JP5151754B2 - Playback apparatus and playback method - Google Patents

Description

  The present invention relates to a reproducing apparatus and a reproducing method for reproducing a signal from a recording medium on which a plurality of tracks are recorded by using one or a plurality of reproducing heads.

  In recent magnetic recording and reproduction, as the capacity of a magnetic recording system is increased, further higher recording density is required. However, if the track width is narrowed in pursuit of higher recording density, there is a problem that the track cannot be tracked during reproduction. Therefore, a non-tracking method has been proposed in which a signal can be read from the track even if the position of the reproducing head is slightly deviated from the track. However, in order to obtain a reproduction signal appropriately by the non-tracking method, severe restrictions are imposed on the setting of the reproduction head. From this aspect, there is a limit to increasing the recording density by narrowing the track width.

  Therefore, the present inventors record a plurality of tracks, which are a unit of signal processing for data detection, on a magnetic recording medium by a recording head, and reproduce a signal across the plurality of tracks during reproduction. With a playback head that can handle multiple tracks, the signals for multiple tracks are played back in multiple different positions with respect to multiple tracks. A generation method has been proposed (for example, Patent Document 1). According to this, the restriction for determining the width of the reproducing head is reduced, and the track width can be narrowed and the recording density can be increased (for example, Patent Document 1).

  FIG. 32 is a diagram showing a configuration of a recording apparatus 800 that employs the magnetic recording / reproducing method described above.

  As shown in the figure, the recording apparatus 800 includes a multitrack unit 110, a multitrack recording encoding unit 120, a multitrack preamble adding unit 130, a multitrack recording unit 140, and a recording head array 150.

  The multitrack unit 110 distributes the recording data 1 to the number of recording heads W-1, W-2, and W-3 (M = 3) provided in the recording head array 150 for multitracking. The data distributor 111 is used.

  The multitrack recording encoding unit 120 includes M recording encoding units 121-1, 121-2, and 121-3 that encode the recording data allocated to M by the data distributor 111.

  The multitrack preamble adding unit 130 adds M specific preambles 131-1, 131-2, 131- to each recording data encoded by the multitrack recording encoding unit 120 for each track. It is composed of three.

  The multi-track recording unit 140 is a means for recording the recording code string of each track to which the preamble is added on a recording medium. More specifically, the multi-track recording unit 140 provides M timings that give a desired timing to the recording code string to which the preamble is added. Output timing setting units 141-1, 141-2, 141-3, M recording compensation units 144-1, 144-2, 144-3 that perform recording compensation processing, and recording code strings after recording compensation processing Originally, it is composed of M recording amplifiers 147-1, 147-2, and 147-3 for driving the individual recording heads W-1, W-2, and W-3.

  FIG. 33 is a flowchart showing the unit recording operation by the recording apparatus 800. In this recording apparatus 100, first, the input recording data 1 is configured by the multitracking unit 110 as data (M = 3) of recording heads W-1, W-2, W-3, that is, a unit. The data is distributed to the data corresponding to the number of tracks to be processed (step S801).

  Each distributed data is encoded into a code string in consideration of recording / reproducing characteristics of the magnetic recording medium 2 by the recording encoding units 121-1, 121-2, and 121-3 of the multi-track recording encoding unit 120, respectively. Is done. At this time, information necessary for data demodulation, such as a demodulating synchronization pattern, is also added to the data code string (step S802).

  Next, control of reproducing unit-unit data by the preamble adding units 131-1, 131-2, and 131-3 of the multi-track preamble adding unit 130 at a predetermined position of each encoded recording data. Therefore, a necessary pattern is added as a preamble, and a recording code string is obtained (step S803).

  Here, the predetermined position of each encoded recording data is a position determined in consideration that recording code strings are continuously recorded and reproduced. The preamble includes, for example, a gain control pattern used for learning for gain control with respect to a reproduction signal, a synchronization pattern used for bit synchronization processing, and a plurality of reproduction heads and a plurality of tracks for one unit. There are separation patterns necessary to calculate a channel matrix corresponding to the positional relationship in the track width direction. Here, the plurality of tracks for one unit are a plurality of tracks constituting one unit of signal processing for reproducing data. The synchronization pattern is also used as information for specifying the separation pattern for each track and the start position of data. These patterns are created in consideration of the rules of the code strings generated by the recording encoding units 121-1, 121-2, and 121-3 of the multitrack recording encoding unit 120.

  The recording code string for each track is given a desired timing by the output timing setting units 141-1, 141-2, and 141-3 of the multitrack recording unit 140, and then the recording compensation units 144-1 and 144. At -2, 144-3, a recording compensation process for optimizing the recording on the magnetic recording medium 2 is performed.

  Thereafter, the recording code string for each track is converted from a voltage to a current by the recording amplifiers 147-1, 147-2, and 147-3 and sent to the recording heads W-1, W-2, and W-3 for recording. Recording is performed on the magnetic recording medium 2 by the heads W-1, W-2, and W-3 (step S804).

  The above unit-unit recording operation on the magnetic recording medium 2 is repeated so that a plurality of units are continuously arranged in the traveling direction of the track.

  Next, a reproducing apparatus employing the above magnetic recording / reproducing system will be described.

  FIG. 34 is a diagram showing the configuration of a playback apparatus 900 that employs the above-described magnetic recording / playback system.

  As shown in the figure, the reproducing apparatus 900 includes a reproducing head array 210, a channel reproducing unit 220, a signal separating unit 230, a multitrack demodulating unit 240, and a restoring unit 260.

  The reproducing head array 210 has N (N = 3) reproducing heads R-1, R-2, and R-3 that read signals from the tracks recorded on the magnetic recording medium 2. Each reproducing head R-1, R-2, R-3 has its head width and arrangement determined so that a signal can be reproduced from one or more adjacent tracks on the magnetic recording medium 2. Yes.

  The channel reproducing unit 220 amplifies signals reproduced by N reproducing heads R-1, R-2, and R-3 mounted on the reproducing head array 210, and N reproducing amplifiers 221-1 and 221-2. , 221-3 and N gain amplifiers 224-1, 224-2 for controlling the gain so that the amplitude levels of the outputs of the N reproduction amplifiers 221-1, 221-2, 221-3 become predetermined values. 224-3, and A / D converters 225-1, 225-2, and 225-3 that quantize the outputs of the gain adjusting units 224-1, 224-2, and 224-3 into digital values having a predetermined bit width. Prepare.

  Note that a low-pass filter that removes unnecessary high-frequency components may be provided immediately before the A / D converters 225-1, 225-2, and 225-3 as necessary.

  Further, the gain adjusting units 224-1, 224-2, and 224-3 may be arranged not in the preceding stage of the A / D converters 225-1, 225-2, and 225-3 but in the subsequent stage. This is because the bit widths of the A / D converters 225-1, 225-2, and 225-3 are used more effectively, and the configurations of the gain adjusting units 224-1, 244-2, and 224-3 are included in the preample. This is effective when it is desired to make it simple considering the detection of each pattern.

  The signal separation unit 230 includes a synchronization signal detector 231 that detects a synchronization pattern from the outputs of the A / D converters 225-1, 225-2, and 225-3, and a synchronization signal detected by the synchronization signal detector 231. Then, the start position of the separation pattern is specified, and the channel estimation calculation and the signal separation calculation are performed using the separation pattern, thereby being reproduced by the plurality of reproduction heads R-1, R-2, and R-3, respectively. And a signal separation processing unit 236 that separates the reproduction signal for each track from the reproduction signal for one unit.

  The multi-track demodulator 240 is configured with M equalizers 241-1, 241-2, 241-3 that perform equalization processing on the reproduction signal for each track separated by the signal separation processor 236, and the like. Generated by the M PLLs 242-1, 242-2, and 242-3 and the PLLs 242-1, 242-2, and 242-3 that perform bit synchronization from the outputs of the generators 241-1, 241-2, and 241-3. For example, M detectors 243-1, 243-2, and 243-3 such as a Viterbi detector, and a detector 243 are used to binarize the reproduction signal for each track using the bit synchronization signal. M synchronization signal detectors 244-1, 244-2, 244-3 for detecting a synchronization pattern on the code string from the binarized reproduction signals output from 1,243-2, 243-3, Synchronization signal detector 244-1 M decoders 245-1, 245-2, and 245-3 that identify the data start position based on the synchronization pattern detected by 44-2 and 244-3 and decode the data string from the code string; Is provided.

  The restoration unit 260 concatenates the data of each track output from the M decoders 245-1, 245-2, and 245-3 in the multitrack demodulation unit 240 by an operation reverse to that at the time of recording, and reproduces data. 3 is provided.

  FIG. 35 is a flowchart showing a unit reproduction operation flow of the reproduction apparatus 900. In the reproducing apparatus 900, first, one unit of the magnetic recording medium 2 is formed by N reproducing heads R-1, R-2, and R-3 that can reproduce signals from one or more adjacent tracks. A signal is reproduced from a plurality of tracks (step S901).

  Next, after the gain adjustment units 224-1, 224-2, and 224-3 adjust the amplitude levels of the outputs of the reproduction amplifiers 221-1, 221-2, and 221-3, the gain adjustment unit 224- The outputs of 1, 244-2 and 224-3 are converted into digital values by A / D converters 225-1, 225-2, and 225-3 and output to the synchronization signal detector 231 (step S902).

  The synchronization signal detector 231 detects a synchronization pattern for knowing the start position of the separation pattern in the preamble for each output of the A / D converters 225-1, 225-2, and 225-3 (step S903). .

  Next, the signal separation processing unit 236 identifies the start position of the separation pattern based on the synchronization signal detected by the synchronization signal detector 231, and uses the separation pattern to perform each reproduction head R− by channel estimation calculation. After obtaining a channel matrix corresponding to the positional relationship in the track width direction between 1, R-2, R-3 and a plurality of tracks for one unit (step S904), each reproducing head R is used by using this channel matrix. The reproduction signal for each track is separated from the reproduction signal for one unit reproduced by -1, R-2, and R-3 (step S905).

Thereafter, the multi-track demodulator 240 decodes the data sequence from the reproduction signal for each track (step S906), and the reconstruction unit 260 concatenates the data for each track to obtain reproduction data 3 (step S906). S907).
JP 2007-265568 A

  Consider a case where the above magnetic recording / reproducing system is applied to a linear tape storage system. As a standard of a linear tape aiming at high-capacity and high-speed reading / writing, there is LTO (Linear Tape-Open). In the case of a linear tape, scanning is performed in one direction (forward direction) along the longitudinal direction of the linear tape, and when the head reaches the end of the linear tape, the head is orthogonal to the length direction of the linear tape. It is conceivable that recording / reproduction is performed by scanning from both directions, such as feeding in the direction and then scanning from the opposite direction.

  However, the preamble of Patent Document 1 corresponds to reading from the same direction (forward direction) as the recording direction, and does not support reading from the direction opposite to the recording direction. Therefore, it cannot be expected that the preamble and data signals can be reproduced satisfactorily by reproduction from the direction opposite to the recording direction. In particular, when the track width is reduced to improve the recording density, the degree to which the positional deviation of the reproducing head with respect to the track affects the reproduction increases, and reproduction from the direction opposite to the recording direction is expected to be difficult. The Further, as in Patent Document 1, when the width of the reproducing head is increased with respect to the recording track width, the same situation as when the track interval is reduced is produced.

  Also, when a plurality of units are recorded in parallel with each other along the track traveling direction, after the reproduction of one unit is completed, the reproduction head is sent to the position of the next unit to reproduce the next unit. Will start. When the reproducing head is sent, the reproducing head is sent in a direction orthogonal to the traveling direction of the track by a fixed feed amount determined according to the track format. Therefore, when the position of the playback head in the track width direction with respect to the track is shifted from the proper position when playback is completed up to the end of the unit, the shift amount is directly brought into the positional relationship between the next unit and the playback head. It can be considered that the subsequent data reproduction is adversely affected.

  In view of such circumstances, the present invention corrects the positional deviation in the track width direction between the unit and the playback head when the playback head is sent in the track width direction in order to switch the unit to be played back. It is an object of the present invention to provide a playback apparatus and a playback method capable of performing processing.

  In order to solve the above problems, the reproducing apparatus of the present invention has a plurality of tracks constituting a unit that is a unit of signal processing for data reproduction, and the track includes data and the data. As a pattern necessary for reproduction control, a preamble including a separation pattern necessary for detecting a positional relationship between the reproduction head and the plurality of tracks in the track width direction is recorded, and the unit is configured to record the track. A reproducing apparatus for reproducing a plurality of tape-like recording media recorded in parallel with each other along a traveling direction, wherein one or more reproducing heads are capable of reproducing a signal across one or more tracks; An estimation unit that estimates a positional relationship in the track width direction during reproduction between the one or more reproduction heads and the plurality of tracks using a reproduction signal; Based on the positional relationship obtained by the parts, comprising a feed amount calculating unit for calculating the feed rate of the reproduction head when switching the unit to play.

  According to the present invention, when the reproducing head is sent between the units, the reproducing head can be sent by an appropriate feeding amount obtained in view of the positional deviation amount in the track width direction between the unit and the reproducing head before sending. Data reproduction can be satisfactorily performed with the reproduction head sent between units.

  The feed amount calculation unit obtains an adjustment amount with respect to a prescribed feed amount of the reproduction head when switching the unit to be reproduced based on the positional relationship obtained by the estimation unit, and calculates the prescribed feed amount. A value adjusted by the adjustment amount may be obtained as a calculation result. Here, the prescribed feed amount is a fixed value determined in advance according to the track format.

  In addition, the playback device of the present invention further includes a determination unit that determines the quality of the reproduced data, and the feed amount calculation unit further includes playback data of a unit that does not satisfy a predetermined quality in the determination unit. If determined, the feed amount of the reproducing head when the unit is retraced may be calculated. As a result, the playback head is retraced by the appropriate feed amount that is calculated in consideration of the positional deviation in the track width direction between the unit before playback and the playback head, as the playback head feed amount for retrace the same unit. The unit that failed to reproduce data can be reproduced well by retrace.

  Further, in the reproducing apparatus of the present invention, the preamble recorded on the recording medium is composed of a pattern that can be reproduced in both the forward direction and the reverse direction in which the track travels, and the reproduction direction for each trace is the forward direction. It may be alternately switched in the reverse direction. That is, according to the present invention, when the reproducing head is sent between the units, the reproducing head is sent by an appropriate feeding amount that is obtained in view of the positional deviation amount in the track width direction between the unit before sending and the reproducing head. A series of data reproduction can be performed satisfactorily with the reproducing head feeding operation between the units.

  In the reproducing apparatus of the present invention, the preamble has a gain control pattern before and after the separation pattern, and the gain for the reproduction output of the reproduction head is obtained based on the reproduction signal of each gain control pattern of the preamble. You may further have a gain control part to control.

  Further, in the playback device of the present invention, the preamble has a pattern that is in the subsequent stage in the playback order and a synchronization pattern for estimating the start position of data before and after the separation pattern, and each synchronization pattern of the preamble It may further have a detection unit for detecting.

  The reproduction method according to another aspect of the present invention includes a plurality of tracks constituting a unit that is a unit of signal processing for data reproduction, and data and the data are reproduced on the track. As a pattern necessary for control, a preamble including a separation pattern necessary for detecting a positional relationship in a track width direction during reproduction between the reproduction head and the plurality of tracks is recorded, and the unit records the track Is a method for reproducing a plurality of tape-shaped recording media recorded in parallel with each other along the traveling direction of the recording medium, wherein a signal can be reproduced across one or more tracks using a reproduction signal of the separation pattern 1 Alternatively, the positional relationship in the track width direction during reproduction between a plurality of reproducing heads and the plurality of tracks is estimated, and the reproduction is performed based on the estimated positional relationship. It is that calculates the feed quantity of the reproduction head when switching the knitting.

  As described above, according to the present invention, when the reproducing head is sent in the track width direction in order to switch the unit to be reproduced, the positional difference between the unit and the reproducing head in the track width direction is corrected, and the data is improved. Playback processing can be performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (First embodiment)

  FIG. 1 is a diagram showing a configuration of a magnetic recording / reproducing apparatus using a multi-head according to a first embodiment of the present invention. The recording apparatus in this magnetic recording / reproducing apparatus is an apparatus for recording signals on a tape-like magnetic recording medium without aligning the recording position for each track, and the reproducing apparatus aligns the reproducing position for each track from the magnetic recording medium. It is a device that reproduces a signal without any problems. Here, the number of recording heads is M, the number of reproducing heads is N, and in this embodiment, M = 4 and N = 4.

  As shown in the figure, the recording apparatus 100 includes a multitrack unit 110, a multitrack recording encoding unit 120, a multitrack preamble adding unit 130, a multitrack recording unit 140, and a recording head array 150.

  The multitrack unit 110 records data 1 for the number of recording heads W-1, W-2, W-3, and W-4 (M = 4) provided in the recording head array 150 for multitracking. The data distributor 111 distributes the data.

  The multi-track recording encoding unit 120 includes M recording encoding units 121-1, 121-2, 121-3, and 121-4 that encode the recording data allocated to M by the data distributor 111. Composed.

  The multitrack preamble adding unit 130 is a symmetric preamble that can be read from the forward and reverse directions as a preamble necessary for data reproduction control in units of each recording data encoded by the multitrack recording encoding unit 120. Is composed of M number of longitudinally symmetric preamble addition units 131-1, 131-2, 131-3, 131-4.

  The multi-track recording unit 140 is a means for recording the recording code string of each track to which the preamble is added on a recording medium. More specifically, the multi-track recording unit 140 provides M timings that give a desired timing to the recording code string to which the preamble is added. Output timing setting units 141-1, 141-2, 141-3, 141-4, M recording compensation units 144-1, 144-2, 144-3, 144-4 for performing recording compensation processing, and recording M recording amplifiers 147-1, 147-2, 147-3 for driving the individual recording heads W-1, W-2, W-3, W-4 based on the recording code string after the compensation processing, 147-4.

  The recording head array 150 has M recording heads W-1, W-2, W-3, and W-4 that are used to record tracks including data on the magnetic recording medium 2.

  FIG. 2 is a flowchart showing the unit recording operation by the recording apparatus 100. In this recording apparatus 100, first, the input recording data 1 is converted into data of the number of recording heads W-1, W-2, W-3, W-4 (M = 4) by the multitracking unit 110, That is, the data is distributed to the number of tracks constituting the unit (step S101).

  Each distributed data is encoded by the recording encoding units 121-1, 121-2, 121-3, 121-4 of the multitrack recording encoding unit 120 in consideration of the recording / reproducing characteristics of the magnetic recording medium 2. Encoded into a column. At this time, information necessary for data demodulation such as a synchronization pattern for demodulation is also added to the data code string (step S102).

  Next, the recording and encoding units 121-1, 121-2, 121-3, 121 are obtained by the symmetric preamble adding units 131-1, 131-2, 131-3, 131-4 of the multi-track preamble adding unit 130. A symmetric preamble that can be read from the forward and backward directions is added to each recording data encoded by -4 as a preamble necessary for controlling data reproduction, and a recording code string is obtained (step S103).

  Here, as a preamble pattern necessary for control for reproducing data, for example, a gain control pattern used for learning for gain control with respect to a reproduction signal, synchronization used for synchronization detection for bit synchronization processing, etc. There are a pattern, an identification pattern for identifying a track, and a separation pattern necessary for calculating a channel matrix corresponding to the positional relationship in the track width direction between a plurality of reproducing heads and a plurality of tracks for one unit. . The plurality of tracks for one unit are a plurality of tracks constituting a unit which is one unit of signal processing for data reproduction. The synchronization pattern is also used as information for specifying the head position of various patterns and data arranged in the subsequent stage for each track. The above pattern is created in consideration of the rules of the code string generated by the recording encoding units 121-1, 121-2, 121-3, 121-4 of the multitrack recording encoding unit 120. .

  The recording code string for each track is given a desired timing by the output timing setting units 141-1, 141-2, 141-3, and 141-4 of the multitrack recording unit 140, and then the recording compensation unit 144- In 1, 144-2, 144-3, 144-4, a recording compensation process for optimizing the recording on the magnetic recording medium 2 is performed. The recording code string for each track subjected to the recording compensation processing is converted from voltage to current by the recording amplifiers 147-1, 147-2, 147-3, 147-4, and the recording heads W-1, W-2, W-3 and W-4 are sent to the magnetic recording medium 2 by the recording heads W-1, W-2, W-3 and W-4 (step S104).

  Next, a reproducing apparatus in the magnetic recording / reproducing system according to the first embodiment of the present invention will be described.

  FIG. 3 is a diagram showing the configuration of the reproducing apparatus 200 in the magnetic recording / reproducing system of the first embodiment.

  As shown in the figure, the playback apparatus 200 includes a playback head array 210, a channel playback unit 220, a signal separation processing unit 230, a multitrack demodulation unit 240, a restoration unit 260, a track feed amount control unit 271, and a track feed amount determination unit. 272 and a track feeding unit 273.

  The reproducing head array 210 has N (N = 4) reproducing heads R-1, R-2, R-3, and R-4 that read signals from the tracks recorded on the magnetic recording medium 2. Each reproducing head R-1, R-2, R-3, R-4 has its head width and arrangement so that signals can be reproduced from one or more adjacent tracks on the magnetic recording medium 2. Is decided.

  The channel reproducing unit 220 amplifies the signals reproduced by the N reproducing heads R-1, R-2, R-3, and R-4 mounted on the reproducing head array 210, and N reproducing amplifiers 221-1. , 221-2, 221-3, 221-4 and the N reproduction amplifiers 221-1, 221-2, 221-3, and 221-4 are controlled in gain so that the amplitude levels of the outputs become predetermined values. The output of the gain adjusting units 224-1, 224-2, 224-3, and 224-4 and the gain adjusting units 224-1, 244-2, 224-3, and 224-4 are converted into digital values having a predetermined bit width. A / D converters 225-1, 225-2, 225-3, and 225-4 for quantization are provided.

  Note that a low-pass filter that removes unnecessary high-frequency components may be provided immediately before the A / D converters 225-1, 225-2, 225-3, and 225-4 as necessary.

  Further, the gain adjusting units 224-1, 224-2, 224-3, and 224-4 are arranged not in the preceding stage of the A / D converters 225-1, 225-2, 225-3, and 225-4 but in the subsequent stage. Also good. This is because the bit widths of the A / D converters 225-1, 225-2, 225-3, and 225-4 are used more effectively, or the gain adjusting units 224-1, 224-2, 224-3, and 224-4 are used. This configuration is effective when it is desired to simplify the configuration considering the detection of each pattern included in the preampule.

  The signal separation processing unit 230 includes a synchronization signal detection unit 231, an identification information detection unit 232, a reproduction signal gain control processing unit 233, a channel estimation calculation unit 234, a reproduction position control processing unit 235, a signal separation calculation unit 236, and a plurality of preamble processes. A control unit 238 is included.

  The synchronization signal detection unit 231 reproduces the reproduction heads R-1, R-2, R-3, and R-4 output from the A / D converters 225-1, 225-2, 225-3, and 225-4. A synchronization pattern arranged before the separation pattern is detected from the signal.

  The identification information detection unit 232 uses the information obtained by the synchronization signal detection unit 231 to determine the start position of the identification pattern in the reproduction signal of each reproduction head R-1, R-2, R-3, R-4. Identify and detect and get track identification information.

  The multiple preamble processing control unit 238 specifies, for each of the tracks identified by the identification information detection unit 232, the head position of various subsequent patterns with respect to the synchronization pattern first detected in the reproduction order. The plurality of preamble processing control units 238, for example, based on the reproduction signals of various patterns in the preamble (third preamble) disposed at the subsequent stage of the separation pattern, for example, each reproduction head R-1, R-2, Predetermined processing control such as calculation of gain for the reproduction signals of R-3 and R-4 is performed.

  The reproduction signal gain control processing unit 233 performs reproduction heads R-1, R-2,... Based on the reproduction signal of the gain control pattern in the preamble (first preamble) arranged in the preceding stage of the separation pattern in the reproduction order. The gains for the reproduction signals of R-3 and R-4 are calculated, and together with the gains input from the multiple preamble processing control unit 238, the reproduction heads R-1, R-2, R-3, R-4 A more appropriate gain for the reproduction signal is determined, and the level of each reproduction signal is controlled by amplifying the reproduction signal with the gain.

  Based on the synchronization pattern detected by the synchronization signal detection unit 231 and the identification information obtained by the identification information detection unit 232, the channel estimation calculation unit 234 performs reproduction heads R-1, R-2, R-3. , R-4, the start position of the separation pattern included in the preamble of the reproduction signal, and a plurality of reproduction heads R-1 based on the reproduction signal of the separation pattern output from the reproduction signal gain control processing unit 233 , R-2, R-3, R-4 and a plurality of tracks, a channel estimation calculation is performed to calculate a channel matrix corresponding to the positional relationship in the track width direction.

  The reproduction position control processing unit 235, based on the information obtained by the synchronization signal detection unit 231, each reproduction head R-1, R-2, R-3, R- that has passed through the reproduction signal gain control processing unit 233. 4 is performed to match the reproduction position of the reproduction signal.

  The signal separation calculation unit 236 is obtained by the channel estimation calculation unit 234 from the reproduction signals of the respective reproduction heads R-1, R-2, R-3, and R-4 whose reproduction positions are aligned by the reproduction position control processing unit 235. Using the obtained channel matrix, a process for separating the reproduction signal for each track is performed by a predetermined calculation process.

  The signal separation processing unit 230 has a storage unit (not shown) that stores information necessary for processing. The signal separation processing unit 230 performs processing by storing information for a predetermined unit including a preamble and data, for example, in the storage unit.

  As shown in FIG. 4, the multi-track demodulation unit 240 performs M equalizers 241-1 and 241-2 that perform equalization processing on the reproduction signal for each track separated by the signal separation operation unit 236. , 241-3, 241-4 and M PLLs 242-1, 242-2, 242-3 that perform bit synchronization processing from the outputs of the equalizers 241-1, 241-2, 241-3, 241-4 242-4 and the bit synchronization signal generated by PLLs 242-1, 242-2, 242-2, and 242-4 to generate a code string by binarizing the reproduction signal of each track, for example, Viterbi detection Binarized as outputs of M detectors 243-1 243-2, 243-3 and 243-4 and detectors 243-1, 243-2, 243-3 and 243-4 The synchronization pattern on the code string is detected from the playback signal. Synchronization patterns detected by the M synchronization signal detectors 244-1, 244-2, 244-3, 244-4 and the synchronization signal detectors 244-1, 244-2, 244-3, 244-4 M decoders 245-1, 245-2, 245-3, and 245-4 that specify the head position of the data and decode the data sequence from the code string. Note that the multitrack demodulation unit 240 has a storage unit (not shown) that stores information such as data necessary for performing the above processing.

  Returning to FIG. 3, the restoration unit 260 records the data of each track output from the M decoders 245-1, 245-2, 245-3 and 245-4 in the multi-track demodulation unit 240 at the time of recording. And a data combiner 261 that restores the reproduced data 3 by connecting them in the reverse operation.

  The track feed amount control unit 271 uses the playback head channel estimation calculation unit 234 to adjust the adjustment amount with respect to the specified feed amount of the read heads R-1, R-2, R-3, and R-4 when the unit to be played is switched. Is calculated based on the channel matrix obtained by the channel estimation calculation.

  The track feed amount determination unit 272 obtains the prescribed feed amounts of the reproducing heads R-1, R-2, R-3, and R-4 determined in advance according to the track format by the track feed amount control unit 271. A value that is increased or decreased by the adjustment amount is determined as an appropriate feed amount, and a control signal corresponding to the appropriate feed amount is output to the track feed unit 273.

  The track feed unit 273 moves the reproducing heads R-1, R-2, R-3, R-4 in the track width direction according to the control signal given by the track feed amount determination unit 272 (step S201). More specifically, the track feed unit 273 includes a mechanism unit for moving the reproducing heads R-1, R-2, R-3, and R-4 in the track width direction, and a control unit that controls the mechanism unit. And have. The control unit receives a control signal from the track feed amount determination unit 272, and controls the mechanism unit to move the reproducing heads R-1, R-2, R-3, R-4 based on the control signal.

  FIG. 5 is a flowchart showing a unit reproduction operation flow of the reproduction apparatus 200.

  In the reproducing apparatus 200, first, the reproducing heads R-1, R-2, R-3, and R-4 are moved in the track width direction based on the feed amount determined by the track feed amount determination unit 272 by the track feed unit 273. It is moved (step S200).

  Next, N playback heads R-1, R-2, R-3, and R-4, each capable of reproducing a signal from one or more adjacent tracks, are used for one unit of the magnetic recording medium 2. Signals are read from a plurality of tracks (step S201).

  Next, the gain adjustment units 224-1, 224-2, 224-3, and 224-4 adjust the amplitude levels of the outputs of the reproduction amplifiers 221-1, 221-2, 221-3, and 221-4. The The outputs of the gain adjusting units 224-1, 224-2, 224-3, and 224-4 are converted into digital values by the A / D converters 225-1, 225-2, 225-3, and 225-4, and the synchronization signal The data is output to the detector 231 (step S202).

  Next, the reproducing heads R-1, R-2, R-3, output from the A / D converters 225-1, 225-2, 225-3, and 225-4 are output by the synchronization signal detector 231. A synchronization pattern is detected from the reproduction signal of R-4 (step S203).

  Next, based on the information obtained by the synchronization signal detection unit 231, the identification information detection unit 232 determines the identification pattern in the reproduction signal of each reproduction head R-1, R-2, R-3, R-4. The head position is specified and the identification pattern is detected to obtain identification information (step S204).

  Subsequently, in the reproduction signal gain control processing unit 233, a preamble (first preamble 23) is generated from the reproduction signal of each reproduction head R-1, R-2, R-3, R-4 that has passed through the synchronization signal detector 231. (See FIG. 7)) a reproduction signal of the gain control pattern is detected. The reproduction signal gain control processing unit 233 calculates gains for the reproduction signals of the reproduction heads R-1, R-2, R-3, and R-4 based on the reproduction signal of this gain control pattern, and this gain. And a gain given from the plurality of preamble processing control units 238, a more appropriate gain is obtained, and the reproduction signals of the reproducing heads R-1, R-2, R-3, and R-4 are amplified with this gain ( Step S205).

  Next, in the multiple preamble processing control unit 238, for each of the tracks identified by the identification information detection unit 232, the following various patterns and head positions of the data with respect to the synchronization pattern first detected in the reproduction order are specified. . Then, the multiple preamble processing control unit 238 detects the reproduction signal of the gain control pattern in the preamble (third preamble) arranged at the subsequent stage of the separation pattern, and based on the reproduction signal of this gain control pattern, Gains for the reproduction signals of the reproduction heads R-1, R-2, R-3, and R-4 are calculated and provided to the reproduction signal gain control processing unit 233 (step S206).

  Next, the channel estimation calculation unit 234 determines the start position of the reproduction signal of the separation pattern based on the synchronization pattern detected by the synchronization signal detection unit 231 and the track identification information detected by the identification information detection unit 232. The channel estimation calculation is performed based on the reproduction signals of the separation patterns of the reproduction heads R-1, R-2, R-3, and R-4 that are specified and output from the reproduction signal gain control processing unit 233. A matrix is obtained (step S207).

  Here, the channel matrix refers to the track width direction of the individual reproducing heads R-1, R-2, R-3, and R-4 for the tracks # 1, # 2, # 3, and # 4 in one unit. In other words, each of the reproducing heads R-1, R-2, R-3, and R-4 indicates which track in the unit overlaps at what ratio. Information.

  Next, in the reproduction position control processing unit 235, each reproduction head R-1, R-2, R that has passed through the reproduction signal gain control processing unit 233 based on the synchronization pattern detected by the synchronization signal detection unit 231. Processing for adjusting the reproduction positions of the reproduction signals of −3 and R-4 is performed (step S208).

  Next, in the signal separation calculation unit 236, channel estimation calculation is performed from the reproduction signals of the reproduction heads R-1, R-2, R-3, and R-4 whose reproduction positions are aligned by the reproduction position control processing unit 235. Using the channel matrix obtained by the unit 234, processing for separating the reproduction signal for each track is performed (step S209).

  Thereafter, the multi-track demodulation unit 240 decodes the data sequence from the reproduction signal for each track (step S210), and the restoration unit 260 concatenates the data of each track to obtain reproduction data 3 (step S210). S211).

  In the above processing, the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 is also sent to the track feed amount control unit 271. The track feed amount control unit 271 switches the playback unit based on the channel matrix input from the channel estimation calculation unit 234 (in this embodiment, when the playback direction is switched between the forward direction and the reverse direction). ) Of the reproduction heads R-1, R-2, R-3, and R-4 is calculated (step S212). The adjustment amount obtained by the track feed amount control unit 271 is sent to the track feed amount determination unit 272.

  In the track feed amount determination unit 272, predetermined values for the feed amounts of the reproducing heads R-1, R-2, R-3, and R-4 are set in advance. In this embodiment, the prescribed feed amount is the sum of the overall width of the plurality of tracks constituting the unit and the width of the guard band 52. When the track feed amount determination unit 272 obtains the adjustment amount from the track feed amount control unit 271, the values obtained by increasing / decreasing the prescribed feed amount between the units by the adjustment amount are read heads R-1, R-. 2, R-3 and R-4 are determined as appropriate feed amounts (step S213), and a control signal corresponding to this feed amount is output to the track feed unit 273.

  The track feeding unit 273 moves the reproducing heads R-1, R-2, R-3, and R-4 in the track width direction in accordance with a control signal from the track feed amount determining unit 272. As a result, the reproduction heads R-1, R-2, R-3, and R-4 start reproduction from an appropriate position in the track width direction from immediately after the unit to be reproduced is switched (in this embodiment, immediately after the reproduction direction is switched). The data reproduction can be performed satisfactorily. Here, the appropriate position in the track width direction is, for example, the center in the track width direction of all the reproducing heads R-1, R-2, R-3, and R-4 having different tracks in the track width direction. It is a matching position.

  FIG. 6 is a conceptual diagram of a track format on the magnetic recording medium 2 on which recording has been performed by the recording apparatus 100 described above.

  Track # 1, track # 2, track # 3, and track # 4 are tracks recorded on the magnetic recording medium 2 by M (M = 4) recording heads of the recording apparatus 100, respectively. Preamble 21 and data 22 are recorded in track # 1, track # 2, track # 3, and track # 4, respectively. As described above, the preamble 21 includes, as information necessary for reproducing the data 22, a gain control pattern, a synchronization pattern, an identification pattern, and a track width direction of a plurality of reproducing heads and a plurality of tracks for one unit. This includes a separation pattern necessary to calculate a channel matrix corresponding to the positional relationship.

  In each track # 1, # 2, # 3, and # 4, the preamble 21 and the data 22 are alternately arranged in the track traveling direction. That is, the preamble 21 is arranged so as to sandwich the data 22, and the preamble 21 is arranged at both ends of the tracks # 1, # 2, # 3, and # 4.

  Here, a group of M preambles 21 and M data 22 in each of M tracks # 1, # 2, # 3, and # 4 is a unit of signal processing for reproducing data. As a unit 51.

  In the magnetic recording medium 2, s of such units 51 are arranged in parallel with each other along the track traveling direction, and an area called a guard band 52 is provided between the adjacent units 51. The purpose of the guard band 52 is to prevent the track of the adjacent unit 51 from being reproduced.

  Here, the recording direction to the magnetic recording medium 2 will be described. In the example of FIG. 6, the recording direction of unit # 1 is from left to right (forward direction) in the figure, and the recording direction of unit # 2 is from right to left (reverse direction) in the figure. That is, when recording is started from the left end of unit # 1 and recording is completed up to the right end, it moves to the position for recording unit # 2, and this time recording starts from the right end and the recording position moves to the left. To do. When recording to the left end of unit # 2 is completed, the recording unit again moves to a position for recording the next unit # 3 (not shown), and recording starts again from the left end. Thus, the recording direction is alternately switched between the forward direction and the reverse direction for each unit, and recording of s units is performed.

  FIG. 7 is a diagram showing the configuration of the preamble 21 of unit # 1 in the track format of FIG.

  As shown in the figure, the preamble 21 includes a first preamble 23, a second preamble 24, and a third preamble 25. In the drawing, the first preamble 23, the second preamble 24, and the third preamble 25 are arranged in this order from left to right.

  The first preamble 23 includes gain control patterns 41-1, 41-2, 41-3, 41-4, synchronization patterns 42-1, 42-2, 42-3, 42-4, identification patterns 43-1, 43-2, 43-3, 43-4. From left to right in the figure, these are gain control patterns 41-1, 41-2, 41-3, 41-4, synchronization patterns 42-1, 42-2, 42-3, 42-4, and identification pattern 43-1. , 43-2, 43-3, 43-4 are sequentially arranged in this order.

  The second preamble 24 is composed of separation patterns 44-1, 44-2, 44-3, 44-4 required for channel estimation calculation.

  Similar to the first preamble 23, the third preamble 25 is a gain control pattern 41-5, 41-6, 41-7, 41-8, and a synchronization pattern 42-5, 42-6, 42-7, 42. −8, and identification patterns 43-5, 43-6, 43-7, and 43-8. From left to right in the figure, these are identification patterns 43-5, 43-6, 43-7, 43-8, synchronization patterns 42-5, 42-6, 42-7, 42-8, and gain control pattern 41-. 5, 41-6, 41-7, and 41-8. That is, in the first preamble 23 and the third preamble 25, the arrangement order of the gain control pattern, the synchronization pattern, and the identification pattern is opposite to each other.

  In track # 1, there are a gain control pattern 41-1, a synchronization pattern 42-1, an identification pattern 43-1, a separation pattern 44-1, an identification pattern 43-5, a synchronization pattern 42-5, and a gain control pattern 41-5. Arranged in order from left to right in the figure.

  On track # 2, gain control pattern 41-2, synchronization pattern 42-2, identification pattern 43-2, separation pattern 44-2, identification pattern 43-6, synchronization pattern 42-6, and gain control pattern 41-6 Arranged in order from left to right in the figure.

  In track # 3, there are a gain control pattern 41-3, a synchronization pattern 42-3, an identification pattern 43-3, a separation pattern 44-3, an identification pattern 43-7, a synchronization pattern 42-7, and a gain control pattern 41-7. Arranged in order from left to right in the figure.

  In track # 4, there are a gain control pattern 41-4, a synchronization pattern 42-4, an identification pattern 43-4, a separation pattern 44-4, an identification pattern 43-8, a synchronization pattern 42-8, and a gain control pattern 41-8. Arranged in order from left to right in the figure.

  As the synchronization pattern, gain control pattern, and identification pattern of the first preamble 23 and the third preamble 25, for example, a symmetrical pattern in which the same signal is read regardless of whether the reproduction is performed from the forward direction or the reverse direction is adopted. Has been. For example, when the synchronization pattern is “4T-4T-3T-2T” (T: symbol), the synchronization pattern of the first preamble 23 is “10001000100101”, and the synchronization pattern of the third preamble 25 is “10100100010001”. In these cases, the same code string is reproduced from both the forward and backward directions. Here, the last one bit in both synchronization patterns indicates inversion. Similarly, a pattern in which the same code string is reproduced from either the forward direction or the reverse direction may be adopted for the gain control pattern and the identification pattern.

  Since the gain control pattern is a repetitive signal having a constant frequency (for example, 3T continuous), it is originally a symmetric pattern.

  Data 22 is arranged after the third preamble 25. The data 22 is a recording code string created by the recording encoding units 121-1, 121-2, 121-3, and 121-4 of the recording apparatus 100 in FIG. The first preamble 23, the second preamble 24, and the third preamble 25 are added to the recording code string by the preamble adding units 131-1, 131-2, 131-3, and 131-4. .

  In the first preamble 23, the gain control patterns 41-1, 41-2, 41-3, 41-4 of the tracks # 1, # 2, # 3, and # 4, the synchronization patterns 42-1, 42-2, 42-3, 42-4 and the identification patterns 43-1, 43-2, 43-3, 43-4 are arranged so that their positions in the direction in which the tracks proceed do not overlap each other. That is, the gain control pattern 41-1 of the track # 1, the synchronization pattern 42-1 and the identification pattern 43-1 are in the Ta section, and the gain control pattern 41-2, the synchronization pattern 42-2 and the identification pattern 43- of the track # 2. 2 is the Tb section, the gain control pattern 41-3, the synchronization pattern 42-3, and the identification pattern 43-3 of the track # 3 are the gain control pattern 41-4, the synchronization pattern 42-4, and the identification pattern 43-3 of the track # 4. The identification pattern 43-4 is arranged in each Td section. A gap 28 for a margin is provided between the recording sections of the first preamble 23 for each track.

  The same applies to the third preamble 25. That is, in the third preamble 25, the gain control patterns 41-5, 41-6, 41-7, 41-8 and the synchronization patterns 42-5, 42- of the tracks # 1, # 2, # 3, and # 4. 6, 42-7, 42-8 and the identification patterns 43-5, 43-6, 43-7, and 43-8 are arranged so that their positions in the direction in which the track proceeds do not overlap each other. That is, the gain control pattern 41-5, the synchronization pattern 42-5, and the identification pattern 43-5 of the track # 1 are in the Te section, and the gain control pattern 41-6, the synchronization pattern 42-6, and the identification pattern 43- of the track # 2. 6 is a Tf section, track # 3 gain control pattern 41-7, synchronization pattern 42-7 and identification pattern 43-7 are Tg section, track # 4 gain control pattern 41-8, synchronization pattern 42-8 and The identification pattern 43-8 is arranged in each Th section. A gap 28 for margin is provided between the recording sections of the third preamble 25 for each track.

  Next, returning to FIG. 6, the identification patterns 43-1, 43-2, 43 arranged in the first preamble 23 and the third preamble 25 of each track # 1, # 2, # 3, # 4 are returned. -3, 43-4, 43-5, 43-6, 43-7, and 43-8 will be described.

  The identification information encoded as the identification pattern is, for example, a combination of a number from “1” to “s” for identifying a unit and a number from “1” to “4” for identifying a track in the unit, for example. It is expressed by. For example, “1_2” indicates the second track of the first unit.

  Further, as described above, instead of giving an identification number to the unit, the unit may be identified by, for example, a system frame unit or an error correction format unit.

  Next, the relationship between the reproduction in the forward direction and the reverse direction and the preamble 21 will be described. Here, the forward direction is the direction in which the playback position moves from left to right in the figure, and the reverse direction is the opposite.

First, the relationship between the forward reproduction and the preamble 21 will be described with reference to FIG.
FIG. 7 is a diagram showing the configuration of the preamble 21 of unit # 1 in the track format of FIG. In unit # 1, recording is performed from left to right in the figure.

  During playback in the forward direction, the gain control patterns 41-1, 41-2, 41-3, and 41-4 in the first preamble 23 of each track # 1, # 2, # 3, and # 4 are gain adjustment units. It is used for gain control of the reproduction amplifiers 221-1, 221-2, 221-3 and 221-4 by 224-1, 224-2, 224-3 and 224-4. The gain control patterns 41-1, 41-2, 41-3, and 41-4 are used for gain control for each reproduction signal in the reproduction signal gain control processing unit 233. Further, the gain control patterns 41-1, 41-2, 41-3, and 41-4 can be used for controlling the reproduction position of each reproduction signal in the reproduction position control processing unit 235.

  At the time of reproduction in the forward direction, the synchronization patterns 42-1, 42-2, 42-3, 42-4 in the first preamble 23 of each track # 1, # 2, # 3, # 4 are synchronized signal detectors. 231 and a plurality of preamble processing control unit 238, which are used as information for estimating various patterns in the subsequent stage and the head position of data. That is, each block that receives the detection information from the multiple preamble processing control unit 238 has a certain number of bits from the time when the synchronization patterns 42-1, 42-2, 42-3, and 42-4 in the first preamble 23 are detected. It is possible to estimate what pattern has a leading position first. Further, the synchronization patterns 42-1, 42-2, 42-3, and 42-4 are also used by the reproduction position control processing unit 235 to perform reproduction position control of each reproduction signal.

  During playback in the forward direction, the identification patterns 43-1, 43-2, 43-3, and 43-4 in the first preamble 23 of each track # 1, # 2, # 3, and # 4 are the identification information detection unit. 232 and used to obtain track identification information.

  In the first preamble 23, the patterns of the tracks # 1, # 2, # 3, and # 4 are arranged so that their positions in the track traveling direction do not overlap each other. Therefore, even when the channel clock positions of the tracks # 1, # 2, # 3, and # 4 are not matched, each of the reproducing heads R-1, R-2, R-3, and R-4 has a plurality of recording heads. When a signal is reproduced across tracks, the output of the reproduction signal does not decrease due to cancellation by the recording signal of each track. Thereby, gain control patterns 41-1, 41-2, 41-3, 41-4, synchronization patterns 42-1, 42-2, 42-3, 42-4, identification patterns 43-1, 43-2, The above processing control using 43-3 and 43-4 can be performed satisfactorily.

  At the time of reproduction in the forward direction, the separation patterns 44-1, 44-2, 44-3, and 44-4 of the tracks # 1, # 2, # 3, and # 4 are reproduced by the reproduction head R at the channel estimation calculation unit 234. Used to obtain a channel matrix necessary for computation for separating the reproduction signals for tracks # 1, # 2, # 3, and # 4 from the reproduction signals of -1, R-2, R-3, and R-4 Is done.

  These separation patterns 44-1, 44-2, 44-3, and 44-4 are also arranged so that the positions in the track traveling direction do not overlap each other. That is, in FIG. 7, the separation pattern 44-1 for track # 1 is in the T1 section, the separation pattern 44-2 for track # 2 is in the T2 section, and the separation pattern 44-3 for track # 3 is in the T3 section. The four separation patterns 44-4 are recorded in the T4 section. As a result, there are four types of separation patterns corresponding to the number of tracks. A gap 29 for a predetermined time for a margin is provided between the recording sections of the separation patterns 44-1, 44-2, 44-3, and 44-4 of adjacent tracks.

  Here, the separation patterns 44-1, 44-2, 44-3, and 44-4 are recorded at a predetermined recording wavelength equal to or greater than the minimum recording wavelength.

  Furthermore, during playback in the forward direction, the gain control patterns 41-5, 41-6, 41-7, and 41-8 in the third preamble 25 are detected by the multiple preamble processing control unit 238, and each playback head R It is used for the calculation of the second gain for the reproduction signals of -1, R-2, R-3, R-4. The reproduction signal gain control processing unit 233 includes a first gain and a plurality of preamble processing control units obtained by itself based on the gain control patterns 41-1, 41-2, 41-3, and 41-4 of the first preamble 23. A more appropriate gain is calculated by combining both gains, such as taking an average value with the second gain input from 238, and each reproduction head R-1, R-2, R-3, R is calculated with this gain. -4 is amplified to optimize the level.

  In the example of FIG. 7, the widths of the reproducing heads R-1, R-2, R-3, and R-4 are 1.5 times the track width. That is, the width of the reproducing heads R-1, R-2, R-3, R-4 is 1.5 times the head width of the recording heads W-1, W-2, W-3, W-4, for example. The signals can be read from a plurality of tracks by the individual reproducing heads R-1, R-2, R-3, and R-4. That is, the reproducing head R-1 reproduces a signal over the tracks # 1 and # 2, and the reproducing head R-2 reproduces a signal over the three tracks # 1, # 2, and # 3. The reproducing head R-3 reproduces a signal across three tracks # 2, # 3, and # 4, and the reproducing head R-4 reproduces a signal across the track # 3 and the track # 4. .

Next, the relationship between reverse playback and the preamble 21 will be described with reference to FIG.
FIG. 8 is a diagram showing the configuration of the preamble 21 of unit # 2 in the track format of FIG.

  During reverse playback, the gain control patterns 41-5, 41-6, 41-7, and 41-8 in the third preamble 25 of each track # 1, # 2, # 3, and # 4 are gain adjustment units. It is used as a learning signal for gain control of the reproduction amplifiers 221-1, 221-2, 221-3 and 221-4 by 224-1, 224-2, 224-3 and 224-4. The gain control patterns 41-5, 41-6, 41-7, and 41-8 are used for gain control for each reproduction signal in the reproduction signal gain control processing unit 233. Further, the gain control patterns 41-5, 41-6, 41-7, and 41-8 are also used for controlling the reproduction position of each reproduction signal in the reproduction position control processing unit 235.

  During reproduction in the reverse direction, the synchronization patterns 42-5, 42-6, 42-7, and 42-8 in the third preamble 25 of the tracks # 1, # 2, # 3, and # 4 are synchronized signal detectors. 231 and a plurality of preamble processing control unit 238, which are used as information for estimating various patterns in the subsequent stage and the head position of data. Further, the synchronization patterns 42-5, 42-6, 42-7, and 42-8 are used by the reproduction position control processing unit 235 to perform reproduction position control of each reproduction signal.

  At the time of reproduction in the reverse direction, the identification patterns 43-5, 43-7, 43-8, and 43-9 in the third preamble 25 of each track # 1, # 2, # 3, and # 4 are the identification information detection unit. 232 and used to obtain track identification information.

  In the third preamble 25, the patterns of the tracks # 1, # 2, # 3, and # 4 are arranged so that their positions in the direction in which the tracks proceed do not overlap each other. As a result, even when the channel clock positions of the tracks # 1, # 2, # 3, and # 4 are not aligned, each of the reproducing heads R-1, R-2, R-3, and R-4 is provided with a plurality of tracks. When the signal is reproduced across the tracks, the output of the reproduction signal does not decrease due to cancellation by the recording signal of each track. Thereby, gain control patterns 41-5, 41-6, 41-7, 41-8, synchronization patterns 42-5, 42-6, 42-7, 42-8, identification patterns 43-5, 43-6, and so on. The above control using 43-7 and 43-8 can be performed satisfactorily.

  During reproduction in the reverse direction, the separation patterns 44-1, 44-2, 44-3, and 44-4 for the tracks # 1, # 2, # 3, and # 4 are reproduced by the reproduction head R at the channel estimation calculation unit 234. Used to obtain a channel matrix necessary for computation for separating the reproduction signals for tracks # 1, # 2, # 3, and # 4 from the reproduction signals of -1, R-2, R-3, and R-4 Is done.

  Further, during reproduction in the reverse direction, the gain control patterns 41-1, 41-2, 41-3, and 41-4 in the first preamble 23 are detected by the multiple preamble processing control unit 238, and each reproduction head R It is used for the calculation of the second gain for the reproduction signals of -1, R-2, R-3, R-4. The reproduction signal gain control processing unit 233 includes a first gain and a plurality of preamble processing control units obtained by itself based on the gain control patterns 41-5, 41-6, 41-7, and 41-8 of the third preamble 25. A more appropriate gain is calculated by combining both gains, such as taking an average value with the second gain input from 238, and each reproduction head R-1, R-2, R-3, R is calculated with this gain. -4 is amplified to optimize the level.

  For the first preamble 23 and the third preamble 25, for example, a pattern in which the same code string is reproduced from either the forward direction or the reverse direction is employed. For example, when the synchronization pattern is “4T-4T-3T-2T”, the synchronization pattern of the first preamble 23 is “10001000100101”, and the synchronization pattern of the third preamble 25 is “10100100010001,” which is a symmetric pattern. Here, the last 1 bit in both sync patterns indicates inversion, so that the same code string is obtained during forward playback and reverse playback, as well as the gain control pattern and identification pattern. For the gain control pattern, a repetitive signal having a constant frequency is used, for example, a 3T continuous pattern.

  Next, details of processing performed in main blocks in the playback apparatus 200 of FIG. 3 will be described. In addition,

(Identification information detection unit 232)
At the time of reproduction in the forward direction, the identification information detection unit 232 is based on the detection results of the synchronization patterns 42-1, 42-2, 42-3, and 42-4 in the first preamble 23 by the synchronization signal detection unit 231. The head positions of the identification patterns 43-1, 43-2, 43-3, 43-4 in the reproduction signals of the reproduction heads R-1, R-2, R-3, R-4 are specified, and the identification pattern 43-1, 43-2, 43-3, 43-4 are detected and track identification information is output.

  At the time of reproduction in the reverse direction, the identification information detection unit 232 similarly uses the detection results of the synchronization patterns 42-5, 42-6, 42-7, and 42-8 in the third preamble 25 by the synchronization signal detection unit 231. Originally, the head positions of the identification patterns 43-5, 43-6, 43-7, 43-8 in the reproduction signals of the reproduction heads R-1, R-2, R-3, R-4 are specified, The identification patterns 43-5, 43-6, 43-7, and 43-8 are detected and track identification information is output.

  When one reproduction head straddles a plurality of tracks, the synchronization signal detection unit 231 detects the synchronization pattern of each track in a different section from the reproduction signal obtained by the reproduction head. The identification information detection unit 232 specifies the head position of the identification pattern of each track using each synchronization pattern, detects each identification pattern, and obtains identification information of each track.

(Reproduction signal gain control processing unit 233)
At the time of reproduction in the forward direction, the reproduction signal gain control processing unit 233, for example, based on the reproduction signals of the gain control patterns 41-1, 41-2, 41-3, and 41-4 in the first preamble 23, for example, In the following manner, the gain for the reproduction signal of each reproduction head R-1, R-2, R-3, R-4 is calculated.

  For example, in FIG. 7, the reproduction signal gain control processing unit 233 outputs the reproduction signals of the gain control pattern 41-1 and the gain control pattern 41-2 of the track # 1 and the track # 2 reproduced by the reproduction head R-1. to add. Similarly, the reproduction signal gain control processing unit 233 includes the gain control pattern 41-1, the gain control pattern 41-2, and the gain control for the track # 1, the track # 2, and the track # 3 reproduced by the reproduction head R-2. The reproduction signals of the patterns 41-3 are added. Similarly, the reproduction signal gain control processing unit 233 has gain control patterns 41-2, gain control patterns 41-3, and gain control for track # 2, track # 3, and track # 4 reproduced by the reproduction head R-3. The reproduction signals of the patterns 41-4 are added. Similarly, the reproduction signal gain control processing unit 233 adds the reproduction signals of the track # 3, the gain control pattern 41-3 of the track # 4, and the gain control pattern 41-4 reproduced by the reproduction head R-4.

  The addition of the reproduction signal of the gain control pattern is performed, for example, by detecting the peak value of the reproduction signal of the gain control pattern in each track and obtaining the average value thereof. Note that this calculation is not limited to the above method, and another method may be used as long as the correlation between the reproduced signals is established.

  The reproduction signal gain control processing unit 233 selects the maximum one of the three calculation results obtained as described above, and selects this one from all the reproduction heads R-1, R-2, R-3, R-. 4 as a reference output. Then, the reproduction signal gain control processing unit 233 obtains a value obtained by multiplying the value of the reproduction signal for each of the input reproduction heads R-1, R-2, R-3, and R-4 by 1 / (reference output). Obtained as a gain of 1.

  The reference output can also be used in channel estimation calculation in the channel estimation calculation unit 234 and can also be used in the signal separation calculation unit 236.

  Further, the reproduction signal gain control processing unit 233 inputs the second gain from the multiple preamble processing control unit 238 and takes both averages of the second gain and the first gain, for example. Thus, a more appropriate third gain is obtained, and the reproduction signals of the reproducing heads R-1, R-2, R-3, and R-4 are amplified with the third gain.

  At the time of reproduction in the reverse direction, the reproduction signal gain control processing unit 233 performs the first reproduction based on the reproduction signals of the gain control patterns 41-5, 41-6, 41-7, and 41-8 in the third preamble 25. A gain of 1 is obtained in a similar manner. The reproduction signal gain control processing unit 233 receives the second gain from the multiple preamble processing control unit 238, takes an average value of the second gain and the first gain, etc. An appropriate third gain is obtained, and the reproduction signals of the reproducing heads R-1, R-2, R-3, and R-4 are amplified with the third gain. As a result, better gain control can be performed on the reproduction signals of the respective reproduction heads R-1, R-2, R-3, and R-4, and the subsequent signal separation calculation is favorably performed. be able to.

(About Multiple Preamble Processing Control Unit 238)
At the time of reproduction in the forward direction, the multiple preamble processing control unit 238, for each of the tracks identified by the identification information detection unit 232, is a synchronization pattern 42- in the first preamble 23 that is a synchronization pattern first detected at the time of reproduction. 1, 42-2, 42-3, 42-4, the heads of gain control patterns 41-5, 41-6, 41-7, 41-8 in the third preamble 25 arranged in the subsequent stage Identify the location. The multiple preamble processing control unit 238 is similar to the reproduction signal gain control processing unit 233 based on the reproduction signals of the gain control patterns 41-5, 41-6, 41-7, and 41-8 in the third preamble 25. The second gain is calculated by the method, and this is output to the reproduction signal gain control processing unit 233.

  At the time of reproduction in the reverse direction, similarly, the multiple preamble processing control unit 238 similarly synchronizes each track identified by the identification information detection unit 232 in the third preamble 25 that is a synchronization pattern first detected at the time of reproduction. Based on the patterns 42-5, 42-6, 42-7, and 42-8, the gain control patterns 41-1, 41-2, 41-3, and 41- in the first preamble 23 arranged in the subsequent stage are used. The head position of 4 is specified. The multiple preamble processing control unit 238 is similar to the reproduction signal gain control processing unit 233 based on the reproduction signals of the gain control patterns 42-5, 42-6, 42-7, and 42-8 in the first preamble 23. The second gain is calculated by the method, and this is output to the reproduction signal gain control processing unit 233.

(About channel estimation calculation unit 234)
The channel estimation calculation unit 234 performs the separation patterns 44-1, 44-2, 44-3, 44- based on the information obtained by the synchronization signal detector 231 during both forward reproduction and reverse reproduction. 4 is specified, channel estimation calculation is performed based on the reproduction signals of these separation patterns 44-1, 44-2, 44-3, and 44-4, and the reproduction signal gain control processing unit 233 receives the signal. Thus, a channel matrix necessary for separating the reproduction signal for each track from the reproduction signal for one unit whose level is controlled is generated. At this time, the channel estimation calculation unit 234 can know the position where the head of the separation pattern of each track is based on the identification information of each track detected by the identification information detection unit 232. The reproduction signal of the separation pattern can be discriminated with high accuracy from the reproduction signal, and the channel estimation calculation can be performed with high accuracy.

(Reproduction position control processing unit 235)
The reproduction position control processing unit 235 performs reproduction heads R-1, R-2, and R-3 whose levels are controlled by the reproduction signal gain control processing unit 233 during both reproduction in the forward direction and reproduction in the reverse direction. , R-4 for each reproduction head R-1, R-2,..., R-4,..., R-4 input to the reproduction signal and the reproduction signal gain control processing unit 233 based on the information obtained by the synchronization signal detector 231. • Performs processing to match the playback position of the R-6 playback signal. As a result, even if the reproduction positions of the respective reproduction signals fetched from the respective reproduction heads do not coincide with each other in the track traveling direction, the reproduction positions of the respective reproduction signals can be aligned and input to the signal separation calculation unit 236. , Stable data reproduction can be performed.

(About the signal separation calculation unit 236)
The signal separation calculation unit 236 performs a predetermined signal separation calculation based on the channel matrix output from the channel estimation calculation unit 234 at the time of forward reproduction and reverse reproduction, thereby generating a reproduction position control processing unit. The reproduction signal for each track is separated from the reproduction signal for one unit whose reproduction position is aligned by 235.

  As a calculation method of signal separation processing by the signal separation calculation unit 236, for example, a method for obtaining a generalized inverse matrix for a channel matrix can be cited. A method for obtaining a generalized inverse matrix for this channel matrix is generally called a zero-forcing method. However, the method of signal separation processing is not limited to this, and for example, the MMSE (Minimum Mean Squared Error) method can also be used.

  As described above, according to the present embodiment, the first preamble 23 corresponding to reproduction from the forward direction and the third preamble 25 corresponding to reproduction from the reverse direction are symmetrical on both sides of the second preamble 24. Therefore, the second preamble 24, that is, the separation patterns 44-1, 44-2, 44-3, and 44-4 can be reproduced from either the forward direction or the reverse direction, and the signal separation process can be performed satisfactorily. Can do. Thereby, it is possible to perform the reproduction process satisfactorily without distinguishing whether the track is recorded from the forward direction or the reverse direction with respect to the magnetic recording medium 2.

  Further, in the present embodiment, at the time of reproduction in the forward direction and the reverse direction, the multiple preamble processing control unit 238 reproduces the reproduction signal based on the reproduction signal of the gain control pattern arranged at the subsequent stage of the second preamble 24. The gain is calculated in the same manner as the gain control processing unit 233 and output to the reproduction signal gain control processing unit 233. The reproduction signal gain control processing unit 233 is input from the first gain of the reproduction signal for each of the reproduction heads R-1, R-2, R-3, and R-4 and the multiple preamble processing control unit 238 obtained by itself. By combining with the second gain, a more appropriate third gain is obtained, and the level of the reproduction signal for each of the reproduction heads R-1, R-2, R-3, R-4 is obtained with this third gain. To control each. As a result, gain control can be performed more satisfactorily, and subsequent signal separation calculation can be performed satisfactorily.

  Also, according to the present embodiment, the reproduction heads R-1, R-2, R-3 based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 in the track feed amount control unit 271. , R-4, the adjustment amount for the specified feed amount is calculated, and the track feed amount determination unit 272 increases or decreases the specified feed amount by the adjustment amount. Thereby, immediately after switching the reproduction direction, reproduction heads R-1, R-2, R-3, and R-4 can be arranged at appropriate positions in the track width direction and reproduction can be started.

  FIG. 9 is a diagram showing a specific example of feed amount adjustment of the reproducing heads R-1, R-2, R-3, and R-4 when the unit to be reproduced is switched. This shows the situation when the reproduction process of unit # 1 is completed and the reproduction heads R-1, R-2, R-3, and R-4 are moved to the position of unit # 2. 210 (A) shows reproducing heads R-1, R-2, R-3, and R-4 positioned at the end of the reproducing direction after the tracing of the unit # 1 is completed. At this time, it is assumed that the positions of the reproducing heads R-1, R-2, R-3, and R-4 are shifted downward in the figure by, for example, 75% of the track width. Since the sum of the width of the unit and the width of the guard band 52 between the units is given as the specified feed amount A1, the reproducing heads R-1, R-2, R- remain at the specified feed amount A1. When 3, R-4 is sent, the deviation at the end of the unit # 1 is brought into the positional relationship with the unit # 2 after the movement. 210 (B) shows the positions of the reproducing heads R-1, R-2, R-3, and R-4 when moved without adjustment.

  Therefore, the track feed amount control unit 271 calculates the adjustment amount B1 for the specified feed amount A1 based on the channel matrix obtained by the channel estimation calculation unit 234. In this specific example, a negative feed amount corresponding to about 75% of the track width is obtained as the adjustment amount B1. The track feed amount determination unit 272 is a value obtained by increasing / decreasing the specified feed amount A1 (in this example, the specified feed amount A1 = track width × 4 (number of tracks constituting the unit) + guard band width) by the adjustment amount B1. Is determined as an appropriate feed amount C1 (C1 = A1 ± B1), and the control signal is transmitted so that the reproducing heads R-1, R-2, R-3, R-4 are moved by the proper feed amount C1. The data is output to the track feeding unit 273. Note that the sign of the value of B1 is negative in the case of FIG. As a result, the reproducing heads R-1, R-2, R-3, and R-4 are moved to appropriate positions in the track width direction. 210 (C) shows the reproducing heads R-1, R-2, R-3, and R-4 moved to appropriate positions in the track width direction. 210 (B) indicates the positions of the read heads R-1, R-2, R-3, and R-4 after movement when the specified feed amount A1 is not increased or decreased by the adjustment amount B1. .

(Modification 1 of the first embodiment)
Next, a modification of the first embodiment is shown.
In the above embodiment, for example, during playback in the forward direction, the multiple preamble processing control unit 238 detects the gain control patterns 41-5, 41-6, 41-7, and 41-8 in the third preamble 25, Based on the reproduction signals of these gain control patterns 41-5, 41-6, 41-7, and 41-8, the reproduction signals for the reproduction heads R-1, R-2, R-3, and R-4 are reproduced. The gain of 2 is calculated and given to the reproduction signal gain control processing unit 233. As a modified example, conversely, when the multiple preamble processing control unit 238 performs the reproduction in the forward direction, the reproduction signal gain control processing unit 233 uses the gain control patterns 41-1, 41-2, 41-3, and 41-4. The first gain for the reproduction signal of each reproduction head R-1, R-2, R-3, R-4 obtained based on the reproduction signal is input and combined with the second gain obtained by itself. A more appropriate third gain may be obtained.

(Modification 2 of the first embodiment)
A modification of the multiple preamble processing control unit 238 will be described below as a modification 2 of the first embodiment.

  The multiple preamble processing control unit 238, for example, at the time of reproduction in the forward direction, the third preamble processing control unit 238 performs the third based on the detection result of the synchronization patterns 42-1, 42-2, 42-3, and 42-4 in the first preamble 23. The head positions of the synchronization patterns 42-5, 42-6, 42-7, and 42-8 in the preamble 25 may be estimated and the information may be given to the synchronization signal detector 231. In this case, the synchronization signal detector 231 detects the synchronization patterns 42-5, 42-6, 42-7, and 42-8 in the third preamble 25 based on the information from the multiple preamble processing control unit 238. Then, readjustment of the synchronization acquired based on the synchronization patterns 42-1, 42-2, 42-3, and 42-4 in the first preamble 23 detected before is performed.

  If a plurality of different patterns are defined as the synchronization pattern in the synchronization signal detector 231, it is only necessary to give the synchronization signal detector 231 only a notification instructing the detection of the synchronization pattern from the multiple preamble processing control unit 238. It becomes like this. That is, the synchronization signal detector 231 itself detects a pattern previously defined as a synchronization pattern from the reproduction signal based on an instruction from the multiple preamble processing control unit 238, and this is detected as the second synchronization pattern in the reproduction order. Recognize as Note that the detection of the first synchronization pattern in the playback order is performed without depending on the instruction from the multiple preamble processing control unit 238, and this is detected as the first synchronization pattern in the playback order.

  In this case, for example, two types of “4T-4T-3T-2T” and “2T-3T-4T-4T” can be used as a plurality of different synchronization patterns. Thereby, it is possible to cope with the reproduction in the forward direction and the reverse direction.

  At this time, the second synchronization pattern can also function as resynchronization detection when the first synchronization pattern cannot be detected. At this time, it can be used to detect the portion of the data 22 recorded at a later position by a predetermined amount from the second synchronization pattern. If only the second synchronization pattern is detected, the processing by the second preamble 24 in the preamble 21 of that portion may not have been performed. Using the information when processing was performed on the preamble that was detected one or more times ago, the processing of the current data 22 portion may be performed.

  In addition, the synchronization patterns 42-1, 42-2, 42-3, and 42-4 in the first preamble 23 and the synchronization patterns 42-5, 42-6, 42-7, and 42- in the third preamble 25 are included. 8 is embedded with an ID pattern for identifying the other preamble synchronization pattern, and the synchronization signal detector 231 identifies each of the two preamble synchronization patterns based on the ID pattern. The synchronization may be captured based on the synchronization pattern detected first, and the synchronization may be readjusted based on the synchronization pattern detected next.

(Modification 3 of the first embodiment)
FIG. 9 shows that the reproducing heads R-1, R-2, R-3, and R-4 are displaced in the track width direction due to the disturbance, and the reproducing head R-4 has a track # 4 of the unit # 1 and an adjacent unit # 2. Across track # 1. In such a case, at the time of reproduction in the forward direction, the identification information detection unit 232 detects the identification pattern 43-4 of the first preamble 23 from the reproduction signal of the reproduction head R-4, and the track # of the unit # 1 4 (track ID = 1_4) (see FIG. 6) is identified, and the identification pattern 43-9 of the first preamble 23 of unit # 2 is detected, and track # 1 (track ID = 2_1) of unit # 2 is detected. ) (See FIG. 6) is detected.

  In the third modification, the track information detected by the identification information detection unit 232 in this way is provided to the track feed amount control unit 271. Based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 and the track information detected by the identification information detection unit 232, the track feed amount control unit 271 reproduces the read heads R-1, R-. 2, the adjustment amount for the specified feed amount of R-3, R-4 is calculated. That is, the track detection result is taken into account in the calculation of the adjustment amount based on the channel matrix. Thereby, the adjustment amount can be obtained more accurately, more stable signal reproduction processing can be performed, and high track density can be realized.

(Modification 4 of the first embodiment)
FIG. 10 is a conceptual diagram of another track format according to the present invention. In this track format, the preamble 21 is arranged in each track, and the first preamble 23 and the third preamble 25 in the preamble 21 are arranged in the guard band 52.

  FIG. 11 is a diagram showing the configuration of the preamble 21 in the track format of FIG. In each of the units # 1 and # 2, the configuration of the preamble 21 arranged in each of the tracks # 1 to # 4 is the same as that in FIGS. The configuration of the first preamble 23 and the third preamble 25 arranged in the guard band 52 is the same as that of the first preamble 23 and the third preamble 25 arranged in each track # 1- # 4.

  Also, in FIG. 11, the tracing of the unit # 1 from the forward direction is completed, and each reproducing head R-1, R-2, R-3, R-4 is sent to a position where the next unit # 2 can be traced. Is shown. Here, when the tracing of the unit # 1 is completed, the reproducing heads R-1, R-2, R-3, and R-4 are shifted from the proper positions by about 75% of the track width downward in the figure and reproduced. The head R-4 straddles the track # 4 of the unit # 1 and the card band 52 between the unit # 1 and the unit # 2. It is assumed that unit # 1 is recorded in the forward direction and unit # 2 is recorded in the reverse direction.

  In this case, at the time of reproduction in the forward direction, the identification information detection unit 232 detects the identification pattern 43-4 of the first preamble 23 from the reproduction signal of the reproduction head R-4, and the track # 4 (track ID = 1_4) ( 6), the identification information detecting unit 232 detects the identification pattern 43-10 of the guard band 52, and the guard band 52 is identified.

  The track and guard band information detected by the identification information detection unit 232 in this way is provided to the track feed amount control unit 271. The track feed amount control unit 271 is based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 and the track and guard band information detected by the identification information detection unit 232, thereby reproducing the head R-1 , R-2, R-3, and R-4, the adjustment amount for the specified feed amount is calculated. That is, the track and guard band identification results are taken into account in calculating the adjustment amount based on the channel matrix. Thereby, the adjustment amount can be obtained more accurately, more stable signal reproduction processing can be performed, and high track density can be realized.

(Other variations)
Next, other modifications of the first embodiment will be described.

  Although the identification pattern is arranged in the first preamble and the second preamble, the identification pattern is eliminated by using the type of pattern corresponding to the track as the synchronization pattern, and identifying the track based on the synchronization pattern. Is possible. Alternatively, the track may be identified by the arrangement of the synchronization pattern and gain control pattern in the preamble 21.

  The gain control pattern is arranged only at the beginning of the reproduction order in each of the first preamble 23 and the third preamble 25. However, the gain control pattern may be arranged behind the synchronization pattern so that synchronization detection is performed a plurality of times. Good.

  The gain control pattern and the separation pattern may be configured by the same pattern, and synchronization detection may be performed based on each pattern.

  Based on the track identification information obtained by the identification information detector 232, the reproduction of the individual reproduction heads R-1, R-2, R-3, R-4 in the section where the separation patterns for the units are arranged. For each signal, the reproduction signal corresponding to the section of the separation pattern reproduced by the reproduction head and the reproduction signal corresponding to the section of the separation pattern not reproduced by the reproduction head are discriminated, and the separation reproduced by the reproduction head. The reproduction signal corresponding to the pattern section may be used as it is, and the reproduction signal corresponding to the separation pattern section that is not reproduced by the reproduction head may be replaced with a predetermined zero value such as zero to perform channel estimation calculation. .

  Furthermore, in the above-described embodiment, a case where a 4 × 4 matrix is calculated as channel estimation information has been described. However, signal separation processing is performed by obtaining a generalized inverse matrix of other square matrices. It is possible. Furthermore, a generalized inverse matrix may be obtained in the same manner for a matrix other than a square matrix. In this case, in order to obtain a generalized inverse matrix of the matrix, the type of separation pattern is made to correspond to the number of tracks.

  In the above embodiment, the separation pattern orthogonal to the time axis is used. However, the present invention is not limited to this. For example, the separation pattern orthogonal to the frequency axis or the orthogonal code is used. Alternatively, a separation pattern using may be used.

  Further, regarding the recording head, if the same reproduction characteristics can be obtained for the recording in the forward direction and the reverse direction, a common recording head may be used for the recording in the forward direction and the reverse direction, or Separate recording heads may be used for recording in the forward and reverse directions. The same applies to the reproducing head.

  As described above, the magnetic recording / reproducing apparatus for recording signals on the recording medium without adjusting the recording position for each track and reproducing without adjusting the reproducing position has been described. However, the scope of application of the present invention is not limited to this, and the track The present invention can be similarly applied to a magnetic recording / reproducing apparatus that records a signal without aligning the recording position every time and reproduces the signal by aligning the reproducing position. Furthermore, the device that records the signal with the recording position aligned for each track and reproduces the signal without aligning the reproduction position, the device that records the signal with the recording position aligned for each track, and reproduces the signal with the reproduction position aligned, The present invention is equally applicable.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the first embodiment described above, the first preamble 23 that can be reproduced from the forward direction and the third preamble 25 that can be reproduced from the reverse direction are arranged on both sides of the second preamble 24, thereby reversing the forward direction. This is a magnetic recording / reproducing apparatus adopting a track format capable of reproducing the second preamble 24 from either direction. However, the present invention does not necessarily require such a track format, and can also be applied to a case where a track format that can be reproduced only from the direction determined for each track in the forward direction and the reverse direction is adopted.

  FIG. 12 is a conceptual diagram of such a track format. FIG. 13 is a diagram showing the track format of the end portion at the time of forward reproduction of the media recording medium 2 in this track format.

  Here, unit # 1 is a unit in which recording is performed in the forward direction, and unit # 2 is a unit in which recording is performed in the reverse direction. The difference from the track format of the fourth modification of the first embodiment will be described. In the track format of the fourth modification, the first preamble 23 and the third preamble 25 are included in each track # 1-4 and the guard band 52. However, in the track format of the second embodiment, the playback order is higher than that of the separation patterns 44-1, 44-2, 44-3, 44-4 as the second preamble 24. The latter pattern is arranged only on the guard band 52. Therefore, in this second embodiment, when unit # 1 is played back, playback is performed in the same forward direction as during recording, and when unit # 2 is played back, playback is performed in the same reverse direction as during recording. Must be done.

  Even when such a track format is adopted, the reproduction heads R-1, R-2, R are based on the channel matrix obtained by the channel estimation calculation unit 234 by the track feed amount control unit 271 in the track feed amount control unit 271. -3 and R-4, the adjustment amount for the specified feed amount is calculated, and the track feed amount determination unit 272 increases / decreases the specified feed amount by the adjustment amount, so that the playback is started immediately after switching the playback direction. Playback of the heads R-1, R-2, R-3, R-4 can be started from an appropriate position in the track width direction.

  Further, in this embodiment, when the unit # 1 is reproduced in the forward direction, the identification pattern 43-4 of the first preamble 23 is detected by the identification information detector 232 from the reproduction signal of the reproduction head R-4, and the track # 4 (track ID = 1_4) (see FIG. 6) is identified, and the identification pattern 43-10 of the guard band 52 is detected by the identification information detection unit 232, and the guard band 52 is identified. The track and guard band information detected by the identification information detection unit 232 in this way is provided to the track feed amount control unit 271. The track feed amount control unit 271 is based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 and the track and guard band information detected by the identification information detection unit 232, thereby reproducing the head R-1 , R-2, R-3, and R-4, the adjustment amount for the specified feed amount is calculated. That is, the track detection result is taken into account in the calculation of the adjustment amount based on the channel matrix. Thereby, the adjustment amount can be obtained more accurately, more stable signal reproduction processing can be performed, and high track density can be realized.

  Furthermore, in this embodiment, since the third preamble 23 is not recorded on each track, the preamble area can be reduced as a whole, and the recording efficiency for data on the magnetic recording medium 2 is improved. Have

(Third embodiment)
Next, a reproducing apparatus in the magnetic recording / reproducing system according to the third embodiment of the present invention will be described.

  FIG. 14 is a diagram showing a configuration of a reproducing apparatus 200 in the magnetic recording / reproducing system of the third embodiment. The difference in configuration from the playback device 200 of the first embodiment is that the multi-track demodulator 240 sends the information about the quality of the reproduced data to the track feed amount controller 271, for example, from the multi-track demodulator 240. Information on the result of error correction (correction success / failure) is notified.

  Further, FIG. 15 shows the configuration of the multitrack demodulator 240 in the present embodiment. As shown in the figure, in the multitrack demodulator 240, the decoders 245-1, 255-2, 245-3, and 245-4 perform error correction of the reproduced data, and the error correction result (correction) Information on (success / failure) is output to the track feed amount control unit 271.

  Note that the track format that is the object of the present embodiment is the track format employed in the first embodiment, that is, the track recorded from either the forward direction or the reverse direction, without distinguishing from the forward direction. It is a track format that can be played back in either the reverse direction or the reverse direction.

  FIG. 16 is a flowchart showing the flow of unit reproduction operation of the reproduction apparatus 200.

  The operations from step S201 to step 212 are the same as the operations of the playback apparatus 200 of the first embodiment shown in FIG.

  In step 214, the track feed amount control unit 271 receives information on the result of error correction (correction success / failure) from the multi-track demodulation unit 240, and if the content is a correction failure, reproduces it up to that point. Information for instructing to retrace the unit that has been sent is sent to the track feed amount determination unit 272.

  The track feed amount control unit 271 also reproduces the reproduction heads R-1 and R- when the units to be reproduced are switched based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 in step S212. 2, the adjustment amount for the specified feed amount of R-3, R-4 is calculated and sent to the track feed amount determination unit 272.

  In step S213A, when the track feed amount determination unit 272 receives information from the track feed amount control unit 271 indicating that the unit that has been played back is retraced, the track feed amount determination unit 272 gives the information to the track feed amount control unit 271. Based on the adjusted amount, the feed amount for moving the reproducing heads R-1, R-2, R-3, R-4 to the proper position in the track width direction with respect to the unit to be retraced is determined. Then, a control signal corresponding to the feed amount is output to the track feed unit 273.

  Further, when the track feed amount determination unit 272 does not receive the information indicating that the retrace is performed from the track feed amount control unit 271, similarly to the first embodiment, the track feed amount determination unit 272 performs a prescribed feed between units. A value obtained by adjusting the amount by the adjustment amount is determined as an appropriate feed amount of the reproducing heads R-1, R-2, R-3, and R-4, and a control signal corresponding to the proper feed amount is tracked. To the unit 273. The track feeding unit 273 moves the reproducing heads R-1, R-2, R-3, and R-4 in the track width direction according to the control signal from the track feeding amount determining unit 272.

  FIG. 17 is a diagram showing a specific example of feed amount adjustment of the reproducing heads R-1, R-2, R-3, and R-4 when the unit is retraced in the present embodiment. This shows a state in which the reproduction process of unit # 1 is completed and then retrace of the same unit is going to be started from the reverse direction. 210 (A) shows reproducing heads R-1, R-2, R-3, and R-4 that are located at the end of the reproducing direction after the tracing of the unit # 1 is completed. At this time, it is assumed that the positions of the reproducing heads R-1, R-2, R-3, and R-4 are shifted downward in the figure by about 75% of the track width. At this time, information indicating the error correction failure is notified from the multitrack demodulator 240 to the track feed amount control unit 271, and the unit # 1 that has been reproduced so far from the track feed amount control unit 271 to the track feed amount determination unit 272. It is assumed that information instructing to retrace is input.

  In this case, the track feed amount determination unit 272 is based on the adjustment amount B2 given from the track feed amount control unit 271 and is positioned at an appropriate position in the track width direction with respect to the unit # 1 to be retraced. 1, an appropriate feed amount C2 (C2 = B2) for moving R-2, R-3, and R-4 is determined, and a control signal corresponding to the proper feed amount C2 is output to the track feed unit 273. To do. 210 (D) is the position of the read heads R-1, R-2, R-3, R-4 after movement.

  As described above, in this embodiment, when the quality of reproduced data is poor, the same unit is retraced from the reverse direction. At this time, the track feed amount determination unit 272 determines the feed amount for moving the reproducing heads R-1, R-2, R-3, R-4 to an appropriate position in the track width direction with respect to the unit. It is determined based on the adjustment amount given from the feed amount control unit 271. As a result, the correct positional relationship in the track width direction between the unit and the reproducing heads R-1, R-2, R-3, and R-4 is obtained immediately after the start of retrace of the unit, and data reproduction is performed satisfactorily. be able to.

  Note that this embodiment can be combined with other embodiments.

(Fourth embodiment)
Next, a magnetic recording / reproducing system using a single head will be described as a fourth embodiment of the present invention.

  The magnetic recording / reproducing system of this embodiment has a recording head and a reproducing head whose number is less than the number of tracks per unit or a unit, and a recording medium on which recording is performed without aligning the recording position for each track. This is a method of reproducing without arranging the reproduction position every time.

  FIG. 18 is a diagram showing a configuration of a recording apparatus 300 in the magnetic recording / reproducing system according to the fourth embodiment of the present invention.

  The recording apparatus 300 performs unit recording with a single head. Here, the predetermined number of times that the unit is recorded by one recording head is M, and the predetermined number of times that the unit is reproduced by one reproducing head is N.

  As shown in the figure, the recording apparatus 300 includes a multitracking unit 110, a multitrack recording encoding unit 120, a multitrack preamble adding unit 130, a multitrack recording unit 140, a recording head array 150, and a storage unit 149. Is done.

  The multi-track recording encoding unit 120 includes M recording encoding units 121-1, 121-2, 121-3, and 121-4 that encode the recording data allocated to M by the data distributor 111. Composed.

  The multi-track preamble adding unit 130 is a symmetric preamble that can be read from the forward and backward directions as a preamble necessary for control of data reproduction in units of each recording data encoded by the multi-track recording encoding unit 120. Is composed of M number of longitudinally symmetric preamble addition units 131-1, 131-2, 131-3, 131-4.

  The storage unit 149 stores a code string of recording data for at least one unit generated by the multitrack preamble adding unit 130.

  The multi-track recording unit 140 is a means for recording the recording code string of each track to which the preamble is added on the recording medium. More specifically, the multi-track recording unit 140 is a single unit that gives a desired timing to the recording code string to which the preamble is added. An output timing setting unit 141, one recording compensation unit 144 that performs recording compensation processing, one recording amplifier 147 that drives each recording head W-1 based on the recording code string after the recording compensation processing, and Consists of.

  FIG. 19 is a flowchart showing a flow of operation during unit recording of the recording apparatus 300.

  In this recording apparatus 300, first, the input recording data 1 is distributed to M (M = 4) pieces of data (data for each track) by the multitracking unit 110 (step S301).

  Each distributed data is encoded by the recording encoding units 121-1, 121-2, 121-3, 121-4 of the multitrack recording encoding unit 120 in consideration of the recording / reproducing characteristics of the magnetic recording medium 2. Encoded into a column. At this time, information necessary for data demodulation, such as a demodulation synchronization pattern, is also added to the code string (step S302).

  Next, at a predetermined position of each encoded recording data, the M number of longitudinally symmetrical preamble adding units 131-1, 131-2, 131-3, 131-4 of the multitrack preamble adding unit 130 As a preamble required for reproduction control of unit-unit data, a longitudinally symmetric preamble that can be read from the forward and reverse directions is added, and a recording code string is obtained (step S303). The recording code string for each track to which the preamble is added in this way is stored in the storage unit 149 (step S304).

  Thereafter, the recording code string of the track to be recorded first is read from the storage unit 149 (step S305), and a desired timing is given to the recording code string of this track by the output timing setting unit 141. The recording compensation unit 144 performs a recording compensation process for optimizing the recording on the magnetic recording medium 2, the recording amplifier 147 converts the voltage into a current, and the recording head W-1 converts the magnetic recording medium 2. (Step S306).

  Thereafter, it is determined whether or not the recording of one unit of track has been completed (step S307). If not completed (NO in step S307), the recording head W-1 is moved to the next position (step S308). ). Thereafter, the recording code string of the next track is read from the storage unit 149, and the processing for recording is similarly repeated. The above operation is repeated until recording of a track for one unit is completed.

  Next, a modification of the recording apparatus in the magnetic recording / reproducing system of the fourth embodiment will be shown.

  FIG. 20 is a diagram showing a configuration of a recording apparatus 301 which is a modification of the recording apparatus in the magnetic recording / reproducing system of the fourth embodiment.

  As shown in the figure, the recording apparatus 301 is different from the recording apparatus 300 in FIG. 18 in the configuration of a multitrack recording encoding unit 120 and a multitrack preamble adding unit 130. The multi-track recording encoding unit 120 includes a single recording encoding unit 121 that records and encodes recording data in a predetermined unit, for example, recording data for a predetermined number of tracks. The multi-track preamble adding unit 130 Each of the encoded recording data is composed of one symmetric preamble adding unit 131 that adds a symmetric preamble necessary for controlling data reproduction in units of units. Further, in this recording apparatus 301, the multitracking unit 110 (data distributor 111) is omitted from the configuration of the recording apparatus 300 shown in FIG.

  FIG. 21 is a flowchart showing a unit recording operation flow of the recording apparatus 301.

  In this recording apparatus 301, first, recording data in a predetermined unit, for example, recording data for a predetermined number of tracks, is encoded into a code string in consideration of recording / reproduction characteristics of the magnetic recording medium 2 by the recording encoding unit 121. Is done. At this time, information necessary for data demodulation such as a synchronization pattern for demodulation is also added to the data code string (step S311).

  Next, before and after being able to read from the forward and reverse directions as a preamble necessary for control of reproducing unit-unit data at a predetermined position of the encoded recording data in the longitudinally symmetrical preamble adding unit 131 A symmetric preamble is added to obtain a recording code string (step S312). The recording code string for each track to which the preamble code is added in this way is stored in the storage unit 149 (step S313).

  Thereafter, the recording code string of the track to be recorded first is read from the storage unit 149 (step S314), and a desired timing is given to the recording code string of this track by the output timing setting unit 141, and then the recording is performed. The compensation unit 144 performs a recording compensation process for optimizing the recording on the magnetic recording medium 2, and the recording amplifier 147 converts the voltage into a current. The recording head W-1 applies the recording compensation process to the magnetic recording medium 2. It is recorded (step S315).

  Thereafter, it is determined whether or not recording of one unit of track has been completed (step S316). If not completed (NO in step S316), the recording head W-1 is moved to the next position (step S317). ), The recording code string of the next track is read from the storage unit 149, and the recording process is repeated in the same manner. The above operation is repeated until recording of a track for one unit is completed.

  FIG. 22 is a conceptual diagram of a track format on the magnetic recording medium 2 recorded by the recording device 300 (or the recording device 301).

  The recording apparatus 300 (or the recording apparatus 301) first records the track # 1 while moving the recording head W-1 in the forward direction at the position of the track # 1. Next, the recording apparatus 300 (or the recording apparatus 301) sends the recording head W-1 to the position of the track # 2, and then records the track # 2 while moving the recording head W-1 in the reverse direction. Next, the recording apparatus 300 (or the recording apparatus 301) sends the recording head W-1 to the position of the track # 3, and then records the track # 3 while moving the recording head W-1 in the forward direction. Finally, the recording apparatus 300 (or recording apparatus 301) records the track # 4 while moving the recording head W-1 in the reverse direction after sending the recording head W-1 to the position of the track # 4. This completes recording for one unit. In FIG. 22, the configuration in which the preamble 21 is arranged in the guard band 52 is adopted. However, as shown in FIG. 6, the preamble 21 may be arranged only in the track.

  FIG. 23 is a diagram illustrating an example of a preamble configuration in the track format. In this track format, the preamble 21 is arranged in each track, and the first preamble 23 and the third preamble 25 in the preamble 21 are also arranged in the guard band 52. Here, the configuration of the preamble 21 arranged in each of the tracks # 1- # 4 is the same as that in FIG. The configurations of the first preamble 23 and the third preamble 25 arranged in the guard band 52 are the same as those of the first preamble 23 and the third preamble 25 arranged in the track.

  Next, a reproducing apparatus in the magnetic recording / reproducing system according to the fourth embodiment of the present invention will be described.

  FIG. 24 is a diagram showing the configuration of a reproducing apparatus 400 in the magnetic recording / reproducing method according to the fourth embodiment of the present invention.

  As shown in the figure, the reproducing apparatus 400 includes a reproducing head array 210, a channel reproducing unit 220, a signal separation processing unit 230, a multitrack demodulating unit 240, a restoring unit 260, a track feed amount control unit 271, and a track feed amount determination. A section 272 and a track feed section 273.

  The reproducing head array 210 has one reproducing head R-1 that reads a signal from each track recorded on the magnetic recording medium 2.

  The channel reproducing unit 220 amplifies the signal reproduced by the reproducing head R-1 mounted on the reproducing head array 210, and the amplitude level of the output of the reproducing amplifier 221 becomes a predetermined value. And a gain adjuster 224 for controlling the gain, and an A / D converter 225 for quantizing the output of the gain adjuster 224 into a digital value having a predetermined bit width.

  Note that a low-pass filter that removes unnecessary high-frequency components may be provided immediately before the A / D converter 225 as necessary.

  Further, the gain adjustment unit 224 may be connected not to the front stage of the A / D converter 225 but to the rear stage. The gain may be controlled after quantization. This is effective when it is desired to use the bit width of the A / D converter 225 more effectively, or to make the configuration of the gain adjustment unit 224 simple in consideration of the detection of each pattern included in the preampule.

  Further, if the multitrack demodulator 240 performs the demodulation process while controlling the output timing for each track, the data concatenation process in the restoration unit 260 becomes unnecessary. Therefore, in this case, the restoration unit 260 is not necessary.

  The signal separation processing unit 230 includes a synchronization signal detection unit 231, an identification information detection unit 232, a reproduction signal gain control processing unit 233, a channel estimation calculation unit 234, a reproduction position control processing unit 235, a signal separation calculation unit 236, a storage unit 237, A multiple preamble processing control unit 238 is provided.

  The synchronization signal detection unit 231 detects a synchronization pattern arranged at the preceding stage of the separation pattern from the reproduction signal of the reproduction head R-1 output from the A / D converter 225.

  The identification information detection unit 232 uses the information obtained by the synchronization signal detection unit 231 to identify and detect the leading position of the identification pattern in the reproduction signal of the reproduction head R-1, thereby obtaining identification information.

  The multiple preamble processing control unit 238 specifies, for each of the tracks identified by the identification information detection unit 232, the head positions of various subsequent patterns with respect to the synchronization pattern first detected in the reproduction order. The plurality of preamble processing control units 238, for example, based on the reproduction signals of various patterns in the preamble (third preamble) arranged at the subsequent stage of the separation pattern, for example, the gain of the reproduction signal of the reproduction head R-1 Predetermined processing control such as calculation is performed.

  The reproduction signal gain control processing unit 233 reproduces the reproduction head R-1 for each trace based on the reproduction signal of the gain control pattern in the preamble from the reproduction signal of the reproduction head R-1 for each trace from the storage unit 237. A gain for the signal is calculated, and together with the gain input from the multiple preamble processing control unit 238, a more appropriate gain for the reproduction signal of the reproduction head R-1 for each trace is determined, and the reproduction signal is amplified with the gain. Thus, the level of each reproduction signal is controlled.

  The channel estimation calculation unit 234 is included in the playback signal preamble of the playback head R-1 for each trace based on the information obtained by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232. The head position of the separated pattern is specified, and the reproduction head R-1 for each trace and the plurality of tracks are reproduced based on the reproduction signal of the separation pattern output from the reproduction signal gain control processing unit 233. Channel estimation calculation is performed to calculate a channel matrix corresponding to the positional relationship in the track width direction.

  The reproduction position control processing unit 235 matches the reproduction position of the reproduction signal of the reproduction head R-1 for each trace that has passed through the reproduction signal gain control processing unit 233 based on the information obtained by the synchronization signal detection unit 231. Process.

  The signal separation calculation unit 236 uses a channel matrix obtained by the channel estimation calculation unit 234 from a reproduction signal of the reproduction head R-1 for each trace whose reproduction position is aligned by the reproduction position control processing unit 235, using a channel matrix. The process of separating the reproduction signal for each track is performed by the above calculation process.

  The storage unit 237 is disposed behind the identification information detection unit 232 and stores a reproduction signal for at least one unit.

  As shown in FIG. 4, the multi-track demodulation unit 240 performs M equalizers 241-1 and 241-2 that perform equalization processing on the reproduction signal for each track separated by the signal separation operation unit 236. , 241-3, 241-4, and M PLLs 242-1, 242-2, 242-3 that perform bit synchronization from the outputs of the equalizers 241-1, 241-2, 241-3, and 241-4. 242-4 and the bit synchronization signal generated by PLL 242-1, 242-2, 242-2, 242-4, and binarizing the reproduction signal of each track to generate a code string, for example, Viterbi detector The binarized reproduction that is the output of the M detectors 243-1, 243-2, 243-3, 243-4 and the detectors 243-1, 243-2, 243-3, 243-4 Detect synchronization pattern on code sequence from signal The synchronization patterns detected by the M synchronization signal detectors 244-1, 244-2, 244-3, 244-4 and the synchronization signal detectors 244-1, 244-2, 244-3, 244-4 are represented by Originally, M decoders 245-1, 245-2, 245-3, and 245-4 are provided which specify the head position of data and decode the data sequence from the code string. Note that the multitrack demodulation unit 240 has a storage unit (not shown) that stores information such as data necessary for performing the above processing.

  Referring back to FIG. 24, the restoration unit 260 records the data of each track output from the M decoders 245-1, 245-2, 245-3, and 245-4 in the multitrack demodulation unit 240 at the time of recording. And a data combiner 261 that restores the reproduced data 3 by connecting them in the reverse operation.

  Note that the track tracing during reproduction by the single head is repeated at least as many times as the number of recording tracks of one unit. That is, the tracing may be repeated more times than the number of tracks. At that time, all tracks for one unit are traced at least once. The storage unit 237 stores a signal corresponding to a unit reproduced at each position where the reproducing head R-1 has moved, that is, a signal reproduced by the reproducing head R-1 from a plurality of tracks at each position, and a synchronization signal detector 231. Thus, the necessary reproduction signal after the separation pattern is stored.

  At the time of reproduction, the direction of the trace is switched between the forward direction and the reverse direction for each trace by the reproduction head R-1. The reproducing head R-1 performs reproduction across a plurality of tracks having different recording directions, and the track format adopted here is the first corresponding to reproduction from the forward direction with the second preamble 24 interposed therebetween. Since the preamble 23 and the third preamble 25 corresponding to reproduction in the reverse direction are arranged symmetrically, it is possible to obtain preamble information necessary for unit-unit data reproduction control. Thereby, it is possible to perform the reproduction process satisfactorily without distinguishing whether the track is recorded from the forward direction or the reverse direction with respect to the magnetic recording medium 2.

  FIG. 25 is a flowchart showing the unit reproduction operation of the reproduction apparatus 400.

  In the reproducing apparatus 400, first, signals are reproduced from a plurality of tracks at the initial position by the reproducing head R-1 (step S401). Next, after the amplitude level of the output of the reproduction amplifier 221 is adjusted by the gain adjusting unit 224, the output is converted into a digital value by the A / D converter 225 and output to the synchronization signal detector 231 ( Step S402).

  Next, after the synchronization signal detection unit 231 detects the synchronization pattern included in the reproduction signal output from the A / D converter 225 (step S403), the identification information detection unit 232 performs the synchronization signal detection unit. Using the information obtained in step 231, the identification pattern is detected by identifying the start position of the identification pattern in the reproduction signal of the reproduction head R- 1 to obtain identification information (step S 404). The reproduction signal that has passed through the identification information detection unit 232 is stored in the storage unit 237 (step S405).

  Next, it is determined whether or not the reproduction signal for one unit is stored in the storage unit 237 (step S406). If the reproduction signal for one unit is not yet stored in the storage unit 237, the reproduction head R- 1 is sent to the next position in the track width direction (step 407), and the operations from step S401 to step S405 are repeated.

  When the reproduction signal for one unit is stored in the storage unit 237, the reproduction signal gain control processing unit 233 reads the reproduction signal for one unit stored in the storage unit 237, and performs gain control in the reproduction signal for each trace. Based on the reproduction signal of the pattern, the gain for the reproduction signal for each trace is calculated, and the level of the reproduction signal for each trace is individually controlled (step S408).

  Next, the multiple preamble processing control unit 238 specifies the start positions of various patterns at the subsequent stage with respect to the synchronization pattern first detected in the reproduction order for the track identified by the identification information detection unit 232. The plurality of preamble processing control units 238, for example, based on the reproduction signals of various patterns in the preamble (third preamble) arranged at the subsequent stage of the separation pattern, for example, the gain of the reproduction signal of the reproduction head R-1 Predetermined processing control such as calculation is performed (step S409).

  Next, in the channel estimation calculation unit 234, based on the information obtained by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232, the reproduction signal of the reproduction head R-1 for each trace is calculated. The head position of the separation pattern included in the preamble is specified, and based on the reproduction signal of the separation pattern output from the reproduction signal gain control processing unit 233, the reproduction head R-1 for each trace and a plurality of tracks are A channel matrix corresponding to the positional relationship in the track width direction during reproduction is calculated (step S410).

  Next, each reproduction position control processing unit 235 passes through the reproduction signal gain control processing unit 233 based on the information obtained by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232. The reproduction position of the reproduction signal of the reproduction head R-1 for each trace is aligned (step S411).

  Next, in the signal separation calculation unit 236, the channel matrix obtained by the channel estimation calculation unit 234 from the reproduction signal of the reproduction head R-1 for each trace whose reproduction position is aligned by the reproduction position control processing unit 235 is obtained. The process of separating the reproduction signal for each track is performed by a predetermined calculation process (step S412).

  Thereafter, the multi-track demodulator 240 decodes the data sequence from the reproduction signal separated for each track (step S413), and the restoration unit 260 concatenates the data for each track to obtain reproduction data 3. (Step S414).

  In the above processing, the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 is also sent to the track feed amount control unit 271. Based on the channel matrix input from the channel estimation calculation unit 234, the track feed amount control unit 271 calculates an adjustment amount with respect to the prescribed feed amount of the reproducing head R-1 when switching the unit to be reproduced (step S415). ). The adjustment amount obtained by the track feed amount control unit 271 is sent to the track feed amount determination unit 272.

  In the track feed amount determination unit 272, a predetermined value for the feed amount of the reproducing head R-1 is set in advance. This prescribed feed amount is the sum of the track width and the guard band 52 width. When the track feed amount determination unit 272 acquires the adjustment amount from the track feed amount control unit 271, the track feed amount determination unit 272 determines a value obtained by adjusting the above-described prescribed feed amount by the adjustment amount as the feed amount of the reproducing head R-1 ( In step S416, a control signal corresponding to the feed amount is output to the track feed unit 273. As a result, the reproducing head R-1 is moved to an appropriate position in the track width direction for tracing the next unit.

  FIG. 26 is a diagram showing a specific example of feed amount adjustment of the reproducing head R-1 when the unit to be reproduced is switched. A state is shown in which the reproducing head R-1 is moved to the position where the reproduction processing of the unit # 1 is finished and the tracing of the unit # 2 is started next. 210 (A) shows the reproducing head R-1 located at the end of the reproducing direction after the reproduction of the unit # 1 is completed. At this time, it is assumed that the position of the reproducing head R-1 is shifted downward in the figure by, for example, 50% of the track width. Since the sum of the track width and the width of the guard band 52 between the units is given as the prescribed feed amount A3, when the reproducing head R-1 is fed with the prescribed feed amount A3, the unit # 1 The shift at the end of is brought into the positional relationship with the unit # 2 after the movement. 210 (B) shows the position of the reproducing head R-1 when moved without adjustment.

  Therefore, the track feed amount control unit 271 calculates the adjustment amount B3 for the specified feed amount A3 based on the channel matrix obtained by the channel estimation calculation unit 234. In this specific example, a negative feed amount corresponding to about 50% of the track width is obtained as the adjustment amount B3. The track feed amount determination unit 272 determines a value obtained by increasing or decreasing the specified feed amount A3 by the adjustment amount B3 as an appropriate feed amount C3 (C3 = A3 ± B3), and the reproducing head R− A control signal is output to the track sending unit 273 so that 1 is moved. In the example of FIG. 26, the sign of the value of B3 is negative. As a result, the reproducing head R-1 is moved to an appropriate position in the track width direction. 210 (C) shows the reproducing head R-1 moved to an appropriate position in the track width direction.

  As described above, according to the present embodiment, even in the magnetic recording / reproducing method using a single head, the track feed amount control unit 271 uses the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234. Then, an adjustment amount with respect to the specified feed amount of the reproducing head R-1 is calculated, and the track feed amount determination unit 272 increases / decreases the specified feed amount by the adjustment amount. Thereby, immediately after switching of the unit to be reproduced, the reproduction head R-1 can be arranged at an appropriate position in the track width direction and reproduction can be started.

  In addition, according to the present embodiment, in the magnetic recording / reproducing system using a single head, the first preamble 23 corresponding to reproduction from the forward direction and the third preamble 25 corresponding to reproduction from the reverse direction are changed to the second. By arranging symmetrically on both sides of the preamble 24, the second preamble 24, that is, the separation patterns 44-1, 44-2, 44-3, 44-4 can be reproduced from either the forward direction or the reverse direction. It is possible to perform signal separation processing. Thereby, it is possible to perform the reproduction process satisfactorily without distinguishing whether the track is recorded from the forward direction or the reverse direction with respect to the magnetic recording medium 2.

  Further, in the present embodiment, at the time of reproduction in the forward direction and the reverse direction, the multiple preamble processing control unit 238 reproduces the reproduction signal based on the reproduction signal of the gain control pattern arranged at the subsequent stage of the second preamble 24. The gain is calculated in the same manner as the gain control processing unit 233 and output to the reproduction signal gain control processing unit 233. The reproduction signal gain control processing unit 233 combines the first gain of the reproduction signal for each trace obtained by itself with the second gain input from the multiple preamble processing control unit 238, so that a more appropriate third Gain is obtained, and the level of the reproduction signal for each trace is controlled by this third gain. As a result, gain control can be performed more satisfactorily, and subsequent signal separation calculation can be performed satisfactorily.

  Further, as shown in FIG. 23, in the present embodiment, at the time of the last tracing of the unit # 1 (forward direction), the identification information detection unit 232 detects the first preamble 23 from the reproduction signal of the reproduction head R-1. The identification pattern 43-4 is detected to identify the track # 4 (track ID = 1_4) (see FIG. 6), and the identification information detection unit 232 detects the identification pattern 43-10 of the guard band 52. The guard band 52 is identified.

  The track and guard band information detected by the identification information detection unit 232 in this way may be provided to the track feed amount control unit 271. In such a configuration, the track feed amount control unit 271 is based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 and the track and guard band information detected by the identification information detection unit 232. In addition, it is possible to calculate an adjustment amount with respect to a specified feed amount of the reproduction head R-1 when the reproduction unit is switched. That is, in the calculation of the adjustment amount based on the channel matrix, the track and guard band identification results can be taken into account. Thereby, the adjustment amount can be obtained more accurately, more stable signal reproduction processing can be performed, and high track density can be realized.

(Fifth embodiment)
Next, a reproducing apparatus in the magnetic recording / reproducing system according to the fifth embodiment of the present invention will be described.

  FIG. 27 is a diagram showing a configuration of a reproducing apparatus 400 in the magnetic recording / reproducing method according to the fifth embodiment of the present invention. The difference in configuration from the playback apparatus 400 of the fourth embodiment is that the multitrack demodulator 240 sends the track feed amount controller 271 and the information on the error correction result (correction success / failure) from the multitrack demodulator 240. Is to be notified. The configuration of the multitrack demodulator 240 is as shown in FIG. 15, and the decoders 245-1, 245-2, 245-3, and 245-4 perform error correction of the data, and the error correction result (correction) Information on (success / failure) is output to the track feed amount control unit 271.

  FIG. 28 is a flowchart showing the flow of unit reproduction operation of the reproduction apparatus 400.

  The operation from step S401 to step 415 is the same as that of the playback apparatus 400 of the fourth embodiment shown in FIG.

  In step 417, the track feed amount control unit 271 receives information on the error correction result (correction success / failure) from the multi-track demodulation unit 240, and if the content is a correction failure, reproduces it up to that point. Information for instructing to retrace the unit that has been sent is sent to the track feed amount determination unit 272.

  Also, the track feed amount control unit 271 defines the reproducing head R-1 when reproducing the next unit based on the channel matrix obtained by the channel estimation calculation by the channel estimation calculation unit 234 in step S212. The adjustment amount for the feed amount is calculated and sent to the track feed amount determination unit 272.

  In step S213A, when the track feed amount determination unit 272 receives information indicating that the unit is to be retraced from the track feed amount control unit 271, the track feed amount determination unit 272 also sets the adjustment amount given from the track feed amount control unit 271. In addition, a feed amount for moving the reproducing head R-1 to an appropriate position in the track width direction with respect to the unit to be retraced is determined, and a control signal corresponding to this feed amount is output to the track feed unit 273. . As a result, the reproducing head R-1 is moved to an appropriate position in the track width direction for re-tracing the unit.

  FIG. 29 is a diagram showing a specific example of the feed amount adjustment of the reproducing head R-1 when the unit is retraced. The reproduction process of the unit # 1 is completed, and then the retrace of the same unit is about to start. Indicates the situation. 210 (A) shows the reproducing head R-1 located at the end of the reproducing direction after the reproduction of the unit # 1 is completed. At this time, it is assumed that the positions of the reproducing heads R-1, R-2, R-3, and R-4 are shifted downward in the figure by about 50% of the track width.

  In this case, the track feed amount determination unit 272 receives unit # 1 from the adjustment amount B4 given from the track feed amount control unit 271 by the track feed amount control unit 271 and the prescribed feed amount A4 for retrace. In order to re-trace, the feed amount C4 (C4 = A4 ± B4) for moving the reproducing head R-1 to an appropriate position in the track width direction is determined, and a control signal corresponding to this feed amount C4 is sent to the track. To the unit 273. In this embodiment, the prescribed feed amount A4 for re-tracking is the track width × 4 (the number of tracks constituting the unit), and the prescribed feed amount A4 is adjusted to increase / decrease the adjustment amount B4. A value is obtained as an appropriate feed amount C4. 210 (D) is the position of the read head R-1 after movement.

  Thus, according to the present embodiment, in the magnetic recording / reproducing system using a single head, when an error correction failure occurs in the multitrack demodulator 240, the same unit is retraced. At this time, the track feed amount determination unit 272 gives a feed amount for moving the reproducing head R-1 to an appropriate position in the track width direction with respect to the unit to be retraced from the track feed amount control unit 271. Determined based on the amount of adjustment. As a result, immediately after the start of re-trace of the unit, it becomes possible to trace the unit from an appropriate position in the track width direction, and data reproduction can be performed satisfactorily.

  The present invention is not limited to the linear recording system and non-azimuth recording system magnetic recording / reproduction described above, but can also be applied to a helical recording system and an azimuth recording system.

  Specific examples are shown below.

  FIG. 30 shows recording on the magnetic recording medium 2 by a non-azimuth method and a helical trace method using a plurality of recording heads W-1, W-2, W-3 integrated as a recording head array 150, for example. It is a conceptual diagram of a track format. Also in the helical trace method, the guard band 52 is arranged between the units 53 composed of the track # 1, the track # 2, and the track # 3. The preamble 21 recorded on the track # 1, the track # 2, and the track # 3 may be the same as that shown in the above embodiment. The recording direction of the first unit (# 1) is from the bottom to the top in the figure, and the recording direction of the second unit (# 2) is from the top to the bottom in the figure. It can be switched alternately. The present invention can also be applied to such a helical trace type magnetic recording / reproducing method, and the configurations of the recording device 100 and the reproducing device 200 in the magnetic recording / reproducing method of the first embodiment can be employed.

  In order to switch the recording direction between the forward direction and the reverse direction, for example, a first drum that rotates in the forward direction and a second drum that rotates in the reverse direction are provided as the drum on which the head is mounted. Just do it.

  FIG. 31 shows a recording medium using a plurality of recording heads W-1, W-2, W-3, W-4, W-4, W-5, and W-6 by a double azimuth method and a helical trace method. It is a conceptual diagram of the track format recorded on. In helical trace magnetic recording, a plurality of heads are independently mounted on a rotating drum. For example, a plurality of recording heads and reproducing heads are alternately arranged on the rotating drum.

  Further, the recording direction of the first unit (# 1) is from the bottom in the figure, and the recording direction of the second unit (# 2) is from the top to the bottom in the figure. In order to switch the recording direction between the forward direction and the reverse direction in this way, there are provided drums that rotate in the forward direction and those that rotate in the reverse direction, and each has six recording heads W-1, W-. 2, W-3, W-4, W-4, W-5, W-6 can be installed.

  Of the six recording heads W-1, W-2, W-3, W-4, W-4, W-5, and W-6, three consecutive recording heads W-1, W-2, and W- 3 and the remaining three consecutive recording heads W-4, W-5, and W-6 are different from each other in the azimuth direction, which is the magnetization direction of the track. That is, track # 1- # 3 and track # 4- # 6 have different azimuth directions. These tracks # 1 to # 6 become a unit 51 including a plurality of units which are a unit of processing for reproducing data. In the case of this double azimuth, no guard band is required.

  In this example, a group of tracks # 1 to # 6 is a unit of signal processing for reproducing data. However, three consecutive tracks (for example, track # 1) having the same azimuth direction are used. -# 3 and tracks # 4- # 6) may each be subjected to signal processing as one unit 51.

  The configuration of the preamble recorded on each track # 1- # 6 may be the same as that shown in the above embodiment. The present invention can also be applied to such a magnetic recording / reproducing system of the double azimuth method and the helical trace method, and the configuration of the recording device 100 and the reproducing device 200 in the magnetic recording / reproducing method of the first embodiment is adopted. be able to.

  It should be noted that the present invention is not limited to the configuration shown in the above-described embodiment, and it is needless to say that various changes and modifications can be made without departing from the technical scope described in the claims.

It is a figure which shows the structure of the magnetic recording / reproducing apparatus using the multi-head which concerns on the 1st Embodiment of this invention. 6 is a flowchart showing a unit recording operation by the recording apparatus according to the first embodiment. It is a figure which shows the structure of the reproducing | regenerating apparatus concerning 1st Embodiment. It is a figure which shows the structure of a multitrack demodulation part. It is a flowchart which shows the flow of operation | movement of the unit reproduction | regeneration of the reproducing | regenerating apparatus which concerns on 1st Embodiment. It is a figure which shows the track format which concerns on 1st Embodiment. FIG. 7 is a diagram showing a configuration of a preamble of unit # 1 in the track format of FIG. FIG. 7 is a diagram showing a configuration of a preamble of unit # 2 in the track format of FIG. It is a figure which shows the specific example of the feed amount adjustment of reproducing head R-1, R-2, R-3, R-4 when the unit to reproduce | regenerate switches. It is a conceptual diagram of another track format according to the present invention. It is a figure which shows the structure of the preamble in the track format of FIG. It is a figure which shows the track format which concerns on the 2nd Embodiment of this invention. FIG. 13 is a diagram showing a track format of a terminal portion at the time of forward reproduction of the media recording medium in the track format of FIG. 12. It is a figure which shows the structure of the reproducing | regenerating apparatus in the magnetic recording / reproducing system of 3rd Embodiment. It is a figure which shows the structure of the multitrack demodulation part which concerns on 3rd Embodiment. It is a flowchart which shows the flow of operation | movement of the unit reproduction | regeneration of the reproducing | regenerating apparatus which concerns on 3rd Embodiment. It is a figure which shows the specific example of the feed amount adjustment of the reproduction | regeneration head in the case of re-tracing a unit in 3rd Embodiment. It is a figure which shows the structure of the recording device in the magnetic recording / reproducing system of the 4th Embodiment of this invention. It is a flowchart which shows the flow of operation | movement at the time of unit recording of the recording device which concerns on 4th Embodiment. It is a figure which shows the structure of the modification of the recording device which concerns on 4th Embodiment. FIG. 21 is a flowchart showing a unit recording operation flow of the recording apparatus of FIG. 20. FIG. It is a conceptual diagram of the track format on the magnetic recording medium on which recording is performed by the recording apparatus according to the fourth embodiment. It is a figure which shows the example of a structure of the preamble in the track format of FIG. It is a figure which shows the structure of the reproducing | regenerating apparatus concerning 4th Embodiment. It is a flowchart which shows the unit reproduction | regeneration operation | movement of the reproducing | regenerating apparatus concerning 4th Embodiment. It is a figure which shows the specific example of the feed amount adjustment of the reproducing head when the unit to reproduce | regenerate switches in the reproducing | regenerating apparatus concerning 4th Embodiment. It is a figure which shows the structure of the reproducing | regenerating apparatus which concerns on the 5th Embodiment of this invention. It is a flowchart which shows the flow of the unit reproduction | regeneration operation | movement of the reproducing | regenerating apparatus which concerns on 5th Embodiment. It is a figure which shows the specific example of the feed amount adjustment of the reproducing head at the time of re-tracing a unit in the reproducing | regenerating apparatus concerning 5th Embodiment. It is a conceptual diagram of a track format recorded on a magnetic recording medium by a non-azimuth method and a helical scan method using a plurality of recording heads. It is a conceptual diagram of a track format recorded on a recording medium by a double azimuth method and a helical scan method using a plurality of recording heads. It is a figure which shows the structure of the recording apparatus which employ | adopted the magnetic recording and reproducing system which the present inventors proposed in the past. FIG. 33 is a flowchart showing an operation of unit recording by the recording apparatus of FIG. 32. FIG. It is a figure which shows the structure of the reproducing | regenerating apparatus which employ | adopted the magnetic recording / reproducing system which the present inventors proposed in the past. FIG. 35 is a flowchart showing a unit playback operation flow of the playback apparatus of FIG. 34. FIG.

Explanation of symbols

2 Magnetic recording medium 21 Preamble 22 Data 23 First preamble 24 Second preamble (separation pattern)
25 Third Preamble 41-1 to 41-8 Gain Control Pattern 42-1 to 42-8 Synchronization Pattern 43-1 to 43-8 Identification Pattern 44-1 to 44-4 Separation Pattern 51 Unit 52 Guard Band 100 Recording Device DESCRIPTION OF SYMBOLS 110 Multitracking part 120 Multitrack recording encoding part 130 Multitrack preamble addition part 131-1 to 131-4 Front-back symmetrical type preamble addition part 140 Multitrack recording part 150 Recording head array 200 Playback apparatus 210 Playback head array 220 Channel playback Unit 230 signal separation processing unit 231 synchronization signal detector 232 identification information detection unit 233 reproduction signal gain control processing unit 234 channel estimation calculation unit 235 reproduction position control processing unit 236 signal separation calculation unit 238 multiple preamble processing control unit 240 multitra Click demodulator 260 restores 271 the track feed amount control unit 272 tracks the feed amount determining unit 273 tracks the feed unit R-1 to R-4 reproducing head W-1 to W-4 recording heads

Claims (12)

It has a plurality of tracks constituting a unit which is a unit of signal processing for data reproduction, and the track is provided in the reproduction head array as data and a pattern necessary for control for reproducing the data. is a preamble, each including a separation pattern necessary to detect one or more of the positional relationship between the track width direction across the track signal and renewable plurality of playback heads and the plurality of tracks are recorded A reproducing apparatus for reproducing a plurality of tape-like recording media recorded in parallel with each other along the direction in which the unit travels the track,
An estimation unit that estimates a positional relationship in the track width direction during reproduction between the plurality of reproduction heads and the plurality of tracks, using reproduction signals of the separation patterns obtained by the plurality of reproduction heads;
A playback apparatus comprising: a feed amount calculation unit that calculates a feed amount of the read head array when switching the unit to be played back based on the positional relationship obtained by the estimation unit. The playback apparatus according to claim 1,
The feed amount calculation unit obtains an adjustment amount with respect to a prescribed feed amount of the reproducing head array when switching the unit to be reproduced based on the positional relationship obtained by the estimation unit, and the prescribed feed amount A playback apparatus that obtains a value obtained by adjusting the value by the adjustment amount as a calculation result. The playback device according to claim 2,
A determination unit for determining the quality of the reproduced data;
The feeding amount calculation unit further calculates a feeding amount of the reproducing head array when the unit is retraced when the determination unit determines reproduction data of a unit that does not satisfy a predetermined quality. . The playback apparatus according to claim 1,
The preamble recorded on the recording medium has a pattern that can be reproduced from both the forward direction and the reverse direction in which the track proceeds, and the reproduction direction at the time of tracing is switched alternately between the forward direction and the reverse direction. Playback device. The playback apparatus according to claim 4, wherein
The preamble has a gain control pattern before and after the separation pattern,
A reproduction apparatus further comprising: a gain control unit that controls a gain with respect to a reproduction output of the reproduction head based on a reproduction signal of each gain control pattern of the preamble. The playback apparatus according to claim 4, wherein
The preamble has a synchronization pattern for estimating a pattern in the subsequent stage in the playback order and a head position of data before and after the separation pattern,
A playback apparatus further comprising: a detection unit that detects each synchronization pattern of the preamble. It has a plurality of tracks constituting a unit which is a unit of signal processing for data reproduction, and the track is provided in the reproduction head array as data and a pattern necessary for control for reproducing the data. A plurality of reproducing heads each capable of reproducing a signal across one or more tracks, and a preamble including a separation pattern necessary for detecting a positional relationship between the plurality of tracks in the track width direction during reproduction. And a unit for reproducing a tape-shaped recording medium in which a plurality of units are recorded in parallel with each other along a direction in which the track travels,
Wherein the plurality of using the reproduction signal of the separation pattern obtained by reproducing head, to estimate the positional relationship between the track width direction at the time of reproduction of the plurality of tracks and multiple read head,
A reproducing method for calculating a feed amount of the reproducing head array when the unit to be reproduced is switched based on the estimated positional relationship. The playback method according to claim 7, comprising:
Based on the estimated positional relationship, an adjustment amount for the specified feed amount of the read head array when switching the unit to be played back is obtained, and a value obtained by adjusting the specified feed amount by the adjustment amount is calculated. As a playback method. The reproduction method according to claim 8, wherein
Judge the quality of the played data,
A reproduction method for calculating, based on an estimated positional relationship, a feed amount of the reproduction head array when the unit is retraced when reproduction data of a unit that does not satisfy a predetermined quality is determined. The playback method according to claim 7, comprising:
The preamble recorded on the recording medium has a pattern that can be reproduced from both the forward direction and the reverse direction in which the track proceeds, and the reproduction direction at the time of tracing is switched alternately between the forward direction and the reverse direction. Playback method. The playback method according to claim 10, comprising:
The preamble has a gain control pattern before and after the separation pattern,
A reproduction method for controlling a gain for a reproduction output of the reproduction head based on a reproduction signal of each gain control pattern of the preamble. The playback method according to claim 10, comprising:
The preamble has a synchronization pattern before and after the separation pattern;
A reproduction method for detecting the respective synchronization patterns of the preamble and estimating a pattern and data head position in the subsequent stage in the reproduction order.

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