JP2010140549A - Magnetic storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high recording density and high-speed transfer, in a magnetic storage device using a patterned medium. <P>SOLUTION: The magnetic storage device includes: a patterned medium for recording information; a buffer having a discrete medium area or a continuous medium area disposed on a part of the same medium as that of the patterned medium for recording information or another medium; writing/reading means 11, 12 and 13 for writing/reading information in/from the patterned medium and the buffer; and a control means 15. When recording certain data, the control means 15 first records the data in the buffer by the writing/reading means 11, 12 and 13, and then reads the data from the buffer to record the data in the patterned medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic storage device using a patterned medium (bit patterned medium) in which a pattern is formed in the bit direction, which is capable of high-speed transfer and suppresses a synchronization error during recording caused by pattern manufacturing variation. .

  While the medium structure of a magnetic storage device, which is the current HDD (hard disk device), is a continuous medium that does not form a pattern, a discrete medium that is patterned only in the track direction to enable high density (see Patent Document 1) In addition, as a further technique, a shift to a bit patterned medium (see Patent Document 2) in which a pattern is formed in both the bit direction and the track direction is assumed.

  In the case of discrete media, the bit direction is the same as that of continuous media, but in the case of bit-patterned media, the groove length is also dug in the bit length direction. It is difficult to make it smaller. Conventionally, in order to increase the processing speed of the HDD, the rotational speed of the HDD has been increased and the density in the bit direction has been increased.

In a conventional continuous medium (for perpendicular magnetic recording), recording bit boundaries (magnetization transition regions) become noise sources and it is difficult to increase the density. On the other hand, in a bit patterned medium in which a pattern is formed on the medium, the boundary of the recording bit is an area that cannot be recorded, so that the noise is low and it is suitable for high density. However, as a disadvantage, increasing the linear density is more difficult than continuous media and discrete media because it requires progress in processing technology. If the pattern variation is large, a positional deviation occurs between the recording signal and the recording bit, and a synchronization error occurs in which the recording is not performed on a predetermined bit.
JP 2007-234070 A JP 2004-62920 A

  The conventional device has the following problems.

  (1): In bit patterned media, it is difficult to reduce the bit length in accordance with the trend of continuous media because the formation of a small bit length depends on the process accuracy. It was an issue.

  (2): Since variations in processing of the bit shape and interval occur, an error (synchronization error) due to head alignment during recording has been a problem.

  An object of the magnetic storage device described here is to enable high recording density, high-speed transfer, and elimination of synchronization errors in a patterned medium.

  FIG. 3 is an explanatory diagram of the magnetic storage device. In FIG. 3, 12 is a write / read section (write / read means) for bit patterned media, 11 and 13 are buffer write / read sections (write / read means), 14 is a reproduction signal comparison section, and 15 is a control. Reference numeral 16 denotes a recording timing adjustment unit.

  This magnetic storage device has the following means in order to solve the above conventional problems.

  (1): A buffer composed of a discrete medium area or a continuous medium area provided on a part of the same medium as the patterned medium for recording information or on another medium, and information is written to the patterned medium and the buffer. Read / write means 11, 12, 13 for reading / reading, and control means 15 are provided. When the control means 15 records certain data, it is first recorded in the buffer by the write / read means 11, 12, 13 Then, the data is read from the buffer and recorded on the patterned medium. Therefore, high recording density and high-speed transfer can be performed in a magnetic storage device using a patterned medium.

  (2): In the magnetic storage device according to (1), the control unit records the data recorded in the buffer on the patterned medium immediately after recording on the patterned medium. And the data on the buffer are compared to detect whether a synchronization error has occurred on the patterned medium. For this reason, it is possible to guarantee the operation against the synchronization error by detecting the synchronization error of the patterned medium after shipment and avoiding or correcting the synchronization error.

  The magnetic storage device disclosed herein has the following effects.

  (1): When recording certain data, a write / read means first records the data in a buffer, and then reads from the buffer and records it on a patterned medium. Therefore, in a magnetic storage device using the patterned medium, a high recording density And high-speed transfer.

  (2): When the data recorded in the buffer is recorded on the patterned medium, the data on the patterned medium is compared with the data on the buffer immediately after recording on the patterned medium. To detect whether or not a synchronization error has occurred, detect the synchronization error of the patterned medium after shipment, and avoid or correct the synchronization error to ensure operation against the synchronization error. Can do.

  Currently, a semiconductor memory is used as a buffer for temporarily storing data for data recording and arithmetic processing in a magnetic storage device such as an HDD. Although the capacity of semiconductor memory is increasing year by year, the capacity of HDD magnetic recording media is much larger.

  Patterned media (bit patterned media) have higher recording density than conventional continuous media and discrete media, but have problems of high-speed transfer and synchronization errors. Therefore, the above-mentioned problem of the bit patterned medium can be solved by using a conventional continuous medium or discrete medium as a buffer during recording. This is because a process of storing information on a bit-patterned medium having a high recording density after the user's recording operation is finished without deterioration of the transfer speed by performing on the buffer when the user records. It is going to be.

(1): Description of Magnetic Storage Device FIG. 1 is an explanatory diagram of a magnetic storage device. In FIG. 1, the magnetic storage device 1 is provided with a magnetic recording medium 2, magnetic heads (recording / reproducing heads) 3 and 4, and a control unit 15. The magnetic recording medium 2 is provided with a bid patterned area (bit patterned medium) 22 at the center and a buffer area (buffer) 23 at the outer periphery.

  In the magnetic recording medium 2, a bit patterned medium 22 is provided at the center of the same medium, and a buffer area 23 is provided at the outer periphery. As the buffer area 23, a discrete medium (which may be a continuous medium) is produced. In the buffer area 23, a discrete medium is superior to a continuous medium in that it has a higher recording density and can temporarily store a larger amount of data. Further, since the user accesses the buffer area 23 at the time of recording, the recording processing speed is improved when the outer peripheral portion having a high transfer speed is applied to the buffer area. There may be two or more magnetic heads as shown in FIG. Since the discrete medium and the bit patterned medium 22 can be manufactured to have the same track density, the same head can be used. When there are two (or more) magnetic heads, they are arranged via a spindle so as not to hinder the operation.

(2): Explanation of Bit Patterned Media Bit patterned media has a backing layer of soft magnetic material on a substrate, a nonmagnetic intermediate layer, and a recording layer of hard magnetic material on it, like a continuous medium. Make it. The recording layer portion has a structure divided by a nonmagnetic layer (nonmagnetic region).

  FIG. 2 is an explanatory diagram of a bit patterned medium. FIG. 2 shows a cross-sectional view of a bit patterned medium. The bit patterned medium 22 is provided with a soft magnetic material backing layer 32 on a nonmagnetic substrate 31 such as glass, and a nonmagnetic material thereon. Further, a recording bit 34 of hard magnetic material and a nonmagnetic region 35 are provided thereon. The recording bits 34 are separated from each other by a nonmagnetic region 35. One bit can be recorded in the recording bit 34 which is one pattern. By reducing the size of the recording bit 34, high-density recording can be performed.

As a method for producing the bit patterned medium 22, a soft magnetic material 32 and an intermediate layer 33 of a nonmagnetic material are formed on a substrate 31 by sputtering, as in a conventional continuous medium. Next, as a method for producing a bit-shaped recording layer (recording bit 34), a recording layer material (for example, Fe—Pt, Co—Pt, Co—Cr—Pt—B, Co—Cr—Pt—SiO ₂ ) is used. There is a method of forming the nonmagnetic region 35 by ion implantation after sputtering. In addition, there is a method of manufacturing by EB (electron beam) drawing.

(3): Description of Block Diagram of Magnetic Storage Device FIG. 3 is a block diagram of the magnetic storage device. The magnetic storage device includes a buffer write unit 11, a bit patterned medium write / read unit 12, a buffer read unit 13, a reproduction signal comparison unit 14, and a control unit. 15 and a recording timing adjustment unit 16 are provided. The reproduction signal comparison unit 14 and the recording timing adjustment unit 16 can also be provided in the control unit 15.

  The buffer write section 11 is a buffer information recording means for writing information to the buffer area 23 by the magnetic head 3 shown in FIG. The write / read unit 12 for the bit patterned medium is information recording / reproducing means for the bit patterned medium in which information is written / read to / from the bit patterned medium 22 by the magnetic head (vertical head) 4. The buffer read unit 13 is buffer information reproducing means for reading buffer information by the magnetic head 3. The reproduction signal comparison unit 14 is reproduction signal comparison means for comparing a signal reproduced from the bit patterned medium 22 with a signal reproduced from the buffer area 23. The control unit 15 is a control unit that controls the entire magnetic storage device such as recording / reproduction to / from the bit patterned medium 22 and the buffer 23. The recording timing adjusting unit 16 is a recording timing adjusting means for performing recording shifted to the front (or back) by a certain interval (for example, 1/20 bit) on the bit patterned medium.

(Description of operation of magnetic storage device)
First, when a user starts a recording operation, recording is performed in the buffer area 23 by the write unit 11 of the buffer. When there is one magnetic head (the total of the buffer and the bit patterned medium), recording on the bit patterned medium 22 is started with the same magnetic head after the end of the user recording operation (end of (1) in FIG. 3). (Start (2) later). If there are two or more magnetic heads (one each for the buffer and the bit patterned medium), recording on the bit patterned medium 22 by another magnetic head is started during recording on the buffer 23. ((2) starts in the middle of (1) in FIG. 3).

  Since the buffer 23 is a discrete medium (or continuous medium), a synchronization error during recording does not cause a problem. In order to save this information in the bit patterned medium 22 having a high recording density, a problem of synchronization error occurs. Therefore, in the process of recording on the bit patterned medium 22, the information in the buffer 23 and the information in the bit patterned medium 22 are Reproduction (write / read unit 12 for bit patterned medium, read unit 13 for buffer) is performed, and the reproduction signal comparison unit 14 compares the reproduction waveforms, and if they do not match, the bit patterned medium 22 is recorded again. . By repeating this, the information in the buffer 23 is stored again in the bit patterned medium 22 while correcting the synchronization error of the bit patterned medium 22.

  At this time, since the user has finished the recording operation, the processing speed is not a problem. As a method of correcting the synchronization error of the bit patterned medium 22, for example, after recording by shifting forward (or rearward) by 1/20 bits, the reproduced waveforms are compared. If the synchronization error is not resolved by this method, the fact that a specific area of the bit patterned medium 22 is not used is stored in a memory such as the control unit 15 as an area where the synchronization error is not resolved. In this case, the data is stored again in another place on the bit patterned medium 22. After all the information in the buffer 23 is transferred to the bit patterned medium 22, the information in the buffer 23 is deleted.

  The reproduction is performed by the bit patterned medium write / read unit 12 reading the bit patterned medium 22 from the magnetic head 4. Further, the information in the buffer 23 may be used during reproduction without being erased. When reproducing from the bit patterned medium 22, there is no problem of synchronization error, but the transfer speed in the bit patterned medium 22 is deteriorated as compared with the discrete medium.

(4): Explanation of processing of magnetic storage device by flowchart When information A recording operation is started, information A is first recorded in the buffer area 23 (information A-1). Thereafter, the same information A as the information A-1 in the buffer area 23 is recorded on the bit patterned medium 22 (A-2). The synchronization error detection process does not cause any problem because the reproduction signals of the bit patterned medium 22 and the buffer area 23 are compared immediately after this recording, and it is determined that there is no synchronization error if the signals match. On the other hand, if they do not match, there is a synchronization error, so that the data on the bit patterned medium 22 is corrected (b) and used without correction (b). In the case of (b), the data is stored in the buffer, recorded at a different location on the bit patterned medium 22 from the case where the data is used at the time of reproduction, and from the beginning of the recording on the bit patterned medium 22 Either restarting (starting the recording operation) may be performed.

  In the case of (A), operation B (FIG. 5) is performed. The reason for the operation B is that, in order to estimate the correction amount of a random position of one or several bits, man-hours (time) are significantly required, so that the recording timing is not shifted every one or several bits, but some data Within the area, the recording timing is shifted uniformly (for example, 1/20 bit before) and repeated while increasing the recording timing deviation until the synchronization error is eliminated. As the method of shifting the recording timing, since either the front or the rear is unknown, the recording timing is similarly shifted to the rear (1/20 bit behind). Whether the synchronization error has been resolved is determined by comparison with the data in the buffer 23 as described above. If the synchronization error is not resolved by the above operation B, the correction is not performed, and the data on the buffer is used or the recording operation is performed again in another area.

  If the above steps are performed for each recording, there is a possibility that the performance may be deteriorated. Therefore, the position where the synchronization error occurs and the correction method are stored in the storage means in the control unit 15 (on the system). Assume that the synchronization error check need not be performed for each recording.

  FIG. 4 is a processing flowchart of the magnetic storage device. Hereinafter, a description will be given according to the processes S1 to S7 of FIG.

  S1: The control unit 15 starts the recording operation of information A according to an instruction from the host device (host) or the like, and proceeds to processing S2.

  S2: The control unit 15 records the information A on the buffer area 23 by the write unit 11 of the buffer (A-1), and proceeds to processing S3.

  S3: The control unit 15 records the same information (A-1) on the buffer area 23 read by the read unit 13 of the buffer on the bit patterned medium 22 by the write / read unit 12 for the bit patterned medium. (A-2) Then, the process proceeds to step S4.

  S4: The control unit 15 records the bit patterned medium reproduced by the write / read unit 12 for the bit patterned medium (A-2) and records on the buffer reproduced by the read unit 13 of the buffer (A-1). Are reproduced by the reproduction signal comparison unit 14, and if the compared signals match, the record (A-1) is erased. If they do not match, the process proceeds to step S5 when the record (A-2) is rewritten. If not, the process proceeds to step S6 (note that the user specifies in advance whether or not to rewrite this record (A-2)).

  S5: The control unit 15 performs the rewrite operation B of recording (A-2) (see correction of synchronization error in FIG. 5). If the synchronization error is resolved in operation B, the process proceeds to step S7. If the synchronization error is not resolved, the process proceeds to process S6.

  S6: The control unit 15 sets the recording (A-2) on the bit patterned medium 22 as a defect and moves to the processing S7 (uses the recording (A-1) on the buffer), or on the bit patterned medium 22 The process returns to step S3 to perform recording on another data area (a defective area where the synchronization error cannot be eliminated is not used) (arrow omitted). The user designates in advance whether to use the recording (A-1) on the buffer or to record in another data area.

  S7: The control unit 15 reproduces the recording (A-2) on the bit patterned medium when there is no synchronization error or when the synchronization error is eliminated during recording data reproduction, and uses the buffer area 23 with the synchronization error. If so, the recording (A-1) is reproduced.

  FIG. 5 is a flowchart for correcting the synchronization error. Hereinafter, the correction of the synchronization error (operation B) in FIG. 5 will be described according to steps S11 to S12.

  S11: The control unit 15 shifts the recording timing forward (and rearward) by 1/20 bit at the recording timing adjustment unit 16 with respect to the data area of the bit patterned medium 22 in which the synchronization error has occurred. The information A-1 is recorded again by the write / read unit 12, and the process proceeds to S12. Note that the range to be shifted forward (and backward) by 1/20 bits is within about 10/20 bits before and after.

  S12: The control unit 15 reproduces the recording of the bit patterned medium 22 reproduced by the write / read unit 12 for the bit patterned medium and the recording (A-1) on the buffer 23 reproduced by the reading unit 13 of the buffer. When the signal comparison unit 14 compares and the compared signals match, this processing ends (synchronization error elimination, recording (A-1) is deleted), and when they do not match, the processing returns to processing S11. Note that shifting forward / backward by 1/20 bit is a case where the synchronization error cannot be resolved if the compared signals do not match even if the specified value is shifted (see step S5 in FIG. 4).

(5): Description of Other Examples a) In a magnetic recording medium, a buffer area 23 (for example, a 30-degree track area is used as a buffer area) in a certain sector in the same medium, and the other is a bit patterned medium 22 You can also Others are the same as the above example.

  b) The magnetic storage device has a plurality of magnetic recording media, and the bit patterned medium 22 and the buffer area 23 are not necessarily on the same medium. Others are the same as the above example.

  c) A part or all of the buffer area 23 may be a semiconductor memory. The semiconductor memory can record more data than the HDD, but can increase the processing speed.

d) Supplementary explanation ・ There are the following (1) to (3) as countermeasures when the synchronization error occurs.

  (1) If a synchronization error occurs, save the data on the buffer and use it during playback.

  (2) Use a place where an error does not occur by recording it on the system (for example, storage means of the control unit) so as not to use an area where an error occurs.

  (3) At the location where the synchronization error has occurred on the bit patterned medium 22, the entire data is shifted forward or backward by a certain interval, and repeated until trial-and-error matches the reproduced waveform on the buffer. It is recorded and used on the system (for example, storage means of the control unit 15).

  The buffer area 23 may be on the same surface of the same medium as the bit patterned medium 22, or the back surface, or another medium, and the area may not be the entire surface of the medium but may be a limited area (sector area). .

  The material of the buffer region 23 may be the same material as that of the bit patterned medium 22 and can be manufactured by partially not patterning (ion implantation or the like). Further, the recording density of the buffer may be low, and if a synchronization error does not occur, it can be erased and used many times.

It is explanatory drawing of the magnetic storage apparatus of this invention. It is explanatory drawing of the bit patterned medium of this invention. 1 is a block diagram of a magnetic storage device of the present invention. It is a processing flowchart of the magnetic storage apparatus of this invention. It is a flowchart of correction | amendment of the synchronization error of this invention.

Explanation of symbols

11, 13 Buffer write / read section (write / read means)
Write / read section for 12-bit patterned media (write / read means)
14 Reproduction signal comparison unit 15 Control unit (control means)
16 Recording timing adjustment unit 22 Bit patterned area (patterned medium)
23 Buffer area (buffer)

Claims (5)

A patterned medium for recording information;
A buffer comprising a discrete medium area or a continuous medium area provided on a part of the same medium as the patterned medium or on another medium;
Write / read means for writing / reading information to / from the patterned medium and the buffer;
Control means for controlling the writing / reading of the information,
When recording certain data, the control means first records the data in the buffer by the write / read means, and then reads the data from the buffer and records it on the patterned medium.   When the data recorded in the buffer is recorded on the patterned medium, the control means compares the patterned medium with the data on the buffer immediately after recording on the patterned medium. 2. The magnetic storage device according to claim 1, wherein whether or not a synchronization error has occurred on the medium is detected.   3. The magnetic storage device according to claim 2, wherein when the synchronization error occurs, the control means stores the data on the buffer and uses it during reproduction.   The control means records the entire data by shifting it forward or backward by a certain interval at the location where the synchronization error has occurred on the patterned medium, and performs the shifting recording until it matches the reproduction information on the buffer. 3. The magnetic storage apparatus according to claim 2, wherein the matching recording correction method is repeatedly recorded in the storage means and used during reproduction.   5. The magnetic storage device according to claim 2, wherein a part or all of the buffer is a semiconductor memory.

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