JPS5846782B2 - Head alignment information - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In magnetic disk storage devices, it is necessary to vertically align heads in order to maintain disk pack compatibility.

At this time, a head alignment disk pack with head alignment information written on the disk surface is used.

The present invention is used as a method for writing head alignment information to a disk pack.

Referring to FIGS. 1 and 2, a track servo type disk pack has a servo surface 7 on which position ρ information is written for positioning the head.

On the servo surface 1, an odd servo track 9 and an uneven servo track 10 are written, and the center of the core of the servo head 5 is placed at the boundary between the odd servo track 9 and the uneven servo trunk 10 (the position shown in FIG. 3, 14). Position yourself so that it will come.

In order to maintain compatibility of the disk pack with this servo head 5, it is necessary to align the data heads 4 in the direction of arrow 8.

For this purpose, a disk pack in which position information is also written on the data surface 6 is required, and this is called a head alignment disk pack.

Conventionally, both the servo head 5 and the data head 4 have had a core width approximately equal to the inter-track pitch 13 to write disk puncture head alignment information.

This method of writing head alignment information by positioning the head using position information other than the disk surface, which does not rely on the track servo method, allows each part within the device to expand and compress uniformly due to changes in ambient temperature and temperature inside the device. There is a large error due to thermal displacement caused by

Also, after writing the odd servo track 9 and the even servo track 10 on the servo surface 7, the head is positioned based on the position information and the odd alignment trunk 11 and the uneven alignment track 12 are written on the data surface. In this case, the center of the core of the servo head 5 is set to 15 and 17.
It is necessary to write to the center of the middle servo track and the middle servo track as in the position of .

In the case of position 15, the information on the even servo track 10 cannot be read at all, so it is not possible to determine whether the servo head has shifted slightly in the original direction, and accurate positioning is not possible.

The same applies to the case of position 17.

An object of the present invention is to provide a method for writing highly accurate head alignment information.

In the present invention, the core width of the data head 4 is set to 1 with the trunk-to-trunk pitch.
By setting the number to be larger than 3, highly accurate alignment information can be written using the track servo method.

An odd servo track 9 and an even servo track 10 are written in advance on the servo surface γ using a servo track writer.

Next, position the head one track away from the target track to be written (positions shown in FIG. 3, 16 and 18).
Odd alignment track 11 is provided in the data head 4 by a head having a core width twice the inter-track pitch 13.
and even alignment track 12.

Since the servo head 5 is located at the boundary between the odd servo track 9 and the even servo track 10 at positions 16 and 18, even if the servo head 5 shifts slightly, the direction of the shift can be read and the servo can correct the shift. This allows for highly accurate positioning.

Also, since it uses a track servo system, thermal displacement errors are small.

Since highly accurate positioning is possible during writing, highly accurate alignment information with little variation can be written to the disk pack.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram when the disk pack 1 is installed on the spindle 2, Fig. 2 is a diagram showing the contents written on the servo surface 7 and the data surface 6, and Fig. 3 is an illustration of the odd alignment track 9 and the even alignment trunk. 10 and the navel position. FIG. 1... Disk pack, 4... Data head, 5... Servo head, 6...
Data surface, 7...Servo surface, 9...Other servo track, 10...Even servo track, 11...Other alignment.
Track, 12... Even alignment track, 13... Inter-track pitch, 14.1
5, 16, 17, 1B... Servo head, 19
．． 20... Alignment-head, 21...
...Head core width.

Claims (1)

[Claims] 1 A disk pack in which a servo surface on which servo information is recorded consisting of an odd servo track and an even servo track, and a data surface on which head alignment information is recorded consisting of an odd alignment track and an even alignment track are stacked. A method for writing head-alignment information on a data surface in a magnetic disk drive having an odd alignment trunk and an even alignment track on the data surface by positioning the servo head on the servo surface one track at a time from the target track. writing of head alignment information on a data surface using an alignment head whose center is positioned at the boundary between the two tracks and whose core width is larger than the inter-track pitch on the servo surface; Method.