal configuration of a lens position detection circuit 41 in the optical disc device according to the embodiment of the present invention.

FIG. 4 is a block diagram illustrating a schematic configuration of an optical disc device according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing an access processing operation of the optical disc device according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing the internal configuration of a correction unit 52 of the optical disc device according to the second embodiment of the present invention.

FIG. 7 is a block diagram showing a schematic configuration of an optical disc device according to a third embodiment of the present invention.

FIG. 8 is a flowchart showing an access processing operation of the optical disc device according to the third embodiment of the present invention.

FIG. 9 is a block diagram showing an internal configuration of a correction unit 52 of the optical disc device according to Embodiment 3 of the present invention.

FIG. 10 is a block diagram showing a schematic configuration of a conventional optical disk device.

And FIG. 11 is a flowchart showing an access processing operation according to the related art.

FIG. 12 is a block diagram showing the internal configuration of a target position movement amount calculation unit 102;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 11 Optical pickup 12 Objective lens 13 Tracking actuator 14 Photodetector 21 Tracking error detection circuit 22 Tracking loop filter 23 Switch 24 Tracking actuator drive circuit 31 Current position detection circuit 41 Traverse movement part 42 Traverse movement control part 51 Lens position detection circuit 52 Correction Unit 53 lens position loop filter 54 switch 100 system controller 101 access control unit 102 target position movement amount calculation unit 511 lens position signal generation circuit 512 gain amplifier 521 correction calculation unit 522 lens position control lens position control unit 523 lens position amount storage unit 524 Remaining moving amount monitoring unit

Continuing on the front page (72) Inventor Katsumi Sumida 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 5D117 AA02 CC06 EE14 EE18 FF14 FF27

Claims (6)

[Claims] An objective lens for focusing a light source on a light spot, and a lens moving means for moving the objective lens in a radial direction of an optical disc, wherein the objective lens is positioned at a predetermined position when the objective lens itself moves. An optical pickup for moving the optical spot to a predetermined position; current position detecting means for detecting light spot position information that is a position of the light spot on the optical disc; and detecting lens position information that is a position of the objective lens with respect to the lens predetermined position. Lens position detection means; target position movement amount calculation means for calculating a traverse provisional movement amount of the optical pickup from the light spot position information and radial position information to be moved next; the traverse provisional movement amount and the lens position information After moving the optical pickup, the objective lens position is moved from the predetermined position of the lens. Optical disc apparatus having the optical spot and a correcting means for calculating a movement amount of said optical pickup so that it can reach the movement target position in the. 2. The lens moving means is controlled based on lens position information detected by the lens position detecting means such that the position of the objective lens coincides with a predetermined radial position in the optical pickup. 2. The optical disk device according to claim 1, further comprising a lens position control unit that operates, and wherein the objective lens position control unit is operated when the optical pickup is moved. 3. An optical pickup comprising: an objective lens for converging a light source to a light spot; a lens moving means for moving the objective lens in a radial direction of the optical disc; and a light spot which is a position of the light spot on the optical disc. Current position detection means for detecting position information; target position movement amount calculation means for calculating a traverse provisional movement amount of the optical pickup from the light spot position information and radial position information to be moved next; A lens position detecting unit that detects lens position information that is a position of a lens; a memory that stores an objective lens position before traverse movement that is a position of the objective lens before stopping a tracking following operation; The traverse movement is set as the traverse provisional movement amount using the traverse movement amount. The objective lens at the objective lens position before the end of the movement from the objective lens position before the end of the movement and the objective lens position before the traverse movement, which is the position of the objective lens before the end of the movement of the traverse provisional movement amount by a predetermined amount. An optical pickup moving means for correcting a traverse movement amount so that a target position is reached. Calculating an amount of traverse movement of the light spot from a current position to a target position; and not moving the objective lens position after the traverse movement from the end of the traverse movement based on the traverse movement amount and the objective lens position. Correcting the traverse movement amount so that the light spot can reach the movement target position. 5. A step of calculating a traverse movement amount of the light spot from a current position to a target position; a step of moving the objective lens position to a predetermined position of the objective lens before the traverse movement; From the amount and the predetermined position of the objective lens,
Correcting the traverse movement amount so that the light spot can reach the movement target position without moving the objective lens position after the traverse movement from the end of the traverse movement. 6. A step of calculating a provisional traverse movement amount of the light spot from a current position to a target position, and a step of storing a position of the objective lens before traverse movement, which is a position of the objective lens before stopping a tracking follow-up operation. Starting a traverse movement using the traverse movement amount as the traverse provisional movement amount; and a movement end objective lens position that is a position of the objective lens a predetermined amount before the movement of the traverse provisional movement amount ends, and the traverse movement. Correcting the traverse movement amount from the front objective lens position so that the objective lens is at the target position at the pre-movement end objective lens position.