JP4577398B2 - Playback apparatus, playback method, and program - Google Patents

Description

The present invention is reproducing apparatus relates to a reproducing method and Burogura arm, in particular from the signal reproduced from a recording medium of an optical disk, and detects a sync signal, the playback device if it fails to detect the insertion of the pseudo synchronization signal, reproduction method and about the Burogura arm.

  Information recorded on various DVDs (Digital Versatile Discs), which are optical disks, is composed of a plurality of frames in which an ECC block is further divided and a synchronization signal (SYNC) is added to the head. The frame length is constant, and SYNC is recorded so as to be detected at regular intervals. Accordingly, since the SYNC is reproduced at regular intervals when the DVD is reproduced, the reproduction time position of the SYNC to be reproduced next (by counting the SYNC to be reproduced with a simple counter and detecting the period thereof ( The position of the next SYNC) can be predicted.

Therefore, in the conventional reproducing apparatus, as shown in FIG. 15A, a SYNC detection window (hereinafter also referred to as a window) having a predetermined width centered on the predicted position is installed. ) Is detected in synchronization with the frame of the reproduction signal schematically shown in FIG. 4C, as shown in FIG. 3C. In practice, since SYNC is a fixed pattern of multiple bits, its detection flag is detected. By ignoring the detection SYNC outside the SYNC detection window indicated by I in the figure (C) and outputting the final SYNC as shown in the figure (D), an incorrect SYNC is detected due to an error. Even so, misunderstandings are prevented. In addition, when SYNC is not detected at the timing when SYNC should be detected, a pseudo synchronization signal is inserted into the final SYNC output as indicated by II in FIG.
Further, the conventional reproducing apparatus compares the number of continuous detections of the synchronization signal in the window with a predetermined value, and corrects the count value of the clock that determines the window position when the number of continuous detections reaches the predetermined value. (Patent Document 1, Patent Document 2).

  Furthermore, as an example of a recording format of an optical disc that is played back by a conventional playback device, as shown in part of FIG. 16, the information recording area is divided into a predetermined number of blocks, and each block is m (m is 2 or more). Each sector is divided into n frames (n is an integer equal to or greater than 2) having a predetermined number of clocks, and a signal in which a synchronization signal is inserted is recorded in each frame. There is a recording format on the optical disc.

  In the figure, one ECC block is composed of a total of m sectors from sector 0 to sector m−1, and each sector has n clocks each having a predetermined number of clocks from frame 0 to frame n−1. Each frame includes a synchronization signal SY and data. The pattern of the synchronization signal SY is selected and recorded according to a certain rule so that the continuity of the ID can be detected by the combination of the patterns of the continuous synchronization signal.

  In a conventional reproducing apparatus that reproduces an optical disc having such a recording format, in order to stably extract information from a synchronization signal and extract data, a direct detection mode (hereinafter simply referred to as a direct mode) in which the synchronization signal is detected by pattern search. Or a inertia detection mode in which a synchronization detection window synchronized with a predetermined number of clocks is generated and a synchronization signal is read out in the synchronization detection window portion.

  That is, in the example of the state transition diagram shown in FIG. 17, Sc indicates the state of the direct detection mode, Sk indicates the state of the inertia mode, and the synchronization signal continuous detection process for shifting from the direct detection mode to the inertia mode is Sc1. As shown by Sc3, the synchronization signal discontinuous detection process for shifting from the inertia mode to the direct detection mode is performed three times, Sk1 to Sk3, three times. If the synchronization signal is not detected three times continuously in the direct detection mode state Sc, the process returns to the initial state Sc. In the inertia mode state Sk, if there is no non-detection of the synchronization signal three times in succession, the state returns to the initial inertia mode state Sk.

JP 2001-243727 A Japanese Patent No. 3256493

  However, in the recording format shown in FIG. 16, as shown in FIG. 16 and FIG. 18 (A), the synchronization signal is not continuous at a predetermined cycle at the joint between two adjacent ECC blocks. In the conventional reproducing apparatus, as shown in FIG. 18 (B), the first frame 0 of the first sector 0 of the next ECC block from the last frame n-1 of the last sector m-1 of the ECC block remains in the inertia mode. When going to frame 0, as shown in FIG. 18 (E), after a pseudo synchronization signal is output to some extent, the mode shifts to a direct detection mode in which the synchronization signal is read out by pattern search. Thereafter, when a predetermined number of synchronization signals SYNC can be detected continuously within the synchronization signal detection window shown in FIG. 18C in this direct detection mode, as shown in FIG. Transition to inertia mode.

  However, if the transition timing from the inertia mode to the direct detection mode enters the sector 0 as schematically shown in FIG. 18B, the important data at the head of the ECC block can be correctly extracted. It will disappear. As schematically shown in FIG. 18B, when shifting from the inertia mode to the direct detection mode, the playback device performs synchronization reprocessing at the first frame 0 of the first sector 0 of the next ECC block. When synchronization signals are detected continuously in the synchronization detection window shown in FIG. 3C, the normal procedure is to move to the inertia mode and determine the synchronization information detection window.

  However, when the mode is shifted to the direct detection mode and the synchronization signal is reprocessed at the first frame 0 of the first sector 0, the synchronization signal detection window is set as shown in FIG. Therefore, when the synchronization signal is erroneously detected as indicated by X in FIG. 4D, the erroneously detected synchronization signal is represented by X in FIG. As indicated by ', the transition to the inertia mode is delayed because it is output as a detection synchronization signal as it is. Therefore, if there is a periodic erroneous detection of the synchronization signal, it is difficult to shift to the inertia mode. In addition, although it is known that it is the first synchronization signal of the frame in terms of processing, it is necessary to perform useless processing such as setting of a window synchronization signal detection window and detection of continuity of the synchronization signal.

  Further, in the conventional reproducing apparatus, since the next synchronizing signal is generally reproduced at the position where the number of bits corresponding to the frame length has elapsed from the previously detected synchronizing signal, the position of the synchronizing signal detection window Is set centering on the expected reproduction position of the sync signal, but it is not known at which position in the sync signal detection window the sync signal is detected. It cannot be inserted. For this reason, in the conventional reproducing apparatus, since the pseudo synchronization signal is inserted at the end of the synchronization signal detection window, a circuit for distinguishing the normal synchronization signal from the pseudo synchronization signal is required in the ECC circuit in the subsequent stage.

The present invention has been made in view of the above points, and prevents an error in reproducing the data at the head of the subsequent ECC block when reproducing a signal having a format in which the synchronization signal is interrupted at the joint between two adjacent ECC blocks. and may reproducing apparatus, and an object thereof is to provide a reproducing method and Burogura beam.

Another object of the present invention, reproduction apparatus with a synchronous detection circuit which can reset the position of the synchronization signal detecting window to the estimated position of the synchronization information of the first frame of the block, providing a reproducing method and Burogura arm There is to do.

Furthermore, another object of the present invention is to reproduce the pseudo-synchronization signal that can be inserted at the same position as the normal sync signal position, thereby eliminating the need for a circuit that distinguishes the normal sync signal from the pseudo-synchronization signal in the subsequent ECC circuit device is to provide a reproducing method and Burogura beam.

  In order to achieve the above object, the reproducing apparatus of the present invention has an information recording area divided into a predetermined number of blocks, each block being divided into a plurality of sectors, and each sector having a plurality of frames having a predetermined number of clocks. In each block, the first special signal is inserted before the first sector, and the second special signal is inserted after the last sector. A reproducing apparatus for detecting the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector and reproducing information from the recording medium based on the detected synchronization signal A direct detection mode for detecting the synchronization signal by pattern search, and a synchronization detection window that is synchronized with the predetermined number of clocks. The synchronization signal detecting means for detecting the synchronization signal from the first reproduction signal of the recording medium according to any one of the inertia modes for detecting the synchronization signal in the recording medium, and the first reproduction signal from the first reproduction signal of the recording medium. First special signal detecting means for detecting the special signal and outputting a first special signal detection flag, and detecting the special pattern signal from the first reproduction signal of the recording medium and outputting the special pattern detection flag Special pattern detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag, and the first special signal detection means When the first special signal detection flag from the special signal detection means is reset, the counting means for counting the special pattern detection flag, and when the count value of the counting means is a predetermined value, Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when the special signal detection flag is input, wherein the synchronization signal detection means is a first reproduced from the recording medium. A delay circuit that delays the reproduction signal for a predetermined time and outputs a second reproduction signal; and a first circuit that determines whether there is a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window. In the inertia mode, the first synchronization signal determination means, the second synchronization signal determination means for determining the presence or absence of a synchronization signal in the second reproduction signal within the second reproduction signal synchronization detection window, When the first synchronization signal determining means determines that no synchronization signal is detected, a pseudo synchronization signal is inserted a predetermined number of times at the estimated position of the synchronization signal in the second reproduction signal estimated from the predetermined number of clocks. , The second synchronization signal When it is determined that the synchronization signal is detected by the determination means, the synchronization signal is output. When the synchronization signal is determined to be detected by the first synchronization signal determination means, the pseudo synchronization signal is inserted. The synchronization signal output means is not included.

  In order to achieve the above object, in the reproducing apparatus of the present invention, the information recording area is divided into a predetermined number of blocks and divided into a plurality of sectors, and each sector is divided into a plurality of frames having a predetermined number of clocks. A sync signal is inserted in each frame, a first special signal is inserted before the first sector in the block, and a second special signal is inserted after the last sector. The sector is a reproducing device that detects the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector, and reproduces information from the recording medium based on the detected synchronization signal. Then, a direct detection mode in which the synchronization signal is detected by pattern search and a synchronization detection window synchronized with the predetermined number of clocks are generated, and the synchronization detection window portion performs the same operation. A synchronization signal detecting means for detecting the synchronization signal from the first reproduction signal of the recording medium, and the first special signal from the first reproduction signal of the recording medium, according to one of inertia modes for detecting a signal; A first special signal detecting means for detecting a first special signal detection flag and outputting a special pattern detection flag by detecting the special pattern signal from the first reproduction signal of the recording medium. Detection means; second special signal detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag; and the first special signal detection Resetting with the first special signal detection flag from the means, and counting means for counting the special pattern detection flag, and when the count value of the counting means is a predetermined value, the second special signal detection Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when a lag is input, and the synchronization signal detection means receives the first reproduction signal reproduced from the recording medium. A delay circuit that outputs a second reproduction signal with a delay of a predetermined time; and a synchronization signal determination unit that determines whether or not there is a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window; In the inertia mode, when the synchronization signal determination means determines that the synchronization signal is not detected, the synchronization signal is estimated at a predetermined number of times in the second reproduction signal estimated from the predetermined number of clocks. When a signal is inserted and it is determined that the synchronization signal is detected by the synchronization signal determination means, the synchronization signal is output, and at the same time, the synchronization signal output that does not insert the pseudo synchronization signal into the second reproduction signal Means.

  In order to achieve the above object, in the playback apparatus of the present invention, each block is divided into m sectors (m is an integer equal to or greater than 2), and the specific position determination means has a count value of the count means. When the second special signal detection flag is input within the period m, the specific position detection flag is output to the synchronization signal detection means.

  In order to achieve the above object, in the playback apparatus of the present invention, the synchronization signal inserted in each frame is selected from 10 or less patterns, and the second special signal can be taken by the synchronization signal. It has a configuration having one of the patterns.

  In order to achieve the above object, the reproducing apparatus of the present invention is configured such that the synchronization signal detecting unit shifts from the inertia mode to the direct detection mode when the specific position detection flag is supplied from the specific position detecting unit. It is set as the structure which carries out.

  In order to achieve the above object, in the playback apparatus of the present invention, the synchronization signal detection means is in a state where the specific position detection flag is supplied from the specific position detection means and the inertia mode is shifted to the direct detection mode. When the first special signal detection flag is supplied from the first special signal detection means, the direct detection mode is shifted to the inertia mode, and at the same time, the position of the synchronization detection window is changed to the first synchronization of the frame. The estimated position of the signal is reset and the synchronization signal after the first frame of the block is detected in the inertia mode.

  In order to achieve the above object, according to the reproducing method of the present invention, an information recording area is divided into a predetermined number of blocks, each block is divided into a plurality of sectors, and each sector has a plurality of frames having a predetermined number of clocks. In each block, the first special signal is inserted before the first sector, and the second special signal is inserted after the last sector. A reproducing apparatus for detecting the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector and reproducing information from the recording medium based on the detected synchronization signal A first address for decoding a reproduction signal of the recording medium and detecting a sector address indicating the last sector of the block from a sector address existing in the data; A second step of detecting the second special signal from the reproduction signal of the recording medium and outputting a second special signal detection flag; a direct detection mode for detecting the synchronization signal by a pattern search; A synchronization detection window is generated that is synchronized with the predetermined number of clocks, and the synchronization signal is detected from the reproduction signal of the recording medium by one of inertia modes in which the synchronization signal is detected in the synchronization detection window portion. A signal detecting means for controlling to shift from the inertia mode to the direct detection mode when both the sector address indicating the last sector of the block and the second special signal detection flag are supplied; A fourth step of detecting the first special signal from the reproduction signal of the recording medium and outputting a first special signal detection flag; The synchronization signal detecting means operating in the direct detection mode includes a fifth step of shifting to the inertia mode by inputting the first special signal detection flag.

In order to achieve the above object, according to the reproducing method of the present invention, an information recording area is divided into a predetermined number of blocks, each block is divided into a plurality of sectors, and each sector has a plurality of frames having a predetermined number of clocks. In each frame, the first special signal is inserted before the first sector, and the second special signal is inserted after the last sector. A reproducing apparatus for detecting the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector and reproducing information from the recording medium based on the detected synchronization signal The first signal for decoding the reproduction signal of the recording medium and detecting the sector address indicating the last sector of the block from the sector address existing in the data And the step,
A second step of detecting the special pattern signal from the reproduction signal of the recording medium and outputting a special pattern detection flag; and synchronization of the first frame in the first sector in the block detected by the synchronization signal detection means A third step of counting the special pattern detection flag, and when the count value of the counting means reaches a predetermined value, or in the block from the address reproducing means. A fourth step of controlling the synchronization signal detection means to shift to the direct detection mode after a fixed time has elapsed from the time when the sector address indicating the last sector is input; and the first step in the block by the synchronization signal detection means The direct detection mode state is maintained until the synchronization signal of the first frame in the sector is detected, and the first sector It is from the time when the synchronizing signal of the first frame is detected those comprising a fifth step of transition to the inertial mode.

  In the program of the present invention, in order to achieve the above object, the information recording area is divided into a predetermined number of blocks, each block is divided into a plurality of sectors, and each sector is divided into a plurality of frames having a predetermined number of clocks. In each block, a synchronization signal is inserted, a first special signal is inserted before the first sector in the block, and a second special signal is inserted after the last sector. A reproducing apparatus that detects the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector, and reproduces information from the recording medium based on the detected synchronization signal. The computer program used is the same as the direct detection mode in which the computer detects the synchronization signal by pattern search and the same number of clocks. A synchronization signal detecting means for detecting the synchronization signal from the reproduction signal of the recording medium, according to any one of inertia modes for generating the synchronization detection window and detecting the synchronization signal in the synchronization detection window portion; Decoding the reproduction signal of the recording medium to extract a sector address and outputting it to the synchronization signal detection means; and detecting the first special signal from the reproduction signal of the recording medium and detecting a first special signal A first special signal detecting means for outputting a signal detection flag to the synchronizing signal detecting means; and a second special signal detecting flag for detecting the second special signal from the reproduction signal of the recording medium and detecting the synchronizing signal. A second special signal detecting means for outputting to the means, wherein the synchronizing signal detecting means is adapted to receive the sector address extracted by the address reproducing means in the inertia mode state. When the second special signal detection flag is supplied at the time of the last sector, the direct detection mode transition means for shifting from the inertia mode to the direct detection mode, and in the state of the direct detection mode, When the first special signal detection flag is supplied, it is made to function as an inertia mode transition means for shifting to the inertia mode.

  In the program of the present invention, in order to achieve the above object, the information recording area is divided into a predetermined number of blocks, each block is divided into a plurality of sectors, and each sector is divided into a plurality of frames having a predetermined number of clocks. In each frame, a synchronization signal is inserted, a first special signal is inserted before the first sector in each block, and a second special signal is inserted after the last sector. The sector is a reproducing apparatus that detects the synchronization signal from a recording medium in which a special pattern signal unique to each sector is recorded in the sector, and reproduces information from the recording medium based on the detected synchronization signal. A direct detection mode in which the computer detects the synchronization signal by pattern search and a synchronization detection window synchronized with the predetermined number of clocks. A synchronization signal detecting means for detecting the synchronization signal from the reproduction signal of the recording medium according to any one of inertia modes for detecting the synchronization signal in the period detection window portion, and a sector by decoding the reproduction signal of the recording medium Address reproduction means for extracting an address and outputting it to the synchronization signal detection means, special pattern detection means for detecting the special pattern signal from the reproduction signal of the recording medium and outputting a special pattern detection flag, and the synchronization signal detection Reset by the detection output of the synchronization signal of the first frame in the first sector in the block detected by the means, the counting means for counting the special pattern detection flag, and the count value of the counting means is a predetermined value Or the sector address indicating the last sector in the block from the address reproducing means is input. From the point, control is performed so that the synchronization signal detection means shifts to the direct detection mode after a certain time has elapsed, and the synchronization signal of the first frame in the first sector in the block is detected by the synchronization signal detection means. The direct detection mode state is maintained, and the control unit functions as control means for performing control to shift to the inertia mode from the time when the synchronization signal of the first frame in the first sector is detected.

As described above, according to the present invention, during the reproduction of a recording format signal in which the continuity of the synchronization signal is not satisfied at the joint between two adjacent blocks, the second value is counted within the period when the count value of the counting means is m. When the special signal detection flag is input, it is determined that the specific position is immediately before the start of the next block, and the synchronization signal detecting means is shifted from the inertia mode to the direct detection mode at the timing of the specific position. Since the transition timing from the inertia mode to the direct detection mode is prevented from entering the first sector 0 of the next block, without inserting a predetermined number of pseudo synchronization signals in the inertia mode, The important data at the head of the next block can be correctly extracted, and stable operation is possible.
Further, according to the present invention, when the first special signal detection flag is supplied in the state of shifting to the direct detection mode, the position of the synchronization detection window is set at the same time as the shift of the direct detection mode to the inertia mode. Since it was reset to the estimated position of the first sync signal, the window sync signal detection window setting, sync signal continuity detection, etc., despite being known as the first sync signal of the frame, etc. Quickly shift from the direct detection mode, which is very vulnerable to false detection of the synchronization signal, to the inertia mode, which is strong against false detection of the synchronization signal, because the detection window for the synchronization signal is not set without performing unnecessary processing. can do.
Further, according to the present invention, when there is no synchronization signal detected in the synchronization detection window in the signal not delayed in the inertia mode, the synchronization signal in the delayed reproduction signal estimated from the predetermined number of clocks. By inserting a pseudo-synchronization signal a certain number of times at the estimated position, and inserting a pseudo-synchronization signal at the end of the synchronization signal detection window, the subsequent ECC circuit distinguishes the normal synchronization signal from the pseudo-synchronization signal. The phenomenon that a circuit is required can be prevented.
In addition, according to the present invention, a synchronization detection window is included in a signal that is not delayed in the inertia mode in a configuration including a circuit for determining whether or not a synchronization signal is detected within the synchronization detection window for the first reproduction signal. When there is no detected sync signal, the pseudo sync signal is inserted a predetermined number of times at the estimated position of the sync signal in the delayed playback signal estimated from the predetermined number of clocks. The ECC circuit in the subsequent stage has a simple circuit configuration that eliminates the need for another synchronization signal determining means for determining whether or not there is a synchronization signal in the second reproduction signal within the delayed synchronization detection window for the second reproduction signal. Thus, it is possible to prevent a phenomenon that a circuit for distinguishing between a normal synchronization signal and a pseudo synchronization signal is required.
Further, according to the present invention, when the sector address is added to the recording data, the sector address is extracted from the reproduction signal, and when the sector address indicates the last sector in the block, the second address When a special signal is detected, or when the synchronization signal detection means is controlled to the direct detection mode after a predetermined time has elapsed and then the first special signal is detected, or the synchronization of the first frame in the first sector in the block Since the transition to the inertia mode is made when the signal is detected, the important data at the head of the next block can be correctly extracted without inserting a predetermined number of pseudo-synchronization signals in the inertia mode, Stable operation is possible. From very weak direct detection mode erroneous detection of the sync signal for setting the use detection window is not performed, it is possible to quickly shift to strong inertial mode erroneous detection of the sync signal. Furthermore, a stable reproduction operation can be performed by accurately extracting the synchronization signal without using the first and second special signals.

Next, embodiments of the present invention will be described with reference to the drawings. First, an embodiment of a recording medium used in the present invention will be described. The recording medium body, information recording area is divided into blocks of a predetermined number, each block is divided into sectors of m (m is an integer of 2 or more), n pieces each sector having a predetermined number of clocks ( n is an integer of 2 or more), and a synchronization signal selected from 10 or less patterns is inserted in each frame, and the first special signal is inserted in the block before the first sector. An optical disc in which a signal is inserted and a signal into which a second special signal having one of the patterns that can be taken by the synchronization signal is inserted after the last sector is recorded.

FIG. 14 shows a recording format of an embodiment of a recording medium used in the present invention. This is almost the same as the recording format of the conventional recording medium shown in FIG. However, in the recording format of FIG. 14 , the synchronization signal of each frame is a signal selected from 10 or less patterns, and the first special signal S1 is inserted before the first sector 0 of the ECC block. The second special signal S2 having one of the possible patterns of the synchronization signal is inserted after the last sector m-1 of the ECC block, which is greatly different from the conventional recording format.

  That is, the synchronization signal of each frame is any one of 10 patterns or less in the same block and the same sector, and they are all different. For example, if 10 types of patterns are SY0, SY1, SY2,..., SY9, the synchronization signals of n frames in the same sector are SY0 in frame No. 0, SY1 in frame No. 1, SY2 is set for frame No.2, SY3 is set for frame No.3, SY3 is set for frame No.4, SY2 is set for frame No.5, and so on.

  By doing so, the frame number can be derived by seeing the continuity of the synchronization signal pattern. In addition, the first special signal and the second special signal are any one of the above ten types of patterns. Further, the above-mentioned “specific special pattern signal that should be detected only once in a sector” is, for example, the above-mentioned SY0 and a signal indicating frame No. 0, but is different from the synchronization signal. May be a simple signal. Further, a combination of two or more continuous synchronization signals in the sector is a combination that should be detected only once. For example, if a combination in which SY1 and SY2 are detected in succession is detected as frame No. 2, only one appears in the same sector, so the sector can be counted.

FIG. 1 shows a block diagram of a first embodiment of a reproducing apparatus according to the present invention. In FIG. 2, an optical disc 11 records information signals in the recording format of the recording medium shown in FIG. 14, and FIG. 2 (A) shows the format near the joint of adjacent ECC blocks. A reproduction signal reproduced from the optical disk 11 by a known optical head 12 is supplied to a synchronization signal detecting means 13, where the synchronization signal (SYNC) of each frame is detected by an inertia mode or a direct (detection) mode. .

  The reproduction signal is supplied to the special pattern detection means 14, the first special signal detection means 15, and the second special signal detection means 16, respectively. The special pattern detection means 14 detects a special signal (sector specific signal) of a specific pattern composed of a combination of two or more continuous sync signal patterns that should be detected only once in each sector. A flag obtained when a special signal is detected by the special pattern detector 14 is supplied to the sector counter 17 which is a counter and counted. Therefore, the count value of the sector counter 17 is counted up in synchronization with the sector in the reproduction signal.

  Immediately after reproduction, the synchronization signal detecting means 13 detects the synchronization signal by pattern search in the direct detection mode, sets a temporary synchronization detection window from the current synchronization signal, and the detected synchronization signal is If it is in the temporary synchronization detection window, the temporary synchronization detection window is determined as the synchronization detection window, and if there is no next detected synchronization signal in the temporary synchronization detection window, The next temporary synchronization detection window is set.

  When a synchronization signal is detected in the synchronization detection window continuously for a fixed number of times, the mode shifts to the inertia mode, and when a synchronization signal is not detected in the synchronization detection window for a fixed number of times, the direct detection mode is activated. Continue operation.

  In the inertia mode, the synchronization detection window synchronized with the number of clocks is determined, and the synchronization signal outside the window is ignored. When a synchronization signal is detected in the synchronization detection window, the next synchronization detection window is set in accordance with the synchronization signal in the synchronization detection window. When the next synchronization signal is not detected within the set next synchronization detection window, a pseudo synchronization signal is inserted, and the synchronization detection window is set in accordance with the pseudo synchronization signal. If a state in which no sync signal is detected within the set sync detection window is not found a certain number of times, the mode is shifted directly to the mode.

Figure 2 (C) the above mode, the count value of the drawing (B) is the sector counter 17, the figure (D) the above synchronization detecting window (window), FIG. (E) is detected FIG . 5F shows the synchronization signal output from the synchronization signal detecting means 13 .

  Here, as described above, at the joint of ECC blocks, at the time of reproduction of a format in which synchronization signals are not continuous, after shifting to the direct detection mode at the ECC block delimiter, switching to the inertia mode due to erroneous detection of the synchronization signal. There is a problem that the transition is delayed, and if the transition to the inertia mode is within the first sector 0 of the next ECC block, there is a problem that the leading data of the ECC block cannot be extracted correctly.

Therefore, in the first embodiment, when the first special signal S1 is detected by the first special signal detection means 15 to which the reproduction signal is input from the optical head 12 in FIG. based resets the sector counter 17 to 0 as shown in FIG. 2 (B). Thereafter, the sector counter 17 counts the special signal detection flag from the special pattern detection means 14, and the count value of the sector counter 17 is counted up in synchronization with the sector in the reproduction signal.

  The counter value of the sector counter 17 is supplied to the specific position determination unit 18 together with the second special signal detection signal from the second special signal detection unit 16. When the count value of the sector counter 17 reaches “m”, the specific position determination means 18 determines that the ECC block is the last sector of the ECC block because it includes m sectors. When the second special signal detection flag is supplied from the special signal detecting means 16, the specific position immediately after the last sector m-1 of the ECC block is determined, and the specific position detection signal is detected as a synchronization signal. Supply to means 13.

Synchronization signal detection means 13, when a specific position detection signal is input, as shown in FIG. 2 (C), the flow directly goes to the detection mode from the inertial mode. Thereafter, the synchronization signal detector 13, the first special signal detection flag from the first special signal detecting means 15 is supplied, as shown in FIG. 2 (C), the process proceeds directly from the detection mode to the inertial mode . The synchronization signal output output from the synchronization signal detecting means 13 is supplied to the reproduction circuit 19 shown in FIG.

  Thus, according to the present embodiment, the synchronization signal detection means 13 directly detects from the inertia mode at the end of the ECC block without inserting a predetermined number of pseudo synchronization signals in the inertia mode. Since the mode is shifted, stable operation is possible without causing an error in the head data of the subsequent ECC block.

  Further, according to the present embodiment, there is no delay in the transition to the inertia mode caused by erroneous detection of the synchronization signal after the transition to the direct detection mode at the end of the ECC block, and the first of the ECC block. Even if a synchronization signal is erroneously detected in the first frame 0 of the first sector 0 as shown by IV in FIG. 2E in order to operate in the inertia mode from the beginning of the sector 0 of FIG. Therefore, the erroneously detected synchronization signal output can be eliminated, and as a result, the leading data of the ECC block can be reproduced correctly.

  FIG. 3 shows the operation of one embodiment of the playback apparatus of the present invention by state transition. In the figure, Sc represents the direct detection mode state, Sk represents the inertia mode state, and the synchronization signal continuous detection process for shifting from the direct detection mode to the inertia mode is performed three times as indicated by Sc1 to Sc3. The synchronization signal discontinuous detection process for shifting from the direct detection mode to the direct detection mode is three times Sk1 to Sk3. Further, in the present embodiment, when the first special signal is detected in the direct detection mode state Sc, the state shifts to the inertia mode state Sk. When the second special signal is detected in the inertia mode state Sk and the sector counter value is 0, the state shifts to the direct detection mode state Sc.

  Next, second and third embodiments of the present invention will be described. In the first embodiment, the direct detection mode is shifted to the inertia mode when the first special signal is detected. However, after the shift to the inertia mode, the detection is performed from the synchronization signal of the first frame detected. Therefore, it is necessary to set the synchronization detection window appropriately. Therefore, in this embodiment, when the first special signal is detected, the mode is shifted from the direct detection mode to the inertia mode, and the position of the synchronization detection window is set to the synchronization signal of the first frame of the ECC block (frame 0 of sector 0). It is reset to the estimated position. For this reason, in the second and third embodiments, the signal A reproduced from the optical disc and the signal B obtained by delaying the signal A by the time L are used. In the subsequent ECC circuit, the delayed signal B is used.

  FIG. 4 shows a block diagram of a main part of a second embodiment of the reproducing apparatus according to the present invention. 4 is provided in the synchronization signal detecting means 13 of FIG. In FIG. 4, the first reproduction signal A reproduced from the optical disk is supplied to the SYNC detection circuit 21 to detect the synchronization signal SYNC of each frame. Here, a part of the first reproduction signal A is shown in FIG. 5A, and the SYNC detection circuit 21 detects the synchronizing signal SYNC in the reproduction signal A, and FIG. The first SYNC detection flag as shown in FIG. This first SYNC detection flag is supplied to the first determination circuit 22 in FIG. 4, where it is determined whether or not it is within the window A shown in FIG. 5C generated from the reproduction signal A in the inertia mode. The

  On the other hand, in FIG. 4, the first reproduction signal A is supplied to the L-stage shift register 23, delayed by L clocks, supplied as the second reproduction signal B to the SYNC detection circuit 24, and the synchronization signal of each frame. SYNC is detected.

  Here, the delay amount L and the sizes (time widths) of the windows A and B by the shift register 23 will be described in detail with reference to FIG. In the present embodiment, the delay amount L and the window size 2M + 1 or 2M are determined so that the end of the window A comes before the center of the window B. The relationship between L and M is divided into the following three.

(1) When the window size is an odd number (2M + 1) In this case, as shown in FIG. 6A, each of the windows A and B has a center width of size 1 and a size M each symmetrical to the center width. To make the window A end before window B center,
L ≧ M + 1 (A)
Is set to the relationship.

(2) The window size is an even number (2M), M before the expected SYNC position, and M- after
In this case, as shown in FIG. 6B, each of the windows A and B has a center width of size 1, a left side size M-1 of the left and right sides of the center width, and a right side size M. In order for window A to end before window B center,
L ≧ M + 1 (b)
Is set to the relationship.

(3) When the window size is an even number (2M) and M-1 before the expected SYNC position, and M after the expected position In this case, as shown in FIG. In order to make the left side of the center width of the left size M and the right size M-1 width so that the end of the window A comes before the center of the window B,
L ≧ M (C)
Is set to the relationship.

  By setting the delay amount L and the window size so as to satisfy the above inequality, the fall of the window A always comes before the expected SYNC position of the window B (center size 1 position).

  Next, the operation of the present embodiment will be described with reference to the flowchart of FIG. The SYNC detection circuit 24 detects the synchronization signal SYNC in the reproduction signal B from the shift register 23, and outputs a second SYNC detection flag as shown in FIG. The second SYNC detection flag is supplied to the second determination circuit 25 in FIG. 4, where it is determined whether or not it is within the window B shown in FIG. 5 (E) generated from the reproduction signal B in the inertia mode. (Step S1 in FIG. 7).

  When the second SYNC detection flag is located in the window B as shown in FIGS. 5D and 5E, the second determination circuit 25 detects the SYNC as shown in FIG. 5F. Output as a flag (step S2 in FIG. 7). However, when the pseudo synchronization signal generation circuit 26 determines that the second determination circuit 25 has reached the expected SYNC position of the window B, the first determination circuit 22 and the second determination circuit 25 allow the windows A and B to be detected. When the SYNC detection flag does not exist in each of them, a pseudo synchronization signal is inserted a predetermined number of times at the expected SYNC position of window B (steps S1, S3, S4, and S5 in FIG. 7). Further, when the synchronization signal can be detected in the window A, the pseudo synchronization signal is not output even after the expected SYNC position of the window B (steps S1, S3, and S4 in FIG. 7).

  Thus, according to the present embodiment, in the inertia mode, only when the synchronization signal in the reproduction signal (signal A) cannot be detected by the synchronization detection window (window A), the estimation is made from the predetermined clock number L. When a predetermined number of pseudo synchronization signals can be inserted into the expected SYNC position of signal B and the synchronization signal can be detected in window A, the pseudo synchronization signal is not inserted even after the expected SYNC position of signal B. it can. As a result, the ECC circuit at the subsequent stage can operate without distinguishing between the pseudo synchronization signal and the normal synchronization signal.

  FIG. 8 is a block diagram showing the main part of a third embodiment of the playback apparatus according to the present invention. FIG. 8 is provided in the synchronization signal detecting means 13 of FIG. 8, the same components as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted. In the embodiment shown in FIG. 4, the signal A and the signal B have independent SYNC detection mechanisms. However, in this embodiment, only the signal A has a SYNC detection mechanism.

  In this embodiment, a reproduction signal A and a reproduction signal B obtained by delaying the reproduction signal A by L clocks by a delay circuit are prepared, and the signal A is detected using a window A which is a synchronization detection window. Do. The delay amount L and the sizes of the windows A and B are set so as to satisfy the conditions shown in the above (a) to (c).

  Next, the operation of the embodiment of FIG. 8 will be described with reference to the flowchart of FIG. In FIG. 8, the SYNC detection circuit 21 detects the synchronization signal SYNC in the reproduction signal A, and outputs a first SYNC detection flag as shown in FIG. This first SYNC detection flag is supplied to the first determination circuit 22 of FIG. 8, where it is determined whether or not it is within the window A shown in FIG. 5C generated from the reproduction signal A in the inertia mode. The

  The first determination circuit 22 determines whether or not the synchronization signal has been detected within the window A (step S11 in FIG. 9). When the synchronization signal is detected in the window A, the first SYNC detection flag is delayed by the time amount L by the L-stage shift register 32, and the SYNC detection flag is output on the window B (step in FIG. 9). S12).

  When the first determination circuit 22 cannot detect the synchronization signal within the window A, the pseudo synchronization signal generation circuit 31 outputs the pseudo synchronization signal at the end of the window A (steps S13 and S14 in FIG. 9). Here, since it is set so that the end of the window A comes before the center of the window B, a pseudo synchronization signal can be output at the expected SYNC position of the signal B. This pseudo synchronization signal is delayed by the amount of time L in the shift register 32 and output.

  When the synchronization signal can be detected in the window A, the pseudo synchronization signal is not inserted even after the expected SYNC position of the window B. As a result, the ECC circuit at the subsequent stage can operate without distinguishing between the pseudo synchronization signal and the normal synchronization signal. This embodiment has an advantage that the configuration can be simplified as compared with the configuration in which the signal A and the signal B shown in FIG. 4 have independent SYNC detection mechanisms.

  Next, a fourth embodiment of the playback apparatus of the present invention will be described. FIG. 10 shows a block diagram of a fourth embodiment of a playback apparatus according to the present invention. In the figure, the same components as those in FIG. In FIG. 10, the sync signal detecting means 41 generates a direct detection mode in which the sync signal is detected by a pattern search and a sync detection window synchronized with a predetermined number of clocks in the same manner as the sync signal detecting means 13, and the synchronization is detected. When the synchronization signal is reproduced in the detection window, it operates in one of the inertia modes for outputting the synchronization signal. Unlike the synchronization signal detection means 13, the value of the sector counter Instead of detecting the specific position from both values of the special signal detection flag, the specific position is detected based on the address information from the reproduction circuit 42.

  That is, in this embodiment, a logical or physical address (serial number) is added and recorded as data on the optical disc 11, and the reproduction circuit 42 decodes this reproduction signal and includes it in the data. The present invention is characterized in that the existing sector address information is supplied to the synchronization signal detecting means 41 and its operation mode is controlled.

  Next, the operation of the present embodiment will be described with reference to the timing chart of FIG. 11D, 11E, and 11F are the same signals as those in FIGS. 2D, 2E, and 2F. FIG. 11A shows a format near the joint of adjacent ECC blocks on the optical disc 11 of FIG. This format is the same as the format shown in FIG. In the inertia mode state, the synchronization signal detection means 41 is supplied with a sector address in the reproduction signal as shown in FIG. 11B from the reproduction circuit 42, and this sector address indicates the last sector of the block “m−”. 1 ", when the detection flag of the second special signal S2 is supplied from the second special signal detection means 16, the mode shifts from the inertia mode to the direct detection mode as shown in FIG. .

  Subsequently, when the detection flag of the first special signal S1 is supplied from the first special signal detection unit 15 to the synchronization signal detection unit 41, as shown in FIG. Migrate to

  As described above, according to the present embodiment, the synchronization signal detecting means 41 does not use the sector counter 17 and does not insert a predetermined number of pseudo synchronization signals in the inertia mode, and at the end of the ECC block. Thus, since the mode is shifted from the inertia mode to the direct detection mode, a stable operation can be performed without causing an error in the head data of the subsequent ECC block.

  Further, according to the present embodiment, there is no delay in the transition to the inertia mode caused by erroneous detection of the synchronization signal after the transition to the direct detection mode at the end of the ECC block, and the first of the ECC block. Even if a synchronization signal is erroneously detected in the first frame 0 of the first sector 0 as shown by IV in FIG. 11E in order to operate in the inertia mode from the beginning of the sector 0 of FIG. Therefore, the erroneously detected synchronization signal output can be eliminated, and as a result, the leading data of the ECC block can be reproduced correctly.

  Next, a first embodiment of the reproducing method of the present invention will be described. FIG. 12 shows a flowchart of the first embodiment of the reproducing method according to the present invention. The present embodiment is performed based on a computer program. When the computer detects the first special signal from the reproduction signal of the optical disc 11 described above, the computer outputs a first special signal detection flag, and the first special signal is detected. When the second special signal is detected, a second special signal detection flag is output (step P1).

  Next, the special pattern signal is detected from the reproduction signal, a special pattern detection flag is output (step P2), and the special pattern detection flag is counted (step P3). This count value is reset by the first special signal detection flag, but when the second special signal detection flag is input within a period in which the count value is equal to the number of sectors m of one ECC block. In addition, a specific position detection flag is output. When the specific position detection flag is supplied, the computer that detects the synchronization signal from the reproduction signal of the optical disk controls to shift from the inertia mode to the direct detection mode (step P4).

  As a result, as in the first embodiment of the playback device, the inertia mode is shifted to the direct detection mode at the end of the ECC block without inserting a predetermined number of pseudo sync signals in the inertia mode. Therefore, stable operation can be performed without causing an error in the head data of the subsequent ECC block.

  Next, a second embodiment of the reproducing method of the present invention will be described. FIG. 13 shows a flowchart of the second embodiment of the reproducing method according to the present invention. The present embodiment is performed based on a computer program. A computer that detects a synchronization signal from a reproduction signal is a sector in the reproduction signal from a reproduction circuit that decodes the reproduction signal of the optical disc 11 described above in the inertia mode. An address is supplied, and it is determined whether this sector address is “m−1” indicating the last sector of the block (step P11). When the second special signal is detected at the last sector (step P12), inertia Transition from the mode to the direct detection mode (step P13). Subsequently, when the computer detects the first special signal (step P14), the computer shifts from the direct detection mode to the inertia mode (step P15).

  As described above, according to the present embodiment, the computer shifts from the inertia mode to the direct detection mode at the end of the ECC block without inserting a predetermined number of pseudo synchronization signals in the inertia mode. Therefore, stable operation is possible without causing an error in the head data of the subsequent ECC block.

  The present invention is not limited to the above embodiment. For example, in the embodiment shown in FIG. 10 and FIG. 13, the sector address indicates the last sector of the ECC block, and In the above description, the synchronization detection state of the synchronization signal detection means or the computer is changed from the inertia mode to the direct detection mode when the special signal S2 of 2 is detected. However, the present invention is not limited to this. When it indicates that it is the last sector of the ECC block, the synchronization signal detection means or the synchronization detection state of the computer is changed from the inertia mode to the direct detection mode after a certain time, and the synchronization signal indicating the head of frame 0 in the direct detection mode It may be configured to shift to the inertia mode when the is detected.

  In this case, important data at the head of the next block can be correctly extracted without using the first and second special signals, and stable operation is possible. Of course, the recording medium to which the present invention is applied can be a recording medium other than the optical disk.

1 is a block diagram of a first embodiment of a playback apparatus of the present invention. 2 is a timing chart for explaining the operation of FIG. 1. FIG. 2 is a state transition diagram of FIG. 1. It is a block diagram of the principal part of 2nd Embodiment of the reproducing | regenerating apparatus of this invention. 5 is a timing chart for explaining the operation of FIG. 4. FIG. 5 is a diagram illustrating a relationship between a signal delay amount L and a window width M in FIG. 4. 5 is a flowchart for explaining the operation of FIG. It is a block diagram of 3rd Embodiment of the reproducing | regenerating apparatus of this invention. It is a flowchart for operation | movement description of FIG. It is a block diagram of 4th Embodiment of the reproducing | regenerating apparatus of this invention. 11 is a timing chart for explaining the operation of FIG. 10. It is a flowchart of 1st Embodiment of the reproducing | regenerating method of this invention. It is a flowchart of 2nd Embodiment of the reproducing | regenerating method of this invention. FIG. 3 is a diagram showing a recording format of an embodiment of a recording medium used in the present invention. It is a timing chart for operation explanation of an example of the conventional reproducing method. It is a figure which shows an example of the typical ECC of the format of a recording / reproducing signal, a sector, and a frame structure. It is a state transition diagram of an example of the conventional reproducing | regenerating apparatus. 10 is a timing chart for explaining synchronization detection of a conventional reproducing apparatus. 10 is another example of a timing chart for explaining synchronization detection of a conventional reproducing apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Optical disk (recording medium), 12 ... Optical head, 13, 41 ... Synchronization signal detection means, 14 ... Special pattern detection means, 15 ... 1st special signal detection means, 16 ... 2nd special signal detection means, 17 ... Sector counter (counting means), 18 ... specific position detecting means, 19,42 ... reproducing circuit, 21,24 ... SYNC detecting circuit, 22 ... first determining circuit, 23,32 ... shift register, 25 ... second Determination circuit, 26, 31 ... pseudo synchronization signal (SYNC) generation circuit

Claims (10)

Information recording area is divided into blocks of a predetermined number, each block is divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, synchronization signal inserted in each frame is, the first special signal is inserted before the first sector in each said block are second special signal is inserted after the last sector, the said sectors specific to said sector, respectively A reproducing apparatus that detects the synchronization signal from a recording medium on which the special pattern signal is recorded, and reproduces information from the recording medium based on the detected synchronization signal,
And direct detection mode for detecting the pattern search of the synchronization signal, the generated sync detection window synchronized with the predetermined number of clocks, by any of the inertial mode for detecting the synchronization signal in the synchronization detection window section Synchronization signal detection means for detecting the synchronization signal from the first reproduction signal of the recording medium;
First special signal detection means for detecting the first special signal from the first reproduction signal of the recording medium and outputting a first special signal detection flag;
Special pattern detection means for detecting the special pattern signal from the first reproduction signal of the recording medium and outputting a special pattern detection flag;
Second special signal detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag;
A counting unit that resets the first special signal detection flag from the first special signal detection unit and counts the special pattern detection flag;
Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when the second special signal detection flag is input when the count value of the counting means is a predetermined value ;
Have
The synchronization signal detecting means includes
A delay circuit for delaying a first reproduction signal reproduced from the recording medium for a predetermined time and outputting a second reproduction signal;
First synchronization signal determination means for determining whether or not there is a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window;
Second synchronization signal determination means for determining the presence or absence of a synchronization signal in the second reproduction signal within the second reproduction signal synchronization detection window;
In the inertia mode, when it is determined by the first synchronization signal determination means that a synchronization signal is not detected, the estimated position of the synchronization signal in the second reproduction signal estimated from the predetermined number of clocks is a predetermined number of times. A pseudo synchronization signal is inserted, and when it is determined that the synchronization signal is detected by the second synchronization signal determination means, the synchronization signal is output, and the synchronization signal is detected by the first synchronization signal determination means. When determined, a synchronization signal output means that does not insert the pseudo synchronization signal;
Reproducing apparatus characterized by having a. The information recording area is divided into a predetermined number of blocks and divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, and a synchronization signal is inserted into each frame, The first special signal is inserted before the first sector, the second special signal is inserted after the last sector, and a special pattern signal unique to each of the sectors is inserted in the sector. Is a reproducing apparatus that detects the synchronization signal from a recording medium on which is recorded, and reproduces information from the recording medium based on the detected synchronization signal,
By either a direct detection mode for detecting the synchronization signal by pattern search or an inertia mode for generating a synchronization detection window synchronized with the predetermined number of clocks and detecting the synchronization signal in the synchronization detection window portion. Synchronization signal detection means for detecting the synchronization signal from the first reproduction signal of the recording medium;
First special signal detection means for detecting the first special signal from the first reproduction signal of the recording medium and outputting a first special signal detection flag;
Special pattern detection means for detecting the special pattern signal from the first reproduction signal of the recording medium and outputting a special pattern detection flag;
Second special signal detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag;
A counting unit that resets the first special signal detection flag from the first special signal detection unit and counts the special pattern detection flag;
Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when the second special signal detection flag is input when the count value of the counting means is a predetermined value;
Have
The synchronization signal detecting means includes
Delay means for delaying a first reproduction signal reproduced from the recording medium for a predetermined time and outputting a second reproduction signal;
Synchronization signal determination means for determining presence or absence of a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window;
In the inertia mode, when the synchronization signal determination means determines that the synchronization signal is not detected, the synchronization signal is estimated at a predetermined number of times in the second reproduction signal estimated from the predetermined number of clocks. A synchronization signal output unit that inserts a signal and outputs the synchronization signal when the synchronization signal determination unit determines that the synchronization signal is detected, and does not insert the pseudo synchronization signal into the second reproduction signal; ,
Playback device further comprising a. Each block is divided into m sectors (m is an integer equal to or greater than 2), and the specific position determining means detects the second special signal within a period when the count value of the counting means is the m. 3. The reproducing apparatus according to claim 1, wherein when the flag is input, a specific position detection flag is output to the synchronization signal detecting means. The synchronization signal inserted in each frame is selected from 10 or less patterns, and the second special signal has one of the patterns that can be taken by the synchronization signal. The playback device according to claim 3. 5. The synchronization signal detection unit shifts from the inertia mode to the direct detection mode when the specific position detection flag is supplied from the specific position detection unit. The playback device according to claim 1. The synchronization signal detection means is supplied from the first special signal detection means to the first special signal in a state where the specific position detection flag is supplied from the specific position detection means and the inertia mode is shifted to the direct detection mode. When the signal detection flag is supplied, the position of the synchronization detection window is reset to the estimated position of the first synchronization signal of the frame at the same time as the transition from the direct detection mode to the inertia mode, and the first frame of the block 6. The reproducing apparatus according to claim 1, wherein subsequent synchronization signals are detected in the inertia mode. Information recording area is divided into blocks of a predetermined number, each block is divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, synchronization signal inserted in each frame is, the block is the first special signal is inserted before the first sector in are second special signal is inserted after the last sector, the said sectors unique to the sector, respectively A reproduction method for detecting the synchronization signal from a recording medium on which a special pattern signal is recorded, and reproducing information from the recording medium based on the detected synchronization signal,
As a method for detecting the synchronization signal in the inertia mode in which the synchronization detection window synchronized with the predetermined number of clocks is generated and the synchronization signal is detected in the synchronization detection window portion,
A first step of outputting a second reproduction signal delayed by a predetermined time from the first reproduction signal of the recording medium;
A first synchronization signal detection flag is output when a synchronization signal is detected from the first reproduction signal, and a second synchronization signal detection flag is output when a synchronization signal is detected from the second reproduction signal. A second step;
A third step of determining whether the position of the second synchronization signal detection flag is not there in the second reproduction signal for synchronization detection within the window,
A fourth step of outputting a synchronization signal flag when the position of the second synchronization signal detection flag is within the second reproduction signal synchronization detection window ;
The position of the second synchronization signal detection flag is not in the second reproduction signal synchronization detection window, and the position of the first synchronization signal detection flag is in the first reproduction signal synchronization detection window. If there is, a fifth step of outputting a synchronization signal flag;
The position of the second synchronization signal detection flag is not in the second reproduction signal synchronization detection window, and the position of the first synchronization signal detection flag is in the first reproduction signal synchronization detection window. If not, a sixth step 6 of outputting a pseudo synchronization signal flag at the estimated position of the synchronization signal in the second reproduction signal;
A playback method comprising: Information recording area is divided into blocks of a predetermined number, each block is divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, synchronization signal inserted in each frame is, the block is the first special signal is inserted before the first sector in are second special signal is inserted after the last sector, the said sectors unique to the sector, respectively A reproduction method for detecting the synchronization signal from a recording medium on which a special pattern signal is recorded, and reproducing information from the recording medium based on the detected synchronization signal,
As a method for detecting the synchronization signal in the inertia mode in which the synchronization detection window synchronized with the predetermined number of clocks is generated and the synchronization signal is detected in the synchronization detection window portion,
A first step of outputting a second reproduction signal delayed by a predetermined time from the first reproduction signal of the recording medium;
A second step of outputting a first synchronization signal detection flag when a synchronization signal is detected from the first reproduction signal of the recording medium;
A third step of determining whether the position of the first synchronization signal detection flag is within the first reproduction signal synchronization detection window ;
When the position of the first synchronization signal detection flag is within the first reproduction signal synchronization detection window, the synchronization signal flag is output at a position delayed by a predetermined time from the position of the first synchronization signal detection flag. A fourth step;
When the position of the first synchronization signal detection flag is not within the first reproduction signal synchronization detection window, the first synchronization signal detection flag is simulated at a position delayed by a predetermined time from the position where the first reproduction signal synchronization detection window has passed. A fifth step of outputting a synchronization signal flag ;
A playback method comprising: Information recording area is divided into blocks of a predetermined number, each block is divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, synchronization signal inserted in each frame is, the block is the first special signal is inserted before the first sector in are second special signal is inserted after the last sector, the said sectors unique to the sector, respectively A program for a computer used in a reproducing apparatus for detecting the synchronization signal from a recording medium on which a special pattern signal is recorded, and reproducing information from the recording medium based on the detected synchronization signal,
Computer
And direct detection mode for detecting the pattern search of the synchronization signal, the generated sync detection window synchronized with the predetermined number of clocks, by any of the inertial mode for detecting the synchronization signal in the synchronization detection window section Synchronization signal detection means for detecting the synchronization signal from the first reproduction signal of the recording medium;
First special signal detection means for detecting the first special signal from the first reproduction signal of the recording medium and outputting a first special signal detection flag;
Special pattern detection means for detecting the special pattern signal from the first reproduction signal of the recording medium and outputting a special pattern detection flag;
Second special signal detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag;
A counting unit that resets the first special signal detection flag from the first special signal detection unit and counts the special pattern detection flag;
Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when the second special signal detection flag is input when the count value of the counting means is a predetermined value;
Have
The synchronization signal detecting means includes
A delay circuit for delaying a first reproduction signal reproduced from the recording medium for a predetermined time and outputting a second reproduction signal;
First synchronization signal determination means for determining whether or not there is a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window;
Second synchronization signal determination means for determining the presence or absence of a synchronization signal in the second reproduction signal within the second reproduction signal synchronization detection window;
In the inertia mode, when it is determined by the first synchronization signal determination means that a synchronization signal is not detected, the estimated position of the synchronization signal in the second reproduction signal estimated from the predetermined number of clocks is a predetermined number of times. A pseudo synchronization signal is inserted, and when it is determined that the synchronization signal is detected by the second synchronization signal determination means, the synchronization signal is output, and the synchronization signal is detected by the first synchronization signal determination means. When determined, a synchronization signal output means that does not insert the pseudo synchronization signal;
A program characterized by making it function. The information recording area is divided into a predetermined number of blocks, each block is divided into a plurality of sectors, each sector is divided into a plurality of frames having a predetermined number of clocks, and a synchronization signal is inserted into each frame. In the block, a first special signal is inserted before the first sector, a second special signal is inserted after the last sector, and the sector is unique to each sector. A program for a computer used in a reproducing apparatus for detecting the synchronization signal from a recording medium on which a special pattern signal is recorded, and reproducing information from the recording medium based on the detected synchronization signal,
Computer
By either a direct detection mode for detecting the synchronization signal by pattern search or an inertia mode for generating a synchronization detection window synchronized with the predetermined number of clocks and detecting the synchronization signal in the synchronization detection window portion. Synchronization signal detection means for detecting the synchronization signal from the first reproduction signal of the recording medium;
First special signal detection means for detecting the first special signal from the first reproduction signal of the recording medium and outputting a first special signal detection flag;
Special pattern detection means for detecting the special pattern signal from the first reproduction signal of the recording medium and outputting a special pattern detection flag;
Second special signal detection means for detecting the second special signal from the first reproduction signal of the recording medium and outputting a second special signal detection flag;
A counting unit that resets the first special signal detection flag from the first special signal detection unit and counts the special pattern detection flag;
Specific position detection means for outputting a specific position detection flag to the synchronization signal detection means when the second special signal detection flag is input when the count value of the counting means is a predetermined value;
Have
The synchronization signal detecting means includes
A delay circuit for delaying a first reproduction signal reproduced from the recording medium for a predetermined time and outputting a second reproduction signal;
Synchronization signal determination means for determining presence or absence of a synchronization signal in the first reproduction signal in the first reproduction signal synchronization detection window;
In the inertia mode, when the synchronization signal determination means determines that the synchronization signal is not detected, the synchronization signal is estimated at a predetermined number of times in the second reproduction signal estimated from the predetermined number of clocks. A synchronization signal output unit that inserts a signal and outputs the synchronization signal when the synchronization signal determination unit determines that the synchronization signal is detected, and does not insert the pseudo synchronization signal into the second reproduction signal; ,
A program characterized by making it function .

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