JP4983460B2 - Data reproducing apparatus, data reproducing method, and data recording / reproducing apparatus - Google Patents

Description

The present invention provides a recording medium in which a plurality of tracks are recorded by one or a plurality of recording heads.
The present invention relates to a data reproducing apparatus, a data reproducing method, and a data recording / reproducing apparatus that reproduce signals from one or more reproducing heads using one or more reproducing heads.

  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. 26 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. 27 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. 28 is a diagram showing the configuration of a reproducing apparatus 900 that employs the above-described magnetic recording / reproducing method.

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

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

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

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

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

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

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

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

  FIG. 29 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 of one unit (step S904), each reproducing head is based on this channel matrix. The reproduction signal for each of the tracks R-1, R-2, and R-3 is separated from the reproduction signal for one unit reproduced by R-1, R-2, and R-3 (step S905).

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

  Incidentally, as a technical problem for obtaining a more stable reproduction signal in the case of adopting such a magnetic recording / reproduction method, for example, there is a decrease in the quality of the reproduction signal when off-track occurs during reproduction. It was.

  That is, when recording a plurality of tracks on a magnetic recording medium as a unit that is a unit of data reproduction and recording a plurality of such units side by side in the width direction of the track, each adjacent unit is between each unit. A guard band is arranged to reduce the interference between the tracks. However, when a large off-track fluctuation occurs during playback and the track of the unit next to the unit that is the target of data playback is also played back by the playback heads at both ends in the track width direction, the playback of the adjacent unit The signal is equivalent to noise in the signal separation processing performed using the channel matrix obtained by the channel estimation calculation, and there is a problem that the quality of the reproduction signal for each track obtained by the signal separation processing is lowered.

  Even when only one unit is recorded in the width direction of the track, when a large off-track fluctuation occurs during playback, the recorded signal of the end track in the unit leaks from the playback by the playback head, and is at a sufficient level. In this case as well, there is a problem that the quality of the reproduction signal for each track obtained by the signal separation processing is deteriorated.

  In view of such circumstances, the present invention is intended to provide a data reproducing apparatus, a data reproducing method, and a data recording / reproducing apparatus that can perform data reproduction satisfactorily even with relatively large off-track fluctuations.

  In order to solve the above problems, the data reproducing apparatus of the present invention uses a reproducing head from a recording medium in which a unit that is a unit of signal processing for data reproduction is configured by a plurality of tracks. Is a device for obtaining a plurality of reproduction signals larger than the number of tracks constituting the unit and reproducing the data in different positional relations in the width direction of the track, the track constituting the unit. A reproduction signal selection unit that selects a plurality of reproduction signals satisfying the signals of all the tracks constituting the unit that is the target of the data reproduction, and a reproduction signal selection unit And an arithmetic unit that performs processing for separating the reproduction signal for each track from the plurality of reproduction signals.

  In the present invention, even when the signal of the track of the adjacent unit is reproduced due to a large off-track fluctuation at the time of data reproduction, for example, the track for the reproduction signal of the reproduction head other than the reproduction head that reproduced the track of the adjacent unit is targeted. By performing arithmetic processing for separating the reproduction signals for each, data reproduction can be performed more stably. That is, even if the signal of the track of the adjacent unit is reproduced, the influence on the quality of data reproduction can be reduced, so that the reproduction width on the medium by the reproduction head can be set wide. Therefore, even if a large off-track fluctuation occurs during reproduction, it is possible to avoid a problem that the signal of the end track in the unit leaks from reproduction or is not reproduced at a sufficient level, and the tolerance to off-track fluctuation can be increased. .

  In the data reproducing apparatus of the present invention, each track is provided with an identification pattern including information for identifying the unit to which the track belongs and a track within the unit, and the reproduction signal selecting unit has the identification pattern. Alternatively, the plurality of reproduction signals may be selected. As a result, a reproduction signal including a signal outside the unit can be discriminated with high accuracy, and resistance to off-track fluctuation can be obtained more reliably.

  In the data reproducing apparatus of the present invention, a preamble including information for controlling the reproduction of this data is arranged in each track so as to be shifted from each other in the direction in which the track travels. Based on the position, a reproduction signal including a signal of a unit other than the unit that is the target of data reproduction may be excluded from selection targets. In this way, it is possible to determine a reproduction signal including a signal outside the unit based on the position of the preamble, and thereby it is possible to accurately determine a reproduction signal including a signal outside the unit.

  In the data reproduction apparatus of the present invention, the reproduction signal selection unit configures the unit in which a reproduction signal excluding a reproduction signal including a signal of a unit other than the unit that is a data reproduction target is the data reproduction target. If the reproduction signals of all the tracks to be played are not satisfied, the signals of the units other than the unit that is the data reproduction target are included so as to satisfy the reproduction signals of all the tracks constituting the unit that is the data reproduction target. A part of the reproduction signal may be added to the selection result of the reproduction signal.

  In the data reproduction apparatus of the present invention, the reproduction signal selection unit may be configured such that the number of reproduction signals excluding reproduction signals including signals of units other than the unit that is the target of data reproduction is the number of tracks constituting the unit. When the number is larger than the number, the selection result of the reproduction signal may be narrowed down to the number of tracks constituting the unit based on the output level of each reproduction signal.

  In the data reproducing apparatus of the present invention, the reproducing head may reproduce a wider range in the track width direction than the track width.

  In the data reproducing apparatus of the present invention, each of the tracks is provided with 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, The unit detects the separation pattern from the plurality of reproduction signals selected by the reproduction signal selection unit, and based on the detection result, the track width during reproduction of the reproduction head and the plurality of tracks A channel estimation calculation unit for calculating a channel matrix corresponding to the positional relationship of directions; and the track from each reproduction signal selected by the reproduction signal selection unit based on the channel matrix obtained by the channel estimation calculation unit It is good also as providing the signal separation calculating part which isolate | separates every reproduction | regeneration signal.

  Further, in the data reproduction device of the present invention, the signal separation operation unit obtains a generalized inverse matrix of the channel matrix obtained by the channel estimation operation unit, and is selected by the generalized inverse matrix and the reproduction signal selection unit. The reproduced signal for each track may be separated from each reproduced signal.

  Further, in the data reproduction device of the present invention, the signal separation calculation unit is selected by the reproduction signal selection unit by a MMSE (Minimum Mean Squared Error) method with respect to the channel matrix obtained by the channel estimation calculation unit. Alternatively, the reproduction signal of the data for each track may be separated from each reproduction signal.

  In the data reproducing apparatus of the present invention, the separation pattern may be a separation pattern that is arranged at a unique position for each track and is composed of a signal having a recording wavelength equal to or greater than the minimum recording wavelength. . Further, tracking servo information may be used as a separation pattern.

  In the data reproducing apparatus of the present invention, each of the tracks is provided with 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, The unit detects the separation pattern from the plurality of reproduction signals selected by the reproduction signal selection unit, and based on the detection result, the track width during reproduction of the reproduction head and the plurality of tracks A channel estimation calculation unit that calculates a channel matrix corresponding to a positional relationship of directions, and a channel matrix estimation that estimates a variable channel matrix within the data interval using the channel matrix obtained by the channel estimation calculation unit And the variable channel matrix estimated by the channel matrix estimation unit, the reproduction signal selection unit for each individual section. It may be provided with a signal separation calculation section for separating the reproduced signal of each of the tracks from the reproduced signal selected.

  According to the present invention, the channel matrix corresponding to the positional relationship between the reproducing head and the plurality of tracks in the track width direction is made variable in the data section according to the off-track fluctuation condition, thereby reducing the off-track fluctuation. In contrast, data reproduction can be performed satisfactorily.

  Further, in the data reproducing apparatus of the present invention, the channel matrix estimation unit is configured to perform the channel estimation calculation unit based on the separation patterns in the plurality of units arranged continuously in the traveling direction of the track. A variable channel matrix may be estimated within the section of the data by using a plurality of obtained channel matrices. As a result, a more appropriate channel matrix can be obtained against off-track fluctuations, and data reproduction can be stabilized.

  In the data reproduction device of the present invention, the channel matrix estimation unit may perform linear interpolation from a plurality of channel matrices respectively obtained by the channel estimation calculation unit based on the separation patterns in the plurality of consecutive units. Thus, it is also possible to estimate a plurality of channel matrices respectively corresponding to individual sections of the data. By using linear interpolation in this way, it is possible to obtain an appropriate channel matrix corresponding to the track shift situation for each section obtained by dividing the data section, and to stabilize the data reproduction against the track shift. be able to.

  Furthermore, in the data reproduction device of the present invention, the channel matrix estimation unit may include the plurality of channel matrices from a plurality of channel matrices respectively determined by the channel estimation calculation unit based on the separation patterns in the plurality of consecutive units. Alternatively, a variable channel matrix may be estimated within a data section located behind both of the separation patterns.

  According to another aspect of the present invention, there is provided a data reproducing method, wherein a recording head in which a unit that is a unit of signal processing for data reproduction is configured by a plurality of tracks is used for the unit using a reproducing head. A method of reproducing the data by obtaining a plurality of reproduction signals larger than the number of tracks constituting the unit with different positional relationships in the width direction of the track, wherein the number of reproduction signals is larger than the number of tracks constituting the unit. A reproduction signal selection step of selecting a plurality of reproduction signals satisfying the signals of all tracks constituting the unit that is the target of the data reproduction from a plurality of reproduction signals, and the plurality of the plurality of reproduction signals selected by the reproduction signal selection step And an arithmetic step for performing processing for separating the reproduction signal for each track from the reproduction signal.

  In the present invention, even when the signal of the track of the adjacent unit is reproduced due to a large off-track fluctuation at the time of data reproduction, for example, the track for the reproduction signal of the reproduction head other than the reproduction head that reproduced the track of the adjacent unit is targeted. By performing arithmetic processing for separating the reproduction signals for each, data reproduction can be performed more stably. That is, even if the signal of the track of the adjacent unit is reproduced, the influence on the quality of data reproduction can be reduced, so that the reproduction width on the medium by the reproduction head can be set wide. Therefore, even if a large off-track fluctuation occurs during reproduction, it is possible to avoid a problem that the signal of the end track in the unit leaks from reproduction or is not reproduced at a sufficient level, and the tolerance to off-track fluctuation can be increased. .

  In the data reproduction method of the present invention, an identification pattern including information for identifying the unit to which the track belongs and a track within the unit is arranged for each track, and the reproduction signal selection step includes the identification pattern. Alternatively, the plurality of reproduction signals may be selected. As a result, a reproduction signal including a signal outside the unit can be discriminated with high accuracy, and resistance to off-track fluctuation can be obtained more reliably.

  In the data reproduction method of the present invention, a preamble including information for controlling the reproduction of this data is arranged in each track so as to be shifted from each other in the direction in which the track travels, and the reproduction signal selection step includes: The plurality of reproduction signals may be selected based on the position. In this way, it is possible to determine a reproduction signal including a signal outside the unit based on the position of the preamble, and thereby it is possible to accurately determine a reproduction signal including a signal outside the unit.

  In the data reproduction method of the present invention, in the reproduction signal selection step, the reproduction signal excluding the reproduction signal including a signal of a unit other than the unit that is the object of data reproduction constitutes the unit that is the object of the data reproduction. If the reproduction signals of all the tracks to be played are not satisfied, the signals of the units other than the unit that is the data reproduction target are included so as to satisfy the reproduction signals of all the tracks constituting the unit that is the data reproduction target. A part of the reproduction signal may be added to the selection result of the reproduction signal.

  In the data reproduction method of the present invention, in the reproduction signal selection step, the number of reproduction signals excluding reproduction signals including signals of units other than the unit that is the target of data reproduction is more than the number of tracks constituting the unit. In many cases, the selection result of the reproduction signal may be narrowed down to the number of tracks constituting the unit based on the output level of each reproduction signal.

  In the data reproducing method of the present invention, the reproducing head may reproduce a wider range in the track width direction than the track width.

  In the data reproduction method of the present invention, each of the tracks is provided with 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, and the signal separation step Detects the separation pattern from the plurality of reproduction signals selected in the reproduction signal selection step, and based on the detection result, the track width direction during reproduction of the reproduction head and the plurality of tracks A channel estimation calculation step for calculating a channel matrix corresponding to the positional relationship of each of the reproduction signals selected by the reproduction signal selection step based on the channel matrix obtained by the channel estimation calculation step for each track. And a signal separation calculation step for separating the reproduced signals.

  In the data reproduction method of the present invention, the signal separation calculation step obtains a generalized inverse matrix of the channel matrix obtained by the channel estimation calculation step, and is selected by the generalized inverse matrix and the reproduction signal selection step. The reproduction signal for each track may be separated from each reproduction signal.

  Furthermore, in the data reproduction method of the present invention, the signal separation calculation step is selected by the reproduction signal selection step by the MMSE (Minimum Mean Squared Error) method with respect to the channel matrix obtained by the channel estimation calculation step. The reproduction signal of the data for each track may be separated from each reproduction signal.

  In the data reproduction method of the present invention, the separation pattern can be a separation pattern that is arranged at a unique position for each track and is composed of a signal having a recording wavelength equal to or greater than the minimum recording wavelength. Further, tracking servo information may be used as a separation pattern.

  In the data reproduction method of the present invention, each of the tracks is provided with 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, and the signal separation step Detects the separation pattern from the plurality of reproduction signals selected in the reproduction signal selection step, and based on the detection result, the track width direction during reproduction of the reproduction head and the plurality of tracks A channel estimation calculation step for calculating a channel matrix corresponding to the positional relationship of, and a channel matrix estimation step for estimating a variable channel matrix within the section of the data using the channel matrix obtained in the channel estimation calculation step And using the variable channel matrix estimated by the channel matrix estimation step, Each may be be provided with a signal separation calculation step of separating the reproduced signal of each of the tracks from the reproduced signal selected by said reproduction signal selecting step.

  According to the present invention, the channel matrix corresponding to the positional relationship between the reproducing head and the plurality of tracks in the track width direction is made variable in the data section according to the off-track fluctuation condition, thereby reducing the off-track fluctuation. In contrast, data reproduction can be performed satisfactorily.

  In the data reproduction method of the present invention, the channel matrix estimation step is obtained in the channel estimation calculation step based on the separation patterns in the plurality of units continuously arranged in the traveling direction of the track. A variable channel matrix may be estimated within the data interval using the plurality of channel matrices obtained. As a result, a more appropriate channel matrix can be obtained against off-track fluctuations, and data reproduction can be stabilized.

  In the data reproduction method of the present invention, the channel matrix estimation step includes linear interpolation from a plurality of channel matrices respectively obtained by the channel estimation calculation step based on the separation patterns in the plurality of consecutive units. A plurality of channel matrices respectively corresponding to the individual sections of the data may be estimated. By using linear interpolation in this way, it is possible to obtain an appropriate channel matrix corresponding to the track shift situation for each section obtained by dividing the data section, and to stabilize the data reproduction against the track shift. be able to.

  In the data reproduction method of the present invention, the channel matrix estimation step includes the plurality of separations from a plurality of channel matrices respectively obtained by the channel estimation calculation step based on the separation patterns in the plurality of consecutive units. A variable channel matrix may be estimated within a section of data located behind both of the patterns.

  A data recording / reproducing apparatus based on another aspect of the present invention includes a data recording apparatus that records a plurality of tracks, and the recording medium on which the unit is recorded by the data recording apparatus. A data recording / reproducing apparatus comprising: a data reproducing apparatus that obtains a plurality of reproduction signals larger than the number of tracks constituting the unit and reproduces the data in different positional relationships with respect to the unit in the track width direction. The data recording device includes a recording encoding unit that encodes data to be recorded for each track, and the data for each track encoded by the recording encoding unit, during reproduction, In order to prevent the preambles of a plurality of tracks from being reproduced simultaneously by the reproduction head, at least each adjacent track is And an independent preamble adding unit for adding a preamble necessary for the control of reproducing the data with a positional relationship shifted in the direction of track movement between the tracks, and data with the preamble added for each track. A multi-track recording unit that performs processing for recording on the recording medium by the recording head, and the data reproduction device reproduces the data from a plurality of reproduction signals that are larger than the number of tracks constituting the unit. A reproduction signal selection unit that selects a plurality of reproduction signals that satisfy the signals of all the tracks constituting the unit that is the target of the reproduction, and a reproduction signal for each track from the plurality of reproduction signals selected by the reproduction signal selection unit And an arithmetic unit that performs processing for separating.

  According to the data recording / reproducing apparatus of the present invention, even when the signal of the track of the adjacent unit is reproduced due to a large off-track fluctuation at the time of data reproduction, for example, the reproduction head other than the reproduction head that reproduces the track of the adjacent unit. By performing arithmetic processing for separating the reproduction signal for each track on the reproduction signal, data reproduction can be performed more stably. That is, even if the signal of the track of the adjacent unit is reproduced, the influence on the quality of data reproduction can be reduced, so that the reproduction width on the medium by the reproduction head can be set wide. Therefore, even if a large off-track fluctuation occurs during reproduction, it is possible to avoid a problem that the signal of the end track in the unit leaks from reproduction or is not reproduced at a sufficient level, and the tolerance to off-track fluctuation can be increased. .

  According to the present invention, it is possible to satisfactorily reproduce data even with a relatively large off-track fluctuation.

  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. Let M be the number of recording heads and N be the number of reproducing heads. In this embodiment, M <N.

  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, a recording head array 150, and a guard band recording unit. 160.

  The multitrack unit 110 includes a data distributor 111 that distributes the recording data 1 to M pieces of data for multitracking.

  The multi-track recording encoding unit 120 includes M recording encoding units 121-1, 121-2,..., 121-M 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, 131-2, 131-2, and 1312 that add a preamble necessary for data reproduction control to each recording data encoded by the multitrack recording encoding unit 120. ..., 131-M.

  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. , 141-M, M recording compensators 144-1, 144-2,..., 144-M that perform recording compensation processing, and recording M recording amplifiers 147-1, 147-2,... For driving the individual recording heads W-1, W-2,. 147-M.

  The recording head array 150 includes M recording heads W-1, W-2,..., WM used for recording tracks including data on the magnetic recording medium 2, and tracks not including data. It has one recording head W-0 used for recording as a guard band.

  The guard band recording unit 160 is means for recording a guard band, to which a preamble including a synchronization pattern, an identification pattern, and the like is added, on the magnetic recording medium 2 using the guard band recording head W-0.

  The guard band recording unit 160 includes an erasure signal generation unit 161, a preamble addition unit 131-0, an output timing setting unit 141-0, a recording compensation unit 144-0, and a recording amplifier 147-0.

  The erase signal generator 161 is a means for generating an erase signal to be recorded in the guard band. For the erasure signal, a code string that is not used for a data code string, such as a repetitive signal having a recording wavelength equal to or shorter than the shortest recording wavelength, or a DC signal, is used.

  The preamble adding unit 131-0 adds a guard band preamble including a synchronization pattern and an identification pattern to the code sequence of the erasure signal output from the erasure signal generation unit 161.

  The output timing setting unit 141-0 gives a desired timing to the recording code string of the erasure signal to which the preamble is added. The recording compensation unit 144-0 performs a recording compensation process on the output of the output timing setting unit 141-0. The recording amplifier 147-0 drives the recording head W-0 based on the recording code string for the guard band after the recording compensation process.

  FIG. 2 is a flowchart showing the operation of unit and guard band recording by the recording apparatus 100. In the recording apparatus 100, an operation of recording M tracks including data and an operation of recording one guard band are switched and executed. First, it is determined whether an object to be recorded is a guard band or a track (step S101).

  When the object of recording to be performed is a track, control is performed to perform the following operation. First, the input recording data 1 is recorded at the multitrack unit 110 by the number of recording heads W-1, W-2,..., WM for track recording, that is, the number of tracks constituting the unit The data is distributed to the minutes (step S102).

  Each of the distributed data is encoded in consideration of the recording / reproduction characteristics of the magnetic recording medium 2 by the recording encoding units 121-1, 121-2, ..., 121-M of the multitrack recording encoding unit 120, respectively. 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 S103).

  Next, the encoded recording data is subjected to preambles of a plurality of tracks by the reproducing head during reproduction by the preamble adding units 131-1, 131-2, ..., 131-M of the multitrack preamble adding unit 130. Are not reproduced at the same time, a preamble necessary for data reproduction control is added at least in a positional relationship where each adjacent track deviates in the direction in which the tracks proceed, and a recording code string is obtained (step S1). S104).

  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 string generated by the recording encoding units 121-1, 121-2, ..., 121-M 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-M of the multitrack recording unit 140, and then the recording compensation unit 144- 1, 144-2,..., 144-M are subjected to a recording compensation process for optimizing the recording on the magnetic recording medium 2. 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-M, and the recording heads W-1, W-2,. .., WM and recorded on the magnetic recording medium 2 by the recording heads W-1, W-2,..., WM (step S105).

  On the other hand, in step S101, if the target of recording to be performed is a guard band, control is performed to perform the following operation. First, an erase signal for a predetermined unit is output from the erase signal generator 161 of the guard band recording unit 160 (step S106). Next, the preamble adding unit 131-0 adds a guard band preamble to the code string of the erasure signal (step S107).

  The erasure signal recording code string output from the preamble adding unit 131-0 is given a desired timing by the output timing setting unit 141-0 in the guard band recording unit 160, and then stored in the guard band recording unit 160. A recording compensation process for optimizing the recording on the magnetic recording medium 2 is performed in the recording compensation unit 144-0. The recording code string of the erasure signal subjected to the recording compensation process is converted from voltage to current by the recording amplifier 147-0 in the guard band recording unit 160 and sent to the recording head W-0. Recording is performed on the magnetic recording medium 2 (step S108).

  As described above, the recording apparatus 100 records the M tracks and one guard band constituting the unit, and then moves the recording head array 150 by a certain amount in the tape width direction of the magnetic recording medium 2. Next, M tracks and one guard band constituting the next unit are recorded, and this is repeated a predetermined number of times (s). Finally, for example, as shown in FIG. 6, the guard band 52 is recorded on the unit 51 so that the guard bands 52 are arranged on both sides of each unit 51 and the guard bands 52 are interposed between the units 51. Performed once more than recording. That is, in the example of FIG. 6, guard band # 1, unit # 1, guard band # 2, unit # 2, guard band # 3,..., Guard band #s, from one end in the width direction of the magnetic recording medium 2. Recording is performed in the order of unit #s and guard band # s + 1. Here, the guard band # s + 1 is created by performing only the recording of the guard band 52 by the guard band recording unit 160 at the position where the recording head array 150 is finally moved in the track width direction.

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

  FIG. 3 is a diagram showing the configuration of the playback apparatus 200.

  As shown in the figure, the reproducing apparatus 200 includes a reproducing head array 210, a channel reproducing unit 220, a signal separation processing unit 230, a multitrack demodulation unit 240, a restoration unit 260, and a tracking control unit 270.

  The reproducing head array 210 has N reproducing heads R-1, R-2,..., RN that read signals from the tracks recorded on the magnetic recording medium 2. Each of the reproducing heads R-1, R-2,..., RN has a head width and an arrangement so that a signal can be reproduced from one or more adjacent tracks on the magnetic recording medium 2. Is decided.

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

  Note that a low-pass filter for removing unnecessary high-frequency components may be provided immediately before the A / D converters 225-1, 225-2,.

  Further, the gain adjustment units 224-1, 224-2,..., 224 -N are arranged not at the previous stage of the A / D converters 225-1, 225-2,. Also good. This is because the bit widths of the A / D converters 225-1, 225-2,..., 225-N are used more effectively, or the gain adjusting units 224-1, 244-2,. This configuration is effective when it is desired to simplify the configuration considering the detection of each pattern included in the preampule.

  The signal separation processing unit 230 includes a synchronization signal detection unit 231, an identification information detection unit 232, a reproduction signal gain control processing unit 233, a channel estimation calculation unit 234, a reproduction position control processing unit 235, a signal separation calculation unit 236, and a reproduction signal selection. Part 238.

  The synchronization signal detector 231 reproduces each reproduction head R-1, R-2,..., RN output from the A / D converters 225-1, 225-2,. The synchronization pattern in the preamble is detected from the signal and the information is output.

  The identification information detection unit 232 uses the information obtained by the synchronization signal detection unit 231 to specify the head position of the identification pattern in the reproduction signal of each reproduction head R-1, R-2,. Then, the identification pattern is detected, and identification information corresponding to the detected identification pattern is output.

  The reproduction signal gain control processing unit 233 detects the gain control pattern in the preamble from the reproduction signal of each reproduction head R-1, R-2,..., RN that has passed through the identification information detection unit 232, and Based on this gain control pattern, the gain for each reproduction head R-1, R-2,..., RN is calculated, and each reproduction head R-1, R-2,. • Controls the level of the RN playback signal.

  Based on the identification information detected by the identification information detection unit 232, the reproduction signal selection unit 238 determines a predetermined selection condition from the reproduction signals of the reproduction heads R-1, R-2,. Accordingly, at least the reproduction signals of the number of tracks constituting the unit are selected, and the channel estimation calculation unit 234 and the signal separation calculation unit 236 are notified of the selection result information.

  The channel estimation calculation unit 234 uses the information from the reproduction signal selection unit 238, the information obtained by the synchronization signal detection unit 231, and the identification information obtained by the identification information detection unit 232 to use the reproduction signal selection unit 238. The head position of the separation pattern included in the preamble of each reproduction signal selected by is specified, and a channel matrix is calculated by channel estimation calculation using these separation patterns.

  The reproduction position control processing unit 235, based on the information obtained by the synchronization signal detection unit 231, each reproduction head R-1, R-2,..., R− that has passed through the reproduction signal gain control processing unit 233. Processing for adjusting the playback position of the N playback signals is performed.

  The signal separation calculation unit 236 passes through the reproduction position control processing unit 235 by a predetermined calculation process based on the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel estimation calculation unit 234. A process of separating the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit 238 is performed.

  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-M and M PLLs 242-1, 242-2,... That perform bit synchronization from the outputs of the equalizers 241-1, 241-2,. 242-M and a bit synchronization signal generated by PLLs 242-1, 242-2,... 242-M, and binarize the reproduction signal of each track to generate a code string. , 243-M, and the binarized reproduction that is the output of the detectors 243-1, 243-2,. M synchronization signal detectors 24 for detecting a synchronization signal on the code string from the signal -1,244-2,..., 244-M and the sync position detected by the sync signal detectors 244-1, 244-2,. M decoders 245-1, 245-2,..., 245 -M that specifically identify and decode a data string from a 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-M in the multitrack demodulation unit 240 at the time of recording. And a data combiner 261 that restores the reproduced data 3 by connecting them in the reverse operation.

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

  In this reproducing apparatus 200, first, the magnetic recording medium 2 is constituted by N reproducing heads R-1, R-2,..., RN that can reproduce signals from one or more adjacent tracks. A signal is reproduced from the M tracks of one unit (step S201).

  Next, the amplitude levels of the outputs of the reproduction amplifiers 221-1, 221-2,..., 221-N are adjusted by the gain adjusting units 224-1, 224-2,. Then, A / D converters 225-1, 225-2,..., 225-N convert them to digital values and output them to synchronization signal detector 231 (step S202).

  Next, each reproducing head R-1, R-2,..., R- output from the A / D converters 225-1, 225-2,. A synchronization pattern in the preamble of the N reproduced signals is detected (step S203).

  Next, by using the synchronization pattern detected by the synchronization signal detection unit 231 by the identification information detection unit 232, the identification pattern in the reproduction signal of each reproduction head R-1, R-2,. An identification pattern is detected by specifying the head position, and identification information corresponding to the detected identification pattern is output (step S204).

  Next, the reproduction signal gain control processing unit 233 detects the gain control pattern in the preamble from the reproduction signal of each reproduction head R-1, R-2,..., RN, and uses this gain control pattern. The reproduction heads R-1, R-2,..., RN calculate gains for the reproduction signals, and the reproduction heads R-1, R-2,. The signal level is controlled (step S205).

  Next, based on the identification information detected by the identification information detection unit 232 by the reproduction signal selection unit 238, a predetermined signal is generated from the reproduction signals of the reproduction heads R-1, R-2,. In accordance with the selection condition, at least the reproduction signals of the number of tracks constituting the unit are selected, and information on the selection result is notified to the channel estimation calculation unit 234 and the signal separation calculation unit 236 (step S206).

  Next, the channel estimation calculation unit 234 uses the information from the reproduction signal selection unit 238, the synchronization pattern detected by the synchronization signal detection unit 231, and the identification information detected by the identification information detection unit 232, The head position of the separation pattern included in the preamble of each reproduction signal selected by the reproduction signal selection unit 238 is specified, and a channel matrix is calculated by channel estimation calculation using these separation patterns (step S207).

  Next, each reproduction head R-1, R-2,... That has passed through the reproduction signal gain control processing unit 233 using the synchronization pattern detected by the synchronization signal detection unit 231 by the reproduction position control processing unit 235. , RN reproduction signal reproduction positions are matched (step S208).

  Next, based on the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel estimation calculation unit 234, the signal separation calculation unit 236 causes the reproduction position control processing unit 235 to perform a predetermined calculation process. A process of separating the reproduction signal for each track from each reproduction signal that has passed and selected by the reproduction signal selection unit 238 is performed (step S209).

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

  FIG. 6 is a conceptual diagram of a data format on the magnetic recording medium 2 recorded by the recording apparatus 100 described above. Note that M, which is the number of tracks, is 6.

  Here, M tracks # 1, # 2,..., # 6 recorded on the magnetic recording medium 2 by the M recording heads are one unit 51. A plurality (s) of such units 51 are recorded side by side in the tape width direction of the magnetic recording medium 2 on the magnetic recording medium 2. On both sides of each unit 51, guard bands 52, which are areas where data is not recorded, are arranged. The purpose of the guard band 52 is to prevent data from being reproduced from a unit adjacent to the unit being reproduced.

  In each track # 1, # 2,..., # 6, a preamble 21 which is information necessary for control of reproducing the data 22 and data 22 to be reproduced are arranged. Although no data is recorded in the guard band 52, a preamble including a synchronization pattern, an identification pattern, and the like is recorded at a predetermined position in the track traveling direction.

  FIG. 7 is a diagram showing details of the data format in FIG. 6 and the arrangement of each reproducing head in the reproducing head array 150. One unit 51 and two units arranged on both sides of this unit 51 are shown in the entire data format in FIG. The part of one guard band 52 is taken out and shown. Note that N, which is the number of reproducing heads, is 7.

  As shown in the figure, each of the preambles 21 of the tracks # 1, # 2,..., # 6 includes a first preamble 23 and a second preamble 24. The first preamble 23 of each of the tracks # 1, # 2,..., # 6 includes gain control patterns 41-1, 41-2,. 2,..., 42-6, and identification patterns 43-1, 43-2,. The second preamble 24 is composed of separation patterns 44-1, 44-2, ..., 44-6. Each track # 1, # 2,..., # 6 has gain control patterns 41-1, 41-2,..., 41-6 and synchronization patterns 42-1, 42-2 from the head side. ,..., 42-6, and identification patterns 43-1, 43-2,. Then, after the second preamble 24, data 22 to be reproduced is arranged.

  On the other hand, the guard band 52 includes only gain control patterns 41-0 and 41-7, synchronization patterns 42-0 and 41-7, and identification patterns 43-0 and 43-7, which are elements of the first preamble 23, as preambles. Is recorded.

  The patterns of the first preamble 23 recorded on the tracks # 1, # 2,..., # 6 are respectively positions in the direction in which the track proceeds with respect to the patterns of the preamble 21 of other tracks in the same unit. So that they do not overlap each other. That is, the pattern (gain control pattern 41-1, synchronization pattern 42-1 and identification pattern 43-1) of the preamble 21 of track # 1 is the pattern (gain control pattern) of the first preamble 23 of track # 2 in the t1 interval. 41-2, synchronization pattern 42-2, identification pattern 43-2) is the pattern of the first preamble 23 of track # 3 (gain control pattern 41-3, synchronization pattern 42-3, identification pattern 43-) in the t2 interval. 3) The pattern of the first preamble 23 of track # 4 (gain control pattern 41-4, synchronization pattern 42-4, identification pattern 43-4) is in the t3 section, and the first preamble of track # 5 is in the t4 section. The pattern of the preamble 23 (gain control pattern 41-5, synchronization pattern 42-5, identification pattern 43-5) is t5. During the pattern of the first preamble 23 of the track # 6 (gain control pattern 41-6, the synchronization pattern 42-6, the identification pattern 43-6) The interval t6, are disposed respectively. A gap 40 for a margin is provided between the recording sections of these patterns.

  On the other hand, gain control patterns 41-0 and 41-7, synchronization patterns 42-0 and 42-7, and identification patterns 43-0 and 43-7, which are patterns of the first preamble 23 recorded in each guard band 52, are also included. The positions of the preambles 21 recorded on the tracks # 1, # 2,..., # 6 do not overlap with the positions in the track traveling direction, for example, the pattern of the preamble 21 of the track # 6. It is arranged in the later t7 section.

  By arranging the pattern of the first preamble 23 in this way, even when the channel clock positions of the tracks # 1, # 2,..., # 6 and the guard band 52 are not aligned, The reproduction signal level is not lowered due to the cancellation of the patterns between the track and the guard band 52, and the process using the pattern of the first preamble 23 can be performed satisfactorily.

  Also, the separation patterns 44-1, 44-2,..., 44-6, which are the second preambles 24 of the tracks # 1, # 2,. On the other hand, the positions in the traveling direction of the tracks are arranged so as not to overlap each other. That is, the separation pattern 44-1 for track # 1 is in the T1 section, the separation pattern 44-2 for track # 2 is in the T2 section, the separation pattern 44-3 for track # 3 is in the T3 section, and the separation pattern for track # 4. 44-4 is recorded in the T4 section, the separation pattern 44-5 of the track # 5 is recorded in the T5 section, and the separation pattern 44-6 of the track # 6 is recorded in the T6 section. As a result, there are six types of separation patterns corresponding to the number of tracks. Between the separation patterns 44-1, 44-2,..., 44-6 of adjacent tracks, a gap 40 for a predetermined time is provided for a margin. Note that no separation pattern is recorded in the guard band 52.

  The separation patterns 44-1, 44-2,..., 44-6 are recorded at a predetermined recording wavelength equal to or greater than the minimum recording wavelength.

  Gain control patterns 41-0, 41-1,..., 41-7 arranged in the tracks # 1, # 2,..., # 6 and the first preamble 23 of the guard band 52 are reproduced. Sometimes, learning for gain control of the reproduction amplifiers 221-1, 221-2,..., 221-N by the gain adjusting units 224-1, 224-2,. In addition to being used as a signal, it is used for control by the reproduction signal gain control processing unit 233. The gain control patterns 41-0, 41-1,..., 41-7 are used for control by the reproduction position control processing unit 235 as necessary. In addition, the gain control patterns 41-0, 41-1,..., 41-7 are used as learning signals for bit synchronization detection in the synchronization signal detection unit 231 in the playback device 200 as necessary. .

  .., # 6 and the sync patterns 42-0, 42-1,..., 42-7 arranged in the first preamble 23 of the guard band 52 are recorded on the playback device. , 43-7, separation patterns 44-1, 44-2,..., 43-7, which are used for detection of the synchronization signal by the synchronization signal detection unit 231 in 200. .., 44-6 and used as information for knowing the head position of the data 22. Furthermore, the synchronization patterns 42-0, 42-1,..., 42-7 are used for controlling the reproduction position of each reproduction signal in the reproduction position control processing unit 235.

  Identification patterns 43-0, 43-1,..., 43-7 arranged in the first preamble 23 of each track # 1, # 2,. It is detected by the identification information detection unit 232 in 200 and used to obtain track and guard band identification information, and is also used for channel estimation calculation in the channel estimation calculation unit 234. Further, this identification information is used for playback position control in the playback position control processing unit 235.

  The separation patterns 44-1, 44-2,..., 44-6 arranged as the second preamble 24 in each track # 1, # 2,. Is used for channel estimation calculation to obtain a channel matrix of This channel matrix is the position in the track width direction of each reproducing head R-1, R-2,..., R-7 for each track # 1, # 2,. This corresponds to information, in other words, information indicating at what rate each track in the unit overlaps with each reproducing head R-1, R-2,..., R-7. It is.

  In the example of FIG. 7, the width of the reproducing heads R-1, R-2,..., R-7 is 1.5 times the track width. That is, the width of the reproducing heads R-1, R-2,..., R-7 is 1.5 times the head width of the recording head, and the individual reproducing heads R-1, R-2,. • R-7 can reproduce signals from multiple tracks.

  FIG. 8 is a diagram showing details of the data format of FIG. 6 and another example of the arrangement of the reproducing heads in the reproducing head array 150. Here, M which is the number of tracks is 6 and N which is the number of reproducing heads is 8.

  In this data format, the first preamble 23 of each track # 1, # 2,..., # 6 is divided into three sections t1, t2, and t3 in the track traveling direction. That is, the pattern of the preamble 21 of the track # 1 and the track # 4 is in the t1 section, and the pattern of the first preamble 23 of the track # 2 and the track # 5 is in the t2 section, and the first pattern of the track # 3 and the track # 6. The pattern of the preamble 23 is arranged in the t3 section. A gap 40 for a margin is provided between the recording sections of these patterns. As described above, even if the first preambles 23 of a plurality of tracks are arranged in the same section, there is no problem if the first preambles 23 of the plurality of tracks are not reproduced simultaneously by one reproducing head.

  The arrangement of the separation patterns 44-1, 44-2,..., 44-6 of the second preamble 24 is the same as that in FIG. Further, the arrangement of the first preamble 23 in the guard band 52 is the same as that in FIG. 7, and the first preamble 23 recorded in the tracks # 1, # 2,. Thus, the positions in the traveling direction of the tracks do not overlap, for example, they are arranged in the t4 section after the pattern of the first preamble 23 of tracks # 3 and # 6.

  According to such a data format, compared with the data format shown in FIG. 7, the consumption amount in the traveling direction of the track of the magnetic recording medium 2 by the pattern of the first preamble 23 can be reduced, and the recording efficiency can be improved. Improvements can be made.

  Next, referring back to FIG. 6, the identification patterns 43-0, 43-1,..., # 6 arranged in the tracks # 1, # 2,. Details of 43-7 will be described.

  As shown in FIG. 6, the identification information is, for example, a combination of a number from “1” to “s” for identifying a unit and a number from “1” to “6” for identifying a track in the unit, for example. It is expressed by. For example, “1_2” indicates the second track of the first unit. In the expression of the identification information, the guard band 52 is treated as a track belonging to the unit on which recording is performed at the same time, and “0” is given to the number for identifying the track of the guard band 52. Therefore, for example, “2 — 0” indicates a guard band in which recording is performed simultaneously with the track of the second unit. Also, from one side in the tape width direction of the magnetic recording medium 2, guard band # 1, unit # 1, guard band # 2, unit # 2, guard band # 3,..., Guard band #s, unit #s, guard Since recording is performed in the order of band # s + 1, the last guard band # s + 1 is a track belonging to the s + 1th unit that does not actually exist, and (s + 1) _0 is given as identification information.

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

  (About the identification information detection unit 232)

  The identification information detection unit 232 identifies the start position of the identification pattern in the reproduction signal of each reproduction head based on the synchronization pattern detected by the synchronization signal detection unit 231, detects the identification pattern, and outputs the identification information To do.

  When one reproduction head straddles a plurality of tracks, the synchronization signal detection unit 231 detects the synchronization pattern of each track from the reproduction signal obtained by the reproduction head at different timings. The identification information detection unit 232 can obtain the identification information by specifying the start position of the identification pattern of each track using the synchronization pattern of each track.

  (Reproduction signal gain control processing unit 233)

  The reproduction signal gain control processing unit 233 outputs the reproduction signals of the gain control patterns 41-0, 41-1, ..., 41-N of the reproduction heads R-1, R-2, ..., RN. Based on, for example, the gains for the reproduction signals of the reproducing heads R-1, R-2,..., RN are calculated as follows, and the reproducing heads R-1, R-2,. ... Controls the level of the RN reproduction signal.

  For example, the reproduction signal gain control processing unit 233 adds the signals of the gain control patterns 41-0 and 41-1 respectively reproduced from the guard band # 1 and the track # 1 by the reproduction head R-1 in FIG. Similarly, the signals of the gain control patterns 41-0, 41-1, and 41-2 reproduced from the guard band # 1, the track # 1, and the track # 2 by the reproducing head R-2 are added. In this way, the reproduced gain control pattern signal is added to each of the reproducing heads R-1, R-2,..., RN.

  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 six calculation results obtained as described above, and uses this to select all reproduction heads R-1, R-2,. Reference output for N. The reproduction signal gain control processing unit 233 controls a value obtained by multiplying the input reproduction signal value for each reproduction head R-1, R-2,..., RN by 1 / (reference output). Output as a result.

  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.

(Reproduction signal selection unit 238)
Based on the identification information detected by the identification information detection unit 232, the reproduction signal selection unit 238 is a track that forms a unit from the reproduction signals of the reproduction heads R-1, R-2,. A number of reproduction signals are selected, and the signal separation calculation unit 236 is notified of information on the selection result.

  That is, the reproduction signal selection unit 238 first determines, based on the identification information detected by the identification information detection unit 232, for each reproduction signal of the reproduction heads R-1, R-2,. It is determined which drag or which guard band includes the reproduction signal. Next, the reproduction signal selection unit 238 determines a reproduction signal satisfying a predetermined non-selection condition from among the reproduction signals for each of the reproduction heads R-1, R-2,. A reproduction signal other than the reproduction signal that satisfies the non-selection condition is set as a selection result. Examples of the predetermined non-selection condition include that the reproduction signal includes a guard band and a track of a unit other than the unit to be reproduced. As described above, the identification information is expressed by the combination of the number for identifying the unit and the number for identifying the track and guard band in the unit, and therefore satisfies the above-mentioned non-selection condition based on the identification information. Judgment can be made.

  For example, in FIG. 7, the reproduction signal that is the output of the reproduction head R-1 satisfies the non-selection condition and is not selected by the reproduction signal selection unit 238. In FIG. 8, the reproduction signals output from the reproduction head R-1 and the reproduction head R-8 satisfy the non-selection condition, and are not selected by the reproduction signal selection unit 238. Note that the number of reproduction signals to be selected is equal to or greater than the number of tracks (N) constituting the unit. Therefore, in FIG. 7, since the number of tracks constituting the unit is six and the number of reproducing heads is seven, the reproduction signals of the reproducing heads R-2,. The reproduction signal selection unit 238 selects the reproduction signal. In FIG. 8, since the number of tracks constituting the unit is 6 and the number of reproducing heads is 8, reproducing heads R-2,..., R-7 other than the reproducing head R-1 and the reproducing head R-8. The reproduction signal selection unit 238 selects the reproduction signal.

  Further, the operation of the reproduction signal selection unit 238 will be described in detail with reference to FIGS.

  FIG. 9 is a diagram modeling the configuration of the data format shown in FIG. In the figure, reference numerals 23-0, 23-1,..., 23-7 denote, for example, a first preamble consisting of a gain control pattern, a synchronization pattern, an identification pattern, and the like, 44-1, 44-2,. .., 44-6 is a second preamble or separation pattern.

  FIG. 10 is a diagram showing a reproduction signal of the recording data of FIG. 9, and when there is no off-track, that is, reproduction heads R-2, R-3,. FIG. 8 is a diagram showing a reproduction signal of each track R-1, R-2,..., R-8 when the center of each coincides with the center of the corresponding track.

  At this time, the reproduction head R-1 causes the reproduction signal 1a of the first preamble of the guard band # 1, the reproduction signal 1b of the first preamble of the track # 1, and the reproduction signal of the first preamble of the adjacent unit to be small. 1c is obtained.

  By the reproducing head R-2, the reproduction signal 2a of the first preamble of the track # 1, the reproduction signal 2b of the first preamble of the guard band # 1, and the reproduction signal 2c of the first preamble of the track # 2 are small. Is obtained.

  The reproduction head R-3 generates a reproduction signal 3a of the first preamble of the track # 2, a reproduction signal 3b of the first preamble of the track # 1, and a reproduction signal 3c of the first preamble of the track # 3. can get.

  The reproduction head R-4 generates a reproduction signal 4a of the first preamble of the track # 3, a reproduction signal 4b of the first preamble of the track # 2, and a reproduction signal 4c of the first preamble of the track # 4. can get.

  The reproduction head R-5 generates a reproduction signal 5a of the first preamble of the track # 4, a reproduction signal 5b of the first preamble of the track # 3, and a reproduction signal 5c of the first preamble of the track # 5. can get.

  The reproduction head R-6 generates a reproduction signal 6a of the first preamble of the track # 5, a reproduction signal 6b of the first preamble of the track # 4, and a reproduction signal 6c of the first preamble of the track # 6. can get.

  By the reproducing head R-7, a reproduction signal 7a of the first preamble of the track # 6, a reproduction signal 7b of the first preamble of the track # 5, and a reproduction signal 7c of the first preamble of the guard band # 2 are small. Is obtained.

  The reproduction head R-8 generates a reproduction signal 8a of the first preamble of the guard band # 2, a reproduction signal 8b of the first preamble of the track # 6, and a reproduction signal 8c of the first unit having a small first preamble. can get.

  By the way, since the channel estimation calculation is performed using the separation patterns 44-1, 44-2,..., 44-6 arranged on each track constituting the unit, the channel obtained by this channel estimation calculation is used. In the signal separation process performed using the matrix, the reproduction signal of another unit as described above is equivalent to noise, and the quality of the reproduction signal obtained by the signal separation process is degraded. Therefore, in this embodiment, the reproduction signal selection unit 238 includes a reproduction signal other than the unit to be processed from among the reproduction signals for each of the reproduction heads R-1, R-2,. Only the unreproduced signal is notified to the signal separation calculation unit 236 that the signal separation processing is to be performed. For example, in the case of FIG. 10, since the reproduction signals of the reproducing head R-1 and the reproducing head R-8 include the reproduction signals 1c and 8c of the adjacent units, the reproducing heads R-2, R-3, R-4, R The reproduction signal selection unit 238 notifies the signal separation calculation unit 236 that the reproduction signals of −5, R-6, and R-7 are to be subjected to signal separation processing.

  FIG. 11 is a diagram showing reproduction signals of the reproducing heads R-1, R-2,..., R-8 when the off-track fluctuation of the reproducing head occurs.

  At this time, the reproduction head R-1 obtains the reproduction signal 1c of the first preamble of the adjacent unit and the reproduction signal 1a of the first preamble of the track # 1.

  A reproduction signal 2b of the first preamble of the guard band # 1 and a reproduction signal 2a of the first preamble of the track # 1 are obtained by the reproduction head R-2.

  The reproduction head R-3 obtains the reproduction signal 3b of the first preamble of the track # 1 and the reproduction signal 3a of the first preamble of the track # 2.

  The reproduction head R-4 obtains the reproduction signal 4b of the first preamble of the track # 2 and the reproduction signal 4a of the first preamble of the track # 3.

  The reproduction head R-5 obtains the reproduction signal 5b of the first preamble of the track # 3 and the reproduction signal 5a of the first preamble of the track # 4.

  The reproduction head R-6 obtains the reproduction signal 6b of the first preamble of the track # 4 and the reproduction signal 6a of the first preamble of the track # 5.

  The reproduction head R-7 obtains the reproduction signal 7b of the first preamble of the track # 5 and the reproduction signal 7a of the first preamble of the track # 6.

  The reproduction head R-8 obtains the reproduction signal 8b of the first preamble of the track # 6 and the reproduction signal 8a of the first preamble of the guard band # 2.

  In this case, since the reproduction signal of the reproduction head R-1 includes the reproduction signal 1c of the adjacent unit, the reproduction signals of the reproduction heads R-2,..., R-8 other than the reproduction head R-1 are signaled. The reproduction signal selection unit 238 notifies the signal separation calculation unit 236 that the signal is to be separated.

  The selection of the reproduction signal by the reproduction signal selection unit 238 is performed so that the reproduction signals of all the tracks constituting the unit are selected. In the example of FIG. 10, when the number of playback heads is larger than the number of tracks constituting the unit, the case where the number of playback signals excluding those including the playback signal of the adjacent unit matches the number of tracks has been described. If the number of playback signals excluding those containing the playback signal of the adjacent unit is less than the number of tracks, playback signals with less disturbance influence among those including the playback signal of the adjacent unit, for example, more output level The number of tracks may be satisfied by selecting a small reproduction signal.

  In the example of FIG. 11, seven reproduction signals are selected. However, it may be narrowed down to six reproduction signals that are the number of tracks by adding another selection condition. For example, among the reproduction heads for which reproduction signals have been selected, the reproduction signals at both ends, that is, reproduction heads R-2 and R-8 are compared with each other, and the reproduction signal with the higher output level is selected. . Alternatively, a reproduction signal of a reproduction head whose output level is significantly different from the others may be unselected.

  In the above description, the reproduction signal including the signal of the adjacent unit is determined based on the identification pattern. However, based on the position of the reproduction signal of the first preamble in the traveling direction of the track, regardless of the identification pattern. In addition, a reproduction signal including the signal of the adjacent unit may be determined.

  (About channel estimation calculation unit 234)

  The channel estimation calculation unit 234 identifies the head positions of the separation patterns 44-1, 44-2,..., 44-6 based on the synchronization pattern detected by the synchronization signal detection unit 231, and separates them. Reproduction signal for one unit whose level is controlled by the reproduction signal gain control processing unit 233 by performing channel estimation calculation based on the reproduction signals of the patterns 44-1, 44-2, ..., 44-6. A channel matrix necessary for separating the reproduction signal for each track is generated. At this time, since the channel estimation calculation unit 234 can know where the head of the separation pattern of each track is based on the identification information for each track detected by the identification information detection unit 232, The separation pattern can be discriminated with high accuracy from the reproduction signal, and channel estimation calculation can be performed with high accuracy.

  Furthermore, the channel estimation calculation unit 234 detects the separation patterns 44-1, 44-2,..., 44-6 for the reproduction signal selected by the reproduction signal selection unit 238. As a result, even if the separation pattern of the adjacent unit is reproduced due to the occurrence of a large off-track fluctuation, the adverse effect on the channel estimation calculation due to this can be avoided, and a more appropriate channel matrix is provided to the signal separation calculation unit 236. be able to.

  Here, a specific example of a method for obtaining the head position of the separation pattern of each track based on the identification information will be described with reference to FIG. In FIG. 12, for the sake of simplicity of explanation, the reproducing head width is equivalent to the track width, the number of tracks is three, the number of reproducing heads is three, and the guard band is ignored.

  In FIG. 12, 51-1 is a reproduction signal of the first preamble reproduced from the track # 1 by the reproduction head R-1, and 51-2 is a first preamble reproduced from the track # 2 by the reproduction head R-2. The reproduction signal 51-3 is a reproduction signal of the first preamble reproduced from the track # 3 by the reproduction head R-3. 52-1 is a reproduction signal of the second preamble reproduced from the track # 1 by the reproduction head R-1, and 52-2 is a reproduction of the second preamble reproduced from the track # 2 by the reproduction head R-2. A signal 52-3 is a reproduction signal of the second preamble reproduced from the track # 3 by the reproducing head R-3.

  Here, first, the first preamble of the track # 1 is reproduced. For example, “1_1” is obtained as the identification information of the track from the identification pattern included in the first preamble of the track # 1. Since this means the first track # 1 of the first unit, in this case, a predetermined amount of data for the track # 1 is detected from the detection end position of the first preamble of the track # 1. It is determined that the rear position is the head position of the second preamble of the track # 1. In the example of FIG. 8, a position that is 90 (10 + 30 + 10 + 30 + 10) data behind the detection end position of the first preamble of track # 1 is the head position of the second preamble of that track # 1.

  Next, the first preamble of track # 2 is reproduced. For example, it is assumed that “1_2” is obtained as the identification information of the track from the identification pattern included in the first preamble of the track # 2. Since this means the second track # 2 of the first unit, in this case, a predetermined amount of data for the track # 2 is detected from the detection end position of the first preamble of the track # 2. It is determined that the rear position is the head position of the second preamble of the track # 2. In the example of FIG. 8, a position 120 (10 + 30 + 10 + 60 + 10) data behind the detection end position of the first preamble of track # 2 is the head position of the second preamble of that track # 2.

  Next, the first preamble of track # 3 is reproduced. For example, “1_3” is obtained as the identification information of the track from the identification pattern included in the first preamble of the track # 3. Since this means the third track # 3 of the first unit, in this case, a predetermined amount of data for the track # 3 is detected from the detection end position of the first preamble of the track # 3. It is determined that the rear position is the head position of the second preamble of the track # 3. In the example of FIG. 8, a position that is 150 (10 + 60 + 10 + 60 + 10) data behind the detection end position of the first preamble of track # 3 is the head position of the second preamble of that track # 2.

  Thus, if the identification information is obtained, the head position of the separation pattern arranged behind the first preamble of the track or guard band can be accurately specified, and the reproduction signal of the subsequent separation pattern can be obtained. The channel estimation calculation based on the original can be performed with higher accuracy.

  (Reproduction position control processing unit 235)

  The reproduction position control processing unit 235 inputs a reproduction signal for each reproduction head whose level is controlled by the reproduction signal gain control processing unit 233, and reproduces the reproduction position based on the synchronization pattern detected by the synchronization signal detection unit 231. Processing for adjusting the reproduction position of the reproduction signal for each of the reproduction heads R-1, R-2,..., RN that has passed through the signal gain control processing unit 233 is performed. As a result, even if the reproduction positions of the respective reproduction signals fetched from the respective reproduction heads do not coincide with each other in the track traveling direction, the reproduction positions of the respective reproduction signals can be aligned and input to the signal separation calculation unit 236. , Stable data reproduction can be performed.

  (About the signal separation calculation unit 236)

  The signal separation calculation unit 236 passes through the reproduction position control processing unit 235 by a predetermined calculation process based on the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel estimation calculation unit 234. A process of separating the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit 238 is performed. Thereby, even if the recording data of the adjacent unit is reproduced due to the occurrence of a large off-track fluctuation, the influence on the signal separation process can be reduced, so that the deterioration of the data reproduction quality can be reduced.

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

  As described above, according to this embodiment, even when the signal of the track of the adjacent unit is reproduced due to a large off-track fluctuation at the time of data reproduction, for example, reproduction other than the reproduction head that reproduced the track of the adjacent unit is performed. By performing computation processing such as channel estimation computation and signal separation computation on the head playback signal, data playback can be performed more stably.

  Further, according to this embodiment, even if the signal of the track of the adjacent unit is reproduced, the influence on the quality of data reproduction can be reduced, so that the reproduction width on the medium by the reproduction head can be set wide. it can. Therefore, even if a large off-track fluctuation occurs during reproduction, it is possible to avoid a problem that the signal of the end track in the unit leaks from reproduction or is not reproduced at a sufficient level, and the tolerance to off-track fluctuation can be increased. .

  In the above embodiment, the first preamble is arranged in the guard band. However, if it can be detected that the track of the adjacent unit is being reproduced, the first preamble is always provided in the guard band. There is no need to place. It is possible to reproduce the track of the adjacent unit by, for example, detecting an identification pattern included in the first preamble of the track of the adjacent unit.

  In the above embodiment, the track is identified based on the identification pattern of the first preamble. However, the internal unit also depends on the positional relationship between the tracks of the gain control pattern, the synchronization pattern, or the separation pattern. In the configuration of the present invention, the identification pattern is not always essential. Further, a plurality of types of patterns may be prepared in the synchronization pattern so that the tracks in the unit can be identified, and identification information may be associated with each type of the synchronization pattern.

  Moreover, the amount of information for gain control may be increased by additionally arranging a gain control pattern arranged in the first preamble 23 behind the synchronization pattern.

  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 44-1 shown in FIG. 7 or the like is used as a pattern necessary for detecting the positional relationship in the track width direction during reproduction between each reproduction head and a plurality of tracks for one unit. , 44-2,..., 44-6 are used, but the present invention is not limited to this, and for example, tracking servo information can be used. In this case, a summary of the positional relationship between each recording pattern of the tracking servo information and each reproducing head in units is generated as channel estimation information.

  Further, the channel estimation calculation may be performed using both the means for detecting the positional relationship using the separation pattern and the means for detecting the positional relationship using the tracking servo information.

  Furthermore, in the above embodiment, the case of calculating a 6 × 6 channel matrix has been described, but it is possible to perform signal separation processing by obtaining a generalized inverse matrix of other square matrices. is there. Furthermore, a generalized inverse matrix may be obtained in the same manner for a matrix other than a square matrix.

  Note that the type of separation pattern needs to correspond to the number of tracks in order to obtain a generalized inverse matrix.

  The separation pattern is a pattern having the number of tracks that are primary independent of each other.

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

  In the above embodiment, the recording apparatus of FIG. 1 has one recording head W-0 for recording as a guard band, but this is added further outside the recording head W-6. A recording head for recording as the second guard band may be provided, and for example, in the recording as shown in FIG. 6, the recording of the guard band # s + 1 may be performed more efficiently.

  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, as a second embodiment of the present invention, another reproducing apparatus capable of reproducing a signal from the magnetic recording medium 2 recorded by the recording apparatus of the first embodiment without aligning the reproducing position for each track. Will be described.

  FIG. 13 is a diagram showing the configuration of the playback apparatus 201 according to the second embodiment.

  As shown in the figure, in this playback apparatus 201, only the configuration of the signal separation processing unit 230 is different from the playback apparatus 200 of the first embodiment shown in FIG.

  The signal separation processing unit 230 includes a synchronization signal detection unit 231, an identification information detection unit 232, a reproduction signal gain control processing unit 233, a channel estimation calculation unit 234, a reproduction position control processing unit 235, a signal separation calculation unit 236, and a reproduction signal selection unit. 238 and a channel matrix estimation unit 239.

  The channel matrix estimation unit 239 uses the information from the reproduction signal selection unit 238 and a plurality of channel matrices respectively obtained by channel estimation calculation using a plurality of preambles sandwiching data on the track, and Estimate a variable channel matrix within the data interval.

  FIG. 14 is a flowchart showing a flow of unit playback operation of the playback apparatus 201.

  In this reproducing apparatus 201, first, the magnetic recording medium 2 is constituted by N reproducing heads R-1, R-2,..., RN that can reproduce signals from one or more adjacent tracks. A signal is reproduced from M tracks of one unit (step S301).

  Next, the amplitude levels of the outputs of the reproduction amplifiers 221-1, 221-2,..., 221-N are adjusted by the gain adjusting units 224-1, 224-2,. Then, the A / D converters 225-1, 225-2,..., 225-N are converted into digital values and output to the synchronization signal detection unit 231 (step S302).

  Next, the reproducing heads R-1, R-2,..., RN output from the A / D converters 225-1, 225-2,. A synchronization pattern in the preamble of each reproduction signal is detected (step S303).

  Next, by using the synchronization pattern detected by the synchronization signal detection unit 231 by the identification information detection unit 232, the identification pattern in the reproduction signal for each of the reproduction heads R-1, R-2,. An identification pattern is detected by specifying the head position, and identification information corresponding to the detected identification pattern is output (step S304).

  Next, the reproduction signal gain control processing unit 233 detects the gain control pattern in the preamble from the reproduction signal for each of the reproduction heads R-1, R-2,..., RN, and uses this gain control pattern. Then, the gain for the reproduction signal for each reproduction head R-1, R-2,..., RN is calculated, and reproduction for each reproduction head R-1, R-2,. The level of the signal is controlled (step S305).

  Next, based on the identification information detected by the identification information detection unit 232 by the reproduction signal selection unit 238, a predetermined value is obtained from the reproduction signal for each of the reproduction heads R-1, R-2,. In accordance with the selection condition, at least the reproduction signals of the number of tracks constituting the unit are selected, and information on the selection result is notified to the channel estimation calculation unit 234 and the signal separation calculation unit 236 (step S306).

  Next, the channel estimation calculation unit 234 uses the information from the reproduction signal selection unit 238, the synchronization pattern detected by the synchronization signal detection unit 231, and the identification information detected by the identification information detection unit 232, The head position of the separation pattern included in the preamble of each reproduction signal selected by the reproduction signal selection unit 238 is specified, and a channel matrix is calculated by channel estimation calculation using these separation patterns (step S307).

  Next, the channel matrix estimation unit 239 uses a plurality of channel matrices obtained by channel estimation calculation using information from the reproduction signal selection unit 238 and separation patterns in a plurality of preambles that are continuous across the data on the track. Are used to estimate a variable channel matrix within the data interval (step S308).

  Next, the reproduction heads R-1, R-2,... That have passed through the reproduction signal gain control processing unit 233 using the synchronization pattern detected by the synchronization signal detection unit 231 by the reproduction position control processing unit 235. The reproduction position of the reproduction signal for each RN is matched (step S309).

  Next, the signal separation calculation unit 236 uses the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel matrix estimation unit 239 to pass through the reproduction position control processing unit 235 by a predetermined calculation process. Then, a process of separating the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit 238 is performed (step S310).

  Thereafter, the multi-track demodulator 240 decodes the data string from the reproduction signal separated for each track (step S311 and the restoration unit 260 concatenate the data of each track to obtain reproduction data 3). (Step S312).

  FIG. 15 is a conceptual diagram of another data format on the magnetic recording medium 2 on which recording is performed by the recording apparatus 100 shown in FIG.

  This data format is obtained by repeating the unit-unit recording operation on the magnetic recording medium 2 by the recording apparatus 100 so that a plurality of units are continuously arranged in the track traveling direction. . For simplicity of explanation, the number of tracks constituting one unit is three.

  Track # 1, track # 2, and track # 3 are tracks recorded on the magnetic recording medium 2 by M (M = 3) recording heads of the recording apparatus 100, respectively. Preamble 21 (1), 21 (2),... And data 22 (1), 22 (2),... Are recorded in track # 1, track # 2, and track # 3, respectively. As described above, the preamble 21 (1) includes a gain control pattern, a synchronization pattern, an identification pattern, and a separation pattern as information necessary for control for reproducing the data 22 (1). The same applies to (2),.

  Here, a unit 51 as a unit of signal processing for reproducing data is a group of M preambles 21 and M data 22 in each of M tracks # 1, # 2, and # 3. (1), 51 (2),..., 51 (E). A group of M tracks # 1, # 2, and # 3 is hereinafter referred to as a “unit configuration track sequence”, and 54 is given as a symbol.

  In the unit configuration track row 54, a plurality of units 51 (1), 51 (2),..., 51 (E) are continuously arranged in the track traveling direction. In this embodiment, for example, two channel matrices respectively obtained by channel estimation calculation based on a plurality of preambles 21 that are continuous across the data 22 on the track, for example, reproduction signals of separated patterns in the two preambles 21. Therefore, a plurality of channel matrices corresponding to the respective sections obtained by dividing the section of the data 22 are estimated as variable channel matrices in the section of the data 22. For this reason, the preamble 21 (E + 1) is also added after the last data 22 (E) of each of M tracks # 1, # 2, and # 3.

  In the magnetic recording medium 2, S unit configuration track rows 54 are arranged in parallel to each other, and there is an area in which nothing is recorded called a guard band 52 between adjacent unit configuration track rows 54. Is provided.

  FIG. 16 is a diagram showing an example of off-track fluctuation of each reproducing head R-1, R-2,..., R-5 on the format shown in FIG. 15 in order to explain the problem in the present invention. .

  Assuming that the moving direction of the reproducing heads R-1, R-2,..., R-5 is the direction indicated by the arrow 13, the preamble is obtained from each track # 1, # 2, # 3 and guard bands # 1, # 2. , Preamble 21 (n) and preamble 21 (n + 1) in this order. When the tracking becomes unstable during reproduction, for example, due to disturbance or the like, the reproduction heads R-1, R-2,..., R-5 and the tracks # 1, # 2 are located at the position of the preamble 21 (n). , # 3 is appropriate, but the position of the preamble 21 (n + 1) may deviate from the proper positional relationship. In the example of FIG. 16, the positional relationship between each reproduction head R-1, R-2,..., R-5 and each track # 1, # 2, # 3 is appropriate at the position of the preamble 21 (n + 1). A state in which 100% of the track width is deviated from the normal state is shown in the lower part of the figure. In such a case, the separation signal obtained using the separation pattern in the preamble 21 (n) can obtain good quality only in a limited portion in the first half of the data 22 (n) section. Here, the reproducing heads R-1, R-2,..., R-5 have been described as moving, but the reproducing heads R-1, R-2,. The same applies to the case where the magnetic recording medium 2 moves in the direction of the arrow 14.

  Therefore, in this embodiment, the section of the data 22 (n) between the two preambles 21 (n) and 21 (n + 1) is divided into k. In this example, k = 3. A section obtained by combining the foremost divided section of the section of the data 22 (n) and the section of the data 22 (n-1) ahead of the preamble 21 (n) having the same length as this is defined as a T1 section. Similarly, a section obtained by combining a rearmost divided section of the section of the data 22 (n) and a section of the data 22 (n + 1) behind the preamble 21 (n + 1) having the same length as this is a T3 section. The remainder of the section of the data 22 (n) is set as a T2 section.

  The channel matrix estimation unit 239 uses the two channel matrices respectively obtained by the channel estimation calculation from the separation patterns in the two preambles 21 (n) and 21 (n + 1), for example, by linear interpolation or the like. A channel matrix corresponding to each of the sections T1, T2, and T3 is estimated.

  In this example, the preconditions for estimating the channel matrix are shown. The maximum value used for the channel matrix is 1.0, and the minimum value is 0.0. For example, in the estimation calculation, when the value of the channel matrix is less than 0.0, it is fixed to 0.0, and when it exceeds 1.0, it is fixed to 1.0. In addition, the width of the reproducing heads R-1, R-2,..., R-5 is 1.5 times the track width, and the individual reproducing heads R-1, R-2,. Each signal can be reproduced from a plurality of tracks.

  The channel matrix estimation unit 239 uses the channel matrix obtained by the channel estimation calculation from the playback signal of the preamble 21 (n) as it is as the estimation result of the channel matrix 34 in the T1 interval. Further, the channel matrix estimation unit 239 uses the channel matrix obtained by the channel estimation calculation from the playback signal of the preamble 21 (n + 1) as it is as the estimation result of the channel matrix 35 in the T3 section. Then, the channel matrix estimation unit 239 estimates the channel matrix 36 of the T2 section by linear interpolation from the channel matrix 34 of the T1 section and the channel matrix 35 of the T3 section.

  The signal separation processing by the signal separation calculation unit 234 is performed for each of the sections T1, T2, and T3. At this time, in each channel matrix estimated for each section of T1, T2, and T3, only the reproduction signal selected by the reproduction signal selection unit 238 is validated, so that it is selected by the reproduction signal selection unit 238. A channel matrix indicating the positional relationship of each reproduction signal with respect to each track is generated, and a predetermined calculation process is performed from the reproduction signal selected by the reproduction signal selection unit 238 using this channel matrix. Separate the playback signal for each track.

  For example, in FIG. 16, in the section T1, the reproduction signals of the reproduction heads R-3, R-4, and R-5 are selected by the reproduction signal selection unit 238, and these reproduction heads R-3, R-4, and R- A signal separation process is performed on the reproduced signal No. 5. In the T2 section, the reproduction signals of the reproduction heads R-2, R-3, R-4, and R-5 are selected by the reproduction signal selection unit 238, and these reproduction heads R-2, R-3, R-4, Signal separation processing is performed on the reproduced signal of R-5. In the T3 section, the reproduction signals of the reproduction heads R-2, R-3, and R-4 are selected by the reproduction signal selection unit 238, and the reproduction signals of these reproduction heads R-2, R-3, and R-4 are selected. The signal separation process is performed.

  As described above, according to the present embodiment, based on a plurality of channel matrices respectively obtained as a result of channel estimation calculation from a plurality of preamble reproduced signals sandwiching data, within the section of the data. A variable channel matrix is estimated by using the variable channel matrix, and the reproduction signal for each track is separated from the reproduction signal of each reproduction head by one unit, thereby performing the process for each reproduction head and one unit. Even when the positional relationship with each track in the track width direction deviates from an appropriate state due to off-track fluctuation due to disturbance or the like, data reproduction can be performed satisfactorily. In this case as well, by removing the reproduction signal of the adjacent unit from the target of signal separation processing, data reproduction can be performed more stably, and high track density can be realized.

  In the above, variable in the data section reflecting the state of off-track fluctuation from the two channel matrices obtained by channel estimation calculation based on the reproduction signal of the separation pattern in the preamble in two consecutive units. The channel matrix is estimated from the three or more channel matrices obtained by the channel estimation calculation based on the reproduction signal of the separation pattern in the preamble in three or more consecutive units. A variable channel matrix may be estimated for each section and used for signal separation processing. In addition, as a channel matrix interpolation method by the channel matrix estimation unit 239, a method other than linear interpolation may be used. Further, the lengths of the sections T1, T2, and T3 are not necessarily equal. The number of sections is not necessarily three. Furthermore, the plurality of preambles to be referred to do not necessarily have to be continuous, and it is sufficient that information for performing channel estimation calculation can be obtained.

  Further, the data section between the two preambles 21 (n) and 21 (n + 1) is divided into two, and signal separation processing is performed using the channel matrix obtained from the separation pattern in the preamble 21 (n) in the front section. In the rear section, signal separation processing may be performed using a channel matrix obtained from the separation pattern in the preamble 21 (n + 1). Therefore, in this method, channel matrix interpolation by the channel matrix estimation unit 239 is not necessary.

  Further, the data section between the two preambles 21 (n) and 21 (n + 1) is not divided, and the channel matrix obtained from the reproduction signal of the separation pattern in the preamble 21 (n) and the separation in the preamble 21 (n + 1). A separation process may be performed by selecting a channel matrix obtained from the reproduction signal of the pattern under a predetermined condition. Also in this case, channel matrix interpolation by the channel matrix estimation unit 239 is not necessary.

  The present invention regenerates a channel matrix suitable for the system and the situation at that time from a predetermined plurality of channel matrices, and uses this to reproduce data more satisfactorily.

  In the present invention, the configuration of the preamble 21 is not limited to that shown in the figure, and any structure can be used as long as it can be used for channel matrix calculation.

FIG. 17 is a diagram showing a modification of the data format of FIG. In the data format of FIG. 15 described above, two channel matrices respectively obtained by channel estimation calculation from separation patterns in two preambles 21 (n) and 21 (n + 1) continuous across data 22 (n). Is used to estimate a variable channel matrix within the section of data 22 (n). For example, a plurality of preambles arranged ahead of data 22 (n + 1), that is, preambles 21 (n), The same effect can be obtained by estimating a variable channel matrix within the section of data 22 (n + 1) using two channel matrices obtained by channel estimation calculation from the reproduction signal of the separation pattern within 21 (n + 1). I can expect. In such a case, the preamble 21 (E + 1) after the last data 22 (E) in FIG. 15 is not necessary. In this case, signal separation processing can be performed even if the reproduction signals of the preamble 21 and the data 22 are not stored in the storage unit of the signal separation processing unit 230.
(Third embodiment)

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

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

  FIG. 18 is a diagram showing the configuration of the recording apparatus 300 in the magnetic recording / reproducing system of the third embodiment.

  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. In this embodiment, M <N.

  As shown in the figure, the recording apparatus 300 includes a multitrack 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 guard band recording unit. 190.

  The multi-track recording encoding unit 120 includes M recording encoding units 121-1, 121-2,..., 121-M 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, 131-2, 131-2, and 1312 that add a preamble necessary for data reproduction control to each recording data encoded by the multitrack recording encoding unit 120. ..., 131-M, and a storage unit 132 for storing a code string of recording data to which a preamble for each track is added.

  The guard band recording unit 190 adds an erase signal generating unit 161 that generates an erase signal, and a guard band preamble including a synchronization pattern and an identification pattern to the code sequence of the erase signal output from the erase signal generating unit 161. It includes a preamble adding unit 131-0 and a storage unit 162 that stores an erase signal to which a guard band preamble is added.

  The multitrack recording unit 140 includes a switching unit 148 that selects a recording code string to be read from the storage unit 132 and the storage unit 162, and one output timing setting unit that gives a desired timing to the recording code string selected by the switching unit 148. 141, one recording compensation unit 144 that performs the recording compensation process, and one recording amplifier 147 that drives the recording head W-1 based on the recording code string after the recording compensation process.

  FIG. 19 is a flowchart showing a flow of operations of the recording apparatus 300 during unit and guard bank recording.

  In the recording apparatus 300, first, the process is branched depending on whether a recording code string for a track or a recording code string for a guard band is generated (step S301). If the process to be performed is generation of a recording code string for a track, the input recording data 1 is distributed to data of the number of tracks for one unit by the multitrack unit 110 (step S302).

  Each of the distributed data is encoded in consideration of the recording / reproduction characteristics of the magnetic recording medium 2 by the recording encoding units 121-1, 121-2, ..., 121-M of the multitrack recording encoding unit 120, respectively. Encoded into a column. At this time, information necessary for data demodulation such as a synchronization pattern for demodulation is also added to the code string (step S303).

  Next, the preamble adding units 131-1, 131-2,..., 131-M of the multi-track preamble adding unit 130 control the data reproduction at predetermined positions of the encoded recording data. A necessary preamble pattern is added to obtain a recording code string for a track (step S304). The track recording code string generated in this way is stored in the storage unit 132 (step S305).

  If the process to be performed is generation of a guard band recording code string, an erasure signal for a predetermined unit is generated from the erasure signal generation unit 161 of the guard band recording unit 190 (step S306), and the preamble addition unit 131. As a result of −0, a guard band preamble including a synchronization pattern and an identification pattern is added to the erasure signal (step S307) and stored in the storage unit 162 as a guard band recording code string (step S308).

  Thereafter, the switching unit 148 performs one recording code sequence in a predetermined order from the track recording code sequence for each track stored in the storage unit 132 and the guard band recording code sequence stored in the storage unit 162. Is read (step S309). Next, after a desired timing is given by the output timing setting unit 141 to the read track recording code sequence or guard band recording code sequence (step S310), the recording compensation unit 144 A recording compensation process for optimizing the recording on the magnetic recording medium 2 is performed. The recording amplifier 147 converts the voltage into a current, and the recording head W-1 records the magnetic recording medium 2 (step S311). ).

  Thereafter, it is determined whether or not the recording of the track and guard band for one unit has been completed (step S312). If the recording has not been completed (NO in step S312), the recording head W-1 is moved to the next position. (Step S313). Next, the process returns to step S309, and the recording code string for the track or the recording code string for the guard band is read from the storage unit 132 or the storage unit 162, and similarly the process of recording on the magnetic recording medium 2 is repeated. The above operation is repeated until recording of a track for one unit is completed.

  For example, when the data format shown in FIG. 6 is used, the guard band # 1 is recorded first, then moved to the position of the track # 1, and the track # 1 is recorded. , Move to the position of track # 2,..., # 6 to record the track. The guard band # 2 is recorded in the recording cycle of the next unit.

  Next, a modified example of the recording apparatus 300 will be described.

  FIG. 20 is a diagram illustrating a configuration of a recording apparatus 301 that is a modification of the recording apparatus 300 of FIG.

  As shown in the figure, the recording apparatus 301 is different from the recording apparatus 300 in FIG. 18 in the configuration of a multitrack recording encoding unit 120 and a multitrack preamble adding unit 130. The multi-track recording encoding unit 120 is composed of one 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 multi-track preamble adding unit 130 includes One preamble adding unit 131 for adding a preamble pattern necessary for data reproduction control to recording data encoded for each track, and a storage unit for storing a recording code string for the track to which the preamble is added 132. Further, in this recording apparatus 301, the multitracking unit 110 (data distributor 111) is omitted from the configuration of the recording apparatus 300 shown in FIG.

  FIG. 21 is a flowchart showing a flow of operations of the unit and guard band recording of the recording apparatus 301.

  The recording apparatus 301 first branches the process depending on whether the process to be performed is to generate a recording code string to be recorded as a track or to generate a recording code string to be recorded as a guard band (step S321). When the process to be performed is generation of a recording code string to be recorded as a track, the recording encoder 121 records and reproduces recording data for a predetermined unit, for example, recording data for a predetermined number of tracks, on the magnetic recording medium 2. Each is encoded into a code string in consideration of characteristics. At this time, information necessary for data demodulation, such as a demodulation synchronization pattern, is also added to the code string of the recording data (step S322).

  Next, a preamble pattern necessary for data reproduction control is added to a predetermined position of each encoded recording data by a preamble adding unit 131, and a recording code string for a predetermined unit of track is recorded. Is obtained (step S323). In this way, the recording code string for the track of a predetermined unit to which the preamble is added is stored in the storage unit 132 (step S324).

  When the process to be performed is generation of a recording code string to be recorded as a guard band, an erasure signal for a predetermined unit is generated from the erasure signal generation unit 161 of the guard band recording unit 190 (step S325), and a preamble addition unit By 131-0, a guard band preamble including a synchronization pattern and an identification pattern is added to the code string of the erasure signal (step S326) and stored in the storage unit 162 as a guard band recording code string ( Step S327).

  Thereafter, the switching unit 148 performs one recording code sequence in a predetermined order from the track recording code sequence for each track stored in the storage unit 132 and the guard band recording code sequence stored in the storage unit 162. Is read (step S328). Next, after a desired timing is given by the output timing setting unit 141 to the read recording code sequence for the track or the recording code sequence for the guard band (step S329), the recording compensation unit 144 A recording compensation process for optimizing the recording on the magnetic recording medium 2 is performed, the voltage is converted from a voltage to a current by the recording amplifier 147, and is recorded on the magnetic recording medium 2 by the recording head W-1 (step S330). ).

  Thereafter, it is determined whether or not the recording of the track and the guard band for one unit has been completed (step S331). If the recording has not been completed (NO in step S331), the recording head W-1 is moved to the next position. (Step S332). Thereafter, the process returns to step S328, and the recording code string for the track or the recording code string for the guard band is read from the storage unit 132 or the storage unit 162, and similarly, the process of recording on the magnetic recording medium 2 is repeated. The above operation is repeated until recording of a track for one unit is completed.

  For example, when the data format shown in FIG. 6 is used, the guard band # 1 is recorded first, then the track # 1 is moved to the position of the track # 1, and thereafter the recording is performed in the same manner. Move to the position of track # 2,..., # 6 and record the track. The guard band # 2 is recorded in the recording cycle of the next unit.

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

  FIG. 22 is a diagram showing a configuration of a reproducing apparatus 400 in the magnetic recording / reproducing method according to the third 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, a restoration unit 260, and a tracking control unit 270.

  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 channel estimation calculation unit 234, a reproduction position control processing unit 235, a signal separation calculation unit 236, a storage unit 237, A reproduction signal selection unit 238 and a channel matrix estimation unit 239 are provided.

  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 a gain control pattern in the preamble from the reproduction signal of the reproduction head R-1 for each scan that has passed through the identification information detection unit 232, and scans based on the gain control pattern. The gain for the reproduction signal of each reproduction head R-1 is calculated to control the level of the reproduction signal of the reproduction head R-1 for each scan.

  Based on the identification information detected by the identification information detection unit 232, the reproduction signal selection unit 238 determines at least the number of tracks constituting the unit from the reproduction signal of the reproduction head R-1 for each scan according to a predetermined selection condition. A reproduction signal is selected, and information on the selection result is notified to the channel estimation calculation unit 234 and the signal separation calculation unit 236.

  The channel estimation calculation unit 234 uses the information from the reproduction signal selection unit 238, the synchronization pattern detected by the synchronization signal detection unit 231, and the identification information detected by the identification information detection unit 232. The head position of the separation pattern included in the preamble of the reproduced signal for each scan selected by 238 is specified, and the channel matrix is calculated by channel estimation calculation using these separation patterns.

  The channel matrix estimation unit 239 uses the information from the reproduction signal selection unit 238 and a plurality of channel matrices respectively obtained by channel estimation calculation using a plurality of preambles sandwiching data on the track, and Estimate a variable channel matrix within the data interval.

  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 information obtained by the synchronization signal detection unit 231. I do.

  The signal separation calculation unit 236 passes through the reproduction position control processing unit 235 by a predetermined calculation process based on the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel matrix estimation unit 239, A process of separating the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit 238 is performed.

  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.

  The storage unit 237 is disposed between the identification information detection unit 232 and the reproduction signal gain control processing unit 233, and stores a reproduction signal for at least one unit.

  As shown in FIG. 4, the multi-track demodulating unit 240 performs M equalizers 241-1 and 241 that perform equalization processing on the reproduction signal for each track separated by the signal separation operation unit 236. ,... 241-M and M PLLs 242-1, 242-2, which perform bit synchronization from the outputs of the equalizers 241-1, 241-2,. .., 242 -M and the bit synchronization signal generated by PLLs 242-1, 242-2,..., 242 -M, and binarize the reproduction signal for each track to generate a code string, for example Binarization that is an output of M detection units 243-1, 243-2,..., 243-M and detection units 243-1, 243-2,. M synchronization signal detections for detecting a synchronization signal on the code string from the reproduced signal , 244-M and the synchronization signal detection units 244-1, 244-2,... M decoders 245-1, 245-2,..., 245 -M that specify positions and decode data strings from code strings. 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. 22, the restoration unit 260 records the data of each track output from the M decoders 245-1, 245-2,..., 245-M in the multitrack demodulation unit 240 at the time of recording. And a data combiner 261 that restores the reproduced data 3 by connecting them in the reverse operation.

  Note that the track tracing during reproduction by the single head is repeated at least as many times as the number of recording tracks of one unit. That is, the tracing may be repeated more times than the number of tracks. At that time, all tracks for one unit are traced at least once. The storage unit 237 stores a signal for 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.

  FIG. 23 is a flowchart showing the unit playback operation of the playback apparatus 400.

  In this reproducing apparatus 400, first, signals are reproduced from one or more 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 adjustment unit 224, the output is converted into a digital value by the A / D converter 225 and output to the synchronization signal detection unit 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 specifying the head position of the identification pattern in the reproduction signal of the reproducing head R-1, and identification information corresponding to the detected identification pattern is output (step S1). 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 S407), 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, based on the reproduction signal of the gain control pattern in the preamble for one unit stored in the storage unit 237, The gain for the reproduction signal of the reproduction head R-1 for each scan is calculated, and the level of the reproduction signal of the reproduction head R-1 for each scan is controlled (step S408).

  Next, based on the identification information detected by the identification information detection unit 232, the reproduction signal selection unit 238 configures at least a unit from the reproduction signal of the reproduction head R-1 for each scan according to a predetermined selection condition. The reproduction signal of the number of tracks is selected, and information on the selection result is notified to the channel estimation calculation unit 234 and the signal separation calculation unit 236 (step S409).

  Next, the channel estimation calculation unit 234 uses the information from the reproduction signal selection unit 238, the synchronization pattern detected by the synchronization signal detection unit 231, and the identification information detected by the identification information detection unit 232, The head position of the separation pattern included in the preamble of each reproduction signal selected by the reproduction signal selection unit 238 is specified, and a channel matrix is calculated by channel estimation calculation using these separation patterns (step S410).

  Next, the channel matrix estimation unit 239 uses the information from the reproduction signal selection unit 238 and a plurality of separation patterns in a plurality of preambles consecutively sandwiching data on a track, respectively, to obtain a plurality of channel estimation operations. Using the channel matrix, a variable channel matrix is estimated within the section of the data (step S411).

  Next, in the reproduction position control processing unit 235, based on the synchronization pattern detected by the synchronization signal detection unit 231, the reproduction signal of the reproduction head R-1 for each scan that has passed through the reproduction signal gain control processing unit 233 is displayed. Processing for adjusting the reproduction position is performed (step S412).

  Next, the signal separation calculation unit 236 uses the information from the reproduction signal selection unit 238 and the channel matrix obtained by the channel matrix estimation unit 239 to pass through the reproduction position control processing unit 235 by a predetermined calculation process. Then, a process of separating the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit 238 is performed (step S413).

  After this, the multi-track demodulator 240 decodes the data sequence from the reproduction signal separated for each track (step S414), and the reconstruction unit 260 concatenates the data for each track to generate the reproduction data 3. Is obtained (step S415).

  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 detection unit 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. 24 is a conceptual diagram of a data format recorded 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. Also in the helical scan method, the guard band 52 is arranged between the unit configuration track rows 54 composed of the track # 1, the track # 2, and the track # 3.

  The preamble 21 recorded on the track # 1, the track # 2, and the track # 3 may be the same as those shown in FIGS. 7 and 8, for example. 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. 25 is a conceptual diagram of a data format recorded on a recording medium by a double azimuth method and a helical scan method using a plurality of recording heads W-1, W-2,..., W-6.

  In this example, six recording heads W-1, W-2,..., W-6 are used for recording and reproduction, respectively. Among 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 track magnetization. The azimuth direction, which is the 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 54 including a plurality of units which are one unit of processing for reproducing data. In the case of this double azimuth, no guard band is required.

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

  The preamble recorded in each track # 1- # 6 may be the same as that shown in FIGS. 7 and 8, for example. 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. 6 is a flowchart showing the unit and guard band recording operation 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. It is a conceptual diagram of the data format on the magnetic recording medium with which recording was performed by the recording device of FIG. FIG. 7 is a diagram showing the details of the data format of FIG. 6 and the arrangement of each reproducing head in the reproducing head array. FIG. 7 is a diagram illustrating another example of the details of the data format in FIG. 6 and the arrangement of each reproducing head in the reproducing head array 150. It is the figure which modeled the structure of the data format shown in FIG. FIG. 10 is a diagram illustrating output of a reproduction signal for the recording data in FIG. 9 when there is no off-track fluctuation of the reproduction head. It is a figure which shows the reproduction signal of each reproducing head when the off-track fluctuation | variation of the reproducing head has generate | occur | produced. It is a figure for demonstrating the method of obtaining the head position of the separation pattern of each track | truck based on identification information. It is a figure which shows the structure of the reproducing | regenerating apparatus which is the 2nd Embodiment of this invention. It is a flowchart which shows the flow of operation | movement of the unit reproduction | regeneration by the reproducing | regenerating apparatus of FIG. It is a conceptual diagram of another data format on the magnetic recording medium with which recording was performed by the recording device of FIG. FIG. 16 is a diagram showing an example of off-track fluctuation of each reproducing head on the format shown in FIG. 15. It is a figure which shows the modification of the data format of FIG. It is a figure which shows the structure of the recording device in the magnetic recording / reproducing system of the 3rd Embodiment of this invention. It is a flowchart which shows the flow of operation | movement of the unit of the recording device of FIG. 18, and guard band recording. It is a figure which shows the structure of the modification of the recording device of FIG. FIG. 21 is a flowchart showing a flow of operations of the unit and guard band recording of the recording apparatus of FIG. 20. FIG. It is a figure which shows the structure of the reproducing | regenerating apparatus in the magnetic recording and reproducing system which is the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement of unit reproduction | regeneration of the reproducing | regenerating apparatus of FIG. It is a conceptual diagram of a data 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 data 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. 29 is a flowchart showing a flow of unit playback operation of the playback apparatus of FIG. 28. 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 41-0, 41-1, ..., 41-7 Gain control pattern 42-0, 42-1, ..., 42-7 Synchronization pattern 43-0, 43-1, ..., 43-7 Identification pattern 44-1, 44-2, ..., 44-6 Separation pattern 51 Unit 52 Guard band 100 Recording Device 110 Multitracking section 111 Data distributor 120 Multitrack recording encoding section 121-1, 121-2, ..., 121-M Recording encoding section 130 Multitrack preamble adding sections 131-1, 131-2, , 131-M preamble adding unit 140 multitrack recording units 141-1, 141-2,. , 144-M recording compensation units 147-1, 147-2,..., 147-M recording amplifier 148 switching unit 150 recording head array 160 guard band recording Unit 161 erasure signal generation unit 131-0 preamble addition unit 141-0 output timing setting unit 144-0 recording compensation unit 147-0 recording amplifier 200 playback device 210 playback head array 220 channel playback units 221-1, 221-2,. .., 221-N reproduction amplifiers 224-1, 224-2,..., 224-N gain adjustment units 225-1, 225-2,..., 225-N A / D converter 230 signal separation processing unit 231 Synchronization signal detection unit 232 Identification information detection unit 233 Playback signal gain control processing unit 234 Channel estimation calculation unit 235 Playback position control Control unit 236 Signal separation calculation unit 237 Storage unit 238 Playback signal selection unit 239 Channel matrix estimation unit 240 Multitrack demodulation unit 260 Restoration unit 261 Data combiner 270 Tracking control unit W-0 Recording head W-1 for guard band recording , W-2,..., WM Recording heads R-1, R-2,.

Claims (15)

A unit which is a unit of signal processing for data reproduction is constituted by a plurality of tracks, and each unit is arranged to be shifted from each other in the traveling direction of the track. Different from each other in the width direction of the track with respect to the unit by using a reproducing head arranged across a plurality of the tracks from a recording medium on which a preamble having an identification pattern including information for identification is arranged An apparatus for obtaining a plurality of reproduction signals larger than the number of tracks constituting the unit in a positional relationship and reproducing the data,
Playback that selects a plurality of playback signals that satisfy the signals of all the tracks that constitute the unit that is the target of data playback, based on the preamble, from a plurality of playback signals that are larger than the number of tracks that constitute the unit. A signal selector;
A data reproducing apparatus comprising: an arithmetic unit that performs processing for separating a reproduction signal for each track from the plurality of reproduction signals selected by the reproduction signal selection unit. The data reproducing apparatus according to claim 1, wherein
The reproduction signal selection unit is configured such that a reproduction signal excluding a reproduction signal including a signal of a unit other than the unit that is a target of data reproduction uses a reproduction signal of all tracks constituting the unit that is a target of the data reproduction. If not satisfied, a part of the reproduction signal including a signal of a unit other than the unit that is the data reproduction target is reproduced so as to satisfy the reproduction signal of all the tracks constituting the unit that is the data reproduction target. A data reproduction device to be added to the signal selection result. The data reproduction apparatus according to claim 1 or 2,
When the number of reproduction signals excluding reproduction signals including signals of units other than the unit that is the target of data reproduction is greater than the number of tracks constituting the unit, the reproduction signal selection unit A data reproducing apparatus that narrows down the selection result of the reproduction signal to the number of tracks constituting the unit based on the output level. The data reproduction device according to any one of claims 1 to 3, wherein
The data reproducing apparatus, wherein the reproducing head reproduces a wider range in a track width direction than the track width. The data reproduction device according to any one of claims 1 to 4, wherein:
Each of the tracks is provided with a separation pattern necessary for detecting the positional relationship in the track width direction during playback between the playback head and the plurality of tracks.
The computing unit is
The separation pattern is detected from each of the plurality of reproduction signals selected by the reproduction signal selection unit, and the position in the track width direction when reproducing the reproduction head and the plurality of tracks based on the detection result A channel estimation calculation unit for calculating a channel matrix corresponding to the relationship;
A data reproduction apparatus comprising: a signal separation calculation unit that separates a reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit based on the channel matrix obtained by the channel estimation calculation unit . The data reproducing apparatus according to claim 5, wherein
The signal separation calculation unit obtains a generalized inverse matrix of the channel matrix obtained by the channel estimation calculation unit, and calculates the generalized inverse matrix and each reproduction signal selected by the reproduction signal selection unit for each track. A data reproducing apparatus for separating reproduced signals. The data reproducing apparatus according to claim 5, wherein
The signal separation calculation unit is configured to perform the MMSE (Minimum Mean Squared Error) method on the channel matrix obtained by the channel estimation calculation unit from each reproduction signal selected by the reproduction signal selection unit for each track. A data reproducing apparatus for separating data reproduction signals. The data reproduction device according to any one of claims 5 to 7,
A data reproducing apparatus, wherein the separation pattern is a separation pattern composed of a signal having a recording wavelength equal to or greater than the minimum recording wavelength and disposed at a unique position for each track. The data reproduction device according to any one of claims 5 to 7,
A data reproducing apparatus in which the separation pattern is tracking servo information. The data reproduction device according to any one of claims 1 to 4, wherein:
Each of the tracks is provided with a separation pattern necessary for detecting the positional relationship in the track width direction during playback between the playback head and the plurality of tracks.
The computing unit is
The separation pattern is detected from each of the plurality of reproduction signals selected by the reproduction signal selection unit, and the position in the track width direction when reproducing the reproduction head and the plurality of tracks based on the detection result A channel estimation calculation unit for calculating a channel matrix corresponding to the relationship;
A channel matrix estimation unit that estimates a variable channel matrix within a section of the data, using the channel matrix obtained by the channel estimation calculation unit;
A signal separation operation unit that separates the reproduction signal for each track from each reproduction signal selected by the reproduction signal selection unit for each individual section using the variable channel matrix estimated by the channel matrix estimation unit A data reproducing apparatus comprising: The data reproduction apparatus according to claim 10, wherein
The channel matrix estimation unit uses a plurality of channel matrices respectively obtained by the channel estimation calculation unit based on the separation patterns in the plurality of units arranged continuously in the traveling direction of the track. A data reproducing apparatus for estimating a variable channel matrix within the data section. The data reproduction apparatus according to claim 10, wherein
The channel matrix estimator may perform linear interpolation on each section of the data from a plurality of channel matrices respectively determined by the channel estimation calculator based on the separation patterns in the plurality of consecutive units. A data reproduction apparatus for estimating a plurality of corresponding channel matrices. The data reproduction apparatus according to claim 10, wherein
The channel matrix estimation unit is positioned behind both of the plurality of separation patterns from a plurality of channel matrices respectively determined by the channel estimation calculation unit based on the separation patterns in the plurality of consecutive units. A data reproducing apparatus for estimating a variable channel matrix within a section of data to be transmitted. A unit which is a unit of signal processing for data reproduction is constituted by a plurality of tracks, and each unit is arranged to be shifted from each other in the traveling direction of the track. Different from each other in the width direction of the track with respect to the unit by using a reproducing head arranged across a plurality of the tracks from a recording medium on which a preamble having an identification pattern including information for identification is arranged A method of obtaining a plurality of reproduction signals larger than the number of tracks constituting the unit in a positional relationship and reproducing the data,
Playback that selects a plurality of playback signals that satisfy the signals of all the tracks that constitute the unit that is the target of data playback, based on the preamble, from a plurality of playback signals that are larger than the number of tracks that constitute the unit. A signal selection step;
A data reproduction method comprising: a calculation step of performing a process for separating a reproduction signal for each track from the plurality of reproduction signals selected in the reproduction signal selection step. A unit that is a unit of signal processing for data reproduction is formed on a recording medium by a recording head, and is arranged so as to be shifted from each other in the direction in which the track travels. A data recording apparatus for recording a plurality of tracks on which a preamble having an identification pattern including information for recording is arranged, and the unit is recorded across the plurality of tracks from the recording medium on which the unit is recorded by the data recording apparatus Data reproduction is performed by using a reproduction head to obtain a plurality of reproduction signals that are different from each other in the width direction of the track with respect to the unit and that are larger than the number of tracks constituting the unit and reproduce the data. A data recording / reproducing apparatus comprising:
The data recording device comprises:
A recording encoding unit that encodes data to be recorded for each track;
Each of the data encoded for each track encoded by the recording encoding unit is configured so that the preambles of a plurality of tracks are not simultaneously reproduced by the reproduction head at the time of reproduction. An independent preamble adding unit for adding a preamble necessary for the control to reproduce the data in a positional relationship shifted in the traveling direction;
A multitrack recording unit that performs processing for recording the data with the preamble added for each track on the recording medium by the recording head;
The data reproduction device includes:
Playback that selects a plurality of playback signals that satisfy the signals of all the tracks that constitute the unit that is the target of data playback, based on the preamble, from a plurality of playback signals that are larger than the number of tracks that constitute the unit. A signal selector;
A data recording / reproducing apparatus comprising: an arithmetic unit that performs processing for separating a reproduction signal for each track from the plurality of reproduction signals selected by the reproduction signal selection unit.

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