JP4055616B2 - Magnetic transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic transfer device for transferring predetermined servo information to a magnetic disk medium mounted on a magnetic storage device widely used as an external storage device of a computer.
[0002]
[Prior art]
A hard disk drive, which is a typical magnetic disk device, has an increased surface recording density by increasing a track density and a linear recording density. The increasing tendency of the track density exceeds the increasing tendency of the linear recording density, thereby improving the surface recording density.
In order to achieve a high recording density, head tracking servo technology for accurately tracking a narrow track of a magnetoresistive head (MR head, GMR head, TMR head, etc.) also plays an important role. .
[0003]
In a hard disk drive using such tracking servo technology, servo information such as tracking servo address information (track data, sector data) is recorded on a disk medium. High accuracy is required for writing and reading these signals. Currently, in hard disk drives, formatting is performed to write servo information to a disk medium by a servo writer incorporating a laser length measuring device for head position detection. The problem is that it takes time to write signals on a large number of tracks while positioning the head with high accuracy, and the servo writer is costly.
[0004]
Therefore, instead of a servo writer, formatting is performed by superimposing a master medium in which servo information is written on a magnetic disk medium to be formatted, and transferring the information on the master medium to the magnetic disk medium by applying an external magnetic field. Came to be done. (For example, see Patent Document 1)
In the transfer method using the master medium, magnetic transfer is performed by supplying an external magnetic field with the master medium in close contact with the magnetic disk medium to be preformatted, and a magnetic recording medium having predetermined servo information in a short time is obtained. Since it can be manufactured, the manufacturing process can be simplified and the cost can be reduced.
[0005]
[Patent Document 1]
JP-A-7-78337 [0006]
[Problems to be solved by the invention]
However, the transfer method using the master medium is caused by the characteristics of the master medium itself, for example, "variation" of the magnetic pattern when the master medium is formed, or the adhesion between the master medium and the magnetic disk medium as the product. Due to the causes, the quality of the transferred signal is greatly affected.
[0007]
FIG. 6 is an explanatory diagram of signals in the conventional example.
Some of the transferred servo signals have poor signal quality. If this magnetic disk medium is used as it is, an error occurs. Thus, when recording is performed using a transfer technique, problems peculiar to transfer such as transfer unevenness occur.
Accordingly, an object of the present invention is to provide a magnetic transfer apparatus that improves transfer accuracy.
[0008]
[Means for Solving the Problems]
A magnetic transfer device for transferring servo information from a master medium to a slave medium by bringing a master medium on which servo information is recorded into close contact with a slave medium and applying an external magnetic field. When the transfer of the image is completed, only the master medium is rotated by a predetermined angle, the re-transfer means for transferring the servo information of the master medium to the slave medium again, and the servo information on the transferred slave medium is reproduced in units of tracks, and the servo is reproduced. An amplitude value comparison unit that compares an amplitude value of information with a predetermined value, and a servo information selection unit that selects servo information to be used in the slave medium from servo information larger than the predetermined value as a result of the comparison. .
[0009]
With this configuration, it is possible to select servo information having a normal signal from a plurality of transfer results without selecting servo information having a deterioration signal caused by transfer unevenness, so that the slave has improved accuracy. The medium can be manufactured.
Also, a magnetic transfer device for transferring servo information from a master medium to a slave medium by bringing a master medium on which servo information is recorded into close contact with a slave medium and applying an external magnetic field, wherein the positions of the servo information are different. When the transfer of the servo information from the master medium to the slave medium is completed, only the master medium is replaced, and the multiple master re-transfer means for transferring the servo information of the master medium to the slave medium again, and the transferred slave Servo information on the medium is reproduced for each track, and the amplitude information comparing means for comparing the amplitude value of the servo information with a predetermined value is compared. Servo information selection means for selecting.
[0010]
With this configuration, it is possible to select servo information having a normal signal from a plurality of transfer results without selecting servo information having a deterioration signal caused by transfer unevenness, so that the slave has improved accuracy. The medium can be manufactured.
The servo information selection means further reproduces the address information of the servo information and selects the servo information that does not cause a read error.
[0011]
With this configuration, since it is determined whether or not the address information can be read normally for a signal with a normal signal level among a plurality of transfer results, it is possible to manufacture a slave medium with higher accuracy.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a configuration diagram of a magnetic transfer apparatus according to an embodiment.
The magnetic transfer apparatus 1 includes a medium rotation exchange unit 2, a medium unit 3, a transfer magnetic unit 4, a reproduction signal selection unit 5, and a rotation exchange instruction unit 6.
The medium rotation exchanging unit 2 causes the master medium 11 and the slave medium 12 to adhere to each other and rotate in a predetermined direction according to an instruction from the rotation exchanging instruction unit 6. Further, only the master medium 11 is rotated by a predetermined angle with respect to the slave medium 12. The master medium 11 is also exchanged.
[0013]
The medium unit 3 includes a master medium 11 and a slave medium 12.
As shown in FIG. 3, the transfer magnetic unit 4 uses a positioner 13 to bring the magnet 14 close to the upper side of the master medium 11 with a predetermined gap, and the master medium 11 and the slave that rotate when the magnet 14 moves in the X-axis direction. An external magnetic field is applied to the medium 12 to transfer the servo information formed by the master medium 11 to the slave medium 12.
[0014]
The reproduction signal selection unit 5 reproduces the signal of the slave medium 12 after the transfer is completed, confirms the amplitude value of the signal for each track, and restores the data of the servo information. Then, servo information is selected according to a predetermined standard.
The predetermined standard is the signal intensity, the youngest number when the transfer times are counted in order from “1”, and the like.
[0015]
The rotation exchange instruction unit 6 instructs the medium rotation exchange unit 2 to rotate, and when the transfer is completed, instructs to rotate only the master medium 11 with respect to the slave medium 12 by a predetermined angle or replaces the transfer master medium 11. Give instructions.
FIG. 2 shows a flowchart of processing of the magnetic transfer apparatus of the embodiment.
An explanation will be given by taking two transfers as an example.
[0016]
First, the master medium 11 and the slave medium 12, which is a magnetic recording medium to be transferred, are set in the medium rotation exchanging unit 2 (step S11).
Next, the first transfer from the master medium 11 to the slave medium 12 is performed (step S12).
FIG. 3 is an explanatory diagram of magnetic transfer.
[0017]
In the magnetic transfer process, a magnetic disk medium is brought into close contact with a master medium 11 having servo information as a slave medium 12 and rotated in the same direction at a predetermined rotation speed. Next, by moving the magnet 14 in the X-axis direction by the positioner 13 of the transfer magnetic unit 4, an external magnetic field is applied to the master medium 11 and the slave medium 12, and the servo information of the master medium is transferred to the slave medium 12. The
[0018]
Next, when the first transfer is completed, the master medium 11 is separated from the slave medium 12, and only the master medium 11 is rotated by a predetermined angle.
Next, the master medium 11 is brought into close contact with the slave medium 12 again. Then, the second transfer is performed (step S13).
Further, instead of rotating the same master medium by a predetermined angle, when the first transfer is completed, the master medium 11 is separated from the slave medium 12, and the position of the servo information of the master medium 11 used for the first transfer is removed. There is also a method of exchanging with the master medium 11 formed at a different position.
[0019]
Another example of the master medium replacement method is as follows.
First, for a plurality of master media 11, servo information is transferred to the slave media 12 in advance, and the servo signals are measured to obtain the characteristics of transfer unevenness in units of tracks. Next, a master medium 11 is selected from the plurality of master media 11 in a combination that does not cause uneven transfer on the same track. A plurality of master media 11 of this combination is used as a transfer master medium 11. This method enables more accurate transfer.
[0020]
FIG. 4 is an explanatory diagram of two transfer processes.
By the first transfer, the servo information is transferred from the master medium 11 shown in FIG. 4A to the slave medium 12 shown in b.
At the time of the second transfer, the master medium 11 is rotated by a predetermined angle from the master medium 11 shown in a as shown in c. When the master medium 11 is transferred, the first transfer indicated by the dotted line and the second transfer indicated by the solid line are transferred onto the same slave medium 12 as indicated by d.
[0021]
When the transfer is completed, 1 is set to N which is a track number (step S14).
Next, the master medium 11 is moved away from the slave medium 12, a magnetic head (not shown) is brought close to the slave medium 12, a servo signal with a track number N is read, and an amplitude value is measured (step S15).
For example, the amplitude value of the address information (track data, sector data) signal included in the servo signal is measured.
[0022]
When the servo signal is read, the servo signal transferred at the first time or the servo signal transferred at the second time is identified by, for example, adding a position detection mark to the slave medium in advance. Then, the first servo signal can be identified as the first and the subsequent servo signals as the second.
Next, the measurement result of the first servo signal 1 is acquired (step S16).
[0023]
Next, the amplitude value is compared with a predetermined value (step S17).
When the amplitude value is larger than the predetermined value, the signal is good, the servo signal 1 is adopted (step S18), and the second servo signal 2 is erased.
At this time, the servo signal selection method is a method of selecting the one with the smaller number of times of transfer.
[0024]
If the first amplitude value is not greater than the predetermined amplitude value, the measurement result of the second servo signal 2 is acquired (step S19).
Next, it is confirmed whether or not the amplitude value of the second servo signal 2 is larger than a predetermined amplitude value (step S20).
When the amplitude value is larger than the predetermined value, the second signal is selected and the first servo information 1 is deleted (step S21). If neither is a predetermined level, an error notification is sent (step S22).
[0025]
It is checked whether N is the end of the track (step S23).
If not final, N = N + 1, and the process returns to step S15 to repeat the process.
When N is final, the process ends.
FIG. 5 shows an explanatory diagram of the signal selection process.
When the servo signal transfer master medium is transferred twice at different angles, servo signals are recorded at different positions as seen in the time domain as shown in FIG. Here, when the servo signal 1 of the first transfer is deteriorated due to the transfer unevenness, the servo signal 2 of the second transfer is adopted.
[0026]
In the case of multiple transfers, if the second servo signal is also deteriorated, the servo signal of the track is lost and position information cannot be obtained by using the subsequent servo signal. Can be prevented. In addition, in the case of multiple transfers, multiple servo signals with amplitude values exceeding a predetermined level may be acquired. In that case, for example, selection is performed by adopting the one with the smallest number of transfers. To do.
[0027]
Further, when the amplitude value is larger than the predetermined value, the address information of the servo information, that is, the gray code is further read to determine whether or not the data can be read normally, and the error information is not selected as the servo information. As a result, transfer unevenness can be detected with high accuracy, and transfer accuracy can be further improved.
Further, the characteristics of the master medium 11 are measured in advance, and the magnetizing conditions such as the pressing pressure when the master medium 11 is brought into contact with the master medium 11 and the magnetic flux density to be applied are changed and transferred every rotation of a predetermined angle. By doing so, the transfer accuracy can be improved.
[0028]
【The invention's effect】
According to the present invention, it is possible to reduce the rate at which defective products appear due to uneven transfer of the magnetic disk medium, thereby reducing costs.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a magnetic transfer device of an embodiment. FIG. 2 is a flowchart of processing of the magnetic transfer device of the embodiment. FIG. 3 is an explanatory diagram of magnetic transfer. 5] Illustration of signal selection processing [FIG. 6] Illustration of conventional signal [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Magnetic transfer apparatus 2 Medium rotation exchange part 3 Medium part 4 Transfer magnetic part 5 Playback signal selection part 6 Rotation exchange instruction | indication part 11 Master medium 12 Slave medium 13 Positioner 14 Magnet

Claims (2)

A magnetic transfer device for transferring a servo signal from a master medium to a slave medium by closely attaching a master medium on which a servo signal for detecting a head position is recorded to the slave medium and applying an external magnetic field,
When the transfer of the servo signal from the master medium to the slave medium is completed, only the master medium is rotated by a predetermined angle, the servo signal of the master medium is again transferred to the slave medium, and the master medium is based on the adhesiveness with the slave medium. Re-transfer means for transferring the pressure by changing the pressing pressure when the medium is brought into close contact with the slave medium from that before rotation ;
Amplitude value comparison means for reproducing the servo signal on the transferred slave medium in units of tracks and comparing the amplitude value of the signal with a predetermined value;
As a result of the comparison, servo signal selection means for selecting a set of servo signals in units of tracks based on a predetermined reference from a set of servo signals for each rotation angle exceeding a predetermined amplitude value ;
Erasing means for erasing servo signals other than the selected one,
A magnetic transfer apparatus comprising:  2. The magnetic transfer apparatus according to claim 1, wherein the servo signal selection means further reproduces an address information signal composed of track data and sector data included in the servo signal, and selects a servo signal which does not cause a read error. .

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