JP3795539B2 - Information reproducing method for information reproducing apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement in an information reproducing method of an information reproducing apparatus that reproduces information recorded on an information recording medium such as a magneto-optical disk or an optical disk, and in particular, a plurality of different information depending on a change in a synchronization signal selection method during reproduction. In an information playback apparatus capable of playback mode, the playback operation of the information recorded on the information recording medium is normally performed in a playback mode different from the method of selecting a regular sync signal and in a preset playback mode. The present invention relates to an information reproduction method that enables a quick and accurate reproduction operation and improves data reliability.
[0002]
[Prior art]
2. Description of the Related Art An information reproducing apparatus capable of a plurality of different reproduction modes (hereinafter, abbreviated as an information reproducing apparatus having a plurality of reproduction modes) according to a change in a synchronization signal selection method is conventionally known.
In the information reproducing apparatus having a plurality of reproduction modes, when reproducing information recorded on an information recording medium such as a magneto-optical disk or an optical disk, the reproduction state is judged according to the quality of the reproduced information. If it is bad, retry is made in another playback mode.
[0003]
In this case, in the information reproducing method of the information reproducing apparatus having a plurality of conventional reproduction modes, first, the reproduction operation is performed in the regular reproduction mode (normal mode), that is, the reproduction mode using all the synchronization signals, When the quality was poor, switching to another playback mode and retrying.
Next, an information reproducing method of a conventional information reproducing apparatus will be described. The synchronization signal is recorded on the information recording medium.
[0004]
Here, the sector format of the magneto-optical disk will be described.
For example, the ISO standard sector format of a 3.5 ″ magneto-optical disk is as shown in FIG.
[0005]
FIG. 4 is a diagram showing the ISO standard sector format of a 3.5 ″ magneto-optical disk. In the figure, the numbers attached below each area indicate the number of bytes.
[0006]
In FIG. 4, SM is a sector mark, VFO1 to VFO3 are PLL continuous data patterns, AM is an address mark, ID1 to ID3 are addresses, CRC is an ID part error detection code, PA is a postamble, ODF ( (Offset detection flag) is an offset detection mark in tracking error detection using the push-pull method, GAP is a gap in which there is no data for a length of 3 bytes, and SYNC is a synchronization signal of the data portion.
[0007]
The sector format shown in FIG. 4 has a sector of 725 bytes, a header portion of 52 bytes at the top, and a recording field of 672 bytes with an ODF of 1 byte in the middle.
The details of ID1 indicating the address (same for ID2 and ID3) are, as shown in the enlarged view above, 2 bytes for the track number, 1 byte for the ID number and sector number, and CRC (error detection code of the ID part) ), 2 bytes, and 5 bytes in total.
[0008]
The data field is an area for writing user data, and is composed of 512-byte user data and 160-byte DMP, ECC, CRC, and RS (a special code for synchronization in the data area: resynchronization signal). Yes.
The buffer is an area for disc rotation fluctuation margin, and no data is recorded.
[0009]
In the magneto-optical disk having the sector format as shown in FIG. 4, in order to read the address ID1 accurately, in general, synchronization is established by the sector mark SM at the head of each sector.
The sector mark SM uses a pattern that can be easily distinguished from data, and is composed of a pattern as shown in FIG.
[0010]
FIG. 5 is a diagram showing a pattern of sector marks SM in the sector format shown in FIG. In the figure, T indicates one channel bit length.
[0011]
The sector mark SM is composed of a pattern as shown in FIG. 5 and is 80 channel bits long. The sector mark SM is embossed data of different lengths following the lead-in to the field of the next PLL lock continuous data pattern VFO1. is there.
Then, a total of five marks of 10T, 6T, 6T, 6T, and 10T that are at the “L” level are detected, and when these marks are at predetermined positions, it is determined that synchronization has been achieved, and the recording / reproducing operation is performed. Do.
[0012]
However, if this synchronization is shifted, information cannot be recorded or reproduced.
In the case of a magneto-optical disk, information recorded on the disk (medium) is reproduced by the following procedure.
[0013]
(1) A sector mark SM indicating the head of a sector is detected.
(2) Pull in the PLL by the pattern of VFO1 and synchronize in bit units.
[0014]
(3) The address mark AM at the head of the ID information for identifying the sector is detected, and synchronization in units of bytes (byte breaks) is taken.
(4) The track number and sector number are detected from ID1, and it is checked whether there is any error in CRC.
[0015]
(5) Similarly to (2), the PLL is pulled in by the VFO2 pattern to synchronize in bit units.
(6) Similarly to (3), the address mark AM is detected and synchronization is performed in units of bytes.
[0016]
(7) Similar to (4), the track number and sector number are detected from ID2, and it is checked whether there is any error in CRC.
(8) Similar to (2) and (5), the PLL is pulled in by the VFO2 pattern to synchronize in units of bits.
[0017]
(9) Similarly to (3) and (6), the address mark AM is detected, and synchronization is performed in units of bytes.
(10) Similar to (4) and (7), the track number and sector number are detected from ID3, and it is checked whether there is any error in CRC.
[0018]
(11) The PLL is pulled in by the VFO3 pattern to synchronize in bit units.
(12) The synchronization signal SYNC at the head of the data is detected and synchronization is performed in units of bytes.
[0019]
(13) Data and ECC are read while synchronizing with the resynchronization signal RS in the data.
(14) Correct the error in the data by the data and ECC.
[0020]
(15) Check the data and CRC of the data part for any errors in the data.
Data (information recorded on an information recording medium such as a magneto-optical disk) is reproduced according to the above procedures (1) to (15).
[0021]
In this case, for example, when the sector mark SM indicating the head of the sector cannot be detected in the first procedure (1) due to a defect on an information recording medium such as a magneto-optical disk, the following processing is performed. Cannot be performed, and data cannot be reproduced.
Therefore, as described above, in the conventional information reproducing apparatus having a plurality of reproduction modes, the sector mark SM shown in FIG. 5, that is, among the total of five marks of 10T, 6T, 6T, 6T, and 10T, Retry using the four marks and play back the data.
[0022]
As described above, when the patterns of the four marks out of the five sector marks SM match, if it is determined that the synchronization is established, even when a part of the long pattern cannot be detected due to a defect or the like in the sector mark SM, Data can be played back.
However, in this conventional information reproducing method, first, reproduction is performed in the normal mode, and retry is performed when the quality is poor.
[0023]
However, in general, a sector that needs to be retried has a problem in the sector itself (for example, a defect or the like exists in part), so that there is a disadvantage that the probability of retrying is high every time playback is performed. is there.
Here, the configuration and reproduction operation of a conventional information reproducing apparatus will be described.
[0024]
FIG. 6 is a functional block diagram showing an embodiment of the main part configuration of a conventional information reproducing apparatus. In the figure, 1 is a host device, 2 is an optical disk device, 3 is its control unit, 31 is a CPU, 32 is a control memory, 4 is a drive unit, 41 is a write control unit, 42 is a read control unit, and 5 is a control unit. A recording medium is shown.
[0025]
FIG. 6 shows a case where the information reproducing apparatus is the optical disk apparatus 2.
The optical disk device 2 includes a drive unit 4 having an interface with the recording medium 5 and a control unit 3 having an interface with the host device 1 and having a control memory 32.
[0026]
Then, the writing control unit 41 and the reading control unit 42 of the drive unit 4 perform writing or reading on the recording medium 5.
Next, with respect to an information reproducing apparatus having a plurality of reproduction modes, an operation at the time of reproduction is shown by a flow.
[0027]
FIG. 7 is a flowchart showing the main processing flow during reproduction for an information reproducing apparatus having a plurality of conventional reproduction modes. In the figure, # 1 to # 5 indicate steps.
[0028]
In step # 1, data is read in the normal mode.
In the next step # 2, it is checked whether or not the read has been correctly performed (CRC error check, etc.).
If it is possible to read correctly, it is determined to be normal and the flow of FIG. 7 is terminated.
[0029]
On the other hand, if the read cannot be performed correctly, the process proceeds to step # 3, and retry processing is performed in another playback mode.
In the next step # 4, it is checked whether or not the lead has been correctly read.
If it is possible to read correctly, it is determined to be normal and the flow of FIG. 7 is terminated.
[0030]
On the other hand, if the result of the check in step # 4 indicates that the read cannot be performed correctly, the process proceeds to step # 5 to determine whether or not the retry process is complete.
If it is not a condition for terminating the retry process, the process returns to the previous step # 3 again to perform the retry process.
[0031]
If it is determined in step # 5 that the retry process is terminated, an error notification or the like is output, and the flow of FIG. 7 is terminated.
In FIG. 7, the processing of steps # 3 to # 5 is a characteristic operation during reproduction in an information reproducing apparatus having a plurality of conventional reproduction modes.
[0032]
In this conventional information reproduction method, reproduction is always performed in the normal mode (reproduction mode based on normal synchronization detection), and when the quality is poor, retry is performed in another reproduction mode.
In the above description, the sector mark SM is used to detect the synchronization signal. However, a detection method using the address mark AM is also used at the same time as the sector mark SM or instead of the sector mark SM. Yes.
[0033]
By the way, as another information reproducing method of the conventional information reproducing apparatus, a retry operation is performed by changing the relative position of the head on the magnetic disk in the magnetic disk apparatus in order to cope with the synchronization failure due to the positional deviation of the head. A method has been proposed (for example, Japanese Patent Laid-Open No. 4-40794).
Since this information reproducing apparatus is a magnetic disk and detects a synchronization signal by sector servo, it is not an information reproducing apparatus using a so-called sector format unlike an optical disk or the like.
[0034]
Therefore, as a conventional example, it is known that a retry method is known in which a reproduction state is determined based on the quality of reproduced information, and when the quality is poor, a retry (retry) is performed at another head position. It has meaning in the points shown.
In this information reproduction method, reproduction is performed at a normal head position, and when the reproduction operation is not performed correctly, reproduction is performed by changing the relative position of the head on the magnetic disk from front to back and left and right in a preset order. The position of the head that has been normally reproduced is recorded (registered) in a register, and thereafter, when the magnetic disk is reproduced, the head position is controlled based on the recorded position information.
[0035]
As described above, in an information reproducing apparatus that reproduces information recorded on an information recording medium such as a magneto-optical disk or an optical disk, a plurality of reproduction modes that are different depending on changes in the method of selecting a synchronization signal are possible during reproduction. As described with reference to FIG. 7, first, the reproduction operation is performed in the normal mode, and when the quality is poor, the retrier operation is performed in a different reproduction mode.
For this reason, when it becomes necessary to perform a retoiler operation, there is a first inconvenience that there is a waiting time during one rotation of the disk until the head comes to the sector on the disk.
[0036]
In this case, if a method of recording the head position (corresponding to the re-lied mode) in a register different from the recording medium as in the head position control of the magnetic disk is used, In the case of reproducing the head, the head can be controlled by the information of the head position.
However, since the head position information uses a register different from the information recording medium, it is suitable for a recording medium built in an information reproducing apparatus, such as a hard magnetic disk, but is removable. There is a second inconvenience that it is not suitable for a recording medium (for example, a magneto-optical disk).
[0037]
[Problems to be solved by the invention]
In the present invention, a disadvantage in the conventional information reproduction method, that is, first, reproduction is performed in the normal mode, and when the quality is poor, the re-toiler operation is performed in a different reproduction mode. The first inconvenience of time and the information necessary for retrying (specifically, information on the head position) is not recorded on the information recording medium, so that it can be removed like a magneto-optical disk. Information reproduction of an information reproducing apparatus that improves the reliability of data by solving the second inconvenience of being unable to be applied to a simple recording medium and enabling a high-quality reproduction operation quickly and reliably It aims to provide a method.
[0038]
[Means for Solving the Problems]
  In this invention, first,
  An information recording medium and a head for recording / reproducing information with respect to the information recording medium, and when reproducing information recorded on the information recording medium,Method for selecting number of sync signal marks in sector formatDifferent playback modes by changingsettings ofIn an information reproducing apparatus capable of
  A method for selecting a normal synchronization signal when reproducing information recorded on the information recording mediumDepending on how the number of marks is selected is different from the number of marks inIn playback mode and other than preset playback modeRegenerationWhen reproducing information on the information recording medium in the mode, the reproduction mode recording means for recording the information of the reproduction mode on the information recording medium,
  A method of selecting information on the information recording medium, usually the normal synchronization signal.By selecting a small number of marks that is different from the number of marks inIt is performed in a playback mode and in a preset playback mode, and when playback mode information is recorded in the playback mode recording means, the subsequent playback operation is performed according to the playback mode information. This is an information reproducing method of the information reproducing apparatus.
[0039]
Second,
In the information reproducing method of the first information reproducing apparatus,
In this information reproduction method, information on a reproduction mode other than the preset reproduction mode is recorded in an area other than the user area on the information recording medium.
[0040]
  In this invention, thirdly,
  A method for selecting the number of marks of a synchronization signal in a sector format when reproducing information recorded on the information recording medium, comprising an information recording medium and a head for recording / reproducing information on the information recording medium In an information reproducing apparatus capable of setting a plurality of different reproduction modes by changing
When reproducing the information recorded on the information recording medium, reproduction is performed in a reproduction mode other than the preset reproduction mode in a reproduction mode using a small number of marks different from the number of marks in the regular synchronization signal selection method. When reproducing information on the information recording medium in the mode, the reproduction mode recording means for recording the information of the reproduction mode on the information recording medium,
The reproduction operation of information on the information recording medium is normally performed in a reproduction mode by selecting a small number of marks different from the number of marks in the regular synchronization signal selection method, and in a preset reproduction mode, An information reproducing method for an information reproducing apparatus, wherein when a reproduction mode information is recorded in the reproduction mode recording means, a subsequent reproduction operation is performed in accordance with the reproduction mode information,
  The reproduction operation of information on the information recording medium is performed in a mode other than the preset reproduction mode.RegenerationA number storage means for storing the past number n performed in the mode;
  A number comparison means for comparing the number n stored in the number storage means with a predetermined threshold value N;
  Reproduction mode recording means for recording information on the reproduction mode on the information recording medium when information on the information recording medium is reproduced in a reproduction mode other than a preset reproduction mode.When n ≧ N as a result of comparing the number of times n stored in the number-of-times storage means with the threshold value N, information on the playback mode other than the preset playback mode at that time is stored in the playback mode recording means. An information reproducing method of an information reproducing apparatus characterized by recording.
[0041]
  Fourth,In the information reproducing method of the third information reproducing apparatus, information on a reproduction mode other than the preset reproduction mode is recorded in an area other than the user area on the information recording medium. This is an information reproducing method of the information reproducing apparatus.
[0042]
[Action]
In the present invention, the first reproduction operation is performed under a preset retry condition, so that the time for waiting for the rotation of the disk is omitted, and the reproduction can be performed quickly and accurately (the invention of claim 1).
Secondly, the recording medium is removed from the specific reproducing apparatus by recording conditions (reproduction mode information) other than the preset retry conditions in an area other than the user area on the information recording medium. However, since conditions other than the preset retry conditions can be detected, the reproduction operation can always be performed under the optimum conditions (the invention of claim 2).
[0043]
Third, when recording information on a playback mode other than the preset playback mode, the threshold value N is used to record the number n of playback operations performed in a mode other than the preset playback mode performed in the past. Therefore, counting the number of retries that occur very rarely due to noise or the like can be eliminated.
Therefore, the inconvenience that the retry condition (reproduction mode) of the originally normal sector is rewritten by the retry that occurs very rarely in this way is avoided. In this case, an area for recording the number of retries in the past is provided (invention of claim 3).
[0045]
[Example 1]
Next, the information reproducing method of the information reproducing apparatus of the present invention will be described in detail with reference to the drawings.
This embodiment mainly corresponds to claim 1, but also relates to the inventions of claims 2 to 4.
[0046]
As already described in connection with the flow of FIG. 7, when detecting the synchronization signal, a normal number of sector marks SM (or address marks AM) cannot be detected due to defects on an information recording medium such as a magneto-optical disk. In some cases (normal mode), an information reproduction method is known in which a reproduction operation is performed according to a retry condition in a reproduction mode in which some of the sector marks SM (for example, four marks out of five marks) are detected. ing.
[0047]
In this case, when the normal mode is executed from the beginning at the time of reproduction, there is a disadvantage that a reproduction operation is performed under a retry condition, so that the rotation of the disk is awaited and the reproduction speed becomes slow.
In the information reproduction method of the present invention, as a retry condition (reproduction mode), for example, among four sector marks SM, a mode in which four marks SM are selected (in a reproduction mode different from the regular synchronization signal selection method, In addition, a mode other than the preset playback mode) and its order are set.
[0048]
At the time of reproduction, reproduction in the normal mode is not performed, and the reproduction operation under the retry condition is executed from the beginning (from the first data read), so that the disk rotation waiting time does not occur.
Also in this invention, the configuration of the information reproducing apparatus is basically the same as that of FIG. 6 shown as the conventional example, and the CPU 31 performs control according to the flow of FIG.
[0049]
FIG. 1 is a flowchart showing a main processing flow during reproduction in the information reproducing method of the present invention. In the figure, # 11 to # 18 indicate steps.
[0050]
In this embodiment, in the flow of FIG. 7 showing the conventional example, the steps # 11, # 12 and # 18 are added in the flow shown in FIG. It is characterized in that data read is performed according to retry conditions (playback mode).
Accordingly, the processes of steps # 14 to # 17 are the same as steps # 2 to # 5 of FIG.
[0051]
As shown in FIG. 1, first, in step # 11, it is determined whether retry has been performed in the past.
This determination is made under a condition (playback mode) other than a preset retry condition (playback mode different from the normal sync signal selection method and a preset playback mode). This is performed to detect whether information (conditions) to be recorded is recorded.
[0052]
If the retry has not been performed in the past, the process proceeds to step # 13, and the reproduction mode is set according to a preset normal condition to read the data.
The subsequent steps # 14 to # 17 are the same as in the prior art.
[0053]
On the other hand, as a result of the determination in the previous step # 11, if the retry has been made in the past, the process proceeds to the next step # 12 to read the recorded retry information (condition) and set the reproduction mode. .
And it progresses to step # 13 and performs the process similar to the case where it is not retried in the past.
[0054]
In the flow of FIG. 1, after performing the retry process in step # 15, if it is determined in step # 16 (corresponding to step # 4 in FIG. 7) that the read has been correctly performed, the process proceeds to step # 18. move on.
In step # 18, the retry condition at that time is recorded, and the flow of FIG. 1 is terminated.
[0055]
Through the above steps # 11 to # 18, data is read from the retry condition from the beginning, and if it can be read correctly by another retry condition, the condition is recorded.
Therefore, at the next reproduction, the reproduction mode is set according to the retry condition, and it is possible to read the data quickly and accurately.
[0056]
[Example 2]
Next, a second embodiment will be described.
This embodiment corresponds to the invention of claim 2.
This embodiment is an improvement of the first embodiment described above. In the case of a removable information recording medium such as a magneto-optical disk, the information recording medium was recorded when it was mounted on another reproducing apparatus. Information on the retry condition (step # 18 in FIG. 1) cannot be used.
[0057]
Therefore, by recording the retry condition (reproduction mode information) in an area other than the user area on the information recording medium (working area: an area not opened for the user), the recording medium can perform a specific reproduction. Even if the device is removed from the apparatus, conditions other than the preset retry conditions can be detected (the flow is omitted).
Therefore, it is possible to always perform the reproducing operation under the optimum retry conditions regardless of the reproducing apparatus set (invention of claim 2).
[0058]
In the magnetic disk apparatus described as the conventional example, since the fixed disk is the target, the head position condition (different from the reproduction mode of the present invention) is recorded in the corresponding register (Japanese Patent Laid-Open No. 4-40794). Publication).
However, this conventional example does not disclose a plurality of reproduction modes due to differences in the detection method of the synchronization signal.
[0059]
[Example 3]
Next, a third embodiment will be described.
This embodiment corresponds to the invention of claim 3.
This third embodiment is executed at this time even when another retry process is executed and an accurate read is performed for an originally normal sector due to an error that occurs very rarely due to an accidentally generated noise or the like. This is characterized in that the inconvenience of the recorded retry condition being recorded as a condition for the subsequent playback mode is avoided.
[0060]
Therefore, when a threshold value N is set and information of a playback mode other than the preset playback mode is recorded, a preset playback mode previously performed using the threshold value N is used. Compared with the number n of reproduction operations in modes other than the above, when the threshold value is N or less, a preset reproduction mode is set.
Also in the third embodiment, the configuration of the information reproducing apparatus is basically the same as that shown in FIG. 6 shown as the conventional example, and the CPU 31 performs control according to the flow of FIG.
[0061]
FIG. 2 is a flowchart showing the main processing flow during reproduction in the third embodiment of the information reproducing method of the present invention. In the figure, # 21 to # 31 indicate steps.
[0062]
The flow of FIG. 2 is different from the flow of FIG. 1 shown in the first embodiment as follows.
In the flow of FIG. 2, the number of retries in the past is set at step # 21, and the point to be compared with the threshold value N at the next step # 22, and steps # 29 and # 30 are added. 2 points.
[0063]
First, in step # 21, the number n of retries in the past is set in the number storage means.
In the next step # 22, it is compared with a predetermined threshold value N.
[0064]
If n.gtoreq.N, the process proceeds to step # 24, and in the same manner as in the first embodiment, the reproduction mode is set according to a preset retry condition and data is read.
The subsequent steps # 25 to # 28 are the same as those in FIG.
[0065]
On the other hand, if n ≧ N as a result of the determination in the previous step # 22, the process proceeds to step # 23 to read the recorded retry information (condition) and set the playback mode (FIG. 1). Step # 12).
Thereafter, the process proceeds to step # 24, and the same processing is performed as when n ≧ N is not satisfied.
[0066]
  In the flow of FIG. 2, after performing the retry process in step # 26, if it is determined in step # 27 (corresponding to step # 16 in FIG. 1) that the read has been correctly performed, the process proceeds to step # 29. move on. In this step # 29, the number of retries is increased by n = n + 1 (increment), and in the next step # 30,n ≧ NIt is determined whether it is.
[0067]
  if,n ≧ NOtherwise, assuming that normal operation has been performed, the flow of FIG. 2 is terminated. Also,n ≧ NIf so, the process proceeds to step # 31, the retry condition at that time is recorded, and the flow of FIG. 2 is terminated.
[0068]
By the above steps # 21 to # 31, retry conditions are set in consideration of the number of retries in the past, and the retry conditions that differ from the original conditions changed due to the influence of noise, etc., happened later. The inconvenience of being recorded as a condition is avoided.
The retry condition set in this case is recorded in a register in the playback apparatus (the invention of claim 1) or recorded in a predetermined area of the information recording medium (invention of claim 2).
[0069]
[Example 4]
Next, a fourth embodiment will be described.
This embodiment corresponds to the invention of claim 4.
The fourth embodiment is an improvement over the previous third embodiment. In particular, when the retry condition (playback mode) changes due to a change over time (usually a scratch or the like occurs), recording is already performed. The present invention relates to a process for rewriting the retry conditions that have been made.
[0070]
In the fourth embodiment, similarly to the previous third embodiment, the number n of retries in the past is set (step # 21) and compared with a preset threshold value N (step # 22). However, as a result, when it becomes necessary to rewrite the retry condition (playback mode) (when n ≧ N), the number of times n is reset to “0” simultaneously with the rewriting of the condition. ing.
Therefore, the inconvenience that another retry condition that is executed due to noise or the like and happens to be successful is rewritten can be avoided.
[0071]
FIG. 3 is a flowchart showing the flow of main processing during reproduction in the fourth embodiment of the information reproducing method of the present invention. Steps # 21 to # 31 in the figure are the same as those in FIG. 2, and # 41 to # 42 indicate steps.
[0072]
The flow of FIG. 3 is different from the flow of FIG. 2 shown in the third embodiment in the following two points.
Step # 29 in FIG. 2 is deleted, and instead step # 41 is provided, and step # 42 is added after step # 31 in FIG.
[0073]
In the flow of FIG. 3, after performing the retry process in step # 26, if it is determined in step # 27 (corresponding to step # 16 of FIG. 1) that the read has been correctly performed, the process proceeds to step # 41. move on.
In step # 41, the retry condition at that time is recorded (corresponding to step # 18 in FIG. 1).
[0074]
  Next, in step # 30,n ≧ NIt is determined whether it is. if,n ≧ NOtherwise, it is determined that the normal operation has ended, and the flow of FIG. 3 ends.
[0075]
  Also,n ≧ NIf so, the process proceeds to step # 31, where the retry conditions at that time are recorded (similar to FIG. 2). Thereafter, in step # 42, n = 0 is set, and the flow of FIG.
[0076]
As described above, in the fourth embodiment, when the number of retries n exceeds the threshold value N, the number of retries n is rewritten to “0”.
Therefore, even when a retry condition is newly set due to a change over time, the original retry condition is prevented from being changed due to a retry that rarely occurs due to noise or the like.
[0077]
In the first to fourth embodiments described above, the case where the synchronization signal is detected based on the coincidence of the sector marks SM has been mainly described.
However, conventionally, a method of using the address mark AM is also used for detecting the synchronization signal, and a combination with the address mark AM or the sector mark SM can be used, which is limited to the embodiment. It is not something.
[0078]
【The invention's effect】
According to the information reproducing method of the information reproducing apparatus of the first aspect, the reproduction is first performed in the retry mode.
Therefore, it is not necessary to wait for rotation as compared with the conventional reproducing method, and data can be read at high speed and accurately.
[0079]
According to the information reproducing method of the information reproducing apparatus of the second aspect, the information of the reproducing mode is recorded on an information recording medium such as a disc.
Therefore, in the case of a removable recording medium such as a magneto-optical disk, the same effect as the information reproducing method of claim 1 can be obtained even when it is removed from a certain device.
[0080]
In the information reproducing method of the information reproducing apparatus according to claim 3, in the information reproducing method of the information reproducing apparatus according to claim 1 or 2, the threshold value N is used to determine the number n of the number of retries already performed. ing. In this case, it is necessary to provide a recording area indicating how many retries have already been performed.
Therefore, when a normal sector is played back under other retry conditions (playback mode) due to retries that occur only rarely due to noise or the like, the other retry conditions are set as the optimum retry conditions. The inconvenience that it ends up is prevented beforehand.
[0081]
According to the information reproducing method of the information reproducing apparatus of claim 4, when the threshold value N is exceeded in the information reproducing method of claim 3, the number of retries n is rewritten to “0”.
Therefore, due to aging (scratches, etc.), the retry condition (playback mode) is newly changed, the changed retry condition is set, and in rare cases due to noise, it happens to retry. As a result of success, the inconvenience that the retry condition is set is prevented.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a main processing flow during reproduction in the information reproducing method of the present invention.
FIG. 2 is a flowchart showing a main processing flow during reproduction according to the third embodiment of the information reproducing method of the present invention;
FIG. 3 is a flowchart showing a main processing flow during reproduction in the fourth embodiment of the information reproducing method of the present invention;
FIG. 4 is a diagram showing an ISO standard sector format of a 3.5 ″ magneto-optical disk.
FIG. 5 is a diagram showing a pattern of sector marks SM in the sector format shown in FIG.
FIG. 6 is a functional block diagram showing an embodiment of the main part configuration of a conventional information reproducing apparatus.
FIG. 7 is a flowchart showing a main processing flow at the time of reproduction for an information reproducing apparatus having a plurality of conventional reproduction modes.
[Explanation of symbols]
1 Host device
2 Optical disk device
3 Control unit
31 CPU
32 Control memory
4 Drive section
41 Write controller
42 Read controller
5 recording media

Claims (4)

A method for selecting the number of marks of a synchronization signal in a sector format when reproducing information recorded on the information recording medium, comprising an information recording medium and a head for recording / reproducing information on the information recording medium In an information reproducing apparatus capable of setting a plurality of different reproduction modes by changing
Wherein when information is reproduced information recorded on the recording medium, the playback mode with a small number of marks selection method different from the number of marks in the selection method of the normal synchronization signal and reproduction of the non-pre-set reproduction mode When reproducing information on the information recording medium in the mode, the reproduction mode recording means for recording the information of the reproduction mode on the information recording medium,
The reproduction operation of information on the information recording medium is normally performed in a reproduction mode by selecting a small number of marks different from the number of marks in the regular synchronization signal selection method, and in a preset reproduction mode, An information reproducing method for an information reproducing apparatus, wherein when the reproduction mode information is recorded in the reproduction mode recording means, the subsequent reproduction operation is performed according to the information of the reproduction mode. In the information reproduction method of the information reproduction apparatus of Claim 1,
An information reproducing method for an information reproducing apparatus, wherein information on a reproduction mode other than the preset reproduction mode is recorded in an area other than a user area on the information recording medium. A method for selecting the number of marks of a synchronization signal in a sector format when reproducing information recorded on the information recording medium, comprising an information recording medium and a head for recording / reproducing information on the information recording medium In an information reproducing apparatus capable of setting a plurality of different reproduction modes by changing
When reproducing the information recorded on the information recording medium, reproduction is performed in a reproduction mode other than the preset reproduction mode in a reproduction mode using a small number of marks different from the number of marks in the regular synchronization signal selection method. When reproducing information on the information recording medium in the mode, the reproduction mode recording means for recording the information of the reproduction mode on the information recording medium,
The reproduction operation of information on the information recording medium is normally performed in a reproduction mode by selecting a small number of marks different from the number of marks in the regular synchronization signal selection method, and in a preset reproduction mode, An information reproducing method for an information reproducing apparatus, wherein when a reproduction mode information is recorded in the reproduction mode recording means, a subsequent reproduction operation is performed in accordance with the reproduction mode information,
A number-of-times storage means for storing a past number n of reproduction operations of information on the information recording medium in a reproduction mode other than the preset reproduction mode;
A number comparison means for comparing the number n stored in the number storage means with a predetermined threshold value N;
When information on the information recording medium is reproduced in a reproduction mode other than a preset reproduction mode, the reproduction mode recording means for recording the information on the reproduction mode on the information recording medium is the number of times stored in the number storage means. As a result of comparing n with a threshold value N, when n ≧ N, information on a playback mode other than a preset playback mode at that time is recorded in the playback mode recording means. Information reproduction method of apparatus. In the information reproduction method of the information reproduction apparatus of Claim 3,
An information reproducing method for an information reproducing apparatus, wherein information on a reproduction mode other than the preset reproduction mode is recorded in an area other than a user area on the information recording medium .

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