JPS59191128A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To perform highly accurate positioning of a magnetic head with a simple circuit, by alternately recording upward magnetization and downward magnetization on the surface of a vertically magnetized recording medium as track servo signals in track pitch, and combining the result with a single magnetic pole type vertical magnetic head of magnetic flux responding type. CONSTITUTION:A vertically magnetized recording medium 3 used for servo disks is composed of a magnetized circulating layer 32 and vertical magnetized film 33 formed on a board 31 and concentric magnetization is recorded on the vertical magnetized film 33 in such a way that upward magnetization and downward magnetization are alternately recorded in track pitch. The arrow Q of the diagram shows the moving direction of a single magnetic pole type vertical magnetic head 4 and the direction coincides with the radial direction of the vertically magnetized recording medium 3. When a reproduced output is to be obtained, an appropriate high-frequency signal is impressed upon an exciting coil 43 and the output of a recording-reproducing coil 42 is shaped at a filter circuit, etc., which are not shown in the diagram. Then a reproduced output as shown in the diagram can be obtained in the form of magnetic flux responding type proportional to the intensity of the magnetization recorded on the recording medium 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a perpendicular magnetization recording/reproducing type magnetic disk device, and particularly relates to a magnetic disk device using a perpendicular magnetization recording/reproducing method, and in particular to a magnetic disk device using a magneturia response type single magnetic pole type perpendicular magnetic head used as a servo head for positioning all tracks. Regarding disk devices.

(b) Conventional technology and problems A conventional example will be explained with reference to the drawings.

FIG. 1(5) shows a structural diagram of a magnetic head and a perpendicular magnetization recording medium of a normal perpendicular magnetization recording/reproducing method.

In the figure, a perpendicular magnetization recording medium 1 is a two-layer film consisting of a magnetization reflux layer 12 (usually made of NiFe) formed on a substrate 11 and a perpendicular magnetization film 15 typified by 0oOr. A main pole 21 made of a thin film of magnetic material is sandwiched between supporting substrates such as ceramics (not shown), and one end thereof faces perpendicularly to the direction of rotation shown by arrow P of the perpendicular magnetization recording medium 1, and the facing surface is polished. It has a shape that allows the tip of the thin film to operate efficiently. The other end is held by a soft magnetic arm (not shown). 22 is a recording/reproducing coil, and the magnetic head 2 having such a configuration
is called a single magnetic pole type.

FIG. 1(B) shows a correspondence diagram between the output waveform and the servo pattern of the same structure. The output induced in the coil/I/22 generates an output voltage corresponding to the temporal change in magnetization, similar to the conventional ring head.

However, a track servo signal was created by demodulating the output voltage of the lever. For this reason, the demodulation circuit becomes complicated, which hinders the simplification of the device.In order to solve this problem, magnetizations in different directions (not shown) are recorded in the radial direction of the disk at track pitches, and magnetic flux response type heads (not shown) (for example, magnetoresistive A method has been proposed in which a track servo signal is reproduced using an effect type head or the like. However, this method also has the drawback that it is difficult to obtain linearity of the output waveform with respect to displacement in the radial direction with a magnetoresistive head, and furthermore, a servo signal cannot be recorded by a single head.

(C) Object of the Invention In view of the above-mentioned conventional drawbacks, the object of the present invention is to provide a magnetic disk device that can perform highly accurate magnetic head positioning with a relatively simple circuit used in a perpendicular magnetization recording system for all servo signal generation systems. The purpose is to provide.

(d) Structure and object of the invention According to the present invention, in a magnetic disk device of a type in which a perpendicular magnetization recording medium is used as a servo disk and a track servo signal is recorded and reproduced, the perpendicular magnetization recording medium is used as the track servo signal. a flux-responsive single-pole perpendicular magnetic head that alternately records upward magnetization and downward magnetization over the entire track pitch on the medium surface, and has a core width equal to the track pitch as a recording/reproducing head for the track servo signal; An object of the present invention is to provide a magnetic disk device characterized by a combination of the following.

(e) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2(4) is a structural diagram of a magnetic flux-responsive single-pole perpendicular magnetic head and a perpendicular magnetization recording medium, and FIG. 2(B) is a diagram showing the correspondence between output waveforms and servo patterns in the same structure.

A perpendicular magnetization recording medium 6 used in a servo disk as shown in FIG.
Concentric magnetization is recorded alternately with upward magnetization and downward magnetization at a track pitch.

The main magnet (main magnet) m141 perpendicularly opposed to the perpendicular magnetization recording medium B is formed equal to the core 1ii1'ff of one pitch of the track pitch for the servo disk, and the recording/reproducing coil /v42
The heavy magnetic pole type perpendicular magnetic head 4 is provided with an excitation coil/v46 as a magnetic flux responsive type as shown in the figure.

Arrow Q is the direction of movement of the single-pole type perpendicular magnetic head 4, which coincides with the radial direction of the perpendicular magnetization recording medium B. When obtaining playback output, multiply the appropriate high frequency +! - A voltage is applied to all the excitation coils 43, and the output of the recording/reproducing coil Jv42 is shaped by a p-wave circuit, etc. (not shown), so that a reproduction output as shown in FIG. 2 [F]) is recorded on the perpendicular magnetization recording medium B. It can be obtained with a magnetic flux response type that is proportional to the strength of magnetization. It is characterized by the ability to obtain a linear output for the upward and downward magnetization reversal positions in the middle and U directions, and is obtained after conventional magnetic disk drives process it with a complex demodulation circuit. It has the same form as the track position signal. In particular, since it is a magnetic flux responsive type, the output does not depend on the relative speed between the disk and the head.

FIG. 6(4) is a structural diagram when a magnetic flux responsive single pole perpendicular magnetic head is installed for servo signal use in a magnetic disk drive. (I3) shows an enlarged principle diagram of the main parts.

In the top view, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and their redundant explanation will be omitted.

In the figure, reference numeral 5 denotes a servo head, which has the same element configuration as the single-pole type perpendicular magnetic head 4 shown in FIG. 2 (5). 6 is a helad arm. Even if there is a small discontinuity in a part of the concentric magnetization pattern shown in Fig. 6 (03) to obtain index marks, sector marks, etc., the rotational speed of the disk is much higher than that of the head series TJ) Ja. There is no problem because it is fast. Further, by stopping the excitation signal to the excitation coil/I/43 and applying a servo signal to the recording/reproducing coil (v42), self-servo write can be easily performed.

(f) Effects of the Invention As explained in detail above, according to the magnetic disk device of the present invention, recording of servo information is extremely easy, and since a complicated demodulation circuit is not required for reproduction, the device can be made smaller. It is effective in increasing the temperature and performance.

[Brief explanation of the drawing]

FIG. 1 (to) is a structural diagram of a magnetic head and perpendicular magnetization recording medium of a normal perpendicular magnetization recording/reproducing method, and FIG. 1 (B) is a correspondence diagram of the output waveform and servo pattern of the same structure. FIG. 2(A) is a structural diagram of a non-responsive single-pole perpendicular magnetic head and a perpendicular magnetization recording medium according to the present invention, and FIG.
3) is a correspondence diagram between the output waveform and servo pattern of the same structure,
Figure 3 (4) shows a structure 1-1, 1P in which the magnetic head of Figure 2 (4) is installed for servo signals of a magnetic disk device.
Figure 3

Claims (1)

[Claims] In a magnetic disk device using a perpendicular magnetization recording medium as a servo disk and recording and reproducing a track servo signal, the track servo signal includes upward magnetization and downward magnetization on the medium surface of the perpendicular magnetization recording medium at a track pitch. A magnetic disk device which alternately records information and is characterized in that a magnetic flux responsive single pole type perpendicular magnetic head having a core width equal to the track pitch is combined as the recording/reproducing magnetic head of the track servo No. 1. .