JPS59142732A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To eliminate the need to write servo data and to perform tracking accurately by using a magnetic head which has a flexed gap for recording and reproduction and detecting data in an area of a format part which is not utilized directly by a user. CONSTITUTION:Half of a series of recording and reproducing gaps are perpendicular to tracks and the other half of them are oblique. For example, when the head is off the track downward, a playback signal 345' at the part of width 34 is generated slightly before a playback signal 35' (time reference) at the part of width 35. On the other hand, when the head gap is off the track upward, a playback signal 39' at the part of width 39 is generated slightly behind a playback signal 38' (time reference) at the part of width 38. Therefore, which direction 34' or 39' shifts in is detected to make a fine adjustment of tracking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording and reproducing apparatus, and relates to a magnetic recording and reproducing apparatus that performs tracking by detecting data in a formant section on a disk (for example, data in an index gap) within 1%.

An object of the present invention is to eliminate the need to write servo data on a disk by using a magnetic head having a ``(''-shaped guyan).

In recent years, the linear focus density and trunk density of magnetic recording/reproducing devices have been increasing, and in particular, products with trunk pitches of 20 to 50 microns are being commercialized. Therefore, in order to correctly move the head position to the trunk in response to disturbances, the mainstream is the close servo method, which uses servo information written on the disk surface. This method can be broadly divided into a servo surface servo method or a trunk servo method using a dedicated servo head, and a method in which the servo potator is read by a recording/reproducing head. As a typical example of the latter, a sector servo method is used in which 8@ servo data are stored at the beginning of each sector. This example is shown in figure i-1. 1 is a servo field in which data for detecting position information is written, and is offset from data trunk 2 by a half pitch.

5 and 4 are signals obtained when the A field and B field are individually reproduced, respectively, and are out of focus. Therefore, when the data of the servo field is read by the recording/reproducing head, it is possible to detect how far the head is deviated from the center of the trunk depending on the relative output peak amplitudes of the A field and B field. If 5 shifts to the A field side, an autopsy will occur where 6 shifts to the B field side. In this way, traditional methods
It is necessary to write the servo field data accurately by shifting only the cow pinch trunk, which requires a high-precision writer and is also a factor in cost amplifier.

The present invention eliminates the need to write servo data.

Moreover, the present invention provides a magnetic recording/reproducing device that can accurately perform tracking.

The invention will be described in detail below using examples.

FIG. 2 is an enlarged view of the vicinity of the gap portion of one embodiment of the magnetic head mounted on the apparatus of the present invention. (b) is - of (a)
\ flat 1Ii of the Gui Young part seen from the sliter surface side
This is an I diagram. In other words, half of the series of recording/reproducing gaps are perpendicular to the trunk, and the other half are diagonal. The principle of the tracking method using the head shown in FIG. 2 will be explained below. FIG. 5(a) is an example of a sector armant used in a conventional device, in which 21 is one trunk period, and 22 is a period in which a plurality of sectors exist. 2
5 and 20 are gigang data on the head and tail of the trunk, 2
4 is data for synchronization, 25 to 30 are seven fields, gaps, data address marks, data areas available to the user, CR', 9, and gaps.

In the present invention, tracking is performed by detecting data other than 28 in this formant part. For example, data for synchronization of \\ is written in the index gap 24, and this data is used.

(k)) The figure is (,) 24″S in the figure, ＼ data FM
This is a part of the data pattern when the magnetization is reversed using an, fc, and the solid line part indicates the reversal part of the recording magnetization, n-1, n,
.

'n+1 indicates the trunk that met next door. Note that relative dimensions such as trunk width, recording bit pinch, etc. are illustrated far from reality. FIG. 4(-) shows a part 61 of the magnetization reversal part of the Intens Gatsfu on one trunk in FIG. It shows a position off-trunk by 66 degrees in the direction. For example, in the case of a downward off-trunk, as shown in the figure (b), the reproduced signal is a portion of 54 width slightly before the reproduction signal 55' (which serves as the time reference) at a portion of width 65. A reproduced signal 34' is generated.

Portions other than 64 and 35 out of the width 33 are hardly reproduced due to azimuth loss between the recording magnetization pattern and the head gap. On the other hand, if the head gap is off-trunk in the upper direction of the paper gap as shown in figure 57, the reproduced signal 58' (which becomes the time reference) at the width part of 38 as shown in Figure (C). A little later, 59
A reproduced signal 69' is generated in a portion having a width of . Therefore, no matter which way the head offtrunks, the timing of the reproduced signals 6da and 68' from the 65 or 38 width portions will not change. The off-tran changes depending on the direction are determined by the timing of the reproduced signals 54' and 39' from the 34 or 590 width portion. Therefore 357 and 58'
By detecting in which direction 64' or C 59' is shifted with reference to , tracking can be finely adjusted. When trunked to the correct position, 64' and 5da or 68' and 39' occur at the same timing.

For example, in the case of a fixed disk of 5 inches or less, the data transfer rate is 5 megabits per second, and the magnetization reversal interval is a time difference of 200'-11 seconds. When using the head of the example, the off-trunk amount is X.

The angle of the inclined part of the gear luff is θ, and the trunk diameter is r.

If the disk rotation speed is 3600 rpm, then 1, for example, 3
The time difference between 4 and 55 is expressed as xtan"/2yrrX6g. Therefore, this value is largest at the innermost trunk, so set this value at the innermost trunk to 200+1 seconds!
If we set σ so that Q, -d1, we can obtain the equation shown in Figure 4 (1
)) *A signal like (C) is obtained.

In the embodiment of this application, the head structure is such that half of the gearing is perpendicular to the trunk and the other half is inclined, but as long as the inclination angles are different, it is necessary that half of the gearing be perpendicular to the trunk. There isn't.

As described above, according to the present invention, it is not necessary to write servo data as in the conventional method, so there is no need to write servo data on the image side, and the effort of writing can be saved. Therefore, it greatly contributes to cost reduction.

In the present invention, an example has been shown in which the index section at the beginning of each sector is detected, but a method of detecting the section 23 at the beginning of the trunk is also possible.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional embodiment. 1... Servo field, 2... Data trunk. 24... Index gear lug (5YNO data),
. 6t...Magnetization reversal section, 28...User use 52.57...Head camp, data area. 55... Trunk width.

Claims (1)

[Claims] (Using a magnetic head with a #-shaped recording/reproducing gear lug shape, the Forman HfB user can detect data in an area (e.g. index gap) that is not directly used by the user of the magnetic head. A magnetic recording/reproducing device characterized by tracking.