JP2008210483A - Magnetic recording device and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording device capable of correctly setting a read-on track even if a track width is shifted from a normal width, and preventing the deterioration of the transfer rate of read data. <P>SOLUTION: The amount of positional shifting in a magnetic disk radial direction between a write head 201 and a read head 202 is measured among a plurality of points from the outer peripheral part to the inner peripheral part of a magnetic disk, interpolation is carried out to obtain positional shifting amount information corresponding to the part from the outer peripheral part to the inner peripheral part of the magnetic disk based on the information of the measured shifting amount, a track where data is written in a position not of the positional shifting amount and the actual writing position of this track are detected, a difference between the actual writing position and the positional shifting amount is stored as an error correction information, and a magnetic head is moved based on the positional shifting amount and the error correction information. Thus, deterioration of a transfer rate caused by a reading error is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic recording apparatus and a method for manufacturing the same, and more particularly to a method for positioning a magnetic head of a magnetic recording apparatus.

  As shown in FIG. 5, the conventional magnetic recording apparatus has a spindle motor 102 disposed at the bottom of a housing 101, and houses a magnetic disk 103 that is a magnetic data recording medium that is rotationally driven by the spindle motor 102 at a constant angular velocity. ing.

  In many cases, the magnetic head 104 for writing and reading data to and from the magnetic disk 103 is composed of a write head 201 and a read head 202, as shown in FIG. It is separated by the read / write gap region 203. A rotary actuator 106 that rotates on the magnetic disk 103 about a support shaft 105 that supports a magnetic head 104 at one end is attached to the housing 101 so as to be rotatable. The read head 202 and the write head 201 are arranged in the magnetic head 104 so as to be arranged through the read / write gap region 203 along the longitudinal direction of the rotary actuator 106 (as shown in FIG. 7B). In the rotary actuator 106, the write head 201 is disposed on the tip side of the read head 202).

  As shown in FIG. 7A, the magnetic head 104 moves in an arc shape on the magnetic disk 103 in response to the rotary actuator 106. As shown in FIG. 7B, the rotary actuator 106 is generally magnetic. The head 104 is installed near the center (MD) in the rotational direction of the magnetic disk 103 so as to be recorded in parallel with the track direction, and the track direction (disk) on the outer peripheral side (OD) and inner peripheral side (ID) of the magnetic disk 103 is set. The skew angle is generated with respect to the rotation direction. That is, in a track in which the magnetic head 104 has a skew angle with respect to the track on the magnetic disk 103, a deviation amount 301 in the radial direction of the magnetic disk 103 occurs between the read head 202 and the write head 201.

  An example of data writing and reading will be described with reference to FIG. Generally, when writing data to the target track Trk, the data is written using the write head 201 while the read head 202 is on-track to the target track Trk. In other words, the written data does not exist on the target track Trk but on a position shifted by the distance that the read head 202 and the write head 201 are separated (the shift amount 301). When data is read from the target track Trk, the read head 202 is on-tracked to a position shifted from the target track Trk by a pre-calculated amount of deviation 301 between the read head 202 and the write head 201 to read the data.

  Tens of thousands of concentric tracks are written on the magnetic disk 103 by a dedicated device called a servo track writer in the manufacturing process. In the servo track writer, the rotary actuator 106 is controlled by an external positioning device and writes a servo signal.

A servo signal writing method will be described with reference to FIG. There are various patterns of servo signals. Here, a trimid 3-pass pattern will be described as an example.
In general, the track width refers to a width in which data is written when the magnetic recording apparatus is actually used (also referred to as a data track), and has a width 1.5 times that of a servo track written by a servo track writer. The center of the servo track corresponds to 910 and 911 in FIG. 9 (refer to the position of step 907), and the center of the data track corresponds to 910 and 912. In order to write the servo signal of one data track, it is necessary to write the servo track signal by rotating the magnetic disk 103 for three rotations. The servo track writer positioning device positions the rotary actuator 106 of the magnetic recording device and writes servo signals.

  First, in step 901, the magnetic head 104 is fixed at a certain position on the magnetic disk 103 by a positioning device, and a digital signal and an A burst signal are written. Next, in step 902, the magnetic head 104 is moved to a position shifted by 50% of the servo track width to be written, and the B burst signal is written. Next, in step 903, the magnetic head 104 is further moved to a position shifted by 50% in the same direction, the digital signal is written, and the portion on the circumference where the A burst signal is currently written is erased. , C burst signal is written. Next, in step 904, the magnetic head is further moved to a position shifted by 50% in the same direction, the portion on the circumference where the B burst signal is currently written is erased, and the D burst signal is written. . Next, in step 905, the magnetic head 104 is further moved to a position shifted by 50% in the same direction, the digital signal is written, the A burst signal is written, and the C burst signal is currently written on the circumference. Erase the part. Next, in step 906, the magnetic head is further moved to a position shifted by 50% in the same direction, and the portion over the circumference where the B burst signal is written and the D burst signal is currently written is erased. When writing a digital signal, the portion overlapping with the digital signal one servo track before is overwritten. The operation from step 903 to step 906 is continued until all servo tracks are covered, and a servo signal is written (step 907).

  Next, a method for measuring the deviation amount of the write head 201 and the read head 202 in the disk radial direction will be described. Regarding how to measure the amount of deviation of the write head 201 and the read head 202, for example, as described in Patent Document 1, a plurality of specific burst patterns are written in the data area, and the output ratio of the burst patterns is set. There is a method of measuring the offset position originally. As another method, in a write-on-track state, one burst pattern is written in the data area, the read head 202 is shifted little by little, a variable gain amplifier (VGA) signal or an automatic gain control (AGC) signal. There is a method of measuring the offset position using the position where these values reach the peak as the center position of the written burst pattern.

In any of the methods, it takes a very long time to measure the deviation amount for all tracks, and presses the tact of the test process of the magnetic recording apparatus in the manufacturing process. Measurement is performed on two or more tracks, and an offset amount in a track between arbitrary measurement points is interpolated by approximation calculation to create an off-track profile, and an offset amount is given to all tracks.
JP-A-8-129732

However, the configuration of the conventional magnetic recording apparatus has the following problems.
In the servo track writer, the rotary actuator 106 is controlled by an external positioning device and writes a servo signal. If the feed width of the magnetic head 104 by the external positioning device becomes large or small during servo signal writing due to a disturbance, the actually written track width also changes to a size width that is larger or smaller than the ideal track width. . In the conventional magnetic recording apparatus, the track width is sufficiently large, and the variation in the track width is not significantly affected by the disturbance. However, with the recent miniaturization of the track width, disturbance has greatly affected the variation in the track width.

  Positioning control of the magnetic head of the magnetic recording apparatus is performed based on the servo signal. Naturally, when the written servo signal varies as described above, the magnetic head 104 cannot originally be accurately moved to the physical position on the magnetic disk 103 to be moved.

  In the conventional method, the on-track method at the time of reading is a method in which the amount of deviation calculated in advance by approximate calculation is shifted from the write on-track position by that value for positioning. At this time, the amount of deviation is measured based on the track width, not the absolute value. For example, a shift of 5.2 tracks or a shift of 10.7 tracks. Therefore, when there is actually a shift of 5.2 tracks, the read head 202 tries to move by 5.2 tracks. However, if even one of the five tracks is not an accurate track width, the read head 202 will be positioned as a read-on track at the wrong location. For example, if the track width of one of these 5 tracks is 80%, the 5 track is supposed to be 4.8 track, and finally the 5.2 track will move only 5.0 track It ’s not moving. When the deviation between the read head 202 and the write head 201 is 5.2 tracks, the read-on-track positioning is mistaken by 20% in the same manner for all five tracks between which the read head 202 and the write head 201 sandwich the track having an abnormal track width. It will be.

  If the magnetic recording device is equipped with a plurality of magnetic heads 104, the servo signal is a problem that affects the servo signals on all the disk surfaces because all the magnetic heads 104 simultaneously write the same pattern. The transfer rate deteriorates due to the effect of error recovery even if it is missing as possible, or the number of tracks where this transfer rate deteriorates is the number of head misalignment tracks multiplied by the number of magnetic heads multiplied It becomes.

  When writing data to the target track, the data is written using the write head 201 while the read head 202 is on-track to the target track using the read head 202. That is, the written data does not exist on the target track but on a position shifted by the separation distance between the read head 202 and the write head 201. When data is read from the target track, the data is read by turning the read head 202 on-track to a position shifted from the target track by a shift amount between the read head 202 and the write head 201 calculated in advance by approximation calculation.

  The radial deviation between the write head 201 of the current magnetic head 104 and the magnetic disk 103 of the read head 202 ranges from several tracks to several tens of tracks as the TPI (Track Per Inch) increases. In the conventional method, when there is one track whose width is sufficiently narrow or wide with respect to the track, the servo signal is used as a reference by using the deviation amount (that is, the ideal deviation amount) calculated by the approximate calculation. Since the read-on track is performed, all the write-on tracks in which the write head 201 and the read head 202 sandwich the track cannot accurately move the read head 202 to the position where data is written at the time of data reading. It will not be usable. Or, even if the size of the track width is small, it is necessary to always perform error recovery processing of off-track read when reading data, and the read data transfer rate on the corresponding track deteriorates. .

  Also, if there is one track whose width is sufficiently narrow or wide with respect to the track where the amount of deviation between the read head 202 and the write head 201 is measured, the data is incorrect and is calculated by approximate calculation. Obviously, the off-track profile itself is incorrect, and all of the peripheral tracks cannot be read-on-tracked correctly.

  SUMMARY OF THE INVENTION The present invention solves the above-described problem, and even when the servo signal track width is deviated from the normal width, the magnetic recording apparatus can correctly perform read-on-track and prevent the read data transfer rate from deteriorating. It is another object of the present invention to provide a method for manufacturing a magnetic recording apparatus.

  In order to solve the above problems, a magnetic recording apparatus according to the present invention includes a magnetic head in which a write head for writing information to a magnetic disk and a read head for reading information are provided separately from each other, and supports the magnetic head. A magnetic recording device in which servo signals for controlling the position of the magnetic head are concentrically recorded on a magnetic disk, from the outer periphery to the inner periphery of the magnetic disk Based on the information on the measured positional deviation of the multiple points in the radial direction of the magnetic disk of the write head and the read head, the positional deviation amount corresponding to the inner peripheral part from the outer peripheral part of the magnetic disk is measured. Servo signal data is written to the position deviation amount information storage means that stores the position deviation amount information obtained by interpolation and the position that is not the position deviation amount. Error correction information storing means for storing a difference between an actual writing position of a track and the positional deviation amount or a value corresponding thereto as error correction information, and a magnetic field based on the positional deviation amount information and the error correction information. And a control means for moving the head.

  The magnetic recording apparatus manufacturing method of the present invention includes a magnetic head in which a write head and a read head are separated from each other, and a rotatable rotary actuator that supports the magnetic head. A method of manufacturing a magnetic recording apparatus in which servo signals for controlling the position of a magnetic head are recorded concentrically, wherein the amount of positional deviation between the write head and the read head in the radial direction of the magnetic disk Measuring between a plurality of points from the outer peripheral part to the inner peripheral part, interpolating corresponding to the inner peripheral part from the outer peripheral part of the magnetic disk based on the information of the measured positional deviation amount, and storing as positional deviation amount information; The track where the servo signal data has been written to a position that is not the positional deviation amount and the actual writing position of this track are detected, and the actual writing is detected. Characterized by a step (track scrutiny process) for storing the difference or value corresponding to the position and the positional deviation amount as the error correction information.

Note that the error correction information is preferably written at the end of the servo signal on the track to be read on track.
More specifically, in the method of manufacturing a magnetic recording apparatus of the present invention, the amount of positional deviation in the radial direction of the magnetic disk between the write head and the read head that are separated from each other in advance is calculated from the number of outer circumferences to the inner circumference of the magnetic disk. Measure and interpolate between points, store this as misregistration information in the nonvolatile memory or on the magnetic disk, place the read head on track on one track, and use the read head in the radial direction of the magnetic disk Data recorded using a write head having a position deviation amount is written to a position other than the previously stored position deviation amount because the track width was not uniformly written during servo writing. The detected track is detected in the magnetic disk inspection process in the manufacturing process, and the positional deviation amount information and actual data stored in advance In order to correct an error between the position, using the position displacement amount information and error correction information, and writes over one place in at least a track around the end of the servo signal on the track to be read on-track.

  According to the magnetic recording apparatus having the above-described configuration and the method of manufacturing the magnetic recording apparatus, the inner circumference of the magnetic disk is changed from the outer circumference to the inner circumference based on the information on the positional deviation amounts of the write head and the read head in the radial direction of the magnetic disk. Even when the servo signal data is written to a position that is not the positional deviation amount information while obtaining the positional deviation amount information interpolated corresponding to the portion, the actual writing position of the track and the positional deviation amount The magnetic head can be moved to the actual track position on the basis of the error correction information that is the difference between the two and the error correction information, or the read data transfer rate can be prevented from deteriorating.

  In other words, when a read command is executed in response to a read instruction in a track where an error occurs because the data position is not a regular position, immediately after a read-on track using pre-stored positional deviation amount information, the above method is used. Based on the written error correction information, it is possible to quickly re-track to the position where the data is actually written and read the data, thereby reducing the delay in reading time due to error processing. Thus, the transfer rate can be prevented from deteriorating. In addition, by writing position shift information at the end of more servo signals, the error correction value can be recognized more quickly and with high sensitivity, and the position error can be corrected quickly.

  According to the present invention, the amount of positional deviation in the radial direction of the magnetic disk between the write head and the read head is measured between a plurality of points, interpolated, and stored as positional deviation amount information. Detecting the track in which data has been written to the position and the actual writing position of this track, storing the difference between the actual writing position and the positional deviation amount or a value corresponding thereto as error correction information; Since the magnetic head is moved based on the positional deviation amount information and the error correction information, the deterioration of the transfer rate due to a read error is reduced, and the number of defective tracks in the manufacturing process of the magnetic recording apparatus is reduced. Yield and the deterioration of the data transfer rate of the magnetic recording apparatus can be reduced.

  That is, since the deviation of the on-track position of the read head due to the size of the track width of the servo signal written in the servo write process can be corrected before the data is read, it is possible to reduce the transfer rate deterioration due to the read error. In addition, in the conventional method, the corresponding track cannot be used due to an on-track control error due to a shift in the on-track position of the read head due to the track width of the servo signal written in the servo write process. The correction based on the information makes it possible to use this track even when the track width fluctuates in size, reducing the number of defective tracks in the manufacturing process of the magnetic recording device, and improving the yield of the manufacturing process. It is also possible to reduce deterioration of the data transfer speed of the recording apparatus. Also. By correcting the misalignment of the position where data signals are written only for problematic tracks, stable data transfer can be performed at all times without making significant changes to the manufacturing method or servo signal writing method. A magnetic recording apparatus can be provided.

  In the future, as the magnetic recording device becomes smaller and higher in density, the track width on the magnetic disk will become increasingly narrower, so that one or more abnormal tracks are sandwiched between the read head and write head and used. There are many cases where the number of tracks cannot be increased or the transfer rate deteriorates. Furthermore, as the density increases, the accuracy of the offset profile that is approximately calculated becomes strict, and even a slight error may increase the possibility of off-track reading. Even for such a problem, the read-on-track position can be flexibly corrected by the above configuration and method.

  In recent years, magnetic recording apparatuses have been used for recording and reproducing multimedia data such as video and audio in addition to personal computers, and data transfer rate deterioration has become an important issue. In order to deal with such a problem, the present invention can quickly control the magnetic head to a position where data is correctly written in response to an off-track read error in an arbitrary track. This will become more useful in the future.

  FIG. 1 is a simplified block diagram of a magnetic recording apparatus according to an embodiment of the present invention. FIG. 2 is a diagram conceptually showing a moving state of a magnetic head of the magnetic recording apparatus according to the embodiment of the present invention. . Compared to conventional magnetic recording devices, the track width is miniaturized, but the structure that rotates the basic magnetic disk, the structure that drives the magnetic head, the arrangement structure of the read head and write head, The servo signal writing method is the same as that described with reference to FIGS. 5 to 9, and the same components are denoted by the same reference numerals.

  1 and 2, reference numeral 103 denotes a magnetic disk as a recording medium of a magnetic recording apparatus, which reads and writes magnetic data by a magnetic head 104 provided at one end of a rotary actuator 106. 604 is a spindle motor for rotating the magnetic disk 1, 605 is a voice coil motor for applying a driving force to the rotary actuator 106, and the rotary actuator 106 is centered on the support shaft by the driving force of the voice coil motor 605. It is rotatably supported by. As described above, the magnetic head 104 includes the write head 201 and the read head 202 as in the case described with reference to FIGS. 6 and 7, and the write head 201 and the read head 202 have a read / write gap. The regions 203 are separated from each other.

  In FIG. 1, reference numeral 606 denotes a drive circuit (power driver) that sends current to the spindle motor 604 or the voice coil motor 605. The magnetic head 104 can be moved to all data zones on the magnetic disk 103 by a spindle motor 604, a voice coil motor 605 and a power driver 606. Further, in response to a request from a host computer (not shown) provided in an electrical apparatus equipped with this magnetic recording device, a hard disk controller 607 as a control means causes a power driver 606 and a read / write circuit (read / write channel) 608 to be connected. Control and write data to the target location or read data from the target location. The hard disk controller 607 includes an error correction circuit, an interface control circuit, a servo circuit, and the like.

  Prior to the track inspection step described below, the magnetic recording apparatus according to the present embodiment is configured to set the positional deviation amount 301 in the radial direction of the magnetic disk between the write head 201 and the read head 202 as described above with reference to FIG. The positional deviation amount information is measured between a plurality of points from the outer peripheral portion to the inner peripheral portion of the magnetic disk 103 and is interpolated corresponding to the inner peripheral portion from the outer peripheral portion of the magnetic disk 103 based on the information of the measured positional deviation amount. As shown, a non-volatile memory (not shown) provided in the magnetic recording device or a step of storing in a part of the magnetic disk 103 (detection and storage step of positional deviation amount information) is executed.

  In the magnetic recording apparatus of the present embodiment, the track inspection step described below is performed after the detection and storage step of the positional deviation amount information is performed in the manufacturing process. Here, FIG. 3 is a flowchart showing the flow of the track inspection process.

  In step 701 in FIG. 3, if the track inspection process is started during the manufacturing process of the magnetic recording apparatus, the tracks on the magnetic disk 103 are inspected from the track 0 to the final track (step 702).

  In the track review process in step 703, the voice coil motor 605 is driven to cause the magnetic head 104 provided at one end of the rotary actuator 106 to seek to the target track (the target track number is defined as Trk) and is currently on-track. The scrutinizing data is written on the track, and then the scrutinizing data is reproduced by shifting the magnetic head 104 by the offset amount of the corresponding track and using the offset table to read-on track.

  In step 704 in this track inspection process, it is confirmed whether or not a read error has occurred. Normally, a read error does not occur, and in step 705, the target track number is incremented to examine the next track. If a read error occurs, a check step for checking whether it is an off-track write error is entered. If branched to the confirmation step, first, the signals of the adjacent tracks (Trk + 1, Trk-1) are erased (step 706), and off-track reading is performed in steps of 1% from -15% to + 15% of the track width on the corresponding track. The VGA signal generated by the read / write channel 608 is measured at each off-track step. Then, the minimum value (defined as VGAmin) of the VGA signal measured in the meantime and the off-track amount (defined as nmin) at which the minimum value is measured are provided in a nonvolatile memory (not shown) provided in the magnetic recording device. Stored (steps 707 to 713). Instead of the non-volatile memory, it may be recorded and stored at a predetermined location on the magnetic disk 103.

  After all off-track read steps are completed, if nmin is 0 (step 714), it is not an off-track write error, so no further steps are taken and Trk is incremented to examine the next track. Enter (step 705).

  If nmin is not 0, a signal is written to the previously erased adjacent tracks (Trk + 1, Trk-1) (step 715), and the off-track amount at which the lowest value among the measured VGA signals is output on the corresponding track The track is examined again after off-tracking by nmin% (step 716). If a read error does not occur in step 716, the corresponding track is authenticated as a usable track without data error recovery by on-tracking to a position shifted by nmin% from the previously stored positional shift information. On the contrary, if a read error occurs, the influence on the adjacent track is taken into consideration, and the corresponding track is registered as unusable (step 717). Then, Trk is incremented and the next track is examined (step 705).

  When it is authenticated that the track can be used, the information of the off-track amount nmin% is stored in advance as the position shift position (that is, the read-on-track position to which the magnetic head first heads after the magnetic recording device receives the read command). In order to write the correction value to (), the offset value is offset by −nmin% from the write-on-track position (step 718), and the correction information is written immediately after one or more burst signals within at least one track (step 719).

  By writing correction information to this position, when actually using the magnetic recording device, when executing a read command for a track on which correction information is written, when performing read-on track using pre-stored positional deviation information, The correction value is recognized immediately after the burst signal. If recognized, the on-track is immediately performed again at the position where the data is written based on the correction value, and the read command processing is performed without waiting for the magnetic disk 103 to go around.

  Thereafter, Trk is incremented and the next track is examined (step 705). This series of operations is repeated until Trk reaches the final track. As a result, it is completed whether or not there is an off-track write error for all the tracks, and correction values (error correction information) are written for the problematic tracks.

  In this way, in the track scrutiny step, the track in which the servo signal data has been written to a position that is not the previously stored misregistration amount due to the fact that the track width was not uniformly written during servo writing. (Referred to as an abnormal track) is detected, the abnormal track and the actual writing position of the abnormal track are detected, and the difference between the actual writing position and the positional deviation amount is used as error correction information to read-on track Write to the end of the servo signal on the track to be played.

  When this magnetic recording apparatus is incorporated and driven in a personal computer or an electrical apparatus for recording / reproducing multimedia data such as video and audio, it is driven while being controlled as follows. Hereinafter, processing when a read command is issued from the host computer provided in the electrical apparatus to the magnetic recording apparatus (when a read instruction is issued) will be described with reference to FIGS. 4 and 2. FIG.

  When a read command is issued from the host computer to the magnetic recording device, first, the rotary actuator 106 is driven by the voice coil motor 605 and stored in advance from the write-on track on the magnetic disk 103 in the same manner as a normal read seek. Then, seek is performed to a position where the read head 202 and the write head 201 are shifted with respect to the corresponding track (step 801). In step 802, it is determined whether an error correction value is written immediately after the burst signal on the read-on track. In step 802, the read head 202 corrects the error immediately after the burst signal on the read-on track. If the value is recognized, in step 803, the magnetic head 104 is immediately finely moved from the current read-on-track position by the amount of the correction value. Thereafter, a read command process of a normal magnetic recording apparatus is performed (step 804). On the other hand, if the magnetic head 104 does not recognize the correction value immediately after the burst signal on the read-on track, the normal read command processing of the magnetic recording apparatus is immediately performed (step 804).

  This processing can reduce a delay in reading time due to error processing, and can prevent a deterioration in transfer rate. Further, by writing the positional deviation information at the end of more servo signals, the correction value (error correction information) can be recognized with higher sensitivity, and the positional error can be corrected quickly.

  In this way, the offset between the read head 202 and the write head 201 is measured at two or more points between the outer periphery and the inner periphery of the magnetic disk 103, and the track offset between them is interpolated by approximate calculation, so that the off-track in all tracks is measured. Secure the profile and improve the error rate during playback. Here, although this kind of technology already exists, it cannot cope with an irregular change in the track width occurring at an arbitrary position.

  In contrast, the positional deviation correction method according to the present invention not only calculates the positional deviation amount of the track existing between measurement points measured by two or more tracks, but also approximates the positional deviation amount information. In addition, since the positional deviation of the track is corrected due to an error in the interpolation value due to the size of the track width, it is possible to completely cope with an irregular change in the track width.

  The magnetic recording apparatus and the manufacturing method thereof according to the present invention are not limited to a magnetic recording apparatus having a magnetic disk servo-written by a servo track writer, and a magnetic transfer method is used as a servo signal writing method. The present invention is also applicable to existing magnetic disks and magnetic recording devices.

A simplified block diagram of a magnetic recording apparatus according to an embodiment of the present invention. The figure which shows notionally the movement state of the magnetic head of the magnetic-recording apparatus based on embodiment of this invention. 7 is a flowchart showing a correction value writing operation in the method of manufacturing the magnetic recording apparatus according to the embodiment of the invention. 7 is a flowchart showing a position correction operation in the method of manufacturing the magnetic recording apparatus according to the embodiment of the invention. Plan view schematically showing the configuration of the magnetic recording apparatus (A) And (b) is the front view and side view which show the structure of a magnetic head (A) and (b) are diagrams for explaining the amount of deviation of the read portion and the write portion of the magnetic head in the circumferential direction due to the skew angle of the rotary actuator, respectively, and (a) is a simplified magnetic recording apparatus. (B) is an enlarged view showing the amount of deviation of the read portion and the write portion of the magnetic head in the circumferential direction due to the skew angle of the rotary actuator. A simplified representation of track write and read processing Diagram showing servo signal writing method

Explanation of symbols

102 Spindle motor 103 Magnetic disk 104 Magnetic head 105 Support shaft 106 Rotary actuator 201 Write head 202 Read head 203 Read / write gap area 301 Deviation 605 Voice coil motor 607 Hard disk controller (control means)

Claims (4)

The magnetic disk includes a magnetic head in which a write head for writing information to a magnetic disk and a read head for reading information are separated from each other, and a rotatable rotary actuator that supports the magnetic head. A magnetic recording apparatus in which servo signals for controlling the position of the head are recorded concentrically,
Based on the information on the measured positional deviations at multiple points in the radial direction of the magnetic disk of the write head and read head measured between multiple points from the outer periphery to the inner periphery of the magnetic disk. Misregistration amount information storage means for storing misregistration amount information obtained by interpolating misregistration amounts corresponding to the sections;
Error correction information storage means for storing, as error correction information, a difference between an actual writing position of a track in which servo signal data has been written at a position other than the positional deviation amount and the positional deviation amount or a value corresponding thereto. When,
A magnetic recording apparatus comprising: control means for moving a magnetic head based on the positional deviation amount information and the error correction information.   2. The magnetic recording apparatus according to claim 1, wherein at least one error correction information is written at the end of a servo signal on a read-on-track track in the magnetic disk. The magnetic head includes a magnetic head in which a write head and a read head are separated from each other, and a rotatable rotary actuator that supports the magnetic head. A servo signal for controlling the position of the magnetic head is provided on the magnetic disk. A method of manufacturing a magnetic recording device recorded concentrically,
The amount of positional deviation of the write head and the read head in the radial direction of the magnetic disk is measured between a plurality of points from the outer peripheral part to the inner peripheral part of the magnetic disk, and the outer peripheral part of the magnetic disk is measured based on the information on the measured positional deviation amount. Interpolating corresponding to the inner periphery from the step of storing as positional deviation amount information,
A track where servo signal data has been written to a position that is not the positional deviation amount and an actual writing position of the track are detected, and the difference between the actual writing position and the positional deviation amount or the equivalent. And a step of storing the value as error correction information.   4. The method of manufacturing a magnetic recording apparatus according to claim 3, wherein the error correction information is written at least at one or more locations in the end of the servo signal on the track to be read on track.

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