JP2006185495A - Information reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the more stable reproduction of a recording medium. <P>SOLUTION: By a micro-controller 6, a setting value affecting the reproduction of an optical disk 13 is changed when a reproduction error is generated at the reproduction of the optical disk 13, and the setting value after the change is made is stored for every kind of the optical disks 13, and at a retry operation when the reproduction error is generated, the setting value affecting the reproduction of the optical disk 13 is changed to repeat the retry operation with a predetermined frequency, and a counted value corresponding to the setting value when the reproduction is succeeded by the retry operation within the predetermined frequency is counted up and stored. When the reproduction of optical disk 13 is started, the setting value corresponding to a stored maximum counted value is set. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an information reproducing apparatus for reproducing a recording medium such as a CD-R disc, a CD-RW disc, a DVD + R disc, a DVD + RW disc, a DVD-R disc, and a DVD-RW disc.

When a recording medium reproduced by an information reproducing apparatus such as an optical disk apparatus has a local scratch or the like, a reproduction error occurs and a retry operation is performed. In that case, it is considered to retry by changing the set value at the time of retry.
Conventionally, there has been an information reproducing apparatus (for example, refer to Patent Document 1) that stores setting conditions for reproduction retry when a reproduction error occurs.
JP 2003-196839 A

However, the conventional information reproducing apparatus has a problem in that the number of retries is limited, and a reproduction error may occur because the number of retries cannot be changed.
Therefore, if various settings are changed at the time of retry and a setting that can be played back with a small number of retries is found, the playback quality can be improved by storing the setting and appropriate settings at the next playback.
The present invention has been made in view of the above points, and an object thereof is to enable more stable reproduction of a recording medium.

In order to achieve the above object, the present invention provides the following information reproducing apparatuses.
(1) In an information reproducing apparatus for reproducing information from a recording medium, when a reproduction error occurs during reproduction of the recording medium, setting value changing means for changing a setting value affecting the reproduction of the recording medium, and the setting value An information reproducing apparatus provided with setting value storage means for storing the changed setting value changed by the changing means for each type of the recording medium.
(2) In the information reproducing apparatus of (1), during a retry operation when a reproduction error occurs, the set value changing means changes the set value that affects the reproduction of the recording medium and performs a predetermined number of retry operations. An information reproducing apparatus provided with a set value count storage means for repeatedly counting up and storing a count value corresponding to a set value when reproduction is successfully performed by retry operation within the predetermined number of times.
(3) In the information reproducing apparatus of (2), an information reproducing apparatus provided with means for setting a set value corresponding to the largest count value stored in the set value count storing means at the start of reproduction of the recording medium .

(4) In the information reproducing apparatus of (2), the set value count storage means sets a set value that affects reproduction of the recording medium by the set value changing means during a retry operation when the reproduction error occurs. Information reproduction as a means for repeating a predetermined number of retry operations and incrementing the count value corresponding to the set value when reproduction is successful within the predetermined number of retry operations and storing it for each type of reproduction error apparatus.
(5) The information reproducing apparatus according to (4), further comprising means for setting a setting value having the largest count value for each type of the reproduction error as a setting value during the retry operation.
(6) In the information reproducing apparatus of (4), means for setting a set value corresponding to the largest count value stored for each type of reproduction error in the set value count storage means at the start of reproduction of the recording medium An information reproducing apparatus.

(7) In an information reproducing apparatus for reproducing information from a recording medium, error rate measuring means for measuring an error rate during reproduction of the recording medium, and reproduction of the recording medium based on the error rate measured by the error rate measuring means An information reproducing apparatus provided with setting value changing means for changing a setting value that affects the setting value and setting value storage means for storing the changed setting value changed by the setting value changing means for each type of the recording medium.
(8) In the information reproducing apparatus according to (7), the set value changing unit may be configured such that a second error rate measured by the error rate measuring unit is greater than or equal to a first threshold value set in advance and greater than the first threshold value. An information reproducing apparatus as means for investigating a setting value that minimizes the error rate when the value is equal to or less than the threshold value and changing the setting value to a setting value obtained as a result of the investigation.
(9) In the information reproducing apparatus of (8), the set value changing unit maintains the set value without changing when the error rate measured by the error rate measuring unit is less than the first threshold value. An information reproducing apparatus provided with means.

(10) The information reproducing apparatus according to (9), wherein the setting value stored in the setting value storage means has a default value, a current value, and a running optimum value.
(11) In the information reproducing apparatus according to (10), the setting value changing means includes means for returning the setting value to the default value when the error rate measured by the error rate measuring means exceeds the second threshold value. An information reproducing apparatus.
(12) In the information reproducing apparatus of (11), when the recording medium is played out after the recording medium is normally reproduced, the number of successful reproductions of the set value at the time of the playing is counted up and reproduced next time. An information reproducing apparatus provided with means for starting reproduction by setting a set value with the largest number of successful reproduction times.

  The information reproducing apparatus according to the present invention can reproduce the recording medium more stably.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an information reproducing system including an optical disk drive according to an embodiment of the present invention.
In this information reproduction system, an optical disk drive 11 and a host computer 12 are connected so that data communication is possible.
In the host computer 12, a control unit realized by a microcomputer including a CPU, a ROM, a RAM, and the like controls the entire apparatus, and receives and uses data reproduced by the optical disk drive 11.

  An optical disk drive 11 includes an optical pickup 2 having a spindle motor 1 that rotates an optical disk 13 that is a recording medium, and a light source such as a laser diode (LD) that emits a laser beam L for reproducing information recorded on the optical disk 13. A rotation control system unit 3 that controls the rotation of the spindle motor 1, a coarse motion motor that moves the optical pickup 2 in the radial direction of the optical disk 13, and a coarse motion motor / light that controls the drive of the optical pickup 2 and the coarse motion motor. A pickup control system unit 4 and a signal processing system unit 5 that performs processing for sending a signal reproduced from the optical pickup 2 to the microcontroller 6 are provided.

  The microcomputer 6 has a microcomputer 6 that controls the entire optical disk drive 11, data reproduced from the optical disk 13, and data received by the microcontroller 6 during various data processing and firmware program writing. Buffer memory 7 for temporarily storing data, setting value affecting reproduction for each type of optical disc 13, setting value corresponding to setting value when reproduction is successful in retry operation, setting when reproduction is successful in retry operation An EEPROM 8 that stores data such as a count value for each type of reproduction error corresponding to the value, a default value of a set value, a current value, and an optimum running value; a flash memory 9 that stores firmware executed by the microcontroller 6; , Host computer 12 and And an external interface control system 10 which controls for exchanging data.

There are ATAPI, SCSI, USB, IEEE1394, and the like as an external interface system of the external interface control system unit 10.
Further, the flash memory 9 may be used in place of the EEPROM 8.
Then, the microcomputer 6 executes the firmware program stored in the flash memory 9, executes the information reproducing method by executing each step of the program, and fulfills the functions of the respective means according to the present invention.

Next, playback processing in the optical disk drive 11 will be described.
In this reproduction process, when a retry operation is performed at the time of a reproduction error, the setting values of various setting values are changed and the retry operation is repeated a predetermined number of times.
In addition, when the reproduction is successful in the retry operation within a certain number of times after changing from the current value at the time of the reproduction error to the previous value, the setting value is counted up in the setting value count table corresponding to the setting value. Then, when the same type of optical disk is reproduced next time, the setting value having the largest count number is selected.
In this way, various settings during playback are set appropriately, and the playback quality can be improved.

The types of the optical disc 13 are DVD-ROM single layer disc, DVD-ROM double layer disc, DVD + R disc, DVD + RW disc, DVD-R disc, DVD-RW disc, CD-ROM disc, CD-R disc, CD-RW disc, etc. There is.
As types of reproduction errors at the time of reproduction, there are a seek error that is an error in a seek operation when performing a mechanical operation, an error in which an address cannot be read for some reason, an error correction (ECC) error, and the like.
The setting values of the control system unit of the optical pickup 2 and the signal processing system unit 5 of the coarse motor / optical pickup control system unit 4 include a boost setting value, an equalizer setting value, a read power setting value, a track servo gain setting value, There is a focus servo gain setting value.

Thereafter, the boost setting value is set to 1, the equalizer setting value is set to 2, the read power setting value is set to 3, the track servo gain setting value is set to 4, and the focus servo gain setting value is set. The value is 5. If there are other effective setting values, they may be added or changed to any one of the above setting values.
FIG. 2 is a diagram showing the format of a table for storing various setting values for each type of optical disk stored in the EEPROM 8.
The various setting value storage tables store default values and current values for each part in the apparatus for each type of optical disc 13 in a table format.
The default value is an initial setting value at the time of shipment from the factory, and the current value is a setting value with the smallest number of retries during a retry operation when a previous playback error occurred, and is set at the start of playback.

Further, each of the set values 1 to 5 is prepared from a maximum value to a standard value to a minimum value. In this embodiment, five levels are prepared.
As the contents of the change of the set value, the standard value (C), the maximum value A, and the minimum value E are set as follows, the set value = A, the set value = B, the set value = C, the set value = D, and the set value = When E (however, A>B>C>D> E), the following set values can be selected.
Setting value 1 (boost setting value): Setting value = A, B, C, D, E
Setting value 2 (equalizer setting value): Setting value = A, B, C, D, E
Setting value 3 (read power setting value): Setting value = A, B, C, D, E
Setting value 4 (track servo gain setting value): Setting value = A, B, C, D, E
Setting value 5 (focus servo gain setting value): Setting value = A, B, C, D, E

FIG. 3 and FIG. 4 are diagrams showing the format of the setting value count table with a small number of retries for each type of optical disk stored in the EEPROM 8.
The setting value count table with a small number of retries is a table for counting up the count value corresponding to the setting value with a small number of retries for each type of optical disc.
FIG. 5 to FIG. 10 are diagrams showing the format of a set value count table in which the number of retries is small for each type of optical disk stored in the EEPROM 8 for each type of reproduction error.
This setting value count table with a small number of retries for each reproduction error type counts up a count value corresponding to a setting value with a small number of retries for each type of optical disk for each reproduction error type (reproduction error types X, Y, Z). It is a table to do.

FIG. 11 is a flowchart showing a reproduction process in the optical disc drive 11 shown in FIG.
When the microcontroller 6 detects the optical disc in step (indicated by “S” in the figure) 1, in step 2, the microcontroller 6 searches the setting value count table with the smallest number of retries for each type of optical disc and searches for the setting value with the maximum value. The setting value is set to the current value, various setting values are set, the reproduction operation is started in step 3, it is determined whether or not a reproduction error has occurred in step 4, and if no reproduction error occurs, After the reproduction is finished, the reproduction is stopped at step 13 and this process is finished.

  If a reproduction error occurs in step 4, the retry setting value for each reproduction error type (setting value at the time of retry operation) is retrieved and set to the setting value in step 5, and the retry operation is started in step 6. The number of retries is counted up, and it is determined whether or not the reproduction is successful as a result of the retry operation in step 7, and if successful, the count value in the setting value count table with a small number of retries for each reproduction error type is counted up in step 16; After the reproduction is finished, the reproduction is stopped at step 13 and this process is finished.

  If the reproduction is not successful in step 7, it is determined whether or not the reproduction is stopped in step 8. If the reproduction is stopped, the reproduction is stopped in step 13 and the process is terminated. It is determined whether or not the number of retries exceeds a preset number of times (here, the value of the number of retry operation repetitions + 1), and if not, the process returns to step 6 and the above processing is repeated. It is determined whether or not the confirmation has been completed for the set values A to E.

  If the confirmation of the setting values A to E is not completed in the determination of step 10, the setting value is changed in step 14 and the process returns to step 6 to repeat the above-described processing. If it is not finished, it is changed to the next setting item in step 15 and the process returns to step 6 to repeat the above processing. When finished, the reproduction error processing is executed in step 12 and the reproduction is executed in step 13. Is stopped and this process is terminated.

For example, when a default value is set as follows for a DVD-ROM single-layer disc, the current value is searched and set in the setting value count table with a smaller number of retries as follows, for example, and playback is started. .
Default value: Setting value 1 = Setting value = C, Setting value 2 = Setting value = C, Setting value 3 = Setting value = C, Setting value 4 = Setting value = C, Setting value 5 = Setting value = C
Current value (set value at start of playback): set value 1 is set value = D, set value 2 is set value = D, set value 3 is set value = B, set value 4 is set value = B, set value 5 Set value = C

In this way, an appropriate set value can be set in a short time depending on the type of the optical disk, and a stable reproduction operation that is unlikely to cause a reproduction error can be performed.
In addition, by storing the set value that has been successfully reproduced within a certain number of times, the set value can be used at the next reproduction, and a stable reproduction operation that is unlikely to cause a reproduction error can be performed.
Furthermore, since the set value with the smallest number of retries in the previous playback retry operation can be used during the next playback, a stable playback operation that is unlikely to cause a playback error can be performed.

In addition, by storing the set values that have been successfully played back for a certain number of times or less for each type of playback error, the set values can be used at the next playback error retry, improving the playback success capability by retry operation. be able to.
Furthermore, by performing retry using the retry setting value stored for each type of playback error, the setting at the time of retry operation is appropriately performed, so that the playback success capability by the retry operation can be improved.
Further, by using the optimum setting value stored in the retry operation, it is possible to perform a stable reproduction operation that hardly causes a reproduction error.

The optical disc drive 11 stores a set value when the retry count is small during a retry operation, and can perform stable playback with a small retry count by using the set value with the low retry count at the next playback start. it can.
In addition, by storing the setting value for each type of optical disc, it is possible to perform a reproduction operation with finer settings.
Furthermore, a learning function that stably performs the playback operation by counting up the count values corresponding to the various current setting values at the time of playout and selecting the setting value with the largest number of count values at the next playback. Can be given.
In addition, by storing the set value for each type of reproduction error, it is possible to perform a reproduction retry operation corresponding to an individual reproduction error.
Furthermore, for an optical disc having a large number of retries during playback, it may be possible to increase the number of retries by notifying the host computer.

Next, another reproduction process in the optical disk drive 11 will be described.
In this reproduction process, reproduction is performed while measuring the error rate at the time of reproduction, and when the error rate is deteriorated, the set value is changed and reproduced before the reproduction error occurs, and the changed set value is stored. Then, when the next reproduction is started, the reproduction can be stably performed by using the previous set value (stored above).
Also, by counting up the various setting values with the lowest error rate at the time of playout, the setting value with the largest count number can be selected at the next playback, which makes the playback operation more stable. Can be done.
In this way, since the optimum value of the reproduction condition can be detected and stored during reproduction, the retry operation is unnecessary, and more stable reproduction performance can be provided for the user.

In this process, a default value, a current value, and a running optimum value are prepared for each type of the optical disc 13.
FIG. 12 is a diagram showing another format for storing various setting values for each type of optical disk stored in the EEPROM 8.
The various set value storage tables store default values, current values, and running optimum values for each part in the apparatus for each type of optical disc 13 in a table format.
The default value is the initial setting value at the time of shipment from the factory, the current value is the setting value that is set at the start of playback, the default value is set in the initial state, and the last running optimal value that was used during the previous playback thereafter Is set, and the current value is set as the set value when playback is started.
The running optimum value is an optimum setting value that is unlikely to cause a reproduction error, obtained as a result of investigating a setting value that minimizes the error rate from the setting value that has started reproduction in the current state.

13 and 14 are diagrams showing the format of the normal reproduction set value count table stored in the EPPROM 8. As shown in FIG.
This normal reproduction set value count table is a table that counts up and stores the count value of the normal reproduction value for each type of the optical disc 13 corresponding to the current value of each set value when the optical disc 13 is played out. By selecting the setting value with the largest number of counts when reproducing the type of optical disk 13, the various settings at the time of reproduction are set more appropriately, and the reproduction quality is improved.
You may make it count up at the time of power-off.

  The signal processing system unit 5 of the optical disk drive 11 has a function of detecting an error rate, and has a function of an error rate measuring means for measuring the error rate when the optical disk 13 is reproduced. In order to measure the error rate, a first threshold value preset in the internal memory as the error rate threshold value and a second threshold value larger than the first threshold value are stored. Here, the first threshold value is set to a value with the smallest error rate, and the second threshold value is set to a value with an error rate larger than the first threshold value by a predetermined value.

First, when the error rate is between the first threshold value and the second threshold value, the setting value is changed and the setting value that becomes the minimum is investigated and set, and the setting value is stored.
In this way, the setting value at which the error rate is always the minimum within the range of the first threshold value to the second threshold value is investigated, and this is determined as the running optimum value for each setting value for each type of the optical disc 13. Memorize at the table.
Also, when the error rate exceeds the second threshold value, abnormal operation is prevented by returning the set value to the default value.
Alternatively, when the error rate is less than the first threshold, the set value is held.

FIG. 15 is a flowchart showing another reproduction process in the optical disc drive 11 shown in FIG.
When the microcontroller 6 detects the optical disc in step (indicated by “S” in the figure) 21, in step 22, the microcontroller 6 searches for the setting value having the maximum value in the normal reproduction setting value count table for each type of optical disc, and sets the setting value. The value is set to the current value and various setting values are set. In step 23, the reproduction operation is started and the measurement of the error rate by the signal processing system unit is started. In step 24, it is determined whether or not the error rate is less than the first threshold value. If it is less than the first threshold value, the set value is stored in the running optimum value in step 31 and the process proceeds to step 27.
On the other hand, if the error rate is not less than the first threshold in step 24 (if it is greater than or equal to the first threshold), it is determined in step 25 whether or not the error rate exceeds the second threshold, and the second threshold is set. If it exceeds, the setting value is changed in step 33, the setting value with the lowest error rate is investigated, the setting value obtained as a result is set, and the process proceeds to step 27.

  If it is determined in step 25 that the error rate does not exceed the second threshold value (if it is equal to or less than the second threshold value), the setting value is set back to the default value in step 26, and it is determined whether or not playback is stopped in step 27. If the playback is not stopped, the process returns to step 24 and the above processing is repeated. If the playback is stopped, the running optimum value is stored in the current value in step 28, the playback is stopped in step 29, and the playout is determined in step 30. If it is not play-out, this process is terminated as it is. If it is play-out, the count value corresponding to the current value of various set values is counted up in step 31 and this process is terminated.

For example, when the default value is set as follows for a DVD-ROM single-layer disc, the current value is changed to the optimum setting value last time, for example, as follows, and playback is performed with the set value at the start of playback.
Default value: Setting value 1 = Setting value = C, Setting value 2 = Setting value = C, Setting value 3 = Setting value = C, Setting value 4 = Setting value = C, Setting value 5 = Setting value = C
Current value (set value at start of playback): set value 1 is set value = D, set value 2 is set value = D, set value 3 is set value = B, set value 4 is set value = B, set value 5 Set value = C
Running optimal value (value set during reproduction): set value 1 is set value = E, set value 2 is set value = C, set value 3 is set value = A, set value 4 is set value = B, Set value 5 is set value = C
The running optimal value is stored by detecting the minimum error rate. For example, as described above, the setting value 1, the setting value 2, and the setting value 3 are changed and copied to the current value when playback is stopped. The value is set when the next playback starts.

In this way, an appropriate set value can be set in a short time depending on the type of the optical disk, and a stable reproduction operation that is unlikely to cause a reproduction error can be performed.
Further, when the error rate is less than the first threshold value (a preset lower limit value), by maintaining the set value, it is possible to perform a stable reproduction operation that is unlikely to cause a reproduction error.
Further, since various setting values that minimize the error rate are stored, the optimum setting values can be used at the next playback, and a stable playback operation that is unlikely to cause a playback error can be performed.
Further, when the error rate is larger than the second threshold value set to a value larger than the first threshold value, the reproduction operation with various setting values operates abnormally by determining that the reproduction is abnormal and returning to the default setting value. By preventing this, it is possible to perform a stable reproduction operation that hardly causes a reproduction error.

Furthermore, since the set values that can be reproduced normally are counted rather than setting the last set value last time, it is possible to perform a stable reproduction operation that is unlikely to cause a reproduction error.
In addition, since each default value, current value, and running optimum value can be stored for each type of optical disc, the current value is used at the start of playback, and the set value by detecting the optimal error rate during playback is set. Separately, the optimum value is copied to the current value when the reproduction is stopped, and a stable reproduction operation that hardly causes a reproduction error can be performed at the next reproduction start.

  An information reproducing apparatus according to the present invention records and reproduces a CD-R disk drive, a CD-RW disk drive, a DVD-R disk drive, a DVD-RW disk drive, a DVD + R disk drive, a DVD + RW disk drive, a DVD-RAM disk drive, etc. The present invention can also be applied to an apparatus that can

1 is a block diagram showing a configuration of an information reproducing system including an optical disk drive according to an embodiment of the present invention. It is a figure which shows the format of the table for various setting value storage for every kind of optical disk stored in EEPROM8 shown in FIG. It is a figure which shows the format of the setting value count table with few retry frequency for every kind of optical disk stored in EEPROM8 shown in FIG. FIG. 4 is a diagram illustrating a format subsequent to FIG. 3. FIG. 2 is a diagram showing a format of a setting value count table with a small number of retries for each type of optical disk stored in the EEPROM 8 shown in FIG. 1 for each type of reproduction error.

FIG. 6 is a diagram showing a format subsequent to FIG. 5. It is a figure which similarly shows the format of a continuation of FIG. It is a figure which similarly shows the format of a continuation of FIG. It is a figure which similarly shows the format of a continuation of FIG. It is a figure which similarly shows the format of a continuation of FIG.

FIG. 2 is a flowchart showing a reproduction process in the optical disc drive 11 shown in FIG. It is a figure which shows the other format of the various setting value storage table for every kind of optical disk stored in EEPROM8 shown in FIG. It is a figure which shows the format of the normal reproduction | regeneration setting value count table stored in EEPROM8 shown in FIG. It is a figure which shows the format of a continuation of FIG. FIG. 10 is a flowchart showing another reproduction process in the optical disc drive 11 shown in FIG. 1.

Explanation of symbols

1: Spindle motor 2: Optical pickup 3: Rotation control system unit 4: Coarse motor / optical pickup control system unit 5: Signal processing system unit 6: Microcontroller 7: Buffer memory 8: EEPROM 9: Flash memory 10: External interface 11: Optical disk drive 12: Host computer 13: Optical disk

Claims (12)

  In an information reproducing apparatus for reproducing information from a recording medium, when a reproduction error occurs during reproduction of the recording medium, a setting value changing unit that changes a setting value that affects reproduction of the recording medium, and the setting value changing unit An information reproducing apparatus comprising: a set value storage means for storing the changed set value for each type of the recording medium.   2. The information reproducing apparatus according to claim 1, wherein, when a retry operation occurs when a reproduction error occurs, the setting value changing unit changes a setting value that affects the reproduction of the recording medium and repeats the retry operation a predetermined number of times. An information reproducing apparatus comprising: a set value count storage means for counting up and storing a count value corresponding to a set value when reproduction is successful within a predetermined number of retry operations.   3. The information reproducing apparatus according to claim 2, further comprising means for setting a set value corresponding to the largest count value stored in the set value count storage means at the start of reproduction of the recording medium. Playback device.   3. The information reproducing apparatus according to claim 2, wherein the set value count storage means changes a set value that affects reproduction of the recording medium by the set value changing means during a retry operation when the reproduction error occurs. It is means for repeating a predetermined number of retry operations, counting up a count value corresponding to a set value when reproduction is successful by the retry operation within the predetermined number of times, and storing it for each type of reproduction error Information playback device.   5. The information reproducing apparatus according to claim 4, further comprising means for setting a setting value having the largest count value for each type of reproduction error as a setting value during the retry operation.   5. The information reproducing apparatus according to claim 4, wherein means for setting a set value corresponding to the largest count value stored for each type of reproduction error is provided in the set value count storage means at the start of reproduction of the recording medium. An information reproducing apparatus characterized by that.   In an information reproducing apparatus for reproducing information from a recording medium, error rate measuring means for measuring an error rate during reproduction of the recording medium, and the reproduction of the recording medium is influenced based on the error rate measured by the error rate measuring means An information reproducing apparatus comprising: a setting value changing unit that changes a setting value; and a setting value storage unit that stores the changed setting value changed by the setting value changing unit for each type of the recording medium. .   8. The information reproducing apparatus according to claim 7, wherein the setting value changing unit is equal to or less than a second threshold value that is greater than or equal to a first threshold value that is greater than a first threshold value that is measured by the error rate measuring unit. The information reproducing apparatus is characterized in that it is means for investigating a set value that minimizes the error rate when the value is, and changing to a set value obtained as a result of the investigation.   9. The information reproducing apparatus according to claim 8, wherein the setting value changing means is provided with means for maintaining the setting value without being changed when the error rate measured by the error rate measuring means is a value less than the first threshold value. An information reproducing apparatus characterized by that.   10. The information reproducing apparatus according to claim 9, wherein the setting value stored in the setting value storage means has a default value, a current value, and a running optimum value.   11. The information reproducing apparatus according to claim 10, wherein the setting value changing means includes means for returning the setting value to the default value when the error rate measured by the error rate measuring means exceeds the second threshold value. An information reproducing apparatus characterized by that.   12. The information reproducing apparatus according to claim 11, wherein the number of successful reproductions of the set value at the time of the playout is counted up when the recording medium is played out after the recording medium is normally reproduced, and An information reproducing apparatus comprising means for starting reproduction by setting a setting value having the largest number of successful reproductions.

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