JP2003297007A - Disk reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk reproducing device capable of reducing time until reproduction is started in reproducing a disk with flaws or dirt. <P>SOLUTION: A disk is started from a minimum rotational speed (e.g. one-fold speed) at reproduction and while read is normally performed, the rotational speed is stepwise increased. For example, in occurrence of a read error at eight-fold speed, the rotational speed of the disk is decreased to a four-fold speed that is a speed just before the error takes place and the disk is again read. Gradually increasing the rotational speed from the minimum speed can read the disk with many flaws or much dirt. Since the apparatus can reach a readable maximum speed earlier than the case with reading the disk by decelerating the speed from the maximum speed, the time until the reproduction is started can be decreased. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CD-ROM, C
The present invention relates to a disc reproducing device for reading and reproducing information recorded on a disc such as a D-R or a CD-RW.

[0002]

2. Description of the Related Art When playing a disc, if the recording surface of the disc is scratched or dirty, the information recorded on the disc cannot be read accurately and a reading error generally occurs. If the number is lowered, it may be possible to read even a disc with some scratches or dirt. Therefore, in the conventional disc reproducing apparatus, after a disc is rotated at a high speed and reproduction is started, if a reading error occurs, the disc rotating speed is lowered until the reading is normally performed, so that there are scratches and the like. Even discs are played back.

FIG. 12 is a diagram for explaining the disc rotation speed control in a conventional disc reproducing apparatus. Here, the case where the rotation speed of the disk is controlled to one of nine speeds from 1 × speed (1 ×) to 40 × speed (40 ×) is given as an example. At the start of playback, the disc rotates at the maximum speed of 40 times, and the information recorded on the disc can be read. However, in the case of a disc with scratches or dirt, such high-speed rotation cannot read the information. , A read error occurs. Therefore, when an error occurs, the rotational speed of the disk is reduced by one step to 32 times speed, and the recorded information on the disk is read again at this speed. If a read error occurs even at 32x speed, the disk rotation speed is further reduced by one step to 24x speed. If a reading error occurs even at 24x speed, the speed is further reduced by 1 step to 16x speed. Similarly, the rotational speed of the disc is gradually reduced until the recorded information on the disc is normally read. In this example, the normal reading is performed when the rotation speed becomes 4 times.

[0004]

However, in the conventional disc, the rotational speed of the disc is gradually decreased from the maximum speed. Therefore, in the case of a disc that is severely scratched or dirty, it takes time until the disc can be read normally. However, there is a problem that it takes a long time and it takes a long time to reproduce.

On the other hand, in Japanese Unexamined Patent Publication No. 11-306696, when a reading error occurs, the rotational speed of the disk is decelerated until the error is resolved, and when the error is resolved, the rotational speed is increased. A disc player is described. Further, in Japanese Unexamined Patent Publication No. 2000-231765, a retry operation is performed when the disc cannot be read at a normal rotation speed, and when the disc is still not read, the disc is driven at a rotation speed lower than normal,
If the disc can be read normally, the disc reproducing apparatus is described so as to read from the beginning at the same rotation speed from the next time. However, each of the above publications is a technique related to processing after a read error occurs after reproduction, and is not a technique related to shortening the time until reproduction.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a disc reproducing apparatus capable of shortening the time required for reproduction when reproducing a disc having scratches or stains.

[0007]

In the disc reproducing apparatus according to the present invention, the disc is started at a low rotational speed during reproduction, and the rotational speed of the disc is gradually increased during normal reading. When a read error occurs at a certain rotation speed, the rotation speed of the disc is reduced to the speed immediately before the error occurs, and the recorded information on the disc is read again at the reduced rotation speed.

In the present invention, the rotational speed of the disk during reproduction is not lowered from high speed, but rather is gradually increased from low speed, and if a read error occurs, the disk rotational speed immediately before the error occurs. By returning to the speed, it is possible to read even a disc with scratches or dirt, and it is possible to reach the maximum readable speed quickly and shorten the time until reproduction.

In the first embodiment of the present invention, the disc is started from the lowest rotation speed during reproduction, and the rotation speed of the disc is increased stepwise while reading is normally performed. When a read error occurs at a certain rotation speed, the rotation speed of the disc is reduced to the speed immediately before the error occurs, and the recorded information on the disc is read again at the reduced rotation speed. By starting the disc from the lowest rotation speed (for example, 1x speed), even if the disc is heavily scratched or dirty,
It can be read from the beginning.

In the second embodiment of the present invention, whether the rotational speed of the disk at the start of reproduction is the maximum speed or the minimum speed is determined based on the setting result at the time of the previous reproduction, and when the maximum speed is determined, At the time of reproduction, the disc is started from the maximum rotation speed, and if a reading error occurs at the rotation speed, the rotation speed of the disc is gradually reduced until the reading is normally performed. If it is determined to be the lowest speed, the disc is started from the lowest rotation speed, and during normal reading, the rotation speed of the disc is increased stepwise, and a read error occurs at a certain rotation speed. When it occurs, the rotation speed of the disk is reduced to the speed immediately before the error occurs, and the recorded information on the disk is read again at the reduced rotation speed. By doing this, in the case of a disc that can be read at high speed without scratches, you can shorten the time until playback by starting from the maximum speed, while on the other hand, if there are scratches or the like, you can rotate at low speed. For unreadable discs, the time required for playback can be shortened by starting from the lowest speed.

Further, in the second embodiment, the rotational speed of the disk at the time of a read error is compared with a threshold value, and when the rotational speed exceeds a predetermined threshold value, the rotational speed of the disk at the start of the next reproduction is When the maximum speed is set and the rotation speed does not exceed the predetermined threshold value, the rotation speed of the disc at the start of the next reproduction is set to the minimum speed.

In the third embodiment of the present invention, it is determined whether or not the rotational speed at the start of reproduction is recorded for the inserted disc, and if the rotational speed is recorded,
At the time of reproduction, the disc is started from the rotation speed.
On the other hand, when the rotation speed is not recorded, the disc is started from the lowest rotation speed during reproduction. And
During normal reading, the disc rotation speed is increased stepwise, and if a read error occurs at a certain rotation speed, the disc rotation speed is reduced to the speed immediately before the error occurs. The recorded information on the disc is read again at the reduced rotation speed. By doing this, since it is possible to start at the optimum rotation speed according to each disc during playback, it is possible to reliably read the disc and to shorten the time until playback. .

In the fourth embodiment of the present invention, the number of read errors is recorded in association with the rotational speed of the disk, and the rotational speed of the disk that allows normal reading is calculated based on this number of errors. Then, the reproduction of the disc is started at the calculated rotation speed, and while the reading is normally performed, the rotation speed of the disc is increased stepwise, and when a read error occurs at a certain rotation speed, The rotational speed of the disk is reduced to the speed immediately before the error occurs, and the recorded information on the disk is read again at the reduced rotational speed. By calculating the rotation speed of the disk at the start from the number of read errors in this way, it is possible to set the optimum rotation speed according to the error status of each disk, and ensure that the disk is read. In addition, the time required for reproduction can be minimized.

[0014]

1 is a block diagram showing the electrical configuration of a disk reproducing apparatus A according to the present invention. In the figure, 1 is an optical disk such as a CD-ROM (hereinafter simply referred to as a disk), 2 is a disk motor for rotating the disk 1, and 3 is a disk drive unit for driving the disk motor 2. Reference numeral 4 denotes an optical pickup that irradiates the disk 1 with laser light and reads the recorded information on the disk 1 from the reflected light. The optical pickup 4 constitutes the reading means in the present invention. Reference numeral 5 is a pickup driving unit that electrically and mechanically drives the optical pickup 4, 6 is a signal processing unit that processes a signal received by the optical pickup 4, and 7 is a signal processing unit.
Is a disc reproducing section for reproducing the recorded information of the optical disc 1 based on the processed signal. The signal processing section 6 and the disk reproducing section 7 constitute the reproducing means in the present invention. Reference numeral 8 denotes a control unit including a CPU that controls each unit, and the control unit 8 controls the control means in the present invention.
A discriminating means and a calculating means are configured. 9 is ROM or R
A memory composed of AM, 10 is an operation unit for performing operations such as reproduction and stop of the disc 1, 11 is a display unit for displaying various messages, and 12 is an interface for exchanging signals and data with an external device. Is.

Next, the rotation speed control of the disc in the disc reproducing apparatus A will be described. FIG. 2 shows the first
It is a figure explaining the rotation speed control which concerns on embodiment of this. In the present embodiment, as shown in FIG. 2A, reproduction is started from the minimum rotation speed of 1 × speed for the disc 1 having scratches and dirt. If the recorded information on the disc 1 can be normally read at 1 × speed, then the rotation speed of the disc 1 is increased to 2 × speed, and if the disc 1 can be normally read at 2 × speed, the rotation speed is increased to 4 × speed. As described above, the rotational speed of the disk 1 is gradually increased while the reading is normally performed. Then, when a reading error of the disc 1 occurs when the disc speed is increased to 8 times, the rotation speed of the disc 1 is set to 4 before the error occurs.
Reduce to double speed. Then, thereafter, the recorded information on the disc 1 is read and reproduced at the quadruple speed. Further, as shown in FIG. 2B, when an error occurs during reproduction at quadruple speed, the rotation speed of the disc 1 is reduced by another step to double speed.

In this way, the rotation speed of the disk is started from the minimum speed and gradually increased, and when a reading error occurs, the rotation speed of the disk is reduced to the speed immediately before the error, so that scratches and dirt can be prevented. Even if the disc has a large degree, it is possible to perform reproduction at the maximum readable speed (4 × speed in FIG. 2A). Further, as can be seen from the comparison with FIG. 12, even when the reproduction is performed at the same quadruple speed, the present embodiment reaches the quadruple speed earlier, so that the time until the reproduction is shortened.

FIG. 3 is a flow chart showing the procedure of the rotational speed control in the first embodiment, and shows the procedure executed by the control unit 8. Hereinafter, the details of the rotational speed control will be described with reference to this flowchart.

When the reproducing operation is started by the operation of the operation unit 10, first, the rotation speed of the disc 1 is set to the minimum speed, that is, 1 × speed (step S1). Then, the disc driving unit 3 drives the disc motor 2 at the lowest speed, and the optical pickup 4 reads the recorded information of the disc 1 rotating at 1 × speed (step S2). continue,
It is determined whether a reading error has occurred (step S3). When the read information does not occur and the recorded information on the disc 1 is normally read (step S3: N
O), the process proceeds to step S7, and it is determined whether the rotation speed of the disk 1 is the maximum speed. If it is not the highest speed (step S7: NO), the speed of the disc 1 is increased by one step (step S8), the process returns to step S2, and the information of the disc 1 is read again. Subsequently, it is determined whether or not a read error has occurred (step S3), and if no read error has occurred (step S3: NO), it is determined whether or not the rotation speed of the disk 1 is the maximum speed (step S7). ),
If it is not the maximum speed (step S7: NO), the speed of the disk 1 is further increased by one step (step S8), and the process returns to step S2 to read the information of the disk 1. If the rotation speed of the disk 1 reaches the maximum speed (step S
(7: YES), return to step S2 at that speed, and read the information on the disk 1. Similarly, the above-mentioned processing is repeated until a read error occurs.

On the other hand, when a read error occurs in step S3 and the recorded information on the disc 1 cannot be read normally (step S3: YES), step S4
Then, it is determined whether the rotation speed of the disk 1 is the minimum speed. If it is not the minimum speed (step S4: N
O), the speed of the disk 1 is reduced by one step (step S
5) After performing the process for rereading (step S
6) Then, the process returns to step S2, and the information on the disc 1 is read again. Then, it is determined whether or not a read error has occurred (step S3). If no read error has occurred (step S3: NO), the process proceeds to step S7 and the above-described processing is performed. If a read error occurs again (step S3: YES), it is determined whether the rotation speed of the disk 1 is the minimum speed (step S4). If it is the minimum speed (step S4: YES), the speed is further increased. Since the value cannot be lowered, an error message is displayed on the display unit 11 and the process ends. At this time, it is done. Also,
If it is not the lowest speed (step S4: NO), the speed of the disk 1 is further reduced by one step (step S5), the process for rereading is performed (step S6), and then the process returns to step S2 and the disk 1 is restarted. Read the information. Similarly, if a read error occurs, the above process is repeated.

FIGS. 4 and 5 are diagrams for explaining the rotation speed control according to the second embodiment. In the present embodiment, a threshold value is set for the rotation speed of the disc, the rotation speed of the disc when a read error occurs is compared with the threshold value, and when the rotation speed exceeds a predetermined threshold value, the next playback is started. The rotation speed of the disk is set to the maximum speed (40 times speed). When the rotation speed does not exceed the predetermined threshold value, the rotation speed of the disk at the start of the next reproduction is set to the minimum speed (1x speed). These set values are stored in the memory 9 in association with disc information (for example, TOC information) for identifying the disc. Then, at the time of reproduction, the rotational speed corresponding to the inserted disc 1 is read from the memory 9, and if it is the maximum speed, reproduction of the disc 1 is started from 40 times speed as shown in FIG. The rotation speed of the disc 1 is gradually decreased until the disc is released. On the other hand, if the rotation speed is the lowest speed, reproduction of the disc 1 is started from the 1 × speed as shown in FIG. 5, and if a read error occurs, the rotation speed of the disc 1 is reduced to the speed immediately before the error.

In FIGS. 4 and 5, the threshold value of the rotation speed is set to 16 times speed, and this threshold value can be arbitrarily set by the user with the operation unit 10. In the case of FIG. 4A, the rotation speed of the disk 1 at the time of the last error occurrence is 32 times speed, and this value exceeds 16 times the threshold value. In this case, the rotation speed of the disc 1 at the start of the next reproduction is set to the maximum speed, and the reproduction is performed from 40 times speed next time. On the other hand, in the case of FIG. 4B, the rotation speed of the disk 1 at the time of the last error occurrence is 12 times speed, and this value is below the threshold value of 16 times speed. In this case, the rotation speed of the disc 1 at the start of the next reproduction is set to the minimum speed, and the reproduction is performed from the 1 × speed next time. In addition,
As shown in FIG. 4B, the reason why the reading error continues and the reproduction can be performed only at the low speed even though the reproduction is started from the maximum speed is that the disc 1 is read from the end of the previous reproduction to the start of the present reproduction. It is possible that there are scratches or stains on the surface.

In the case of FIG. 5A, the rotation speed of the disk 1 at the time of occurrence of an error is 12 times the speed, which is below the 16 times the threshold value. In this case, the rotation speed of the disc 1 at the start of the next reproduction is set to the minimum speed, and the reproduction is performed from the 1 × speed next time. On the other hand, FIG.
In the case of (b), the rotation speed of the disk 1 at the time of error occurrence is 32 times speed, and this value exceeds 16 times the threshold value. In this case, the rotation speed of the disc 1 at the start of the next reproduction is set to the maximum speed, and the reproduction is performed from 40 times speed next time. It should be noted that the reason why normal reading continues and high-speed reproduction is possible even if the reproduction is started at the lowest speed as shown in FIG. It is considered that the dirt adhering to 1 was removed.

In the case of a disc free from scratches and dirt, high-speed reading is possible, and even if a reading error occurs, the rotation speed at that time usually exceeds the threshold value as shown in FIG. 4 (a). Therefore, the speed at the start of the next reproduction is set to the maximum speed. Therefore, by starting the reading from the maximum speed, the time until the reproduction can be shortened. If the disc is scratched or dirty,
Since it is possible to read only at low speeds and the rotation speed when a read error occurs does not normally exceed the threshold as shown in Fig. 5 (a), the speed at the start of the next playback is set to the minimum speed. It Therefore, by starting the reading from the lowest speed, the time until the reproduction can be shortened.

FIG. 6 is a flow chart showing the procedure of the rotational speed control in the second embodiment, and shows the procedure executed by the control unit 8. Hereinafter, the details of the rotational speed control will be described with reference to this flowchart.

When the reproduction operation is started by the operation of the operation unit 10, it is determined by referring to the memory 9 whether or not the rotation speed at the reproduction start set for the inserted disc 1 is the maximum speed (step S11). If the result of determination is that the rotation speed is the maximum speed (step S11: YE
S), the rotation speed of the disk 1 is the maximum speed, that is, 40
The speed is set to double speed (step S12). When the rotation speed is the lowest speed (step S11: NO), the rotation speed of the disk 1 is set to the lowest speed, that is, 1 × speed (step S13). Next, the disc driving unit 3 drives the disc motor 2 to read the recorded information of the rotating disc 1 with the optical pickup 4 (step S14). Then, it is determined whether a reading error has occurred (step S15). When the read error does not occur and the recorded information on the disc 1 is normally read (step S15: NO), the process proceeds to step S22. The steps after step S22 will be described later.

If a read error occurs in step S15 and the recorded information on the disc 1 cannot be read normally (step S15: YES), then it is determined whether the rotation speed of the disc 1 at the time of the error exceeds the threshold value. It is determined (step S16). When the rotation speed exceeds the threshold value (step S16: YES), the speed of the disk 1 is decreased by one step (step S20), and the process for rereading is performed (step S21), and then step S14.
Then, the information on the disc 1 is read again. Then, it is determined whether a reading error has occurred (step S1).
5) If no reading error occurs (step S1)
5: NO), and proceeds to step S22. If a read error occurs again (step S15: YE
S), it is determined whether the rotation speed of the disc 1 at that time exceeds a threshold value (step S16). If the rotation speed exceeds the threshold value (step S16: YES), the speed of the disc 1 is further increased by 1. Step down (step S2
0), and after performing the process for rereading (step S2
1) The process returns to step S14 and the information on the disc 1 is read again.

In step S16, if the rotation speed of the disk 1 does not exceed the threshold value (step S16: N
After the error occurrence flag is turned ON in the memory 9 (step S17), the rotation speed of the disk 1 at the start of the next reproduction is set to the minimum speed (step S18). Subsequently, it is determined whether or not the rotation speed of the disk 1 at the time of occurrence of an error is the minimum speed (step S19). If the rotation speed is the minimum speed (step S19: YES), the speed cannot be reduced any further, so the display unit An error message is displayed on 11, and the process ends. If it is not the lowest speed (step S19: NO), the speed of the disk 1 is reduced by one step (step S20), the process for re-reading is performed (step S21), the process returns to step S14, and the disk is read again. Read the information in 1. Similarly, if a read error occurs, the above process is repeated.

If no reading error occurs in step S15, the process proceeds to step S22, and it is determined whether or not the rotation speed of the disk 1 is the maximum speed. If it is the maximum speed (step S22: YES), the process directly returns to step S14 to read the disc information. If it is not the highest speed (step S22: NO), the speed of the disk 1 is increased by one step (step S23), and then it is determined whether or not a reading error has occurred at that rotation speed (step S24). This determination is made by referring to the error occurrence flag (step S17) in the memory 9. If the error occurrence flag is ON, that is, if an error has occurred (step S24:
YES), the process directly returns to step S14 and the disc 1
Read. If the error occurrence flag is OFF, that is, if no error has occurred (step S24: NO), then it is determined whether the rotation speed of the disk 1 exceeds the threshold value (step S25). If the rotation speed does not exceed the threshold value (step S25: N
O), the process directly returns to step S14 to read the disc 1. If the rotation speed exceeds the threshold (step S25: YES), the rotation speed of the disc 1 at the start of the next reproduction is set to the maximum speed (step S25).
26) and returns to step S14 to read the disc 1. Similarly, if the reading error does not occur, the above processing is repeated.

FIG. 7 is a diagram for explaining the rotation speed control according to the third embodiment. In this embodiment, the rotation speed at the start of reproduction is set for each disc. That is, it is determined whether or not the rotation speed at the start of reproduction is recorded for the inserted disc, and if the rotation speed is recorded, the disc is started from the rotation speed at the time of reproduction. In the example of FIG. 7, 24 times speed is recorded as the rotation speed of the disk A, and the rotation is started from the 24 times speed. Further, as for the disc B, the 8 × speed is recorded, and the rotation is started from the 8 × speed. On the other hand, when the rotation speed is not recorded, the disc is started from the lowest rotation speed during reproduction. The disk C corresponds to this case, and the disk C in which the rotation speed is not recorded starts the rotation from the 1 × speed. The information about the rotation speed may be recorded in the memory 9 in association with disc information (for example, TOC information) for identifying the disc.

In FIG. 7, the operation after reproduction of each disk is the same as that in FIG. 2, and during normal reading, the rotational speed of the disk is gradually increased to prevent a read error. If the error occurs, the rotational speed is decelerated by one step to the speed immediately before the error occurs, and the recorded information on the disk is read again at the reduced rotational speed. At this time, if an error occurs again, the rotation speed is further reduced by one step and the reading is performed. In this way, by setting the rotation speed for each disc individually, it is possible to start playback at the optimum rotation speed for each disc during playback, which ensures that the disc is read. In addition, it is possible to minimize the time until the reproduction.

FIG. 8 is a flow chart showing the procedure of rotation speed control in the third embodiment, and shows the procedure executed by the control unit 8. Hereinafter, the details of the rotational speed control will be described with reference to this flowchart.

When the reproducing operation is started by the operation of the operation section 10, it is determined by referring to the memory 9 whether or not there is information on the rotational speed of the inserted disc 1 (step S31). As a result of the determination, if there is information on the rotation speed (step S31: YES), a predetermined rotation speed stored in the memory 9 is set as the rotation speed of the disk 1 (step S32). If there is no information on the rotation speed (step S31: NO), the rotation speed of the disk 1 is set to the minimum speed, that is, 1 × speed (step S33). Next, the disc driving unit 3 drives the disc motor 2 to read the recorded information of the rotating disc 1 with the optical pickup 4 (step S34). Then, it is determined whether a reading error has occurred (step S35). Disk 1 without reading error
If the recorded information of is successfully read (step S3
5: NO), and proceeds to step S41. Step S4
Items 1 and later will be described later.

When a read error occurs in step S35 and the recorded information on the disk 1 cannot be read normally (step S35: YES), the error occurrence flag is set to ON in the memory 9 (step S3).
6) The disc information of the inserted disc and the readable rotation speed are paired and stored in the memory 9 (step S37). As the readable rotation speed, the rotation speed of the disk immediately before the error occurs is stored, and this rotation speed is referred to in step S31 at the time of the next reproduction. Then, it is determined whether the rotation speed of the disk 1 is the minimum speed (step S38), and if it is the minimum speed (step S3).
8: YES), since the speed cannot be further reduced, an error message is displayed on the display unit 11 and the process ends. If it is not the minimum speed (step S38:
NO), the speed of the disk 1 is decreased by one step (step S
39), after performing the process for rereading (step S
40), the process returns to step S34, and the information of the disc 1 is read again. Similarly, if a read error occurs, the above process is repeated.

If no reading error occurs in step S35, the process proceeds to step S41, and it is determined whether or not the rotation speed of the disk 1 is the maximum speed. If it is the maximum speed (step S41: YES), the process directly returns to step S34 to read the disc information. If it is not the maximum speed (step S41: NO), the speed of the disk 1 is increased by one step (step S42),
It is determined whether or not a reading error has previously occurred at that rotation speed (step S43). This judgment is made in the memory 9
This is performed by referring to the error occurrence flag in step S36 (step S36). If the error occurrence flag is ON, that is, if an error has occurred (step S
(43: YES), the process directly returns to step S34 to read the disc 1. In addition, the error occurrence flag is O
In the case of FF, that is, when an error has not occurred (step S43: NO), the disc information of the inserted disc and the readable rotation speed are stored in the memory 9 as a pair (step S43). S44). As the readable rotation speed, the rotation speed set in step S42 is stored, and this rotation speed is stored in step S during the next reproduction.
Referenced at 31. Then, return to step S34,
Read the disc information. Similarly, if the reading error does not occur, the above processing is repeated.

FIG. 9 is a diagram for explaining the rotation speed control according to the fourth embodiment. In this embodiment, the rotational speed of the readable disk is calculated based on the number of read errors, and the reproduction is started at this rotational speed. Therefore, the rotation speed at the start of reproduction is different, such as 2 × speed, 8 × speed, and 16 × speed, depending on the status of the error that has occurred. An example of the method of calculating the rotation speed will be described below. Figure 10
Is an example of error data recorded in the error recording table 20, and corresponds to the rotation speed (double speed) of the disc,
The number of errors and the cumulative total of errors are recorded. The error recording table 20 is provided in the memory 9 and constitutes the recording means in the present invention. Here, α = (cumulative number of errors up to n times speed / total number of readings) × threshold is set as an index indicating the error rate when the rotation speed is increased, and the next reproduction is performed according to the value of α. Determine the rotation speed (double speed) at the start. The threshold can be arbitrarily set by the user.

For example, assuming that the threshold value in the above equation is 10%, 24
If the error occurrence situation when the reading process is performed 25 times with the double speed disk drive is as shown in FIG.
When reading at double speed, α = (2/25) × 0.1 = 8%
When reading at 12 times speed, α = (4/25) ×
It becomes 0.1 = 16%. When these values are compared with 10% of the threshold value, α is smaller than the threshold value in the case of 8 × speed and the error occurrence rate is small, and in the case of 12 × speed, α is larger than the threshold value and the error occurrence rate is large. Become.
Therefore, in the case of the present example, the reading of the disc is started from the 8 × speed when the next reproduction is started. The operation after reproduction is the same as in the case of FIG. 2, and during normal reading,
When the disc rotation speed is increased stepwise and a read error occurs at a certain rotation speed, the disc rotation speed is decelerated to the speed immediately before the error, and the disc recording information is re-recorded at this decelerated rotation speed. To read.

In this way, the value of α corresponding to each double speed is calculated based on the number of errors, and this value is compared with the threshold value to determine the double speed at the start of reproduction, so that the error occurrence condition for each disk can be met. Since the optimum rotation speed can be set, the disc can be read reliably and the time until reproduction can be minimized.

FIG. 11 is a flow chart showing the procedure of the rotation speed control in the fourth embodiment, and shows the procedure executed by the control unit 8. Hereinafter, the details of the rotational speed control will be described with reference to this flowchart.

When the reproducing operation is started by the operation of the operation unit 10, the disc speed at the start of reproduction is calculated according to the above-mentioned principle (step S51), and the disc rotation speed is set to the calculated speed (step S52). ). Then, the disc driving unit 3 drives the disc motor 2 at a set speed to record information on the disc 1 by the optical pickup 4
Is read (step S53). Then, it is determined whether a reading error has occurred (step S54). When the read error does not occur and the recorded information on the disc 1 is normally read (step S54: NO), the process proceeds to step S59, and it is determined whether the rotation speed of the disc 1 is the maximum speed. If not the maximum speed (step S5
9: NO), the speed of the disc 1 is increased by one step (step S60), the process returns to step S53, and the information of the disc 1 is read again. Subsequently, it is determined whether or not a read error has occurred (step S54). If no read error has occurred (step S54: NO), it is determined whether or not the rotation speed of the disk 1 is the maximum speed (step S5).
9) If it is not the maximum speed (step S59: NO),
Increase the speed of the disc 1 by one step (step S6
0), the process returns to step S53 to read the information on the disc 1. If the rotation speed of the disk 1 reaches the maximum speed (step S59: YES), the speed is changed to step S5.
Returning to step 3, the information on the disk 1 is read. Similarly, the above-mentioned processing is repeated until a read error occurs.

On the other hand, when a read error occurs in step S54 and the recorded information on the disk 1 cannot be read normally (step S54: YES), the memory 9
The number of errors is recorded in the error recording table 20 (FIG. 10) corresponding to the current double speed (step S55). At this time, the error cumulative value in the table 20 is automatically updated. Then, it is determined whether the rotation speed of the disk 1 is the minimum speed (step S56). If it is not the lowest speed (step S56: NO), the speed of the disk 1 is decreased by one step (step S57), the process for re-reading is performed (step S58), and then the process returns to step S53 and the disk 1 is read again. Read the information. Then, it is determined whether or not a read error has occurred (step S54), and if no read error has occurred (step S54: N
O), the process proceeds to step S59 and the above-mentioned processing is performed. If a read error occurs again (step S5)
4: YES), and the number of errors is recorded in the error recording table 20 in association with the current double speed (step S55).
Then, it is determined whether the rotation speed of the disk 1 is the minimum speed (step S56), and if it is the minimum speed (step S56).
56: YES), since the speed cannot be reduced any further, an error message is displayed on the display unit 11 and the process ends. If it is not the minimum speed (step S5)
6: NO), the speed of the disk 1 is further reduced by one step (step S57), the process for re-reading is performed (step S58), the process returns to step S53, and the information of the disk 1 is read again. Similarly, if a read error occurs, the above process is repeated.

In each of the above-mentioned embodiments, the rotation speed at the start of reproduction of the disc 1 is automatically set on the apparatus side, but this may be arbitrarily set by the user. Further, the operation unit 10 may be provided with a selection switch for starting a disc with scratches or dirt at the lowest speed and a disc without scratches or the like at the highest speed.

The present invention can be applied not only to a disc drive mounted on a personal computer but also to a CD player, a DVD player, etc. for reproducing music and video. Further, the disc reproducing apparatus according to the present invention may be a reproduction-only apparatus or an apparatus having both reproduction and recording functions.

[0043]

According to the present invention, since the disc is read while gradually increasing the rotation speed from the low speed at the start of reproduction, it is possible to read a disc with scratches and dirt, and the maximum readable speed is obtained. It is possible to reach early and shorten the time until playback.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating rotation speed control according to the first embodiment.

FIG. 3 is a flowchart showing a procedure of rotation speed control in the first embodiment.

FIG. 4 is a diagram illustrating rotational speed control according to a second embodiment.

FIG. 5 is a diagram illustrating rotation speed control according to a second embodiment.

FIG. 6 is a flowchart showing a procedure of rotation speed control in the second embodiment.

FIG. 7 is a diagram illustrating rotation speed control according to a third embodiment.

FIG. 8 is a flowchart showing a procedure of rotation speed control in the third embodiment.

FIG. 9 is a diagram illustrating rotation speed control according to a fourth embodiment.

FIG. 10 is an example of error data recorded in an error recording table.

FIG. 11 is a flowchart showing a procedure of rotation speed control in the fourth embodiment.

FIG. 12 is a diagram for explaining disk rotation speed control in a conventional disk reproducing device.

[Explanation of symbols]

A disc player 1 disc 2 disk motor 3 disk drive 4 Optical pickup 5 Pickup drive 6 Signal processing unit 7 Disc playback section 8 control unit 9 memory 10 Operation part 11 Display 12 interfaces 20 Error record table

Claims (6)

[Claims] 1. A disc reproducing apparatus comprising: a reading unit for reading information recorded on a disc; a reproducing unit for reproducing the information read by the reading unit; and a control unit for controlling a rotation speed of the disc. The control means starts the disc from the lowest rotation speed during reproduction, and during normal reading,
When the disc rotation speed is increased stepwise and a read error occurs at a certain rotation speed, the disc rotation speed is decelerated to the speed immediately before the error, and the disc recording information is re-recorded at this decelerated rotation speed. A disc reproducing device characterized by reading a disc. 2. A disc reproducing apparatus comprising: a reading unit for reading information recorded on the disc; a reproducing unit for reproducing the information read by the reading unit; and a control unit for controlling the rotation speed of the disc. The disc rotation speed at the start of reproduction is provided with a discriminating means for discriminating whether it is the highest speed or the lowest speed based on the setting result at the time of the previous reproduction, and the control means, when the discriminating means judges the highest speed, When the disc is started at the highest rotation speed during playback and a reading error occurs at that rotation speed, the rotation speed of the disc is gradually decreased until the reading is normally performed, and the discriminating means discriminates the lowest speed. When the reading is successful, the disc is started from the lowest rotation speed, and during normal reading, the rotation speed of the disc is increased. If a read error occurs at a certain rotation speed, the disk rotation speed is reduced to the speed immediately before the error occurred, and the recorded information on the disk is read again at this reduced rotation speed. A disc reproducing device characterized by. 3. The disc reproducing apparatus according to claim 2, wherein the control means, when a read error occurs and the rotational speed of the disc exceeds a predetermined threshold value, the disc at the next reproduction start time. Is set to the maximum speed, and when the rotational speed of the disk does not exceed a predetermined threshold value, the rotational speed of the disk at the start of the next reproduction is set to the minimum speed. 4. A disc reproducing apparatus comprising: a reading unit for reading information recorded on the disc; a reproducing unit for reproducing the information read by the reading unit; and a control unit for controlling the rotation speed of the disc. A discriminating means for discriminating whether or not the rotation speed at the start of reproduction is recorded for the inserted disc is provided, and the control means reproduces when the discriminating means judges that the rotation speed is recorded. Sometimes the disc is started from the rotation speed, and if the discriminating means discriminates that the rotation speed is not recorded, the disc is started from the lowest rotation speed during reproduction, and while the reading is normally performed. , The rotation speed of the disk is increased stepwise, and if a read error occurs at a certain rotation speed, the rotation speed of the disk Slowing the speed just before the error, the disk reproducing apparatus, characterized in that to read the information recorded on the disk again at this reduced rotation speed. 5. A disc reproducing apparatus comprising: a reading unit for reading information recorded on the disc; a reproducing unit for reproducing the information read by the reading unit; and a control unit for controlling the rotation speed of the disc. When a read error occurs, a recording unit that records the number of errors in association with the rotation speed of the disc, and based on the number of errors stored in the recording unit,
And a calculating means for calculating the rotational speed of the disc that can be read normally, wherein the control means starts the disc from the rotating speed calculated by the calculating means at the time of reproduction, and while the reading is normally performed. Increases the disc rotation speed in stages, and if a read error occurs at a certain rotation speed, the disc rotation speed is reduced to the speed immediately before the error occurs, and the disc rotation speed is reduced again at this reduced rotation speed. A disc reproducing device characterized by reading recorded information. 6. A disc reproducing apparatus for reading and reproducing information recorded on a disc, wherein the disc is started at a low rotational speed during reproduction.
During normal reading, the disc rotation speed is gradually increased, and if a read error occurs at a certain rotation speed, the disc rotation speed is decelerated to the speed immediately before the error occurs. A disc reproducing apparatus characterized in that the recorded information on the disc is read again at a controlled rotation speed.