JP4844490B2 - Playback apparatus and playback method - Google Patents

Description

The present invention relates to a reproducing apparatus and reproducing how with renewable reproduction head signals over a plurality of tracks.

  In recent years, magnetic heads are required to have higher density recording in order to increase the capacity of magnetic recording media, and are suitable for narrowing the track width of tracks (hereinafter referred to as “narrowing”). Magnetic heads have been adopted. In general, improving the accuracy of the track servo is the key to narrowing the track.

  In a magnetic tape recording / reproducing apparatus, a so-called non-tracking system has been proposed as a countermeasure for making servo difficult as the width becomes narrower, and has been put into practical use (for example, Patent Documents 1-5). In this non-tracking method, the track that was recorded in double azimuth by helical scan is recorded in blocks for identification, so that the target track cannot be reproduced in a single trace. Can reconstruct data. With this non-tracking method, a margin of four times or more is allowed for tracking control within one track required by the conventional track servo.

  Further, the possibility of using non-tracking technology not only in helical scanning but also in linear recording has been studied (for example, Patent Documents 6 and 7).

  By the way, when a non-magnetic support having elasticity such as a polyester film is used for the magnetic recording medium substrate, even if double azimuth recording is performed, the allowable deformation amount is obtained by using a track servo. For example, when it is up to about twice the track width and further deformation occurs, the signal cannot be reproduced with a sufficient SN ratio. Also, in the case of recording without double azimuth, the width of the so-called guard band that does not cross the track is less than the amount of deformation of the tape so as not to deteriorate the reliability such as error rate even when the track servo is used. It was necessary to hold in

  Such a problem is caused by the fact that in the signal reproduction method that has been realized so far, the signal quality is significantly deteriorated when at least one reproduction head reads signals from a plurality of tracks simultaneously. In order to avoid this, it has been devised to perform guard band and double azimuth recording and to pick up only the signal from one track from the reproducing head.

However, when the track density is further increased, the installation of the guard band first hinders the installation. Also, the effect of double azimuth recording, which can reduce interference from adjacent tracks during reproduction, is reduced when the width is narrowed.

  This is the same even in the non-tracking method, and the reproducing head seems to reproduce the signal across a plurality of tracks. However, when time division is performed, the signal being reproduced always corresponds to one track. It wasn't going to play multiple tracks at the same time.

  Also, when trying to cope with higher track density with the non-tracking method, noise is mixed in by picking up signals from the adjacent track of the target track, so the limit to narrowing the track is the limit. It is coming.

  In addition to the background technology of the magnetic head device, a technique for recording a plurality of data frames at a time as a method of arranging a plurality of heads in one block and forming the same azimuth block in order to improve recording density. (For example, Patent Document 8 and Patent Document 9).

  Since these known techniques require that the reproducing head width be about half the width of the track, there is a restriction that the output of the reproducing signal cannot be made large, which is disadvantageous, for example, in securing the SN ratio. It was not necessarily suitable for higher density recording.

  A MIMO (Multi-Input / Multi-Output) technique is widely known as one used for wireless communication (for example, Patent Document 10).

  In addition, a technique using a technique related to MIMO for magnetic recording is also known (for example, Non-Patent Document 1). However, for example, when a reproducing head having a width wider than that of a recorded track is used, problems that occur in practical use have not been solved.

In the present invention, as a magnetic recording method using MIMO, it is not foreseeable from the publicly known technology to realize the practical application of the MIMO technology to the magnetic recording / reproducing method, which could not be realized by the paper introduced in the previous section. The technical contents will be clarified.
Japanese Patent No. 1842057 Japanese Patent No. 1842058 Japanese Patent No. 1842059 Japanese Patent Laid-Open No. 04-370580 Japanese Patent Laid-Open No. 05-020788 JP-A-10-283620 JP 2003-132504 A JP 2003-338812 A Japanese Patent Laid-Open No. 2004-071014 Japanese Patent No. 3664993 Paper IEEE Trans.Mag.Vol.30.No.6 Nov.1994 5100 pages

  As described above, in the conventional magnetic recording / reproducing system, a method of narrowing the track width on the magnetic recording medium has been adopted to increase the recording density. However, if the track width is narrowed in pursuit of a high recording density as it is, there arises 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.

  Accordingly, 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 of the magnetic recording medium. 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 method of generating was proposed. 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.

  FIG. 22 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. 23 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. 24 is a diagram showing the configuration of a playback apparatus 900 that employs the above 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 each of the plurality of reproducing heads R-1, R-2, and R-3. 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. 25 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).

  By the way, as a technical problem for obtaining a more stable reproduction signal in the case of employing the same method, there is stabilization of signal separation processing at the time of reproduction, for example.

  That is, when reproducing a recording medium in which one unit of signal processing is recorded as a plurality of tracks, the quality of the reproduced signal may be deteriorated due to disturbance or media noise. This is the same for both the data portion and the preamble portion. Therefore, the quality of the input reproduction signal used when the signal separation processing is performed may also be deteriorated.

  Specific factors of quality degradation in signal separation processing include, for example, when a synchronization pattern or identification pattern cannot be detected correctly in the preamble portion, occurrence of a separation pattern reading error due to loss of a certain section due to a burst error, or the like. For example, a bit synchronization signal shift due to a long non-signal portion.

In view of such circumstances, performs signal separation processing by detecting the information more stably preamble, can that playback apparatus to realize a high recording density, and to provide a reproducing how Is.

Reproducing apparatus of the present invention, a signal for a plurality of tracks of a magnetic tape, a plurality of reproduction in a positional relationship different to a plurality of tracks, these reproduced signals combined into one unit, by performing signal processing, for each track A reproduction apparatus for generating a reproduction signal, wherein 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 on the track, and the separation pattern Are provided in a part of the tracks, separated from each other in the track traveling direction for each track, and separated in the track traveling direction from the separation pattern portion of the same track. Of the separation pattern portion in the reproduction signal of the reproduction head. And determines whether to use the reproduction signal of the separation pattern portion as it is or replace it with a predetermined value, and 2 for the reproduction signal of the separation pattern portion for each track of the partial track. In the first determination, the reproduction signal of one separation pattern portion of the two separation pattern portions is used as it is, and the reproduction signal of the other separation pattern portion is replaced with a reproduction signal having a predetermined value. In the second determination, the reproduction signal of the other separation pattern portion of the two separation pattern portions is used as it is, and the reproduction signal of the one separation pattern portion is replaced with a reproduction signal of a predetermined value. and determining the preamble processing controller to use, the reproduction signal of the first it is determined to be used in the said one separation pattern portion and The result of combining the reproduction signal of the other separation pattern portion determined to be used as it is for the second time as the value of the reproduction signal of the one separation pattern portion is replaced with a predetermined value at the first time. A result obtained by combining the reproduction signal of the other separation pattern portion determined to be used with the reproduction signal of the one separation pattern portion determined to be used by being replaced with a predetermined value for the second time is used. As the value of the reproduction signal of the other separation pattern portion, using the reproduction signal for each separation pattern portion for each track of the partial track and the reproduction signal for the separation pattern portion of a track other than the partial track, A channel estimation calculation unit for calculating a channel matrix corresponding to a positional relationship in the track width direction during reproduction between the reproduction head and the plurality of tracks; A signal demultiplexing unit that separates the reproduction signals for each track by combining the reproduction signals for one unit reproduced by the reproduction head into the one unit using a channel matrix and performing signal processing ; .

  By adopting this configuration, it becomes possible to stably perform the processing for the separation pattern, and it is possible to perform the channel estimation calculation satisfactorily. For example, even if a continuous error such as a burst error occurs in one separation pattern part, by performing channel estimation calculation using a reproduction signal of another separation pattern, a good channel estimation calculation result is obtained as a result. can get.

  In the reproduction apparatus of the present invention, the preamble processing control unit may estimate the position of the separation pattern in the reproduction signal of the reproduction head according to a track.

  In the playback apparatus of the present invention, the preamble includes an identification pattern for identifying the track, detects the identification pattern, identifies the track, and outputs the result to the preamble processing control unit. An identification information detection unit may be further provided. Thereby, a track can be identified easily and accurately, and channel estimation calculation can be performed satisfactorily.

  In the reproducing apparatus of the present invention, the pattern may be a pattern that can be used for bit synchronization processing, and may further include means for performing bit synchronization processing using the pattern. Thereby, the part which has the pattern used for a bit synchronous process for every track | truck can be increased, and a bit synchronous process can be stabilized.

A reproduction method according to another aspect of the present invention reproduces a plurality of signals for a plurality of tracks on a magnetic tape with different positional relationships with respect to a plurality of tracks, and collects these reproduction signals as a unit and performs signal processing. In the method for generating a reproduction signal for each track, a separation pattern necessary for detecting a positional relationship in the track width direction during reproduction between the reproduction head and the plurality of tracks is recorded on the track. The separation patterns are provided in a part of the separation pattern portions arranged one by one in the track advancing direction for each track, and in part of the tracks. A separation pattern portion arranged at a position separated in the traveling direction, and the separation pattern in the reproduction signal of the reproduction head. The position of the pattern portion is estimated, it is determined whether the reproduced signal of the separation pattern portion is used as it is or replaced with a predetermined value, and the separation pattern portion is reproduced for each track of the partial track. The signal is judged twice, and in the first judgment, the reproduction signal of one of the two separation pattern parts is used as it is, and the reproduction signal of the other separation pattern part is used as a reproduction signal of a predetermined value. In the second determination, the reproduction signal of the other separation pattern portion of the two separation pattern portions is used as it is, and the reproduction signal of the one separation pattern portion is reproduced to a predetermined value. It is determined that the signal is replaced with a signal, and the reproduction signal of the one separation pattern portion determined to be used as it is for the first time and the reproduction signal for the second time are determined. The result of combining the reproduction signal of the other separation pattern portion determined to be used as it is is used as the value of the reproduction signal of the one separation pattern portion, and is used by replacing it with a predetermined value for the first time. The result obtained by combining the reproduction signal of the other separation pattern portion determined and the reproduction signal of the one separation pattern portion determined to be replaced with a predetermined value for the second time is used as the other separation pattern. A reproduction signal value of a portion, and using the reproduction signal for each separation pattern portion for each track of the partial track and the reproduction signal for the separation pattern portion of a track other than the partial track, A channel matrix corresponding to the positional relationship in the track width direction at the time of reproduction with the plurality of tracks is calculated, and the reproduction head is used with the channel matrix. The reproduction signals for one unit reproduced in one unit are collected into one unit, and signal processing is performed to separate the reproduction signals for each track .

  As described above, according to the present invention, it is possible to detect the information of the preamble portion more stably and perform the signal separation processing, thereby realizing high recording density.

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

  (First embodiment)

  As a first embodiment of the present invention, a recording apparatus and a reproducing apparatus in a magnetic recording / reproducing system using a multi-head will be described. The recording apparatus of this embodiment is an apparatus for recording signals on a tape-shaped magnetic recording medium without aligning the recording position for each track, and the reproducing apparatus does not align the reproducing position for each track from the magnetic recording medium. This is a device for reproducing a signal. Here, the number of recording heads is M, the number of reproducing heads is N, and in this embodiment, M = 4 and N = 4.

  FIG. 1 is a diagram showing a configuration of a recording apparatus 100 in the magnetic recording / reproducing system according to the first embodiment of the present invention.

  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 adds M preamble adding units 131-1 for adding a preamble necessary for controlling data reproduction in units of units to each recording data encoded by the multitrack recording encoding unit 120. , 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, by the preamble adding units 131-1, 131-2, 131-3, 131-4 of the multitrack preamble adding unit 130, by the recording encoding units 121-1, 121-2, 121-3, 121-4. A preamble necessary for data reproduction control is added to each encoded recording data, 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 separation pattern for each track and the head 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, 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, and a restoration unit 260.

  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 preamble processing control unit 238, a channel estimation calculation unit 234, a reproduction position control processing unit 235, and a signal separation calculation. Part 236.

  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 in the preamble is detected from the signal.

  The identification information detection unit 232 is based on the synchronization pattern detected by the synchronization signal detection unit 231 and the position of the identification pattern in the reproduction signal of each reproduction head R-1, R-2, R-3, R-4. And identification information of the track is obtained by detecting this identification pattern.

  The reproduction signal gain control processing unit 233 detects the gain control pattern in the preamble from the reproduction signals of the respective reproduction heads R-1, R-2, R-3, R-4 that have passed through the synchronization signal detection unit 231, and Based on the signal of this gain control pattern, the gain for the reproduction signal of each reproduction head R-1, R-2, R-3, R-4 is calculated, and each reproduction head R-1, R-2, Controls the level of the reproduction signal of R-3 and R-4.

  For example, the preamble processing control unit 238 uses a separation pattern for each reproduction signal of the reproduction heads R-1, R-2, R-3, and R-4 based on the identification information obtained by the identification information detection unit 232, for example. , And whether to use the reproduced signal of the separation pattern as it is or replace it with a predetermined value, and outputs this information to the channel estimation calculation unit 234.

  Based on the synchronization pattern detected by the synchronization signal detector 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 head position of the separation pattern included in the preamble of the reproduction signal, and the reproduction head R-1, R- using the reproduction signal of the separation pattern portion and information from the preamble processing control unit 238. Channel estimation calculation is performed to calculate a channel matrix corresponding to the positional relationship in the track width direction during reproduction of 2, R-3, R-4 and a plurality of tracks.

  The reproduction position control processing unit 235 is based on the synchronization pattern detected by the synchronization signal detection unit 231 and 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 from the outputs of the equalizers 241-1, 241-2, 241-3, and 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, a 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 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.

FIG. 5 is a flowchart showing a unit reproduction operation flow of the reproduction apparatus 200.
In the reproducing apparatus 200, first, the magnetic recording medium 2 is formed by N reproducing heads R-1, R-2, R-3, and R-4, each of which can reproduce a signal from one or more adjacent tracks. A signal is reproduced from a plurality of tracks of one unit (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. After that, 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. Is output to the synchronization signal detector 231 (step S202).

  Next, the reproducing heads R-1, R-2, R-3, R output from the A / D converters 225-1, 225-2, 225-3, 225-4 by the synchronization signal detector 231. Synchronization patterns are detected from the reproduction signals for every -4 (step S203).

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

  Subsequently, the reproduction signal gain control processing unit 233 obtains a gain control pattern in the preamble from the reproduction signals of the reproduction heads R-1, R-2, R-3, and R-4 that have passed through the synchronization signal detector 231. Based on this gain control pattern, the gains for the reproduction signals of the reproducing heads R-1, R-2, R-3, and R-4 are calculated, and the reproducing heads R-1, R-2 are calculated. , R-3 and R-4 are individually controlled (step S205).

  Next, in the preamble processing control unit 238, for example, for each reproduction signal of the reproduction heads R-1, R-2, R-3, R-4 based on the identification information obtained by the identification information detection unit 232, and the like. Then, the position of the separation pattern is estimated, it is determined whether the reproduction signal of the separation pattern is used as it is or replaced with a predetermined value, and this information is output to the channel estimation calculation unit 234 (step S206).

  Next, based on the synchronization pattern detected by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232 in the channel estimation calculation unit 234, each reproducing head R-1, R-2 is recorded. , R-3, R-4, the start position of the separation pattern included in the preamble of the reproduction signal, and a predetermined channel estimation using the reproduction signal of the separation pattern portion and information from the preamble processing control unit 238 A channel matrix is obtained by calculation (step S207). This channel matrix is the position information in the track width direction of the individual reproducing heads R-1, R-2, R-3, R-4 for each track # 1, # 2, # 3, # 4 in one unit. In other words, it is information that indicates at what ratio and in what proportion each reproducing head R-1, R-2, R-3, R-4 each position in the unit. is there.

  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).

  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 identifies, as information necessary for reproducing the data 22, a gain control pattern used for learning for gain control on a reproduction signal, a synchronization pattern used for bit synchronization processing, and 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.

  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 units 51 are arranged in parallel to each other, and an area where nothing is recorded, which is 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.

  By the way, the identification information encoded as the identification pattern includes, for example, a number for identifying a unit, for example, “1” to “s”, and a number for identifying a track in the unit, for example, “1” to “4”. It is expressed by a combination of 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.

FIG. 7 is a diagram showing the configuration of the preamble 21 in the track format of FIG.
The first preamble 23 includes a gain control pattern 41-1, 41-2, 41-3, 41-4, a synchronization pattern 42-1, 42-2, 42-3, 42-4, an identification pattern 43-1, 43-2, 43-3, 43-4. The second preamble 24 includes separation patterns 44-1, 44-2, 44-3, 44-4, 44-5, and 44-6.

  On the track # 1, the gain control pattern 41-1, the synchronization pattern 42-1, the identification pattern 43-1, and the separation patterns 44-1, 44-5 are arranged in this order from the head side, and on the track # 2, from the head side. , Gain control pattern 41-2, synchronization pattern 42-2, identification pattern 43-2, and separation pattern 44-2 are arranged in this order. On track # 3, gain control pattern 41-3 and synchronization pattern 42- 3, the identification pattern 43-3, and the separation pattern 44-3 are arranged in this order. On the track # 4, the gain control pattern 41-4, the synchronization pattern 42-4, the identification pattern 43-4, and the separation pattern 44- are arranged from the head side. 6, 44-4. Data 22 is arranged after the second preamble 24.

  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 and the second preamble 24 are added to the recording code string by the preamble adding units 131-1, 131-2, 131-3, and 131-4.

  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. Each of the reproducing heads R-1, R-2, R-3, and R-4 can reproduce signals from a plurality of tracks. 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. Then, the reproducing head R-3 reproduces the signal across the three tracks # 2, # 3, and # 4, and the reproducing head R-4 reproduces the signal across the track # 3 and the track # 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, in FIG. 7, the gain control pattern 41-1 of the track # 1, the synchronization pattern 42-1 and the identification pattern 43-1 are the Ta section, the gain control pattern 41-2 of the track # 2, the synchronization pattern 42-2 and The identification pattern 43-2 is in the Tb section, the gain control pattern 41-3 of the track # 3, the synchronization pattern 42-3, and the identification pattern 43-3 is in the Tc section, the gain control pattern 41-4 of the track # 4, and the synchronization pattern. 42-4 and the identification pattern 43-4 are arranged in the Td section. And adjacent track gain control patterns 41-1, 41-2, 41-3, 41-4, synchronization patterns 42-1, 42-2, 42-3, 42-4, and identification patterns 43-1, 43. A gap 28 for a margin is provided between the recording sections of −2, 43-3, and 43-4.

  At the time of reproduction, the gain control patterns 41-1, 41-2, 41-3, and 41-4 of the tracks # 1, # 2, # 3, and # 4 are stored in the reproduction apparatus 200 shown in FIG. It is used as a learning signal for gain control of the reproduction amplifiers 221-1, 221-2, 221-3, and 221-4 by the gain adjusting units 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 learning for bit synchronization detection by the synchronization signal detector 231 and a reproduction signal gain control processing unit 233 as necessary. It is also used to control the level of each reproduction signal. Furthermore, the gain control patterns 41-1, 41-2, 41-3, and 41-4 are used for reproduction position control of each reproduction signal by the reproduction position control processing unit 235 as necessary.

  At the time of reproduction, the synchronization patterns 42-1, 42-2, 42-3, and 42-4 of the tracks # 1, # 2, # 3, and # 4 are detected by the synchronization signal detector 231, for example, Identification patterns 43-1, 43-2, 43-3, 43-4 for tracks # 1, # 2, # 3, and # 4, and separation patterns 44- for tracks # 1, # 2, # 3, and # 4 1, 44-2, 44-3, 44-4, 44-5, and 44-6, and information 22 is used as information for knowing the head position of the data 22. The synchronization patterns 42-1, 42-2, 42-3, and 42-4 are also used for playback position control of each playback signal in the playback position control processing unit 235.

  Further, the identification patterns 43-1, 43-2, 43-3, and 43-4 of the tracks # 1, # 2, # 3, and # 4 during reproduction are the synchronization patterns detected by the synchronization signal detector 231. 42-1, 42-2, 42-3, and 42-4 are detected by the identification information detection unit 232 and used to obtain track identification information, and the channel estimation calculation unit 234 performs channel estimation calculation. Used for. The identification information is used for playback position control in the playback position control processing unit 235. Further, the identification information is used for processing the reproduction signal of the separation pattern portion in the preamble processing control unit 238.

  In this track format, in the first preamble 23, gain control patterns 41-1, 41-2, 41-3, 41-4 and synchronization pattern 42-1 of each track # 1, # 2, # 3, # 4 are provided. , 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. Therefore, even when the channel clock positions of the tracks # 1, # 2, # 3, and # 4 are not aligned, a plurality of individual reproducing heads R-1, R-2, R-3, and R-4 are provided. When a signal is reproduced across two 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, Said control using 43-3, 43-4 can be performed favorably.

  On the other hand, in the second preamble 24, the separation patterns 44-1, 44-2, 44-3, 44-4, 44-5, and 44-6 of the tracks # 1, # 2, # 3, and # 4 are Channels required for computation to separate the reproduction signals for tracks # 1, # 2, # 3, and # 4 from the reproduction signals of reproduction heads R-1, R-2, R-3, and R-4 during reproduction This is a pattern used for obtaining a matrix by the channel estimation calculation unit 234.

  In FIG. 7, the separation pattern 44-1 for track # 1 is in the T1 interval, the separation pattern 44-2 for track # 2 is in the T2 interval, the separation pattern 44-3 for track # 3 is in the T3 interval, The separation pattern 44-4 is provided in the T4 section, the separation pattern 44-5 is the same T4 section as the separation pattern 44-4 of the track # 4, and the separation pattern 44-6 is the separation pattern 44-1 of the track # 1. Are provided in the same T1 section. A gap 29 for a predetermined time is provided for each margin between the sections.

  The separation pattern is recorded with a predetermined recording wavelength equal to or greater than the minimum recording wavelength.

  The second preamble 24 uses the channel estimation calculation unit 234 to generate a reproduction signal for each track from the reproduction signals for one unit obtained by the reproduction heads R-1, R-2, R-3, and R-4. Used to compute channel estimation information for separation.

  The separation patterns 44-1, 44-2, 44-3, 44-4, 44-5, and 44-6 are arranged so as not to be reproduced simultaneously by one reproducing head. That is, the separation patterns arranged in the same section are arranged apart from each other in the track traveling direction and the track width direction so as not to be reproduced by one reproducing head.

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

(About the identification information detection unit 232)
In the identification information detection unit 232, the reproducing heads R-1, R-2, R- based on the synchronization patterns 42-1, 42-2, 42-3, 42-4 detected by the synchronization signal detection unit 231. 3 and the leading position of the identification pattern 43-1, 43-2, 43-3, 43-4 in the reproduction signal for each R-4 is specified, and the identification pattern 43-1, 43-2, 43-3, 43 is identified. -4 is detected and the 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.

  Also, as in the track format shown in FIG. 10, when a plurality of identification patterns are recorded separately on one track, the identification information detection unit 232 detects each identification pattern, and the same track Identification information is obtained. Thereby, if either one of the identification patterns can be detected, the identification information of the track can be obtained, and the process can be stabilized.

(Reproduction signal gain control processing unit 233)
The reproduction signal gain control processing unit 233 outputs the reproduction signals of the gain control patterns 41-1, 41-2, 41-3, and 41-4 for each of the reproduction heads R-1, R-2, R-3, and R-4. Based on, for example, the gain of the reproduction signal for each of the reproduction heads R-1, R-2, R-3, and R-4 is calculated as follows, and the level of each reproduction signal is controlled.

  For example, the reproduction signal gain control processing unit 233 adds the signals of the gain control pattern 41-1 and the gain control pattern 41-2 respectively reproduced from the track # 1 and the track # 2 by the reproduction head R-1 in FIG. To do. Similarly, the reproduction signal gain control processing unit 233 controls the gain control pattern 41-1 and the gain control pattern 41-2 reproduced from the track # 1, the track # 2, and the track # 3 by the reproduction head R-2. The signals of the pattern 41-3 are added. Similarly, the reproduction signal gain control processing unit 233 performs gain control pattern 41-2, gain control pattern 41-3, and gain control reproduced from the track # 2, track # 3, and track # 4 by the reproduction head R-3. The signals of the pattern 41-4 are added. Similarly, the reproduction signal gain control processing unit 233 adds the signals of the gain control pattern 41-3 and the gain control pattern 41-4 reproduced from the track # 3 and the track # 4 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. The reproduction signal gain control processing unit 233 outputs, as a control result, a value obtained by multiplying the input reproduction signal value for each reproduction head by 1 / (reference output).

  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.

(About Preamble Processing Control Unit 238 and Channel Estimation Calculation Unit 234)
For example, the preamble processing control unit 238 separates the reproduction signals of the reproduction heads R-1, R-2, R-3, and R-4 for each reproduction signal based on the identification information obtained by the identification information detection unit 232, for example. The position of the pattern is estimated, it is determined whether the reproduced signal of the separation pattern is used as it is or replaced with a predetermined value, and this information is output to the channel estimation calculation unit 234.

  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 unit 234 reproduces the read heads R-1, R-2, R-3. , R-4, the start position of the reproduction signal of the separation pattern portion in the reproduction signal is specified, and this reproduction signal is used as it is based on the information given from the preamble processing control unit 238, or other predetermined A channel estimation calculation is performed by substituting values, and a channel matrix necessary for signal separation processing is generated. When the reproduction signal is used as it is, the channel estimation calculation unit 234 obtains a value that establishes a correlation between the tracks, for example, obtains an average value of the peak value of the reproduction signal or an addition value of the reproduction signal. In the case of replacing with another predetermined value, for example, “0” or a predetermined value corresponding to the gain is replaced.

  This channel estimation information corresponds to position information in the track width direction of each of the reproducing heads R-1, R-2, R-3, and R-4 in a unit that is a unit of a plurality of tracks. In other words, the channel estimation information is information indicating at what ratio each reproducing head R-1, R-2, R-3, R-4 overlaps with which track in the unit.

  The process of replacing the value of the reproduction signal with a predetermined value may be performed not by the channel estimation calculation unit 234 but by the preamble processing control unit 238 and the result may be output to the channel estimation calculation unit 234.

  Next, channel estimation calculation processing when the track format of FIG. 7 is used will be described in detail.

  In the example of FIG. 7, the head widths of the reproducing heads R-1, R-2, R-3, and R-4 are 1.5 times the recording track width, and the individual reproducing heads R-1, R- 2, R-3, and R-4 can reproduce signals from a plurality of tracks. 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 the signal across the three tracks # 2, # 3, and # 4, and the reproducing head R-4 reproduces the signal across the track # 3 and the track # 4. To do.

  FIG. 8 is a diagram showing a reproduction signal for the track format of FIG. Here, when there is no off-track, that is, the centers of the reproducing heads R-1, R-2, R-3, and R-4 coincide with the centers of the tracks # 1, # 2, # 3, and # 4, respectively. The reproduction signals of the reproducing heads R-1, R-2, R-3, and R-4 are shown in the case of In FIG. 8, the size of the reproduction signal in the track width direction corresponds to the output size. For the sake of simplicity, it is assumed that there is no phase shift during recording and reproduction.

  In the example of FIG. 8, 20 data is allocated to each track as the first preamble 23, and 40 data is allocated to each track as the second preamble (one separation pattern) 24. A gap for data is given. At this time, the reproduction signal portion used in the channel estimation calculation unit 234 includes 20 data in the separation pattern section (T1 section) of track # 1, and 20 data in the separation pattern section (T2 section) of track # 2. 20 data of the separation pattern section (T3 section) of track # 3 and 20 data of the separation pattern section (T4 section) of track # 4.

  Here, the reproduction signal obtained by the reproducing head R-1 in the section of the second preamble 24 is the reproduction signal 1-1 from the separation pattern 44-1 in the T1 section of the track # 1 and the T2 section of the track # 2. Reproduction signal 1-2 with a small output from the separation pattern 44-2, a reproduction signal 1-3 of originally "0" from the T3 section of the track # 3, and a separation pattern 44-5 of the T4 section of the track # 1 Are reproduced signals 1-4.

  The reproduction signal obtained in the second preamble 24 section by the reproducing head R-2 includes the reproduction signal 2-1 having a small output from the separation pattern 44-1 in the T1 section of the track # 1, and the T2 section of the track # 2. Reproduction signal 2-2 from the separation pattern 44-2, reproduction signal 2-3 having a small output from the separation pattern 44-3 in the T3 section of the track # 3, and separation pattern 44- in the T4 section of the track # 1. 5 is a reproduction signal 2-4 with a small output from 5.

  The reproduction signal obtained by the reproducing head R-3 in the second preamble 24 section is the reproduction signal 3-1 having a small output from the separation pattern 44-6 in the T1 section of the track # 4 and the T2 section of the track # 2. Reproduction signal 3-2 having a small output from the separation pattern 44-2, reproduction signal 3-3 from the separation pattern 44-3 in the T3 section of the track # 3, and separation pattern 44- in the T4 section of the track # 4. 4 is a reproduction signal 3-4 having a small output from the output signal 4.

  The reproduction signal obtained by the reproducing head R-4 in the second preamble 24 section is the reproduction signal 4-1 from the separation pattern 44-6 in the T1 section of the track # 4 and the original from the T2 section of the track # 2. Playback signal 4-2 of “0”, playback signal 4-3 with a small output from the separation pattern 44-3 in the T3 section of the track # 3, and playback from the separation pattern 44-4 of the T4 section of the track # 4 Signal 4-4.

  The channel estimation calculation unit 234 performs channel estimation calculation as follows based on the information given from the preamble processing control unit 238.

  First, the channel estimation calculation unit 234 performs processing on the reproduction signal of the reproduction head R-1. Here, the processing for channel estimation calculation is performed twice for the reproduction signal in the T1 section of the reproduction head R-1. That is, the first time uses the reproduction signal 1-1 of the T1 section as it is, and the second time replaces the reproduction signal 1-1 of the T1 section with another predetermined value.

  Further, the channel estimation calculation unit 234 performs processing for channel estimation calculation using the reproduced signal 1-2 having a small output in the T2 section of the reproducing head R-1 as it is.

  In addition, the channel estimation calculation unit 234 determines that the reproduction signal 1-3 in the T3 section of the reproduction head R-1 is a reproduction signal from a position where the reproduction signal of the separation pattern portion is not originally obtained. Replace with a value.

  Further, the channel estimation calculation unit 234 performs the process for the channel estimation calculation twice for the reproduction signal 1-4 in the T4 section of the reproduction head R-1. That is, in the first time, the reproduction signal 1-4 in the T4 section is replaced with another predetermined value, and in the second time, the reproduction signal 1-4 in the T4 section is used as it is.

  Next, the channel estimation calculation unit 234 combines the reproduction signal 1-1 obtained by the first processing in the T1 section and the reproduction signal 1-4 obtained by the second processing in the T4 section, and the result of the reproduction head The reproduction signal of the T-1 section of R-1 is used.

  Further, the channel estimation calculation unit 234 combines the reproduction signal 1-1 obtained by the second process in the T1 interval and the reproduction signal 1-4 obtained by the first process in the T4 interval, and the result of the reproduction head R −1 is the processing result of the reproduction signal in the T4 section. When the predetermined value to be replaced is zero, the processing result of the reproduction signal in the T4 section of the reproduction head R-1 is “0”.

  Subsequently, the channel estimation calculation unit 234 performs processing on the reproduction signal of the reproduction head R-2. Here, the processing for channel estimation calculation is performed twice for the reproduction signal in the T1 section of the reproduction head R-2. That is, in the first time, the reproduction signal 2-1 in the T1 section is used as it is, and in the second time, the reproduction signal 2-1 in the T1 section is replaced with another predetermined value.

  In addition, the channel estimation calculation unit 234 performs processing for channel estimation calculation using the reproduced signal 2-2 in the T2 section of the reproducing head R-1 as it is.

  In addition, the channel estimation calculation unit 234 also performs processing for channel estimation calculation using the reproduced signal 2-3 in the T3 section of the reproducing head R-1 as it is.

  Further, the channel estimation calculation unit 234 performs the process for channel estimation calculation twice for the reproduction signal 2-4 in the T4 section of the reproduction head R-1. That is, in the first time, the reproduction signal 2-4 in the T4 section is replaced with another predetermined value, and in the second time, the reproduction signal 2-4 in the T4 section is used as it is.

  Next, the channel estimation calculation unit 234 combines the reproduction signal 2-1 obtained by the first processing in the T1 section and the reproduction signal 2-4 obtained by the second processing in the T4 section, and the result of the reproduction head It is assumed that the playback signal is in the T1 section of R-2.

  In addition, the channel estimation calculation unit 234 adds the reproduction signal 2-1 obtained by the second process in the T1 interval and the reproduction signal 2-4 obtained by the first process in the T4 interval to the reproduction head R. −2 is the processing result of the reproduction signal in the T4 section.

  Note that, as a method of combining the two reproduction signals, for example, a method of making the reproduction signal having the larger reproduction output effective as well as taking the average of the reproduction output can be considered.

  Thereafter, the same processing is performed on the signal reproduced by the reproducing head R-3 and the signal reproduced by the reproducing head R-4.

  As described above, the processing for the separation pattern can be stably performed, and the channel estimation calculation can be favorably performed. For example, even if a burst error or the like occurs in the second preamble 24 section, if the error occurs only in either the T1 section or the T4 section of the track format of FIG. Thus, the channel estimation calculation is performed by removing the reproduced signal, so that the influence of the error signal in the channel estimation calculation can be canceled. As a result, for example, a high-quality channel matrix H having 4 rows and 4 columns as shown in FIG. 9 is obtained.

  Also, when the separation pattern is used for bit synchronization processing for signal separation, the more the portion having the pattern, the more stable the bit synchronization processing, so the second preamble 24 of one track. By separating the separation patterns at a plurality of positions in the interval, it becomes possible to perform bit synchronization more stably and to perform separation processing more favorably.

  The case where the separation pattern is arranged at a plurality of positions on the track has been described above, but each pattern in the first preamble 23 may be arranged at a plurality of positions on the track. This case will be described below.

  FIG. 10 shows a modification of the track format. In this track format, the continuation of the gain control pattern 41-5, the synchronization pattern 42-5, and the identification pattern 43-5 in the section of the first preamble 23 of the track # 1 with respect to the track format of FIG. It is added to the section. The continuation of these gain control pattern 41-5, synchronization pattern 42-5, and identification pattern 43-5 is not reproduced simultaneously by one reproducing head with respect to the pattern arranged in the Ta section of the same track # 1. In addition, the patterns of the other tracks # 2, # 3, and # 4 are arranged at positions where they are not reproduced simultaneously by one reproducing head.

  In this way, by arranging a series of gain control patterns, synchronization patterns, and identification patterns at a plurality of positions on a track, it becomes possible to detect the pattern at two locations during signal reproduction for that track. Thereby, for example, even if the detection of the gain control pattern, the synchronization pattern, and the identification pattern in the first place fails due to a burst error or the like, it is possible to try to detect the pattern in the next place. More stable processing can be performed. Also, in the bit synchronization process, the more parts that have a pattern that can perform bit synchronization, the more stable the bit synchronization process. By arranging gain control patterns at multiple positions on the track, Synchronization can be performed more stably.

  By the way, when attention is paid to the relationship between the identification pattern and the separation pattern, the identification patterns 43-1 and 43-5 are arranged at two locations in the section of the first preamble 23 of the track # 1 in the track format of FIG. In addition, separation patterns 44-1 and 44-5 are arranged at two locations in the section of the second preamble 24. Here, different patterns are given to the identification pattern 43-1 and the identification pattern 43-5 so that the identification information detection unit 232 can distinguish between the identification patterns 43-1 and 43-5. Preamble processing control of information on the position and length of the separation pattern 44-1 with reference to the position of 43-1 and information on the position and length of the separation pattern 44-5 with reference to the position of the identification pattern 43-5 By giving to the unit 238, the preamble processing control unit 238 makes the separation patterns 44-1 and 44-5 based on the detection results of the identification patterns 43-1 and 43-5 from the identification information detection unit 232. Can be accurately estimated.

  FIG. 11 is a diagram showing a modification of yet another track format.

  In this track format, the number of tracks for one unit is five. Here, focusing on the relationship between the separation pattern 44-1 and the separation pattern 44-6 of the track # 1, the reproduction signals of the separation pattern 44-1 and the separation pattern 44-6 are as described above. Each process is performed twice, and the reproduction signal itself and the output replaced with a predetermined value are obtained in each process. A combination of the respective reproduced signals of the separation pattern 44-1 and the separation pattern 44-6 is used as a reproduction signal of the T1 section of the reproduction head R-1, and the separation pattern 44-1 and the separation pattern 44-6. A signal obtained by replacing each reproduction signal with a predetermined value is used as a reproduction signal in the T4 section of the reproduction head R-1 and used for channel estimation calculation. The same applies to the relationship between the separation pattern 44-2 and the separation pattern 44-7, the relationship between the separation pattern 44-4 and the separation pattern 44-8, and the relationship between the separation pattern 44-5 and the separation pattern 44-9. .

  Guard bands 52 and 52 are provided on both sides of the track row for one unit. Each guard band 52, 52 has a gain control pattern 41-6, 41-7, 41-8, corresponding to the section of the first preamble 23 and the section of the second preamble 24 on the track, respectively. 41-9, synchronization patterns 42-6, 42-7, 42-8, 42-9 and identification patterns 43-6, 43-7, 43-8, 43-9 are arranged. That is, in one guard band 52, a gain control pattern 41-6, a synchronization pattern 42-6, and an identification pattern 43-6 are arranged corresponding to the section of the first preamble 23, and the second preamble 24 A gain control pattern 41-8, a synchronization pattern 42-8, and an identification pattern 43-8 are arranged corresponding to the section. In the other guard band 52, a gain control pattern 41-7, a synchronization pattern 42-7, and an identification pattern 43-7 are arranged corresponding to the section of the first preamble 23, and in the section of the second preamble 24. Correspondingly, a gain control pattern 41-9, a synchronization pattern 42-9, and an identification pattern 43-9 are arranged. No significant information is recorded in the positions of the guard bands 52, 52 corresponding to the section of the data portion 22 of the track. For example, an erase signal is recorded instead.

  The reproducing apparatus 200 can obtain the position information in the track width direction of each track including the guard bands 52 and 52 by detecting the patterns arranged in the guard bands 52 and 52. Positioning control in the track width direction can be performed better.

  As described above, when the gain control pattern, the synchronization pattern, and the identification pattern are arranged at the positions corresponding to the second preamble 24 of the guard bands 52 and 52, the processing of the separation bands is performed with respect to the pattern of the guard bands 52 and 52. In order to prevent the reproduction signals from interfering, the reproduction signals for those patterns are replaced with a predetermined value, for example, “0”. As a result, patterns such as a gain control pattern, a synchronization pattern, and an identification pattern can be arranged at positions corresponding to the second preamble 24 of the guard bands 52 and 52, and the length of the first preamble 23 is increased. Without this, patterns can be arranged at many positions of the individual guard bands 52 and 52. As a result, it is possible to satisfactorily detect the gain control pattern, the synchronization pattern, and the identification pattern from the guard bands 52 and 52.

  Further, in this track format, the separation pattern 44-3 in the T3 section is longer than those in other periods. This is due to the following reason. In this track format, the separation pattern 44-1 and the separation pattern 44-6, the separation pattern 44-2 and the separation pattern 44-7, the separation pattern 44-4 and the separation pattern 44-8, and the separation pattern 44-5 and the separation pattern In each combination of 44-9, a value obtained by combining the reproduction signals of the respective separation pattern portions and a value replaced with a predetermined value, for example, “0” are obtained. It is difficult to perform a similar process because a track on which a separation pattern that is paired with the separation pattern 44-3 is not secured. In this track format, the length of the separation pattern 44-3 is made longer than the separation pattern of the other period in order to balance the value of the reproduction signal of the separation pattern of the other period.

  In addition, the length of the separation pattern 44-3 is set in consideration of the length necessary for unique patterns such as a gain control pattern, a synchronization pattern, and an identification pattern, so that the separation can be performed while achieving a more efficient format configuration. The processing for the pattern can be performed more stably, and a good channel estimation calculation result can be obtained.

  FIG. 12 is a diagram showing another modification of another track format.

  In this track format, the number of tracks for one unit is five. Guard bands 52 and 52 are provided on both sides of the track row for one unit. In each guard band 52, 52, corresponding to the section of the first preamble 23 on the track, gain control patterns 41-6, 41-7, synchronization patterns 42-6, 42-7, identification pattern 43- 6, 43-7 are arranged. Further, gain control patterns 41-11, 41-12, 41-13, 41-14, and 41-15 are arranged immediately before the second preamble 24 section of each track.

  In order to perform signal separation, it is necessary to perform bit synchronization processing. However, the more portions having the pattern used for this bit synchronization processing, the more stable the bit synchronization processing can be. As described above, the gain control patterns 41-11, 41-12, 41-13, 41-14, and 41-15 are also added just before the second preamble 24 section, so that bit synchronization is performed for each track. The part which has the pattern used can be increased.

  FIG. 13 is obtained by omitting an identification pattern from the track format of FIG. Thus, even if the identification pattern is not included in the preamble, a unique pattern can be adopted for each of the synchronization patterns 42-1, 42-2, 42-3, 42-4 for each track, Relationships between positions of unique patterns such as 42-2, 42-3, 42-4 and separation patterns 44-1, 44-2, 44-3, 44-4, 44-5, 44-6 on the track , Each track in the unit may be identified.

  Further, the same pattern may be adopted as the gain control pattern arranged in the first preamble 23 and the separation pattern arranged in the second preamble 24.

  In the above embodiment, the separation pattern orthogonal to the time axis is used, but the present invention is not limited to the applicable separation pattern. For example, the present invention can also be applied to a case where a separation pattern that is orthogonal on the frequency axis or a separation pattern that uses orthogonal codes is used.

  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.

  In the above embodiment, the magnetic recording / reproducing system has been described in which a signal is recorded on the magnetic recording medium without aligning the recording position for each track, and the signal is reproduced from the magnetic recording medium without aligning the reproducing position for each track. The present invention is not limited to this, for example, a magnetic recording / reproducing method for recording a signal without aligning the recording position for each track, and reproducing from the magnetic recording medium by aligning the reproducing position for each track. The same applies to the above. Further, the present invention can be similarly applied to a magnetic recording / reproducing system in which a signal is recorded with the recording position aligned for each track, and reproduction is performed from the magnetic recording medium without aligning the reproducing position for each track.

  (Second Embodiment)

  Next, a magnetic recording / reproducing system using a single head will be described as a second 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. 14 is a diagram showing a configuration of a recording apparatus 300 in the magnetic recording / reproducing system according to the second 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 multitrack preamble adding unit 130 adds M preamble adding units 131-1 for adding a preamble necessary for controlling data reproduction in units of units to each recording data encoded by the multitrack recording encoding unit 120. , 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. The output timing setting unit 141, one recording compensation unit 144 that performs recording compensation processing, and each recording head W-1 based on the recording code string after the recording compensation processing
And a single recording amplifier 147 for driving.

  FIG. 15 is a flowchart showing a flow of operations 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 preamble adding units 131-1, 131-2, 131-3, 131-4 of the multitrack preamble adding unit 130 are unit units. A pattern necessary for reproduction control of the data is added as a preamble to obtain a recording code string (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 second embodiment will be shown.
FIG. 16 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 second embodiment.

  As shown in the figure, this recording apparatus 301 is different from the recording apparatus 300 in FIG. 14 in the configuration of a multitrack recording encoding unit 120 and a multitrack preamble adding unit 130. The multitrack recording encoding unit 120 includes a recording encoding unit 121 that records and encodes recording data of a predetermined unit, for example, recording data for a predetermined number of tracks, and the multitrack preamble adding unit 130 is configured for each track. The encoded recording data includes an independent preamble adding unit 131 that adds a preamble necessary for controlling data reproduction in units. Further, in the recording apparatus 301, the multitrack unit 110 (data distributor 111) is omitted from the configuration of the recording apparatus 300 shown in FIG.

  FIG. 17 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, a pattern necessary for control for reproducing data in units is added as a preamble to a predetermined position of each encoded recording data by the preamble adding unit 131, and a recording code string is obtained. (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.

  For example, when the track format shown in FIG. 7 is used, first, the track # 1 is moved to the track # 1, and the track # 1 is recorded. Thereafter, the track # 2 is moved to the track # 2, and the track # 2 is recorded. Next, it moves to the position of track # 3 to record track # 3, and finally moves to the position of track # 4 to record track # 4.

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

FIG. 18 is a diagram showing a configuration of a reproducing apparatus 400 in the magnetic recording / reproducing method according to the second 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 demodulation unit 240, and a restoration unit 260.

  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.

  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 preamble processing control unit 238, a channel estimation calculation unit 234, a reproduction position control processing unit 235, and a signal separation calculation unit. 236 and a storage unit 237.

  The synchronization signal detection unit 231 detects a synchronization pattern in the preamble 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, and outputs the identification information.

  The reproduction signal gain control processing unit 233 detects the gain control pattern in the preamble from the reproduction signal of the reproduction head R-1 for each scan from the storage unit 237, and reproduces for each scan based on the gain control pattern. The gain for the reproduction signal of the head R-1 is calculated to control the level of the reproduction signal of the reproduction head R-1 for each scan.

  The preamble processing control unit 238 estimates the position of the separation pattern in the reproduction signal of the reproduction head R-1 for each scan based on, for example, the identification information obtained by the identification information detection unit 232, and reproduces the separation pattern. It is determined whether the signal is used as it is or replaced with a predetermined value, and this information is output to the channel estimation calculation unit 234.

  Based on the synchronization pattern detected by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232, the channel estimation calculation unit 234 converts the preamble of the reproduction signal of the reproduction head R-1 for each scan. A track at the time of reproduction of the reproduction head R-1 and a plurality of tracks for each scan by using the reproduction signal of the separation pattern portion and information from the preamble processing control unit 238, specifying the start position of the included separation pattern A channel estimation calculation is performed to calculate a channel matrix corresponding to the positional relationship in the 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 scan 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. Process.

  The signal separation calculation unit 236 uses a channel matrix obtained by the channel estimation calculation unit 234 from the reproduction signal of the reproduction head R-1 for each scan in which the reproduction position is aligned by the reproduction position control processing unit 235, and uses a predetermined matrix. A process of separating the reproduction signal for each track is performed by arithmetic processing.

  The storage unit 237 is disposed behind the synchronization signal detector 231 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 a bit synchronization signal generated by PLLs 242-1, 242-2, 242-2, and 242-4 to binarize a reproduction signal for each track to generate a code string, for example, a 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 The synchronization pattern on the code string is detected from the 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. 18, 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.

  Note that the track scanning during reproduction by the single head is repeated at least as many times as the number of recording tracks of one unit. In other words, scanning may be repeated more times than the number of tracks. At this time, all the tracks for one unit are scanned 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.

  FIG. 19 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 synchronization pattern detected by H.231, the identification pattern is detected by identifying the head position of the identification pattern in the reproduction signal of the reproduction head R-1, and identification information is obtained (step S404). 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 shifted 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 out the reproduction signal for one unit stored in the storage unit 237 and arranges it in the reproduction signal for each scan. Based on the gain control pattern, the gain for the reproduction signal for each scan is calculated, and the level of the reproduction signal for each scan is individually controlled (step S408).

  Next, in the preamble processing control unit 238, for example, based on the identification information obtained by the identification information detection unit 232, the position of the separation pattern in the reproduction signal of the reproduction head R-1 for each scan is estimated, It is determined whether the reproduced signal of the separation pattern is used as it is or replaced with a predetermined value, and this information is output to the channel estimation calculation unit 234 (step S409).

  Thereafter, the channel estimation calculation unit 234 uses the reproduction pattern of the reproduction head R-1 for each scan based on the synchronization pattern detected by the synchronization signal detector 231 and the identification information obtained by the identification information detection unit 232. The head position of the separation pattern included in the preamble is specified, and reproduction from the reproduction head R-1 and a plurality of tracks for each scan is performed using the reproduction signal of the separation pattern portion and information from the preamble processing control unit 238. A channel estimation calculation for calculating a channel matrix corresponding to the positional relationship in the track width direction at the time is performed (step S410).

  Next, the reproduction position control processing unit 235 passes through the reproduction signal gain control processing unit 233 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 reproduction position of the reproduction signal of the reproduction head R-1 for each scan is aligned (step S411).

  Next, the signal separation calculation unit 236 calculates an inverse matrix of the channel matrix obtained by the channel estimation calculation unit 234, and uses this inverse matrix for one unit output from the reproduction signal gain control processing unit 233. The process of separating the reproduction signal for each track from the reproduction signal is performed (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).

  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 adjusting unit 224 may be connected to the subsequent stage of the A / D converter 225 to control the gain 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. Alternatively, the gain adjustment unit 224 may perform gain adjustment using information obtained by taking an error from the target gain value in the synchronization signal detector 231.

  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 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. 20 shows recording on the magnetic recording medium 2 by a non-azimuth method and a helical scan method using a plurality of recording heads W-1, W-2, and W-3 integrated as a recording head array 150, for example. It is a conceptual diagram of the track format used. Also in the helical scan method, the guard band 52 is disposed between the unit-configured track rows 53 including 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 present invention can also be applied to such a helical scan 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.

  FIG. 21 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 scan method. It is a conceptual diagram of the track format recorded on. In helical scan magnetic recording, a plurality of heads are independently mounted on a rotating drum. For example, a plurality of recording heads and a reproducing head are alternately arranged on a rotating drum.

  In this example, six recording heads W-1, W-2, W-3, W-4, W-4, W-5, and W-6 are used for recording and reproduction, respectively. Of these recording heads, the 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 mutually connected to each other. The azimuth direction, which is the magnetization direction, is made different. That is, track # 1- # 3 and track # 4- # 6 have different azimuth directions. These tracks # 1 to # 6 form a unit configuration track row 53 including a plurality of units as 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.

  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 scan method, and the configuration of the recording apparatus 100 and the reproducing apparatus 200 in the magnetic recording / reproducing system 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 recording device in the magnetic recording / reproducing system of the 1st Embodiment of this invention. 3 is a flowchart showing an operation of unit recording by the recording apparatus of FIG. 1. It is a figure which shows the structure of the reproducing | regenerating apparatus in the magnetic recording / reproducing system of the 1st Embodiment of this invention. FIG. 4 is a diagram illustrating a configuration of a multitrack demodulator in the playback device of FIG. 3. 4 is a flowchart showing an operation of unit playback by the playback device of FIG. 3. FIG. 2 is a conceptual diagram of a track format on a magnetic recording medium on which recording is performed by the recording apparatus of FIG. 1. FIG. 7 is a diagram illustrating a configuration of a preamble in the track format of FIG. 6. It is a figure which shows the reproduction signal with respect to the track format of FIG. It is a figure which shows the example of the ideal channel matrix obtained by channel estimation calculation. It is a figure which shows the modification of the track format of FIG. It is a figure which shows another modification of the track format of FIG. It is a figure which shows another modification of a track format. It is a figure which shows another modification of the track format of FIG. It is a figure which shows the structure of the recording device in the magnetic recording / reproducing system of the 2nd 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 of FIG. It is a figure which shows the modification of the recording device of FIG. FIG. 17 is a flowchart showing an operation flow during unit recording of the recording apparatus of FIG. 16. FIG. It is a figure which shows the structure of the reproducing | regenerating apparatus in the magnetic recording / reproducing system of the 2nd Embodiment of this invention. FIG. 19 is a flowchart showing a unit playback operation by the playback device of FIG. 18. FIG. 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. It is a flowchart which shows the operation | movement of unit recording by the recording device of 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. 25 is a flowchart showing a flow of unit playback operation of the playback apparatus of FIG. 24. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording data 2 Magnetic recording medium 3 Reproduction | regeneration data 21 Preamble 22 Data 23 1st preamble 24 2nd preamble 41-1, 41-2, 41-3, 41-4 Gain control pattern 42-1, 42-2, 42-3, 42-4 Synchronization pattern 43-1, 43-2, 43-3, 43-4 Identification pattern 44-1, 44-2, 44-3, 44-4 Separation pattern 51 Unit 100 Recording device 110 Multi Tracking section 111 Data distributor 120 Multitrack recording encoding section 121-1, 121-2, 121-3, 121-4 Recording encoding section 130 Multitrack preamble adding section 131-1, 131-2, 131-3 131-4 Preamble adding unit 140 Multitrack recording unit 141-1, 141-2, 141-3, 141 -4 Output timing setting unit 144-1, 144-2, 144-3, 144-4 Recording compensation unit 147-1, 147-2, 147-3, 147-4 Recording amplifier 149 Storage unit 150 Recording head array 200 Playback Apparatus 210 reproducing head array 220 channel reproducing unit 221-1, 221-2, 221-3, 221-4 reproducing amplifier 224-1, 224-2, 224-3, 224-4 gain adjusting unit 225-1, 225- 2,225-3,225-4 A / D converter 230 Signal separation processing unit 231 Synchronization signal detector 232 Identification information detection unit 233 Playback signal gain control processing unit 234 Channel estimation calculation unit 235 Playback position control processing unit 236 Signal separation calculation Unit 237 storage unit 238 preamble processing control unit 240 multi-track demodulation unit 241-1, 241-2, 2 1-3, 241-4 Equalizers 243-1, 243-2, 243-3, 243-4 Detectors 244-1, 244-2, 244-3, 244-4 Synchronization signal detector 245-1 245-2, 245-3, 245-4 Decoder 260 Restoration unit 261 Data combiner R- 1, R- 2, R- 3, R- 4 Playback head W- 1, W- 2, W- 3, W -4 Recording head

Claims (4)

A reproduction device that reproduces a plurality of signals for a plurality of tracks on a magnetic tape with different positional relationships with respect to the plurality of tracks, collects these reproduction signals as one unit, and performs signal processing to generate a reproduction signal for each track. Because
In the track, a separation pattern necessary for detecting a positional relationship in the track width direction during reproduction between the reproducing head and the plurality of tracks is recorded, and the separation pattern is positioned with respect to each other in the track advancing direction for each track. The separation pattern portions arranged one by one at different positions, and another separation pattern portion provided in a part of the tracks and disposed at a position separated from the separation pattern portion of the same track in the track traveling direction Consists of
The position of the separation pattern portion in the reproduction signal of the reproduction head is estimated, it is determined whether the reproduction signal of the separation pattern portion is used as it is or replaced with a predetermined value, and the track of the part of the tracks The reproduction signal of each separation pattern portion is determined twice, and the reproduction signal of one separation pattern portion of the two separation pattern portions is used as it is in the first determination, and the reproduction signal of the other separation pattern portion is used as it is. Is replaced with a reproduction signal of a predetermined value, and in the second determination, the reproduction signal of the other separation pattern portion of the two separation pattern portions is used as it is, and the separation pattern portion of the one separation pattern portion is used as it is. A preamble processing control unit for determining that the reproduction signal is used by replacing the reproduction signal with a predetermined value;
The result obtained by combining the reproduction signal of the one separation pattern portion determined to be used as it is for the first time and the reproduction signal of the other separation pattern portion determined to be used for the second time as it is is described above. The value of the reproduction signal of one separation pattern portion is used, and the reproduction signal of the other separation pattern portion determined to be used in the first time is replaced with a predetermined value, and the value is replaced with the predetermined value in the second time. The result of combining the reproduction signal of the one separation pattern portion determined to be used as the value of the reproduction signal of the other separation pattern portion, and reproducing the separation pattern portion for each track of the part of the tracks Signal and a reproduction signal of the separation pattern portion of the track other than the part of the tracks, and the reproduction head and the plurality of tracks are reproduced. A channel estimation calculation unit for calculating a channel matrix corresponding to the positional relationship between the rack width direction,
Using the channel matrix, a signal separation calculation unit that separates the reproduction signals for each track by collecting the reproduction signals for one unit reproduced by the reproduction head into the one unit and performing signal processing;
A playback apparatus comprising: The playback apparatus according to claim 1,
The channel estimation calculation unit sets the average of two reproduction signals as the result of the combination
Playback device . The playback apparatus according to claim 1,
The channel estimation calculation unit uses the larger value of the two reproduction signals as the result of the combination.
Playback device . A method for generating a reproduction signal for each track by reproducing a plurality of signals for a plurality of tracks on a magnetic tape in a different positional relationship with respect to the plurality of tracks, collecting these reproduction signals into one unit, and performing signal processing. There,
A separation pattern necessary for detecting a positional relationship in the track width direction during reproduction between the reproducing head and the plurality of tracks is recorded on the track, and the separation pattern is positioned mutually in the track advancing direction for each track. The separation pattern portions arranged one by one at different positions, and another separation pattern portion provided in a part of the tracks and disposed at a position separated from the separation pattern portion of the same track in the track traveling direction Consists of
The position of the separation pattern portion in the reproduction signal of the reproduction head is estimated, it is determined whether the reproduction signal of the separation pattern portion is used as it is or replaced with a predetermined value, and the track of the part of the tracks The reproduction signal of each separation pattern part is determined twice,
  In the first determination, it is determined that the reproduction signal of one separation pattern portion of the two separation pattern portions is used as it is, and the reproduction signal of the other separation pattern portion is replaced with a reproduction signal of a predetermined value. In the second determination, it is determined that the reproduction signal of the other separation pattern portion of the two separation pattern portions is used as it is, and the reproduction signal of the one separation pattern portion is replaced with a reproduction signal of a predetermined value. And
  The result obtained by combining the reproduction signal of the one separation pattern portion determined to be used as it is for the first time and the reproduction signal of the other separation pattern portion determined to be used for the second time as it is is described above. The value of the reproduction signal of one separation pattern portion is used, and the reproduction signal of the other separation pattern portion determined to be used in the first time is replaced with a predetermined value, and the value is replaced with the predetermined value in the second time. The result of combining the reproduction signal of the one separation pattern portion determined to be used as the value of the reproduction signal of the other separation pattern portion, and reproducing the separation pattern portion for each track of the part of the tracks Signal and a reproduction signal of the separation pattern portion of the track other than the part of the tracks, and the reproduction head and the plurality of tracks are reproduced. Calculating a channel matrix corresponding to the positional relationship between the rack width direction,
  Using the channel matrix, the reproduction signals for one unit reproduced by the reproduction head are grouped into the one unit, and signal processing is performed to separate the reproduction signals for each track.
  Playback method.

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