JP2000173067A - Disc reproducing method and disc apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disc reproducing method and a disc apparatus for shortening the shifting time by reducing the number of shifts until the target position. SOLUTION: A linear velocity track pitch compensating means 17 is provided to calculate an error of the number of tracks until the target data address from the moving position after the carriage is moved until the target position with an access command means 16 based on the number moving tracks calculated with the track count calculating means and moving direction and compensate for the line velocity and track pitch value when such track count error exceeds the predetermined threshold value of track count error. Accordingly, the count of tracks which move to the target position can be calculated accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear velocity (CL)
V) relating to a disk device for reproducing data.

[0002]

2. Description of the Related Art Optical discs are being actively developed for application to various fields such as audio CDs and for high performance. An information track on which an information signal is recorded is formed on an optical disc. In order to accurately detect the information signal, it is necessary to control the positioning of the optical pickup with respect to the rotating optical disc with high accuracy. In addition, when moving largely between tracks, it is necessary to move the optical pickup to the target track at high speed and stably.

FIG. 9 is a configuration diagram of an optical pickup and a feed motor of a conventional optical disk device. In FIG.
1 is an objective lens, 2 is an objective lens actuator, 3 is a feed motor, 4 is a carriage, 5 is a gear section, 6 is a screw shaft, 7 is an encoder, and 8 is a wire. The configuration of an optical pickup and a feed motor in a conventional optical disk access control device will be described below with reference to FIG.

The configuration shown in FIG. 9 is a configuration generally called a lead screw shaft system, in which the rotation of a feed motor 3 is transmitted to a screw shaft 6 via a gear section 5 having an appropriate reduction ratio, and the rack is further moved. The carriage 4 is driven in the horizontal direction (in the radial direction of the disk) via the control unit. On the other hand, the feed motor 3 is provided with an encoder 7, and when the feed motor 3 rotates, generates an encoder signal according to the rotation angle position. The objective lens actuator 2 is supported on the carriage 4 by a wire 8, and is configured to be movable in a focus direction and a tracking direction.

FIG. 10 shows a block diagram of an access control unit and a controller of a conventional optical disk device. In FIG. 10, 9 is a binarization circuit, 10 is a counter circuit, 11 is a motor drive circuit, 12 is an access control unit, and 13 is a controller. The controller 13 includes a track number calculating means 14 for calculating a track number in which the specified data exists from the linear velocity and the track pitch defined by the standard for each optical disc, and a track necessary for moving to the specified track number. It comprises a track number calculating means 15 for calculating the number and the moving direction, and an access command means 16 for sending a command to the access control unit. Hereinafter, a conventional access control method will be described with reference to FIG.

In the access operation, first, the track number calculating means 14 of the controller 13 calculates a current track number and a target track number. From the calculated track number, the number of tracks to be moved and the moving direction are obtained by the track number calculating means 15. The calculated number of tracks (converted to the number of encoder pulses when an encoder is used) is initialized in the counter circuit 10. Subsequently, a tracking servo control unit (not shown) is operated by the access command unit 16.
, A drive command signal corresponding to the calculated moving direction is input to the motor drive circuit 11, and the feed motor rotates and the carriage starts to move. The binarization circuit 9 converts the tracking error signal (encoder signal in the case of using an encoder) generated during the movement of the feed motor into a pulse and outputs the pulse, and the counter circuit 10 performs a counter operation. The counter operation is performed by, for example, converting the initially set value each time a pulse is input, thereby completing the movement of the target number of tracks (the number of encoder pulses when using an encoder). Is set to 0. The motor drive circuit 11 performs acceleration / deceleration control according to the moving distance of the feed motor, and when the counter value becomes 0, the access command unit cancels the drive command signal to the motor drive circuit 11 and sends the signal to the tracking servo control unit. To send a servo-on command to end the operation.

[0007]

However, since the linear velocity and the track pitch are slightly different for each optical disk in practice, the track number is always calculated at a constant linear velocity and the track pitch defined by the standard. Causes an error in the calculated track number. As a result of the occurrence of the error, the number of times of movement to reach the target position increases, and there is a problem that the movement time is lengthened.

An object of the present invention is to provide a disk reproducing method and a disk apparatus which can reduce the number of times of movement and shorten the time required for movement in an access operation.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, an optical disk access control device according to the present invention performs a single move from a current data address to a target data address, and then moves the position of the move to the target data address. A means is provided for calculating the track number error up to the data address, and correcting the linear velocity and the track pitch values when the error exceeds a predetermined track number error threshold. According to the present invention, the number of tracks up to the target address can be accurately obtained, and an access control device for an optical disk having a short moving time can be obtained.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claims 1 and 2 of the present invention provides an optical pickup for optically reading information recorded on a track of an optical disk, and access control means for moving the optical pickup to a target track. A disk playback method and a disk device having control means for controlling access control means and controlling the entire operation of the disk device, wherein the control means calculates a track number where data exists, Means for calculating the number of tracks for moving the pickup, the number of tracks for calculating the moving direction; access command means for outputting a drive command value for moving the optical pickup; linear velocity and track from the error in the number of tracks after the movement of the optical pickup; Linear velocity track pitch correction means for correcting pitch and pitch. A disc reproducing method and a disk device. This has the effect of shortening the time required for moving the optical pickup.

The third aspect of the present invention is the second aspect.
In the disk device described above, the number of times the optical pickup is moved is determined in advance, and when the optical pickup is moved by the access command means, the linear velocity track pitch correction means corrects the linear velocity and the track pitch if the number of times is exceeded. It has a correction amount changing means for changing the amount. This has the effect of shortening the time required for moving the optical pickup.

The invention described in claim 4 of the present invention is claim 2.
In the disk device described above, a plurality of thresholds are prepared in advance according to the distance to move the optical pickup, and the track number error is determined based on the threshold adopted according to the moving distance of the optical pickup moved by the access command means. It is characterized by having a correction threshold value changing means for calculating. This has the effect of shortening the time required for moving the optical pickup.

Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a configuration diagram of an optical disk device according to Embodiment 1 of the present invention. In FIG. 1, FIG.
The access control unit 12 and the controller 1
3 in which the contents of the controller 13 are different. The controller 13 includes a track number calculating unit 14 for calculating a track number at which data to be read exists, a track number calculating unit 15 for calculating the number of tracks for moving the carriage of the optical pickup, and a moving direction. Access command means 16 for outputting a carriage drive command value for moving
Linear velocity track pitch correcting means 1 for correcting the linear velocity and the track pitch from the error in the number of tracks of the carriage movement
7 and a control operation unit 1 which receives an A / D-converted RF signal output from the optical pickup and controls the entire apparatus.
30 and a preset threshold value of the track number error / correction amount and a standard value of the linear velocity / track pitch are stored as an initial setting value, and the initial setting value is used as a newly set correction area after correction, and Memory 1 for rewriting and storing speed
31.

An access operation of the optical disk device according to the first embodiment based on the above configuration will be described with reference to FIG. FIG. 2 is a flowchart of the linear velocity track pitch correction means of FIG. As a premise of this access operation, first, a threshold value of a track number error and a correction amount are set, a linear velocity and a track pitch are initialized to standard values, and these are stored in a memory 13.
1 is stored. In such a state, access to the address of the disk stored in the optical disk is started. First, the track number calculation means 14 calculates a track number from the center position of the optical disk where each data exists, from the current data address and the target data address (S201). The value obtained by subtracting the current track number from the target track number is the number of tracks to be moved. When the value is positive, the movement is in the outer circumferential direction, and when the value is negative, the movement is in the inner circumferential direction (S202).

When the number of moving tracks and the moving direction are determined,
The optical pickup is moved to the track number where the target data exists by the access command means 16 (S203). When using the number of pulses of the encoder at the time of movement, it is necessary to convert the number of tracks calculated based on the track pitch into the number of encoder pulses. The access command means 16 initializes the calculated number of tracks or the number of encoder pulses in the counter circuit 10. Subsequently, a servo-off command is sent to a tracking servo control unit (not shown), and at the same time, a feed motor drive command is input to the motor drive circuit 11 to move the feed motor. A tracking error signal (encoder pulse signal when an encoder is used) generated while the feed motor is moving is pulsed by a binarization circuit 9,
The counting operation is performed by the counter circuit 10.

In the count operation, the counter value is set to 0 when the movement of the target number of tracks is completed by subtracting each time a pulse is input from the initially set value as in the conventional case. When the movement of the carriage is completed by the access command means 16, the track number is calculated by the track number calculating means 14 from the data address of the moved position (S204). The remaining track number and the next moving direction are determined from the calculated track number and the track number difference between the previously calculated target data address (S205), and the remaining track number is compared with the previously set track number error threshold value (S205). S206). As a result of the comparison, if the number of remaining tracks exceeds the threshold value of the track number error, the linear velocity / track pitch correction means 17 corrects the linear velocity and the track pitch initialized to the specified values. Since it is difficult for the linear velocity track pitch correcting means 17 to simultaneously correct the two variables of the linear velocity and the track pitch, one of them is fixed,
Correct only the other.

When the track pitch is fixed, the linear velocity includes an error of the track pitch. In the correction, first, it is checked whether or not the direction of movement by the access command means 16 is the inner circumferential direction (S207). If it is the inner circumferential direction, the direction of the next movement is checked (S208). When moving in the inner circumferential direction, the linear velocity (or the track pitch) is incremented by the correction amount set first (S210).
When moving in the outer circumferential direction, the linear velocity (or track pitch) is decremented by the correction amount set first (S211). Even when the direction in which the access instruction means 16 first moves is the outer peripheral direction, the direction to move next is checked (S209).

When moving in the inner circumferential direction, the linear velocity (or track pitch) is decremented by the correction amount set first (S211). When moving in the outer peripheral direction, the linear velocity (or the track pitch) is incremented by the correction amount set first (S210).
By repeating this operation each time the movement occurs, the value converges to an optimum value. The threshold value, the correction amount, the linear velocity, and the track pitch of the error of the number of tracks thus converged are stored in the memory 1.
The data is stored in the memory 31 and is used for the next operation of reading the optical disk.

(Embodiment 2) FIG. 3 is a configuration diagram of an optical disk device according to Embodiment 2 of the present invention. In FIG. 3, the configuration of the optical disk device according to the second embodiment of the present invention is similar to the configuration of the optical disk device shown in the first embodiment, except that the controller 13 uses a track number calculating unit 14, a track number calculating unit 15, an access commanding unit 16, Linear velocity track pitch correction means 17, control operation unit 130, memory 131
And a correction amount changing means 18 is added to the configuration of the controller 13.

With respect to the optical disk access control device configured as described above, the correction amount changing means 18 in this embodiment will be described with reference to the flowchart of FIG. FIG. 4 is a flowchart of the correction amount changing means of FIG. First, the correction amount changing unit 18 initially sets the amount to be corrected by the linear velocity track pitch correcting unit 17 and the number of times of change (S301).

Next, when one movement is completed by the access command means 16 (S302), the number of times of change movement is incremented (S303). It is confirmed whether the number of times of change movement exceeds a certain number (S304). If it exceeds, the amount to be corrected by the linear velocity track pitch correcting means 17 is reduced and the correction amount is updated (S305).

(Embodiment 3) FIG. 5 is a configuration diagram of an optical disk device according to Embodiment 3 of the present invention. In FIG. 5, the configuration of the optical disk device according to the third embodiment of the present invention is the same as the configuration of the optical disk device shown in the first embodiment, except that the controller 13 uses the track number calculating unit 14, the track number calculating unit 15, the access commanding unit 16, The controller 13 includes a linear velocity track pitch correction unit 17, a correction amount changing unit 18, a control calculation unit 130, and a memory 131.

With respect to the optical disk access control device configured as described above, the correction threshold value changing means 19 in this embodiment will be described with reference to the flowchart of FIG. FIG. 6 is a flowchart of the correction threshold value changing means of FIG. First, the correction threshold value changing unit 19 prepares a plurality of track number error threshold values in accordance with the number of tracks to be moved (the number of encoders when using an encoder) (S40).
1). Next, when one movement is completed by the access command means 16 (S402), different thresholds of track number errors corresponding to the number of tracks actually moved (or the number of encoder pulses when an encoder is used) are obtained (S402). S40
3). Thereafter, the acquired threshold value of the track number error is updated as the actual threshold value of the track number error (S404).

(Embodiment 4) FIG. 7 is a configuration diagram of an optical disk apparatus according to Embodiment 4 of the present invention. In FIG. 7, the configuration of the optical disk access control device according to the fourth embodiment of the present invention is similar to the configuration of the optical disk access control device shown in the first embodiment, except that the controller 13 has a track number calculating unit 14 and a track number calculating unit 15. , An access command unit 16, a linear velocity track pitch correcting unit 17, a correction amount changing unit 18, a correction threshold changing unit 19, a control operation unit 130, and a memory 131, and an encoder pulse number determining unit 20 is added to the configuration of the controller 13. It is composed.

With respect to the optical disk access control device configured as described above, the encoder pulse number judging means 20 in the present embodiment will be described with reference to the flowchart of FIG. FIG. 8 is a flowchart of the encoder pulse number determination means of FIG. First, the encoder pulse number determination means 20 sets a threshold value of an encoder pulse number error (S501). Next, when one movement is completed by the access command means 16 (S502), an error between the number of encoder pulses actually moved and the number of encoder pulses to be moved is calculated (S503). Thereafter, the calculated encoder pulse number error is compared with a preset threshold value (S504). If the error in the number of encoder pulses is within a preset threshold value, a determination flag indicating that the linear velocity track pitch correction means may be called is turned on (S50).
5). If the error of the encoder pulse number exceeds the set threshold value, the determination flag indicating that the linear velocity track pitch correction should not be called is turned off (S506).

[0026]

As described above, according to the present invention, the linear velocity and track pitch different for each optical disk can be corrected to optimal values, and the moving distance required for moving can be accurately calculated. It is possible to move with a small number of movements, and it is possible to reduce the time required for movement.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of a linear velocity track pitch correction unit of FIG. 1;

FIG. 3 is a configuration diagram of an optical disc device according to a second embodiment of the present invention.

FIG. 4 is a flowchart of a correction amount changing unit of FIG. 2;

FIG. 5 is a configuration diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 6 is a flowchart of a correction threshold value changing unit of FIG. 5;

FIG. 7 is a configuration diagram of an optical disc device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart of the encoder pulse number determination means of FIG. 7;

FIG. 9 is a configuration diagram of an optical pickup and a feed motor of a conventional optical disk device.

FIG. 10 is a block diagram of an access control unit and a controller of a conventional optical disc device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Objective lens actuator 3 Feed motor 4 Carriage 5 Gear part 6 Screw shaft 7 Encoder 8 Wire 9 Binarization circuit 10 Counter circuit 11 Motor drive circuit 12 Access control unit 13 Controller 14 Track number calculation means 15 Track number calculation means DESCRIPTION OF SYMBOLS 16 Access command means 17 Linear velocity track pitch correction means 18 Correction amount change means 19 Correction threshold value change means 20 Encoder pulse number determination means 130 Control operation unit 131 Memory

Claims (4)

[Claims] 1. A disc reproducing method for reproducing information from an optical disk by moving an optical pickup to a target position, comprising: a track number calculating step of calculating a track number in which information exists; and a track number for moving the optical pickup. A track number calculating step of calculating a moving direction, an access command step of moving the optical pickup, and a linear velocity track pitch correcting step of correcting a linear velocity and a track pitch from a track number error after the movement of the optical pickup. A disk reproducing method comprising: 2. An optical pickup for optically reading information recorded on a track of an optical disk, an access control means for moving the optical pickup to a target track, and an operation of the entire disk device while controlling the access control means. A disk number having a track number calculating means for calculating a track number where data exists, and a track number calculating means for calculating a number of tracks for moving the optical pickup and a moving direction. Means, an access command means for outputting a drive command value for moving the optical pickup, and a linear velocity track pitch correction means for correcting a linear velocity and a track pitch from an error in the number of tracks after movement of the optical pickup. A disk device characterized by having: 3. The number of times the optical pickup is moved is determined in advance. When the number of times the optical pickup is moved by the access command means exceeds the number, the linear velocity track pitch correction means sets the linear velocity and the track pitch. 3. The disk device according to claim 2, further comprising a correction amount changing unit that changes an amount to be corrected. 4. A method according to claim 1, wherein a plurality of thresholds are prepared in advance in accordance with a moving distance of the optical pickup, and a track number error is determined based on the threshold adopted in accordance with a moving distance of the optical pickup moved by the access command means. 3. The disk device according to claim 2, further comprising a correction threshold value changing unit that calculates the threshold value.