JPH11296871A - Disk drive device - Google Patents

Abstract

(57) Abstract: The present invention provides a simple process for quickly passing a scratched area when a scratch is generated on an optical disk that repeatedly causes a track jump in a direction to return an optical head. It is an object of the present invention to provide a disk drive device capable of preventing the same portion on an optical disk from being traced over and over again and not proceeding further. When a track jump in a direction in which the head is returned is detected, an offset for moving the head in the direction opposite to the track jump direction is added to a tracking control signal for controlling the head in the tracking direction. In the state where the head 11 is controlled in the tracking direction by the added tracking control signal, the amount of the offset is varied according to the detection result of whether or not the address data of the predetermined section is continuously read from the disk. I have to.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a disk drive device that records and reproduces data on and from an optical disk such as an mpact disk, and in particular, a device in which the same part is repeatedly traced due to a scratch on the disk and cannot be advanced further. .

[0002]

2. Description of the Related Art As is well known, in recent years, not only audio data but also moving image data can be compressed and recorded on an optical disc having a diameter of 12 cm, for example, the same as an audio CD. As this kind of optical disk, for example, a CD-ROM (Read Only Memory) is widely used in a wide range of fields from information use to karaoke use.

On the other hand, at present, moving image data corresponding to a movie for about two hours and audio data in eight different languages are recorded at high density by compression encoding on an optical disk having the same diameter as a CD. In addition, there has been developed an optical disc called a DVD capable of recording sub-picture data representing captions and the like in 32 different languages.

There is a disk drive device for recording and reproducing data on and from the above optical disk. This disk drive device writes and reads data on the optical disk by rotating the optical disk at a predetermined rotation speed and tracing tracks formed on the optical disk using an optical head. .

When the optical head is tracing the track of the optical disk, the optical head may undesirably cause a track jump due to a scratch on the optical disk or a defective track shape. In this case, the direction and distance of the track jump depend on the nature of the flaw and the state of the tracking servo applied to the objective lens of the optical head, but generally the same result is repeated at the same location.

For this reason, if a scratch is made on the optical disk that causes a track jump in a direction to return the optical head to the track already traced, the optical head is returned by a certain distance each time it reaches the position of the scratch. As a result, there is a possibility that the same portion on the optical disk is repeatedly traced many times, and there is a problem that the operation cannot proceed.

In order to cope with this problem, conventionally, when a track jump is repeatedly generated in the direction in which the optical head is returned, the address on the optical disk where the track jump has been generated is learned, and a fixed amount from the address is learned. Means have been considered in which the optical head is forcibly track-jumped to the previous address, thereby jumping over the damaged area.

However, in such conventional means, if the position reached by the optical head by making the track jump to a predetermined address ahead of the learned address by a certain amount is still within the damaged area, further address learning is performed. And the optical head is caused to track jump to a further position, so that the processing becomes complicated, and it takes a long time to completely pass through the damaged area.

[0009]

As described above, in the conventional disk drive device, if a scratch on the optical disk that causes a track jump in the direction in which the optical head is returned occurs on the optical disk, the same portion on the optical disk is repeated many times. There is a problem that it is traced and cannot proceed. Further, the means for learning the address at which the repeated track jump has occurred and causing the track jump to the next address is still unsuitable for practical use.

Therefore, the present invention has been made in view of the above circumstances, and when a scratch having the property of repeatedly causing a track jump in the direction in which the optical head is returned on the optical disk occurs, the scratch can be easily and quickly processed. It is an object of the present invention to provide an extremely good disk drive device that can pass through an area and can prevent the same part on an optical disk from being traced over and over again so that it cannot proceed further.

[0011]

According to the present invention, there is provided a disk drive apparatus comprising: first detection means for detecting occurrence of a track jump in a head returning direction based on address data read from a disk; Offset adding means for adding an offset for moving the head in the direction opposite to the track jump direction to a tracking control signal for controlling the head in the tracking direction based on the detection result of the first detecting means; Second detection means for detecting whether or not address data of a predetermined section is continuously read from the disk while the head is controlled in the tracking direction by the tracking control signal to which the offset has been added, Offset adding means based on the detection result of the second detecting means The amount of the addition is an offset is obtained as comprising an offset amount varying means for variably.

According to the above configuration, by determining the continuity of the address data, the occurrence of a track jump in the direction of returning the head is detected, and the offset for controlling the head in the opposite direction is determined by the tracking control signal. Is added to The offset varies while monitoring the continuity of the address data.

[0013] Therefore, compared to the conventional method in which the address on the optical disc where the track jump has occurred is learned and the optical head is forcibly jumped to the next address by a fixed amount, the operation is simpler. In the process, a track jump that does not go too far according to the size of the flaw is performed, and the track can be quickly passed through the flaw area, which is very suitable for practical use.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an optical disk reproducing apparatus will be described below in detail with reference to the drawings. In FIG. 1, reference numeral 11 denotes an optical pickup for reading recorded data from an optical disk (not shown). The data read by the optical pickup 11 is supplied to a tracking error signal generation circuit 12.

This tracking error signal generation circuit 12
Generates and outputs a tracking error signal corresponding to a tracking error of a built-in objective lens (not shown) based on data supplied from the optical pickup 11. Then, the tracking error signal output from the tracking error signal generation circuit 12 is supplied to one input terminal of the addition circuit 13.

An offset output from a tracking offset adjusting circuit 18 described later is supplied to the other input terminal of the adding circuit 13. Then, the offset output from the tracking offset adjustment circuit 18 is added to the tracking error signal output from the tracking error signal generation circuit 12 by the addition circuit 13.

The tracking error signal to which the offset is given by the adding circuit 13 is supplied to a tracking servo filter 14 and converted into a signal for driving a tracking actuator driving unit (not shown) for driving the objective lens in the tracking direction. Is done. As a result, the objective lens is controlled in the tracking direction.

In a state where the optical disk is being reproduced stably without causing an undesired track jump, the offset output from the tracking offset adjusting circuit 18 is "0", and the tracking error signal generating circuit 12 The control of the tracking direction of the objective lens, that is, the tracking servo, is performed only by the tracking error signal output from the controller.

On the other hand, data read by the optical pickup 11 is supplied to an address data demodulation circuit 15. The address data demodulation circuit 15 demodulates address data included in data supplied from the optical pickup 11. The address data output from the address data demodulation circuit 15 is supplied to a track jump detection circuit 16.

The track jump detecting circuit 16 detects whether or not a track jump in the direction of returning the objective lens of the optical pickup 11 has occurred based on the address data supplied from the address data demodulating circuit 15. I have. The detection operation of the track jump detection circuit 16 is performed by determining the continuity of the input address data.

That is, when a CD is taken as an example of an optical disk, since data is recorded on the CD so as to have a constant linear velocity, the data amount changes depending on the radial position. More specifically, data is recorded on the CD in units of blocks having addresses continuously assigned from the inner circumference to the outer circumference, and data is recorded at the innermost circumference position.
Blocks, and 24 blocks exist at the outermost peripheral position.

Therefore, by determining the continuity of the 24 blocks, it is possible to determine whether or not a track jump has occurred during one round of the track. If it is determined that a track jump has occurred, and if the address difference between the blocks before and after the track jump is 8 or less, it can be determined that the track jump is one track.

In this case, since the address of the block is reduced before and after the track jump, it can be determined that the track jump is in the direction of returning the objective lens of the optical pickup 11. Then, the track jump detection circuit 16 uses these three determinations to detect whether or not a one-track jump in the direction of returning the objective lens of the optical pickup 11 has occurred.

When the track jump detecting circuit 16 detects that one track jump in the direction of returning the objective lens of the optical pickup 11 has occurred, the correction value calculating circuit 17 responds to the track jump distance. The correction value is calculated, and the tracking offset adjustment circuit 18 generates an offset corresponding to the correction value and outputs the offset to the addition circuit 13.

That is, the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 indicate that the track jump detection circuit 16 has caused a one-track jump in the direction of returning the objective lens of the optical pickup 11 in the reproduction state of the optical disk. When detected, an offset is generated for moving the objective lens in the advancing direction. This offset is initially given a predetermined reference amount.

Then, reproduction is performed with the offset of the reference amount given, and the continuity of 24 blocks is determined. As a result, when it is determined that there is no continuity in the 24 blocks, the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 generate an offset twice as large as the reference amount and add the offset to the tracking error signal. .

Thereafter, reproduction is performed with an offset of twice this reference amount, and the continuity of 24 blocks is determined. As a result, when it is determined that there is no continuity among the 24 blocks, the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 generate an offset three times the reference amount and add the offset to the tracking error signal. .

As described above, the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 increase the offset to be added to the tracking error signal in units of the reference amount until continuity is obtained in the 24 blocks. Then, when continuity occurs in the 24 blocks,
While monitoring the continuity of the 24 blocks, the offset is reduced by the reference amount.

FIG. 2 is a flowchart summarizing the above operation. First, when started (step S1), the track jump detection circuit 16 determines in step S2 whether a one-track jump in the direction of returning the objective lens of the optical pickup 11 has occurred, and has not occurred. Is determined (NO), the process is terminated (step S11).

If it is determined in step S2 that a one-track jump in the direction of returning the objective lens of the optical pickup 11 has occurred (YES), the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 execute step S3. Then, an offset of the reference amount 1 is generated. This offset is added to the tracking error signal in step S4.

Then, in step S5, the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 set the offset in an offset register (not shown), and in step S6, write the tracking error signal to which the offset has been added. Jump detection circuit 16
Determines in step S7 whether 24 blocks have continuity.

If it is determined that 24 blocks cannot be obtained continuously (NO), the correction value calculation circuit 17
In step S8, the tracking offset adjusting circuit 18 increments the reference amount of the offset by one, and returns to the process of step S4. If it is determined in step S7 that 24 blocks are continuous (YES), the correction value calculation circuit 17 and the tracking offset adjustment circuit 18
In step S9, it is determined whether or not the reference amount of the offset is 0, that is, whether or not the offset is “0”.

If it is determined that the offset is not "0" (NO), the correction value calculation circuit 17 and the tracking offset adjustment circuit 18 decrement the reference amount of the offset by one in step S10, and perform the processing in step S4. Is returned to. If it is determined that the offset is “0” (NO), the process is terminated (step S11).

In the above embodiment, by determining the continuity of the blocks, the occurrence of a one-track jump in the direction of returning the objective lens of the optical pickup 11 is detected, and the offset for controlling the direction of moving the objective lens is set. It is added to the tracking error signal. The offset is increased or decreased in units of a predetermined reference amount while monitoring the continuity of the block for one round.

For this reason, it is simpler than the conventional method in which the address on the optical disk where the track jump has occurred is learned and the optical head is forcibly jumped to the next address by a fixed amount. In the process, a track jump that does not go too far according to the size of the flaw is performed, and the track can be quickly passed through the flaw area, which is very suitable for practical use. It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the scope of the invention.

[0036]

As described in detail above, according to the present invention,
In the event that a scratch occurs that repeatedly jumps the track in the direction in which the optical head is returned on the optical disc, simple processing can be performed quickly through the scratched area, and the same portion on the optical disc can be traced repeatedly. It is possible to provide an extremely good disk drive device which can prevent the disk drive from being advanced.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating an operation of the embodiment.

[Explanation of symbols]

 11: Optical pickup, 12: Tracking error signal generation circuit, 13: Addition circuit, 14: Tracking servo filter, 15: Address data demodulation circuit, 16: Track jump detection circuit, 17: Correction value detection circuit, 18: Tracking Offset adjustment circuit.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 21/10 G11B 21/10 G

Claims (6)

[Claims] A first detecting means for detecting that a track jump has occurred in a direction to return a head based on address data read from a disk; and Offset adding means for adding an offset for moving the head in a direction opposite to the track jump direction to a tracking control signal for controlling the head in the tracking direction; and a tracking control signal to which an offset has been added by the offset adding means. A second detecting means for detecting whether or not address data of a predetermined section is continuously read from the disk in a state where the head is controlled in a tracking direction; and a detection of the second detecting means. Based on the result, the amount of the offset to be added by the offset adding means can be determined. A disk drive device comprising: a variable offset amount changing means. 2. An apparatus according to claim 1, wherein said offset amount changing means changes an offset to be added to said tracking control signal step by step in a predetermined reference amount unit.
The disk drive device according to the above. 3. The method according to claim 2, wherein the offset amount changing means is configured to control the second
3. The method according to claim 2, wherein the offset to be added to the tracking control signal is increased stepwise by a predetermined reference amount until address data of a predetermined section is continuously read from the disk by the detecting means. Disk drive device. 4. The method according to claim 1, wherein the offset amount changing means is configured to control the second
When the address data of the predetermined section is continuously read from the disk by the detecting means, the data is added to the tracking control signal until the address data of the predetermined section is not continuously read from the disk by the second detecting means. 4. The disk drive device according to claim 3, wherein the offset to be performed is reduced stepwise in units of a predetermined reference amount. 5. The first detecting means detects a track jump corresponding to one track, and the second detecting means determines continuity of address data corresponding to one round of the disk. 5. The disk drive device according to claim 1, wherein: 6. The disk drive device according to claim 1, wherein said first detecting means detects that address data of the same portion on said disk is repeatedly read.