JPS62270072A - Reference track writing method - Google Patents

Abstract

PURPOSE:To secure a writing accuracy easily and inexpensively by supporting a writing head and a reading head by the same carriage, and positioning a carriage to the position to read the signal written by the writing head with the reading head without shifting the carriage. CONSTITUTION:At a carriage 4, a writing head 5 and a reading head 6 are opposed and supported by sandwiching the rotation center of a spindle 3 between them. The carriage 4 can be shifted in an X direction. In order to provide a reference track, the carriage 4 is positioned to a suitable position in the X direction, the position data are written to a disk 2 by the head 5 and it is confirmed whether or not the position data can be read by the head 6. When the data cannot be read, the position data are deleted, the carriage 4 is suitably shifted in the X direction and the writing and confirming are executed again. When the data are read, the track, into which the position data are written, is made into a reference track. Thus, without improving the processing accuracy of the reference surface of an individual HDA (head disk assembly), a writing accuracy can be secured.

Description

Detailed Description of the Invention Detailed Description of the Invention [Industrial Application Field] The present invention provides a method for creating a reference track (in this specification, a reference track is a track with a known diameter) on a disk-type recording medium in which a positioning error exists. or at least a track whose diameter can be calculated.

[Conventional technology]

Conventionally, in a servo track writer that writes to a magnetic disk in an HDA (head disk assembly), a reference surface is machined on the fDA case and a corresponding reference surface is provided on the servo track side. By aligning the surfaces and positioning the magnetic disk at a predetermined position with high precision, the writing accuracy of the servo pattern on the magnetic disk (writing positional accuracy and angular accuracy of the servo head relative to the center of rotation of the disk) was ensured. . Therefore, in order to ensure writing accuracy, it was necessary to improve the processing accuracy itself of the reference surface of each HDA.

[Problem that the invention seeks to solve]

However, when writing to many HDAs with a servo track writer, it is necessary to write to each HDA in this way.
Improving the machining accuracy of the reference surface A has been problematic in that it increases costs.

The invention was made in view of the above points, and the invention was made in view of the above points.
It is possible to ensure the writing accuracy of the servo pattern without improving the machining accuracy of the DA reference surface (that is, while maintaining the positioning error of the magnetic disk caused by the low machining accuracy of the reference surface). This is what we are trying to do.

[Means for solving problems]

The present invention is characterized in that a reference track can be provided on a magnetic disk where a positioning error exists, in order to ensure the writing accuracy of the servo pattern.

That is, one aspect of the present invention (first BA) is to support a write head and a read head on the same carriage with a predetermined distance apart, and to transmit signals written by the write head onto a disk-type recording medium. positioning the carriage at a position where it can be read by the read head without moving the carriage; and at the position, tracks on the disk-type recording medium on which signals have been written by the write head are recorded. The present invention is characterized in that a reference track in a disk-type recording medium has a diameter corresponding to the predetermined distance.

Another aspect of the present invention (second invention) is to support a write head and a read head on the same carriage with a predetermined distance apart, and to write a signal to a disk-type recording medium by the write head, A track on the disk-type recording medium on which the signal is written is set as a reference track on the disk-type recording medium, and the carriage is moved to a position where the signal on the reference track can be read by the read head. and determining the diameter of the reference track based on the amount of movement of the carriage and the separation distance between the write head and the read head in the carriage.

[Effect]

(1) Regarding the first invention, when the signal written on the disk-type recording medium by the write head can be read by the read head without moving the carriage, the write head and the read head are on the same track.

That is, the diameter of the track corresponds to the separation between the write and read heads in the carriage and is known. Therefore, by using this track as a reference track, it is possible to provide a reference track on a disk-type recording medium in which a positioning error exists.

Therefore, in the above-mentioned servo track writer, the present invention is adopted to provide a reference track on each magnetic disk, and for example, each time writing is performed on each magnetic disk, the position of the servo head is calibrated based on reading of the reference track. By doing so, it becomes possible to ensure the writing accuracy of the servo pattern without improving the processing accuracy of the reference surface of each HDA (that is, while maintaining the positioning error of the magnetic disk).

(2) Regarding the second invention, the diameter of the track on which the signal is written by the writing head is:
It can be calculated based on the amount of movement of the carriage when the carriage is moved to a position where the signal on the track can be read by the read head and the separation distance between the write head and the read head in the carriage. Therefore, by using the track as a reference track, a reference track can be provided on a disk-type recording medium in which a positioning error exists.

Therefore, if this invention is adopted in the above-mentioned servo track writer in the same manner as shown in the first invention, the servo pattern can be processed without improving the machining accuracy of the reference surface of each T (DA). Writing accuracy can now be ensured.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a reference track writing method according to one aspect of the present invention (first invention). 1 is an HDA positioned on a servo track writer (not shown) by aligning reference surfaces; 2 is a magnetic disk mounted on a spindle 3 in HDAl; 4 is a magnetic disk to be written by the servo track writer; 4 is a magnetic disk according to the present invention; A carriage specifically provided on the servo track writer for implementation.

The carriage 4 has a write head 5 and a read head 6 mounted on the ideal rotation center of the spindle 3 (that is, the rotation of the spindle 3 assuming that the reference plane of the positioned HDA 1 has no machining errors at all). They are supported in a state where they face each other with the center (position where the center is located) sandwiched between them.

The gear IJ and gear 4 are movable in a straight line connecting the head 5.6 (direction of arrow X in the figure).

In order to provide a reference track on the disk 2, position data is written on the disk 2 by the write head 5 while the carriage 4 is positioned at an appropriate position in the X direction.
At the same time, it is checked whether the position data can be read by the read head 6 (that is, whether both heads 5 and 6 are on the same track). At this time, the write head 5 writes adjacent DDD EVEV patterns, and when the head 5 is placed on track in the middle, the read head 6
By looking at the position signal, the accuracy can be further improved.

If the position data cannot be read by the read head 6 (that is, if both heads 5 and 6 are not on the same track), after erasing the position data, move the carriage 4 by an appropriate distance in the X direction and read it separately. position, and perform the above writing and confirmation again in that state. By repeating writing and checking in this way, the carriage position where the position data can be read by the read head 6 (that is, both heads 5 and 6 are on the same track) is determined.

Once the carriage position is determined (FIG. 1 shows the carriage 4 at this position), the write head 5 (at this position) writes the track T1 on which the position data has been written on the disk 2. Use as reference track.

Due to the low machining accuracy of the HDAl reference surface, the actual rotation center O° of the spindle 3 is shifted ΔX in the X direction from the ideal rotation center O, as shown in FIG.

If there is a shift of ΔY in the Y direction (direction perpendicular to the X direction) (that is, the disc 2 is shifted in the X direction).

(If there is a positioning error in the Y direction by △X and ΔY, respectively)
, radius r of track T1 and distance 2R between both heads 5 and 6
There is a relationship between . Here, if ΔR= r - R (= b - R), when ΔR is below a certain value (that is, when ΔY is below a certain value), r can be approximated by R (for example, R=
In the case of 60 igm, if ΔR≦0.01++m and r can be approximated by R, ΔY can be allowed up to 1.1 mm). Therefore, as long as the positioning error △Y caused by the low processing accuracy of the HDA reference surface is below the above-mentioned certain value, it is possible to track by accurately measuring the distance 2R between both heads 5 and 6 in advance. T1 can be a track with a known radius. To measure the distance 2R between both heads 5 and 6, for example, the carriage position is determined in advance using the method described above for another magnetic disk, and the diameter of the track on which position data has been written at that position is determined using a magnetic phenomenon method. This shall be done by measuring using methods such as

When writing the servo pattern to disk 2,
The position data of the reference track T1 thus provided is read out by the servo head in the servo track writer to first calibrate the position of the servo head, and then writing is performed by the servo head. As a result, it is possible to ensure the writing accuracy of the servo pattern on the disk 2 without improving the machining accuracy of the reference surface of 1 (DA i (i.e., the positioning errors ΔX and ΔY of the disk 2 remain). .

Thereafter, by similarly installing a reference track and calibrating the position of the servo head for each magnetic disk in each HDA positioned in the servo track writer, the processing accuracy of the reference surface of each HDA is improved. Therefore, the accuracy of writing servo patterns to each disk can be ensured.

Next, FIG. 2 shows an embodiment of a reference track writing method according to another one (second invention) of the present invention. HDAl
, disk 2. Spindle 3. Carriage 4. Write head 5. The read head 6 is completely similar to that in the first invention.

In order to provide a reference track on disk 2, the steps shown in Fig. 2 (
As shown in a), with the carriage 4 positioned at an appropriate position in the X direction (for example, a position where the ideal rotation center 0 is located exactly in the middle of both heads 5),
Position data is written on the disk 2 by the write head 5, and the track 2 on which the position data is written is set as a reference track on the disk 2.

Thereafter, the carriage 4 is moved in the X direction at a position where the read head 6 can read out the position data of the track T2, as shown in FIG.

If this moving distance is S, the radius r of the track T2 is
As already shown for the first invention, as long as the positioning error △Y due to the variation in the dimensions of each HDA is below a certain value, it can be approximated as r; (determined by the direction of) Therefore, if the distance 2R between both heads 5.6 is accurately measured in advance as already shown in the first invention, the track T2 can be made into a track whose radius can be calculated by finding S. Can be done.

When writing the servo pattern to disk 2,
2 on this reference track to calibrate the position of the servo head as already shown in the first invention,
After that, writing is performed using the servo head. This results in
As with the first invention, writing accuracy of the servo pattern can be ensured.

In this embodiment, this invention is adopted in order to provide a reference track on the magnetic disk in each HDA in a servo track writer that writes to a magnetic disk in an HDA. The invention may be employed in any other suitable field where providing a reference track on a medium is of some value.

〔Effect of the invention〕

As described above, the reference track writing method according to the present invention has the effect that a reference track can be provided on a disk-type recording medium in which a positioning error exists using simple and inexpensive means and methods. Therefore, for example, in a servo track writer that writes to a magnetic disk in an HDA, if the present invention is adopted and a reference track is provided on each disk, the servo head can be adjusted for each disk based on the reading of the reference track. By calibrating the position, the accuracy of writing servo data to each disk can be easily and inexpensively improved without improving the processing accuracy of the reference surface of each HDA (that is, while maintaining the positioning error of the magnetic disk). can be secured.

[Brief explanation of drawings]

FIG. 1 is a top view showing an embodiment of the reference track writing method according to one aspect of the present invention, in which the carriage is positioned at a position where the writing head and the reading head are on the same track; FIG. 2 is a top view showing an embodiment of a reference track writing method according to another aspect of the present invention;
(a) is a diagram showing a state where the carriage is positioned at an appropriate position and position data is written by the write head, (b) 4
i is a diagram showing a state in which the carriage has been moved to a position where the position data can be read by a read head; DESCRIPTION OF SYMBOLS 1... HDA, 2... Magnetic disk, 3... Spindle, 4... Carriage, 5... Write head,
6...Reading head

Claims (1)

[Scope of Claims] 1. A write head and a read head are supported on the same carriage with a predetermined distance apart, and the signals written by the write head to the disk-type recording medium are transmitted to the disk-type recording medium without moving the carriage. positioning the carriage at a position that can be read by a read head; and at the position, a track on the disk-type recording medium on which a signal has been written by the write head is transferred to the predetermined position on the disk-type recording medium. A method for writing a reference track, characterized in that the reference track has a diameter corresponding to a distance. 2. In a servo track writer that writes to a magnetic disk in an HDA (head disk assembly), the method according to claim 1 is used to provide a reference track for each magnetic disk in each HDA. Reference track writing method. 3. A write head and a read head are supported on the same carriage at a predetermined distance apart, and the write head writes a signal on a disk-type recording medium, and the track on the disk-type recording medium where the signal is written is is set as a reference track on the disk-type recording medium; moving the carriage to a position where the signal on the reference track can be read by the read head; and determining the amount of movement of the carriage and the writing in the carriage. Based on the separation distance between the head and the read head,
A reference track writing method comprising: determining a diameter of the reference track. 4. The standard according to claim 3, which is used to provide a reference track for each magnetic disk of each HDA in a servo track writer that writes to a magnetic disk in an HDA (head disk assembly). Track writing method.