JPH1186419A - Method for reproducing disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the unnecessary degradation of the number of revolutions of a disk and to prevent the degradation of a reproducing rate by measuring the number of retry times, checking the number of revolutions of the disk when a preset value is attained, waiting for the decrease of the number of revolutions down to the number of revolutions which does not exceed a signal processing capability and executing the retry. SOLUTION: In the case reading is executed by moving the disk from its inner peripheral side to its outer peripheral side, a CPU 205 for control checks the number of retry times when the data incorrectable by the ECC in a CD-ROM signal processing circuit 206 arises. If the number of retry times is the preset value, for example, 5 times, the rotation pulses from a motor 202 for disk rotation are counted for a specified time and the rotating speed of the disk 201 is checked. If the circuit of the lowest signal processing capability, for example, the CD-ROM signal processing circuit 206, is at a speed higher than the rotating speed corresponding to the processable multiple speed on the basis of this speed, the retry is executed after the lowering of the speed down to the reference speed is waited for.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing method capable of reproducing data in a form close to an upper limit performance inherent in the apparatus at the time of a read access accompanied by movement of an optical pickup requiring a reduction in the number of rotations of the disk.

[0002]

2. Description of the Related Art FIG. 3 is a schematic diagram showing an example of a disk device for reproducing data from a disk such as a CD-ROM. The disk device 200 shown in the figure mounts a disk 201 such as a CD or a CD-ROM as a recording medium, and reads and reproduces digital data spirally recorded on one side of the disk 201. The disk 201 is driven to rotate by a spindle motor 202. At this time, the optical pickup 203 reads data from the signal recording surface of the disk 201 with the amount of light reflected, and supplies the data to the CD signal processing circuit 204. The CD signal processing circuit 204
Command from control CPU 205 and optical pickup 203
Driver 208 based on the analog signal read from
Is controlled so that the optical pickup 203 can track information spirally recorded on the disk 201, and converts an analog signal from the optical pickup 203 into digital data, thereby obtaining address information recorded on the disk 201. And sends the converted digital data to the CDROM signal processing circuit 206. C
The D-ROM signal processing circuit 206 is a CD signal processing circuit 2
04 is subjected to error correction processing and decoded, and the decoded result is transmitted to the HOST I / F 20.
Send to 7. The HOST I / F 207 transmits data to a HOST device (not shown) on the I / F to which the disk device 200 is connected, and receives a command from the HOST device.

On the disk 201, data is spirally recorded by CLV recording so that the linear velocity becomes constant. That is, when the disk 201 is rotated at a constant rotation speed, the speed at which information is read out is higher when the optical pickup 203 is on the outer peripheral side than when the optical pickup is on the inner peripheral side. Generally, a CD is read in accordance with the reading position of the optical pickup 203 so that the information reading speed from the disk 201 is constant regardless of the reading position of the optical pickup 203.
Normally, the signal processing circuit 204 issues a command to the driver 208 to control the rotation speed of the disk rotation motor 202. Therefore, there is a difference of about 2.5 times in rotational speed between when the optical pickup 203 is at the innermost circumference of the disk and when it is at the outermost circumference of the disk. In the case of a so-called audio reproduction CD, the optical pickup 203 rotates at about 500 revolutions per second when the optical pickup 203 is at the innermost circumference of the disc, whereas it rotates at about 200 revolutions per second when the optical pickup 203 is at the outermost circumference of the disc. The CD signal processing circuit 204 and the CD-ROM signal processing circuit 206 have the ability to process signals at a speed of 10 times or more of these rotation speeds, and therefore, play back at n times the normal playback speed. N speed reproduction is sufficiently possible.

In the case of the disk device 200, the disk 20
The maximum speed of the information reading speed from No. 1 depends on the signal processing capability of the CD signal processing circuit 204, the signal processing capability of the CD-ROM signal processing circuit 206, and the disk rotation motor 20.
2 driving capability. In general, when the optical pickup 203 is at the innermost circumference of the disk, the maximum speed is determined according to the capability of the motor 202 for rotating the disk, and when the optical pickup 203 is at the outermost circumference of the disk, the CD signal processing circuit 204 and the control CPU 2O5 are connected. Among the CD-ROM signal processing circuit 206 and the optical pickup 203, the speed is determined according to the speed specification of the one having the lowest capability. Here, the case where the respective abilities are as follows will be described as an example. Capacity of disk rotation motor 202 5000 revolutions per second (about 10 times speed) Capacity of optical pickup 203 30 times speed Capacity of CD signal processing circuit 25 25 times speed Capacity of CD-ROM signal processing circuit 206 20 times speed

First, when the optical pickup 203 is located at the innermost circumference of the disk, the information reading speed is determined by the capability of the disk rotating motor 202. Therefore, the disk 201 can be rotated at 10 times speed here. If the disk rotation motor 202 is rotated at approximately 5000 revolutions per second while the optical pickup 203 is at the outermost periphery of the disk, information is sent to the CD signal processing circuit 204 at approximately 25 times speed. In this case, the optical pickup 203 and the CD signal processing circuit 204 have a processing capability of 25 times or more, but the signal processing capability of the CD-ROM signal processing circuit 206 is up to 20 times the speed, so that correct data reproduction is not possible. You can't expect it. That is, here, the signal output from the optical pickup 203 is 20
It is necessary to control the rotation of the disk rotation motor 202 so as not to exceed the double speed. Actually, by rotating the disk 201 at about 4000 revolutions per second, data reproduction at about 20 times speed is performed.

There are two methods for controlling the number of rotations of the disk rotation motor 202 according to the reading position of the optical pickup 203. There are two methods for controlling the number of rotations: the control from the CD signal processing circuit 204 and the control from the control CPU 205. . In general, the control from the CD signal processing circuit 204 takes time to reduce the speed, and the control CPU 2
It can be said that the control from 05 can reduce the speed relatively quickly. Therefore, in order to simplify the description, the number of rotations is set to 5,000 and 4,000 at half the position of the innermost peripheral position of the optical pickup 203 and the outermost peripheral position of the disk.
Switch to rotation. Specifically, as shown in FIG. 4, when the optical pickup 203 is in the inner peripheral area A, the rotation speed is 5000 revolutions per second, and when the optical pickup 203 is in the outer peripheral area B, it is 4000 revolutions per second.

In this case, a control operation by the control CPU 205 when reading data on the outermost circumference after reading data when the optical pickup 203 is in the inner area A will be described. FIG. 5 is a flowchart illustrating an example of the control operation of the control CPU 205.

Now, the optical pickup 203 is located at the innermost position 2
03a. In this case, the innermost position 203
The position is the same at any position in the inner peripheral region A, not limited to a, but for convenience of explanation, it is assumed to be at the innermost peripheral position 203a. Therefore, the disk 201 is rotating at about 5000 revolutions per second. As described above, in this environment, it is possible to reproduce the recorded information at about 10 times speed. Therefore, it is assumed that a command for reading data at the innermost position 203c is received from the HOST computer via the HOST I / F 207.
The control CPU 205 analyzes this command and starts control for moving the optical pickup 203 to the outermost position 203c.

First, in order to move the optical pickup 203 to the outermost position 203c, the optical pickup 203
Need to know how long and in what direction must be moved. Therefore, in order to obtain the current position of the optical pickup 203, step (1) in FIG.
000), address information of the current position of the optical pickup 203 is obtained. This information can be obtained via the CD signal processing circuit 204, and it can be seen that the current position is the innermost position 203a. Further, the rotational speed of the disk 201 can be determined from the position information. Next, H
Since the rotation speed of the disk 201 after movement is known from the destination and address information obtained via the OST I / F 207, it is determined whether or not the rotation speed needs to be changed as shown in step (1010). Can be. In this example, the disc 20 is located at the outermost peripheral position 203c after the movement.
Since it is necessary to reduce the number of rotations of 1 to about 4000 rotations,
As shown in step (1011), an instruction to change the disk rotation speed is issued. This instruction is performed by controlling the driver 208 through the CD signal processing circuit 204. However, in general, it takes time from when an instruction to change the speed is issued to when the specified number of revolutions is settled, so that the number of revolutions is not changed simultaneously with the instruction.

Further, as shown in the following step (1020), the current position information obtained in step (1000) is compared with the target position information, and the driver 208 is directly controlled to move to the optical pickup 203. Give instructions. Further, the position address information of the optical pickup 203 is acquired again through the CD signal processing circuit 204, and it is determined whether or not the target position to be moved has been reached as shown in step (1030). If the target position has been reached, the process proceeds to step (1040), but if the target position has not been reached, the process returns to step (1020) to control the driver 208 to move the optical pickup 203 further.

In step (1040), it is detected whether the disk rotation speed has settled down to a speed that can be processed by the CD-ROM signal processing circuit 206, that is, whether the disk 201 has reached an appropriate rotation speed. If it is not appropriate, as shown in step (1041), after waiting for an appropriate time, the confirmation of the rotational speed is repeated again. When the disk rotation speed becomes appropriate,
Data reading is started as shown in step (1050). The reading of this data is performed by the CD-ROM signal processing circuit 206.
Modified by CC. The data obtained here is HO
It is sent to the HOST computer via the ST I / F 207. On the other hand, when the error data cannot be completely corrected by the ECC, the step (100) is repeated.
Processing for data read is started from 0). This is usually called a retry. This retry processing will be described with reference to FIG.

First, step (2000) shown in FIG.
In, data correction by ECC is performed. It is checked in step (2010) whether there is any uncorrectable data as a result of the data correction by the ECC, and if all the corrections have been completed, the process proceeds to step (206).
Move to the data transfer shown in 0). On the other hand, when there is uncorrectable data, in the following step (2020), the number of times of retry is checked, and the retry is performed by further lowering the disk rotation speed, or the disk rotation speed is not changed. Determine whether to retry again. When the disk rotation speed is to be reduced, the process proceeds to step (2050) after performing step (2021) and retry. On the other hand, if the rotation is not reduced, it is checked in step (2030) whether the specified number of retries has been performed. If the specified number of retries has been performed, in step (2040), an unreadable address is regarded as a read error. If the retry has not been performed the specified number of times, the retry is performed again.
The retry in step (2050) is performed from step (1000) described above.

Here, the determination of whether the rotation of the disk 201 should be reduced or not will be described with reference to an example. For example, if reading is not possible even after reading at the same speed (here, 20 times speed) five times, the speed is reduced to 10 times speed and a retry is performed. In step (2020), if a read error occurs, the process proceeds to step (2021) if the retry is the fifth retry, and in step (2030),
If it is the tenth retry, the process may proceed to step (2040). In this case, although the data was read several times at about 20 times speed in step (2021), the data could not be read as a result. It is necessary to confirm that the number of rotations of the disk has decreased, and to proceed to the next step. It should be noted that step (1011) is different from the case of proceeding to the next process only by instructing a change in the number of revolutions.

The waiting at the steps (1040) and (1041) is an operation that should be deleted if possible from the viewpoint of shortening the access time, which is one of the important performances required for the disk device 200. In other words, if the disk rotation speed does not reach approximately 4000 rotations after issuing an instruction to change the rotation speed in step (1011) and starting data reading, inevitably wait for the time specified in step (1041). Is required. However, the CD-ROM signal processing circuit 206 shown in FIG.
Although the performance is guaranteed only up to 0 × speed, there is also a device which operates without any problem up to 22 × or 23 × speed depending on the variation of the device. Therefore, in a set using such a device, it is apparent that the access speed can be increased by omitting steps (1040) and (1041). That is, from the viewpoint of improving the drive performance, the deletion of steps (1040) and (1041) was effective.

However, in the case of the disk device 200 equipped with the CD-ROM signal processing circuit 206 having a signal processing capacity of only about 21 times, the elimination of the steps (1040) and (1041) requires the CD-ROM signal processing capacity. Therefore, signal processing at a speed of 22 times higher than the above is required, and the error correction processing in step (2000) cannot be normally performed. As a result, step (201)
In step (0), it is determined that there is uncorrectable data. Therefore, the retry shown in step (2020) and thereafter is performed, and the number of disk rotations reaches about 4000 rotations per second while repeating this retry. become. Therefore, finally, the CD-ROM signal processing circuit 2
The rotation speed is within the processing capability range of 06, and data can be read normally, or the rotation speed is reduced to 10 times speed by executing step (2021). That is, if the CD-ROM signal processing circuit 206 does not reach a processable speed while performing the retry at 22 × speed, the speed is reduced to 10 × speed and the retry is performed. Therefore, even if steps (1040) and (1041) are deleted, a situation in which data that should be readable cannot be read can be avoided.

As described above, when steps (1040) and (1041) are deleted, before the disk rotation speed is reduced and retried in step (2020), the disk rotation speed is reduced by the CD-ROM signal processing circuit 20.
When the number of rotations falls within the processing capacity range of No. 6, data can be reproduced without significant performance degradation, but the number of times that the disk rotation number must be reduced in step (2020) (in this example). If the disk rotation speed does not reach the rotation speed that can be processed by the CD-ROM signal processing circuit 206 even after retrying only five times, the data can be read only at 10 × speed. There was a problem that it disappeared.

The present invention has been made to solve the above-mentioned problem, and in read access involving movement of an optical pickup in which the number of rotations of a disk must be reduced, the number of times is close to the upper limit of a device unique to each device. It is an object of the present invention to be able to reproduce data at a speed.

[0018]

In order to achieve the above object, the present invention provides a retry for re-reading data from a disk at the time of a read access accompanied by a movement of a pickup to a reading position where a reduction in the number of rotations of the disk is required. When the counted value reaches a preset value, the disk rotation speed is checked, and if the disk rotation speed exceeds the signal processing capability, the disk rotation speed is waited for a decrease. And performing a retry.

Further, in the present invention, when a retry is required even when the number of retries exceeds the predetermined value, when the number of retries reaches a second predetermined value exceeding the predetermined value, the disk rotation speed is increased. It is characterized by ordering a decrease in the number of rotations of the disk as exceeding the signal processing capability.

Further, the predetermined value is a value of 2 or more.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. FIG. 2 is a flowchart for explaining an operation mode when data on the outermost circumference of the disk is read from the inner circumference side of the disk by the disk reproduction method of the present invention. FIG. 2 illustrates one embodiment of a retry operation by the disk reproduction method of the present invention. It is a flowchart for the.

FIG. 1 omits steps (1040) and (1041) that hinder high-speed access from the flowchart of FIG. 5 used in the description of the prior art. Therefore, by executing the processing flow shown in FIG. 1, it is apparent that the access speed, which is one of the main performances of the disk device 200, can be improved. However, on the other hand, the CD-ROM signal processing circuit 20
As described above, there is a possibility that data correction or the like by ECC may be performed at a rotation speed exceeding the capability range of No. 6. Therefore, while improving the access speed by adopting the processing flow of FIG. 1 described above, it is not necessary to perform the data reading by lowering the rotation speed more than necessary as in the related art, as shown in FIG. This is a retry operation.

Also in this embodiment, it is assumed that the processing capability of the CD-ROM signal processing circuit 206 is equivalent to 21 times speed. In this case, in step (1011) shown in FIG. 1, the rotation speed control is performed by the CD signal processing circuit 204, and the rotation speed is adjusted to a speed equivalent to 20 times speed. The control takes time and does not immediately reach the specified number of revolutions. Therefore, for example, at the start of data reading in step (1050), it is considered that the rotation speed is still equivalent to 24 × speed. Since this rotation speed exceeds the processing capability range of the CD-ROM signal processing circuit 206, step (10) in FIG.
Is not completed, and it is determined in step (20) that there is uncorrectable data.
Proceed to step (30). In step (30) and subsequent steps, the retry is checked, and the subsequent processing is determined according to the number of retries.

In the case of the present embodiment, it is checked in step (30) whether or not the fifth retry is performed, and in step (40), it is checked whether or not the tenth retry is performed.
In (0), it is confirmed whether or not the retry is the fifteenth retry. First, the data correction by the ECC is performed under the condition that the rotation speed is equivalent to 24 times speed. However, since the correction is naturally impossible, the process proceeds from the step (20) to the step (30). In step (30), since this is the first retry, the process passes through steps (40) and (50) and proceeds to step (70). As a result, in the first retry, the read operation is repeated once without changing the rotation speed.

Here, after the processing shown in FIG. 1, the processing returns to step (10) again.
4, control is performed to make the rotation speed equivalent to about 20 times speed, so that it is assumed that the rotation speed becomes equivalent to about 23.5 times speed in the second retry. In this case, as in the case of the first retry, the CD-ROM signal processing circuit 20
6 exceeds the processing capability range, there is uncorrectable data, and the retry is repeated again.

Assuming that the rotation speed is such that it cannot be corrected even at the fifth retry, for example, a rotation speed equivalent to about 22 times speed, it is determined in step (20) that there is uncorrectable data. Proceed to (31).
That is, since this is the fifth retry, the disk rotation speed is confirmed, and based on the confirmation that the disk is rotating at about 22 times speed, the process waits until the speed reaches about 20 times speed.

In this case, the disc rotation speed is confirmed by a rotation pulse from the disc rotation motor 202, for example,
A signal is generated so that one pulse is generated for each rotation.
The control can be performed based on how many times the control CPU 205 can count within a certain period of time. After waiting in step (31) until the rotation speed is equivalent to about 20 times speed, step (4)
0), (60), and (70), in order to reach a state where data can be read at a speed equivalent to about 20 times speed at the time of the sixth retry.

It should be noted that there is a sufficient reason that the disk rotation speed is checked not at the time of the first retry but at the fifth retry. For example, in the case where the disk rotation speed is equivalent to about 21 times speed at the first retry, a disturbance happens to occur at the time of ECC data correction in step (10), and it is determined that the data cannot be corrected. If the number of rotations has been checked since the first retry, the conventional step (1040)
And (1041), which is almost the same as the above, which is against the purpose of improving the access speed. In addition, in the case where the correction cannot be performed during the first read by chance due to a disturbance, the read operation is simply repeated again at the same rotation speed, and in many cases, the read operation can be performed without any problem. In other words, it can be considered that it is sufficient as a measure against disturbance.

If it is confirmed in step (40) that the retry is the tenth retry, the disk rotation speed is not checked in step (31) but the disk rotation speed is determined in step (41). Is immediately reduced to a rotation speed equivalent to 10 times speed. This is a step (20) following the conventional step (2020).
Same as 21).

As described above, according to the above-described disk reproducing method, the number of retries for re-reading the data of the disk at the time of the read access accompanied by the movement of the optical pickup 203 to the reading position where the reduction of the disk rotation speed is required. Counting, when the counted value reaches a predetermined value set in advance, check the disk rotation speed, and if the disk rotation speed exceeds the signal processing capability, wait for the disk rotation speed to decrease and retry. Since the execution is performed, the rotational speed control cannot be performed in time while the retry is performed the specified number of times as in the related art, and the result that the disk rotational speed is unnecessarily reduced does not occur. Therefore, at the time of a read access involving movement of the optical pickup 203 in which the rotation speed of the disk 201 must be reduced, data can be reproduced at a speed close to the upper limit performance inherent in the device. In a CD-ROM device or the like that is not linear velocity recording or complete CAV (constant angular velocity recording), a retry can be executed without sacrificing access time and without causing a remarkable decrease in the reproduction rate.

When a retry is required even if the number of retries exceeds the predetermined value, a second predetermined value (here, ten times) in which the number of retries exceeds the predetermined value (here, five times) When the disk rotation speed reaches the limit, it is assumed that the disk rotation speed exceeds the signal processing capacity, and the disk rotation speed is ordered to decrease. In other words, it is possible to eliminate the disadvantage that the number of retries is increased and the time required until the data can be finally reproduced is unnecessarily extended, and appropriate disk rotation control according to the situation can be performed.

Further, since the predetermined value is set to 2 or more, even if the error correction processing fails due to disturbance at the first retry, there is a problem if the read operation is simply repeated once again at the same rotation speed. In most cases, it is possible to read without error, so by repeating the read operation multiple times, it is possible to accurately recognize that the cause of error correction is the disk rotation speed exceeding the signal processing capacity without being disturbed by disturbance, and Responsive processing is possible.

[0033]

As described above, according to the disk reproducing method of the present invention, the data of the disk is re-read at the time of the read access accompanied by the movement of the pickup to the reading position where the rotation speed of the disk is required to be reduced. The number of retries is counted, and when the counted value reaches a predetermined value set in advance, the disk rotation speed is checked.If the disk rotation speed exceeds the signal processing capability, a decrease in the disk rotation speed is checked. Since the retry is performed after waiting, the speed control cannot keep up during the specified number of retries as in the past, and there is no possibility that the result of lowering the disk speed more than necessary is brought about. At the time of read access involving the movement of the pickup that requires lowering the rotation speed of the Thus, for example, in a CD-ROM device that is not full CLV (constant linear velocity recording) or full CAV (constant angular velocity recording), the access time is not sacrificed and the reproduction rate is significantly reduced. Excellent effects such as retry can be executed without inviting.

Further, in the present invention, when a retry is required even when the number of retries exceeds the predetermined value, when the number of retries reaches a second predetermined value exceeding the predetermined value, the disk rotation speed is increased. Because we ordered the reduction of the disk rotation speed because it exceeded the signal processing capacity,
Eliminating the disadvantage that the disk rotation speed is reduced little by little because priority is given to high-speed playback at the time of retry, rather the number of retries is increased, and the time required until finally data playback can be extended unnecessarily. This produces effects such as appropriate control of disk rotation according to the situation.

Further, since the predetermined value is set to a value of 2 or more, even if the error correction processing fails due to disturbance at the first retry, it is problematic if the read operation is simply repeated once again at the same rotation speed. In most cases, it is possible to read without error, so by repeating the read operation multiple times, it is possible to accurately recognize that the cause of error correction is the disk rotation speed exceeding the signal processing capacity without being disturbed by disturbance, and This makes it possible to perform an appropriate response process.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining an operation mode when reading data on the outermost circumference of a disk from the inner circumference side of a disk by a disk reproducing method of the present invention.

FIG. 2 is a flowchart illustrating one embodiment of a retry operation according to the disk reproducing method of the present invention.

FIG. 3 is a circuit configuration diagram showing an example of a conventional disk device.

FIG. 4 is a diagram illustrating a relationship between a reading position of an optical pickup and a disk rotation speed.

FIG. 5 is a flowchart for explaining an example of an operation when reading data on the outermost circumference of the disk from the inner circumference side of the disk by a conventional disk reproduction method.

FIG. 6 is a flowchart illustrating an example of a retry operation according to a conventional disk reproducing method.

[Explanation of symbols]

 Reference Signs List 200 disc reproducing device 201 disc 202 disc rotation motor 203 optical pickup 204 CD signal processing circuit 205 control CPU 206 CD-ROM signal processing circuit 207 HOST I / F 208 driver 203a innermost reading position 203b rotation speed switching position 203c Peripheral reading position

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI G11B 20/18 576 G11B 20/18 576A

Claims (3)

[Claims] The present invention counts the number of retries for re-reading data of a disk at the time of a read access accompanied by movement of a pickup to a reading position where a reduction in the number of rotations of the disk is required, and the counted value is a predetermined value set in advance. A disk rotation speed is checked when the number of disk rotations reaches a value, and when the disk rotation speed exceeds the signal processing capability, a retry is executed after waiting for a decrease in the disk rotation speed. 2. When a retry is required even when the number of retries exceeds the predetermined value, when the number of retries reaches a second predetermined value exceeding the predetermined value, the disk rotation speed decreases the signal processing capability. 2. The disc reproducing method according to claim 1, wherein the disc rotation number is ordered to be lower than the disc rotation number. 3. The method according to claim 1, wherein the predetermined value is a value of 2 or more.