JPS6018814A - Control method of magnetic disk head - Google Patents

Abstract

PURPOSE:To control the position of a magnetic head by performing the self-writing at a position excepting for an alignment track through the read/write head part of a magnetic disk device to be controlled and then measuring the distance between the data position and the alignment track. CONSTITUTION:An alignment disk containing an alignment track A written with high accuracy by an alignment writer is loaded to a prescribed track. Then a magnetic head is shifted by a track toward the inner circumferential side, for example, from the track A by a head feed mechanism of magnetic disk device to be controlled. The disk device peforms the self-writing by itself at the position of the head. Then a track B which has performed the self-writing is read as it is by the head. The head is shifted and fixed at the inner and outer circumferential sides in case the diference between the track pitch and the (b)-(d) shift distance is positive and negative respectively by an amount equivalent to said difference. This eliminates a control error due to an assembling common difference between an R/W gap 1 of the the magnetic head and the center between E gaps 2 and 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic disk head adjustment method for adjusting the amount of deviation in the track radial direction of a magnetic disk device, that is, the amount of off-track.

-1- Conventional configuration and melting point thereof Magnetic heads for magnetic disks generally include tunnel erase heads and straddle erase heads, and the two types are distinguished by the structure of the erase head. The straddle erase head is a read/write head (hereinafter referred to as
The head gap between the R/W head (hereinafter referred to as the R/W head) and the erase head (hereinafter referred to as the E head) is in a straight line, making it easy to use the electrical timing, but
There is a problem with magnetic properties.

In recent years, the magnetic disk industry has tended to become a big industry, and in order to achieve this, there are two ways to increase TPI (tracks per inch) and BPI (bits per inch in the circumferential direction).
There are two ways to raise it.

According to the latter, a new format must be created and there is no compatibility with conventional products, so many manufacturers adopt a method of increasing the TPI. In order to increase the TPT, a tunnel erase head is generally used from the viewpoint of magnetic properties.

This tunnel erase head is shown in Fig. 1 and Fig. 2-2.
- ・As shown in the figure, the R/W head gap 1 (hereinafter referred to as R
/W gap) and the E head gap 2°3 (hereinafter referred to as E gap) are separated by a certain distance 11111. In addition, cores 4a and 4b that constitute the R/W head
, 4c and a core 5a forming the F head.

5b, 5c and spacers 6a, 6b are bonded together. In addition, 7 is R/W'-1yl and 8 is E]yl.

Conventionally, for head adjustment of a magnetic disk drive, an alignment disk having a recorded data pattern as shown in FIG. 3 is usually used. On this CF disk, two concentric continuous data 01 and 02 are recorded at a center point P' that is slightly shifted from the center point P in normal use. The read waveform when the magnetic head moves a-b-c-d using the rack 03 as a trajectory is as shown in a-d in Fig. 4, and one revolution of the disk results in one rotation.
A waveform resembling two cat's eyes is obtained. The amplitude ratio A/B of these two waveforms corresponds to the off-track version of track 03 based on the center point P, and a method of adjusting the herald position using this is widely used.

In the tunnel erase head, as shown in FIG. 5, the data first written in the R/W gap 1 is erased at both ends by the E gaps 2 and 3, and the data width becomes narrower. The center of this narrowed data is the track center of this drive, and this track center is not determined by the R/W gap 1, but by the E gap 2.3.
determined by Note that 9 is the center of rotation of the magnetic disk. Therefore, according to the conventional adjustment method described above, R/
The center of W gap 1 is aligned with the center of the data, and the center deviation due to the difference in curvature between the outermost track and the innermost track, and the R/R when manufacturing the head as shown in Figure 6.
The center of the distance between the W gap 1 and the E gap 2.3 is controlled to be A±α, but there is a drawback that this dimensional tolerance α becomes a direct error.Especially in drives with high TPI, this adjustment error is a fatal flaw.

Purpose of the Invention The present invention provides an alignment dee written in concentric circles.
- It is an object of the present invention to provide a magnetic head adjustment method that allows the position of the magnetic head to be adjusted with high precision using a spoon.

Structure of the Invention The method for adjusting a magnetic disk head of the present invention is to adjust the position of a tunnel erase type magnetic head having one read/write head section and two erase head sections in a disk device to be adjusted. The reading/writing head section of the magnetic disk device to be adjusted self-writes data to a position other than the alignment track of an alignment disk having an alignment track, and magnetically connects this self-written data position to a position other than the alignment track by measuring the distance between the self-written data position and the alignment track. The purpose is to adjust the head position.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 7 shows self-writing by the adjusted magnetic disk device in one embodiment of the present invention. First, an alignment disk having alignment tracks written in predetermined tracks with high precision by an alignment writer is loaded into the magnetic disk device to be adjusted, and the head feeding mechanism (stepping mechanism) of the magnetic disk device itself is loaded. The head is moved, for example, one track inward from the alignment track A using a steel belt system connected to a motor, a spiral cam system, a single lead screw system, etc. (not shown here), and the magnetic field to be adjusted is adjusted. The disk device itself writes to that location.

This self-writing track is B. In addition, 1 is R/W
The gap 2 is the outer E gap of the two E heads, 3 is the inner E gap, and 9 is the center of rotation of the magnetic disk. Next, track B on which self-writing has been performed is read at the same head position. That is, in Fig. 8, R/
The W head 1 is in a positional relationship with the track B as shown in A. Even if the R/W gap 1 is moved slightly from state A to state A, the data width detected by the R/W head remains the same, so the head output remains unchanged (because the head output is proportional to the data width). Furthermore, when moving from state A to The output voltage gradually increases after reading track A.The change in output voltage during the above process is shown in the 9th section.
It is a diagram.

Here, the track pitch is known by design, and
If (track pitch) - (travel distance between tracks) is positive, move the head toward the inner circumference by that difference, and if it is negative, move the head by that difference. By moving it to the outer circumferential side and fixing it, the magnetic disk device to be adjusted can be adjusted to the track position with high precision without any adjustment errors due to the center assembly tolerance of the magnetic head's R/W-f sep 1 and E gap 2.3. can.

As described in the detailed description of the invention, the magnetic disk head adjustment method of the present invention does not require writing with the alignment disk eccentric as in the conventional example, so it is not only easy to create an alignment disk, but also easy to use in practice. Since the recording position of the magnetic disk device itself and the track position of the alignment disk are compared and adjusted, differences in curvature from the outermost track to the innermost track can be absorbed, and variations in the assembly of the R/W head and E head can be absorbed. Because it can also absorb
This makes it possible to adjust the head position with high precision, especially the high precision position adjustment required for high track density devices.

[Brief explanation of the drawing]

Figures 1 and 2 are a perspective view and a plan view of the main parts of a conventional tunnel erase head, Figure 3 is an explanatory diagram of the conventional head adjustment method, and Figure 4 is an illustration of the R/W head in Figure 3. Output waveform diagram, Figure 5 is an explanatory diagram showing how the data width is formed in the tunnel erase head, Figure 6 is a plan view of the main part of the head showing the center dimensions of the R/W head and F head, and Figure 7 is an explanatory diagram showing how the data width is formed in the tunnel erase head. FIG. 8 is an explanatory diagram of an alignment track and a self-writing track in an embodiment of the present invention. FIG. 18 - A dimensional explanatory diagram showing the relative relationship between alignment 1 and rack A. FIG. 9 is an explanatory diagram of the head output in FIG. 8. 1...R/W gap, 2.3...E gap, 9
... Magnetic disk rotation center, A... Alignment track, B... Self-inclusion track agent Yoshihiro Morimoto 9- fI/! 1lrI! J 2nd figJ 3rd 4th 55th figure O'X? Figure 4 Figure 7

Claims (1)

[Claims] 1. When adjusting the position of a tunnel erase type magnetic head having one read/write head section and two erase head sections in a magnetic disk device to be adjusted, the alignment of an alignment disk having alignment tracks written concentrically. A magnetic disk head adjustment method in which the read/write head unit of the magnetic disk device to be adjusted self-writes data to a non-track position, and the distance between the self-written data position and the alignment track is measured to adjust the magnetic head position. .