JP2836561B2 - Disk unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive, and more particularly to an optical disk drive for performing a repair process when an optical head is out of a track of an optical disk.

[0002]

2. Description of the Related Art An optical disk apparatus records and reproduces data by an optical head following a track on an optical disk rotating at a high speed. At this time, known tracking control is performed so that the optical head follows the track of the optical disk. However, during this tracking control, the optical head may go off-track due to a medium defect such as a scratch on the optical disk.

[0003] As a countermeasure processing against this track deviation, conventionally, when a desired track is repeatedly scanned,
If the off-track is detected when kicking back from the end of the desired track to the beginning of the track,
After reading the address of the nearest track on track, the target track is changed to one track upstream, seek to one track upstream of the target track, and then track jump of the light beam spot until the address of the target track is detected. The inactive state is restored (Japanese Patent Application Laid-Open No. 2-254636).

[0004] Further, in another conventional optical disk apparatus, there is an apparatus that terminates processing when an off-track is detected due to a medium defect or the like during data recording / reproduction.

[0005]

However, the detection of the off-track by the conventional optical disk apparatus is performed by detecting a medium defect such as a scratch on the track or moving to an adjacent track, in addition to the off-track servo. The case has also been made. In such a case, since recording and reproduction of data can be continued as it is, the conventional optical disk device performs the positioning operation of the optical head although the positioning operation of the optical head is unnecessary. Therefore, the conventional optical disk device has a problem that the entire processing time is required due to unnecessary recovery processing for track deviation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and when the off-track is detected, the recovery processing is performed in accordance with the state without performing the recovery processing unconditionally, so that the entire processing time is reduced. It is an object of the present invention to provide an optical disk device capable of shortening the time.

[0007]

In order to achieve the above object, an optical disk apparatus according to the present invention comprises: a head for reading or writing data from / to a disk; and a head for shaping data read at the time of recording. A read / write circuit for shaping the data that the head writes to the disk, a servo circuit for controlling the movement of the head by following the track of the disk, detecting a head off-track, and modulating and reading data to be recorded. A modulation / demodulation circuit for demodulating a reproduction signal input from the read / write circuit while inputting to the write circuit, a data buffer for storing data demodulated by the modulation / demodulation circuit and reading data modulated by the modulation / demodulation circuit, and a modulation / demodulation circuit. A sector detection circuit for extracting sector information from the demodulated signal; When the servo circuit detects that the head is off-track, it calculates the amount of movement of the head from the input sector information to the target sector and outputs it to the servo circuit. The controller includes a controller for switching a head off-track recovery method based on a detection signal, sector information from a sector detection circuit, and a comparison result of a target sector.

That is, the controller makes an inquiry to the servo circuit when the off-track detection signal is input to determine whether the servo is valid, and determines whether the servo is valid and the value of the current sector information from the sector detection circuit. If is the current value to be processed, determine whether the mode is the data read mode or write mode.If the mode is the data read mode, continue reading.If the mode is the data write mode, write from the next sector. The operations of the read / write circuit, the modulation / demodulation circuit, and the data buffer are controlled so as to restart the processing.

Thus, according to the present invention, even if an off-track is detected, the processing is continued without unconditionally positioning the head at the sector position where the off-track is detected.

Further, the controller according to the present invention inquires of the servo circuit when the off-track detection signal is input to determine whether the servo is valid, and determines whether the servo is valid and the current sector from the sector detection circuit. When the value of the information is smaller than the value to be currently processed, the read / write circuit performs processing for the sector for which processing is stopped after resuming the processing after obtaining the sector information of the value to be currently processed, Controls the operation of the modulation / demodulation circuit and the data buffer, when the servo is valid, and the value of the current sector information from the sector detection circuit is larger than the value to be currently processed, and the difference is within the processable sector range. After controlling the operation of the read / write circuit, the modulation / demodulation circuit and the data buffer so that the processing for recording or reproduction is continued, A processing control for for positioning to recording or reproducing head relative to the sectors previously untreated missing sector.

According to the present invention, when the value of the current sector information at the time when the off-track is detected is different from the value to be currently processed, recording or reproduction is performed according to the magnitude and polarity of the difference. The head is unconditionally positioned at the sector position where the off-track is detected, because the processing for the pause is resumed after the suspension or the processing is continued, and then the processing of the suspended or missing sector is performed. Instead, the processing can be continued as much as possible.

[0012]

FIG. 1 is a block diagram showing an embodiment of the present invention. This optical disk device includes an optical head 1, a read / write circuit 2, a modulation / demodulation circuit 3, a data buffer 4, a sector detection circuit 5, a servo circuit 6,
And a controller 7.

The optical head 1 emits a light beam to a rotating optical disk (not shown) to form a light spot on the track so as to be focused on the track, and the reflected light from the optical disk obtained by this is made incident. An electric signal is obtained by photoelectric conversion. The optical disc has spiral tracks. Each track has a user data area in which a user can record and reproduce data, and identification information indicating a track number and a sector number indicating the location on the optical disc. There is a preformat area recorded in stages, and one track includes, for example, 17 sectors.
The optical head 1 accesses the optical disk while moving in the radial direction of the optical disk.

The read / write circuit 2 is used for reading (for reproducing).
Shapes the data of the optical disk read by the optical head 1 and outputs the shaped signal to the modulation / demodulation circuit 3. The read / write circuit 2 shapes data input from the modulation / demodulation circuit 3 during writing (recording), inputs the data to the optical head 1, and modulates the light intensity of the light beam emitted from the optical head 1. The reading and writing operations are controlled based on a command to the controller 7.

The modulation / demodulation circuit 3 demodulates a reproduction signal input from the read / write circuit 2 and modulates recording data output to the read / write circuit 2. Whether the modulation / demodulation circuit 3 performs the modulation operation or the demodulation operation is controlled by the controller 7. Further, the modulation / demodulation circuit 3 reproduces the identification information from the preformat area of the optical disk and outputs it to the sector detection circuit 5 not only during reproduction but also during recording.

The data buffer 4 is constituted by a memory for temporarily storing data from the modulation / demodulation circuit 3 and for inputting read data to the modulation / demodulation circuit 3. The sector detection circuit 5 detects and extracts sector information from the data demodulated by the modulation / demodulation circuit 3. Then, the extracted sector information is output to the controller 7.

The servo circuit 6 generates a known tracking servo signal and a focus servo signal based on the photoelectric conversion signal from the optical head 1 and supplies these servo signals to the optical head 1 to be emitted from the optical head 1. The tracking control is performed so that the position of the light spot formed on the track of the optical disc follows the track, and the focus control is performed so that the focal point matches. Further, the movement of the optical head 1 in the radial direction of the optical disk is controlled by a motor (not shown).

Further, the servo circuit 6 detects the track off of the optical head 1 based on the signal inputted from the optical head 1 (strictly, the track of the optical spot is off track. Is detected by known means. Then, the detected off-track detection signal is output to the controller 7.

The controller 7 comprises the read / write circuit 2, the modulation / demodulation circuit 3, the data buffer 4 and the modulation / demodulation circuit 6.
Control the operation of. The controller 7 calculates a movement amount to a target sector (track) based on the sector information extracted from the sector detection circuit 5. Then, the controller 7 outputs the calculated value to the servo circuit 6, whereby the servo circuit 6 moves the optical head 1 by the calculated movement amount.

When the optical head 1 reaches a target sector by this movement, the controller 7 instructs the data buffer 4 at the start position (address) of data writing at the time of reading, and the read / write circuit 2 reads the data. The operation is instructed, and the modulation / demodulation circuit 3 is instructed to perform the demodulation operation. on the other hand,
At the time of writing, the controller 7 instructs the data buffer 4 on the data read start position (address), and instructs the read / write circuit 2 on write operation.
The modulation / demodulation circuit 3 is instructed to perform a modulation operation.

The controller 7 performs a countermeasure process for the off-track of the optical head 1 in addition to the above control. This process is performed based on an out-of-track detection signal input from the servo circuit 6 during the read / write control. This off-track detection signal causes the controller
Switches between recovery of the optical head 1 to the track and continuation of data reading and data writing on the track based on the input sector information.

Next, the operation of this embodiment at the time of off-track will be described with reference to the flowchart shown in FIG. For example, when the tracking error signal input from the optical head 1 is at a level higher than a predetermined level, the servo circuit 6 detects the off-track and outputs the off-track detection signal to the controller 7 (step 10).
0). Thereby, the controller 7 inquires of the servo circuit 6 about the current servo state (step 10).
1).

When it is determined that the optical head 1 is completely off the track, the controller 7 instructs the optical head 1 to recover to the track, and executes the same recovery processing as before (step 113). That is, in this restoration process, the optical head 1 is moved to a predetermined position (for example, track number 0).
), The servo is pulled in, the sector information is read, and the servo is restarted from the beginning.

When detecting an off-track, the servo circuit 6 also outputs an off-track detection signal to the read / write circuit 2. As a result, in the data write mode, the read / write circuit 2 stops writing data and protects the data.

On the other hand, when the servo circuit 6 detects the off-track, but does not actually go off-track, or when the servo circuit 6 is off-track but moves to an adjacent track, the controller 7 is in a valid state. Reads the current sector information from the sector detection circuit 5 and checks whether the value of the sector information has changed from the value to be currently processed (step 102).

If the value of the sector information has not changed and is the value to be processed at present, the controller 7 determines whether the mode is the data read mode or the write mode (step 10).
3) In the data reading mode (during reproduction), the reading is continued (step 104). In the data writing mode (during recording), the writing process is restarted from the next sector (step 105). .

In this write mode, an alternative process of writing data to be written to an error-detected sector after the process into an alternative area provided in advance on the optical disk is performed (step 106). Thus, in this embodiment, unnecessary recovery work of the optical head 1 can be omitted.

On the other hand, if the value of the sector information input from the sector detection circuit 5 is different from the value to be currently processed, the controller 7 compares these values and determines whether the value of the input sector information is the current value to be processed. It is determined whether it is greater than (step 107). As a result of the comparison, when the value of the sector information is smaller than the value to be currently processed, the controller 7
Stops the operation of the data buffer 4. This is because the track of the optical disk is spiral and the optical head 1 reaches a continuous sector if it is standing by.

For this reason, the controller 7 monitors the sector information, and instructs the read / write circuit 2, the modulation / demodulation circuit 3 and the data buffer 4 to resume the processing when the current sector value reaches the sector to be processed. Is output (step 108). And, after this process ends,
The controller 7 performs the replacement processing or the retry processing on the sector in which the error is detected (step 109).

On the other hand, in step 107, when a comparison result in which the value of the sector information is larger than the value to be currently processed is obtained, the controller 7 determines whether or not the value of the sector information is within the range to be processed. Judgment (Step 11
0). If it is within the range of the sector to be processed, the controller 7 re-designates the data buffer position corresponding to the sector where the optical head 1 is present in the data buffer 4 and issues an instruction to the read / write circuit 2 and the modulation / demodulation circuit 3. The remaining processing is performed (step 111). After this processing, the controller 7 performs processing for the missing sector (step 112).

That is, in this embodiment, if the value of the read sector is larger than the value to be processed at present and is within the range of the sector to be processed, the process is continued as it is, Since the optical head 1 is positioned with respect to the missing sector after the completion, and the read / write processing is performed on the missing sector, the optical head 1 is read each time when the value of the read sector differs from the value to be currently processed. The processing time can be reduced as compared with the conventional positioning.

In step 110, when the value of the sector information is out of the range of the value to be currently processed,
Since the off-track amount is large and the original data cannot be recorded / reproduced if the processing is continued as it is, the controller 7 performs the conventional recovery processing on the optical head 1 (step 113).

The present invention is not limited to the above embodiment. For example, the present invention is applicable not only to a device for recording / reproducing information on / from an optical disk but also to a device for recording / reproducing information on / from a magnetic disk. The present invention can also be applied to the present invention.

[0034]

As described above, according to the present invention,
Even if an off-track is detected, the head is not unconditionally positioned at the sector position where the off-track is detected, but processing for recording or reproduction is continued as much as possible. Restoration work can be omitted, the overall countermeasure processing time for track deviation can be shortened, and data processing can be performed at high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation when detecting an off-track in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical head 2 Read / write circuit 3 Modulation / demodulation circuit 4 Data buffer 5 Sector detection circuit 6 Servo circuit 7 Controller

Continuation of the front page (56) References JP-A-5-135365 (JP, A) JP-A-6-12695 (JP, A) JP-A-5-54383 (JP, A) JP-A-7-287856 (JP) JP-A-7-262578 (JP, A) JP-A-7-201048 (JP, A) JP-A-64-79942 (JP, A) JP-A-63-291223 (JP, A) 62-243179 (JP, A) JP-A-61-216129 (JP, A) JP-A-5-50529 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 21/10 G11B 7/085

Claims (2)

(57) [Claims] A head for reading or writing data from / to a disc; a read / write circuit for shaping data read by the head during recording and shaping data to be written to the disc during reproduction; A servo circuit for controlling the movement of the head by following the track of the disk, and detecting the off-track of the head; modulating data to be recorded and inputting the data to the read / write circuit; And a data buffer for storing data demodulated by the modulation / demodulation circuit and reading data modulated by the modulation / demodulation circuit, and extracting sector information from the signal demodulated by the modulation / demodulation circuit. A sector detection circuit; and sector information from the sector detection circuit. Calculating the amount of movement of the head from the sector information to the target sector and outputting the calculated amount to the servo circuit, and when the servo circuit detects a head off-track, the off-track detection signal from the servo circuit; on the basis of the sector information and the comparison result of the target sector from the sector detection circuit, it has a controller for switching the recovery method for the off-track of the head, the controller
When the off-track detection signal is input, the
Query the servo circuit to see if the servo is valid
Judge that the servo is valid and the sector detection circuit
When the current sector information value is the value to be processed now
Determines whether data is read or written.
When in data reading mode,
And in the data write mode, the next
The read operation is restarted by the
A write circuit, the modulation / demodulation circuit, and the data buffer.
A disk device for controlling operation . 2. A method of reading data from or reading data from a disk.
The head for writing and the data read by the head during recording are shaped, and during playback,
A head that formats the data that the head writes to the disc.
A write circuit and movement control of the head following the track of the disk.
And a sensor for detecting the off-track of the head.
Circuit and the data to be recorded are modulated and input to the read / write circuit.
And read from the read / write circuit.
A modulation / demodulation circuit for demodulating a raw signal, storing data demodulated by the modulation / demodulation circuit,
A data bar for reading data modulated by the modem
And sector information from the signal demodulated by the modem circuit.
And sector information from the sector detection circuit to be output.
Of head movement from target sector information to target sector
And outputs it to the servo circuit.
When the circuit detects that the head is out of track,
An off-track detection signal from the circuit and the sector detection
With the sector information from the road and the comparison result of the target sector
How to recover the head from off track on the basis of
And a controller for switching law, the controller
When the off-track detection signal is input, the
Query the servo circuit to see if the servo is valid
Judge that the servo is valid and the sector detection circuit
The value of the current sector information is smaller than the value currently to be processed.
The sector information of the value to be currently processed is obtained.
And then restart the process, and then
The read / write circuit, the recovery
Control the operation of the adjustment circuit and the data buffer, and
Is valid and the current sector from the sector detection circuit is
Data value is larger than the value to be processed at present, and the difference
When it is within the sector range that can be managed,
The read / write circuit, the
Controlled the operation of the modem and the data buffer
After that, the unprocessed skip before the sector of the value to be currently processed
The head is positioned with respect to the sector
A disk device for performing control for performing a raw process .