JPH01276418A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To eliminate a magnetic shield material, to safely execute positioning and to simplify structure by composing a servo magnetic head of a thin film magnetic head and arranging an adjacent data magnetic head and the servo magnetic head dislocated in a plane surface direction. CONSTITUTION:When the write or read of information is commanded, an actua tor 6 is moved by a prescribed distance according to the position information of a servo magnetic head 10 in the diameter direction of a magnetic disk 4 and the write or read of the information is executed in the respective recording surfaces of the magnetic head 4 for plural data magnetic heads 9. At such a time, since the data magnetic head 9, which is adjacent with the servo mag netic head 10, is arranged dislocated only by a prescribed distance (d) in a tangent line direction and the magnetic head 10 is composed of the thin film magnetic head which is hardly influenced by external magnetism, a noise, which is caused by a leaking magnetic flux to be outputted from the magnetic head 9, is prevented without fail. Then, the magnetic shield material, etc., is eliminat ed and the structure is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and particularly to a technique that is effective when applied to a magnetic disk device that positions a magnetic head using a servo track method.

[Conventional technology]

For example, in a magnetic disk drive, as an example of a method for positioning a data magnetic head with respect to a rotating magnetic disk, servo tracks on which position information is recorded are provided concentrically on a part of the magnetic disk. A so-called servo track method is known in which the radial positioning operation of a data magnetic head with respect to a magnetic disk is controlled by reading position information using a servo magnetic head.

In this case, in a magnetic disk drive equipped with a plurality of magnetic disks, the influence of vibrations, temperature, etc. caused by the positional relationship between the plurality of data magnetic heads and servo magnetic heads provided corresponding to each magnetic disk must be individually controlled. For the purpose of equalizing the data magnetic heads, the servo magnetic head is generally placed in the center of a plurality of data magnetic heads arranged in a row in the direction in which the magnetic disks are arranged. Because the magnetic head and servo magnetic head are adjacent to each other in the direction in which the magnetic disks are arranged, leakage magnetic flux generated during write operations in the data magnetic head causes noise in the position information read through the servo magnetic head. There's a problem.

For this reason, for example, as disclosed in Japanese Unexamined Patent Publication No. 60-140524, a magnetic shielding material is interposed between the data magnetic head and the servo magnetic head, and the leakage magnetic flux generated in the data magnetic head is protected from the servo magnetic head. It is known to magnetically shield a magnetic head.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 60-29986, it is known that a data magnetic head and a servo magnetic head are mounted on a head arm having a branched tip with their positions shifted.

[Problem to be solved by the invention]

However, in the former technology, a magnetic shielding material is interposed between the data magnetic head and the servo magnetic head, which increases the size in the magnetic disk arrangement direction and the number of parts. There is a problem in that this goes against the demands for miniaturization and structural simplification of disk devices.

Furthermore, in the latter conventional technology, for example, when a normal wire-wound head structure is used for the data magnetic head and the servo magnetic head, the spacing between the two must be set relatively large, and the data magnetic head The displacement direction of the head and the servo magnetic head deviates significantly from the direction toward the rotation center of the magnetic disk, and there is a problem in that the floating characteristics of each head tend to vary.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to prevent the servo magnetic head from being adversely affected by the data magnetic head without complicating the structure or deteriorating the head flying characteristics.
An object of the present invention is to provide a magnetic disk device capable of realizing stable positioning operation of a data magnetic head.

Another object of the present invention is to provide an inexpensive magnetic disk device.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, a data magnetic head that performs at least one of recording and reproducing information on a rotating storage medium;
A magnetic disk device comprising a servo magnetic head that moves together with the data magnetic head and grasps the relative position of the data head to the storage medium by reading position information recorded in advance on the storage medium, the servo magnetic head The head is composed of a thin film magnetic head, and adjacent data magnetic heads and servo magnetic heads are arranged offset in the plane direction of the storage medium.

[Effect]

According to the above means, there is no need to interpose extra parts such as a magnetic shield material between the data magnetic head and the servo magnetic head, the structure is simplified, and the servo magnetic head is protected from external magnetic fields. Since it is composed of a thin-film magnetic head that is less susceptible to magnetic influences, it is possible to minimize the amount of misalignment between the data magnetic head and the servo magnetic head, so the head flying characteristics are not impaired and the servo magnetic head is A stable positioning operation of the data magnetic head can be realized based on position information from the magnetic head.

Further, by constructing a plurality of data magnetic heads other than the servo magnetic head from inexpensive Mn-Zn ferrite or the like, the cost of the magnetic disk device can be reduced.

〔Example〕

FIGS. 1(a) and (b) are a plan view and a side view, respectively, showing an example of a main part of a magnetic disk device that is an embodiment of the present invention, and FIG. 2 is an overview of the magnetic disk device. FIG.

First, as shown in FIG. 2, the magnetic disk drive of this embodiment includes a spindle 3 provided on a base 1 and rotated by a motor 2 at a predetermined speed. magnetic disks 4 are fixed in parallel at predetermined intervals in the axial direction.

An actuator 6 is provided near the plurality of magnetic disks 4 fixed to the spindle 3 and is slidably guided by a bearing 5 in the radial direction of the magnetic disks 4 .

On the side surface of the actuator 6 facing the magnetic disks 4, base end portions of a plurality of helad arms 7 arranged in parallel at predetermined intervals in the arrangement direction of the plurality of magnetic disks 4 are supported.

A plurality of gimbals 8 each made of a flexible metal plate or the like is fixed to the tip of each of the plurality of helad arms 7, with the tip pointing toward the center of rotation of the magnetic disk 4.

A data magnetic head 9 and a servo magnetic head 10 are fixed to each of the plurality of gimbals 8, and each data magnetic head 9 and servo magnetic head 10 face the upper and lower recording surfaces of the plurality of magnetic disks 4, respectively. There is.

The servo magnetic head 10 is fixed via a gimbal 8a to a head arm 7a located in the center of the plurality of data magnetic heads 9 in the arrangement direction, and the head arm 7a is adjacent to the coexisting data magnetic head 9. There is.

On the recording surface 4a of the magnetic disk 4 at the center facing the servo magnetic head 10, a servo track (not shown) on which position information is pre-recorded concentrically is provided, and the position information recorded on this servo track is read by the servo magnetic head 10 and returned to the control of the displacement of the actuator 6, thereby controlling the magnetic disks 4 of the plural data magnetic heads 9 supported by the actuator 6.
The positioning operation in the radial direction is controlled.

Here, FIGS. 1(a) and 1(b) are a plan view and a side view, respectively, of a central helad arm 7a shared by the servo magnetic head 10 and the data magnetic head 9; As shown in the figure, in this embodiment, the data magnetic head 9 and the servo magnetic head 10 are arranged in a predetermined direction in the left-right direction of the figure (a), that is, in the tangential direction of the rotating magnetic disk 4. The gimbals 8 and 8a are fixed at different positions in the width direction of the helad arm 7a so that they are deviated by a value d, and the servo magnetic head 10 is relatively unaffected by external magnetic influences, for example. The magnetic head 10a is made up of a thin film magnetic head 10a that is difficult to use.

In this case, the value of d is set so that the leakage magnetic flux generated from the data magnetic head 9 is minimized within a range that does not affect the servo magnetic head 10.

Further, the data magnetic helad 9 is made of, for example, inexpensive M n -Z which is generally used as a magnetic head material.
It is made of n-ferrite or the like.

The operation of this embodiment will be explained below with reference to the drawings.

First, by operating the motor 2, the spindle 3
A plurality of magnetic disks 4 fixed to rotate in a predetermined direction at a predetermined speed.

At this time, the data magnetic head 9 and the servo magnetic head 10 float to a predetermined height above the magnetic disk 40 surface due to the airflow formed on the magnetic disk 40 surface.

In this state, when a command to write or read information to or from the magnetic disk 4 is issued from a higher-level information processing device (not shown), the actuator 6 operates in the radial direction of the magnetic disk 4 based on device information constituted by the servo magnetic head 10. A plurality of data magnetic heads 9, which are moved by a predetermined distance and supported by an actuator 6 via a head arm 7, a gimbal 8, etc., are positioned equidistant from the center of rotation on the recording surface of each of the plurality of magnetic disks 4. They are simultaneously positioned at a target position, and information is written to or read from the target area of the magnetic disk 4 via the data magnetic head 9.

Here, leakage magnetic flux is generated during the write operation of the data magnetic head 9, but if the servo magnetic head 10 and the data magnetic head 9 are simply placed adjacent to each other, the positional information read via the servo magnetic head 10 may be affected by noise. This may cause problems such as lowering the positioning accuracy.

However, in the case of this embodiment, the servo magnetic head 10
and the data magnetic head 9 adjacent to the servo magnetic head 10 are disposed apart from each other by a predetermined distance M1d in the tangential direction of the rotating magnetic disk 4. Since it is composed of a thin film magnetic head 10a that is relatively unsusceptible to external magnetic influences, leakage magnetic flux generated in the data magnetic head 9 causes noise in the position information read out via the servo magnetic head IO. This is definitely prevented.

Thereby, the positioning operation of the plurality of data magnetic heads 9 with respect to the magnetic disk 4 can be accurately and stably controlled based on the position information obtained via the servo magnetic head IO.

In the case of this embodiment, the data magnetic head 9 and the servo magnetic head 10 are connected to each other for the purpose of protecting the servo magnetic head 10 from leakage magnetic flux generated from the data magnetic head 9.
There is no need to interpose extra parts such as a magnetic shielding material between the magnetic disk drive and the magnetic disk drive, and the structure of the magnetic disk drive can be simplified and downsized.

Furthermore, since the thin film magnetic head 10a constituting the servo magnetic head 10 is relatively less susceptible to external magnetic influences, it is possible to minimize the misalignment between the servo magnetic head 10 and the data magnetic head 9. , the displacement direction of the servo magnetic head 10 and the data magnetic head 9 by the actuator 6 does not deviate greatly from the rotation center of the magnetic disk 40, and there is no variation in the floating characteristics of the servo magnetic head 10 and the data magnetic head 9 with respect to the magnetic disk 4. occurrence is prevented.

In addition, it is possible to operate multiple data magnetic heads 9 other than the servo magnetic head 10 using inexpensive Mn-
It can be constructed using Zn ferrite, and the cost of the magnetic disk device can be reduced.

Further, in order to keep the servo magnetic head 10 away from leakage magnetic flux from the data magnetic head 9, the servo magnetic head 10 is placed at the end of the plurality of data magnetic heads 9, and is fixed to the spindle 3. Compared to a case where, among the plurality of magnetic disks 4, the magnetic disk 4 located at the end is exclusively assigned to record servo tracks, all the recording surfaces of the magnetic disks 4 can be used effectively.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly described below.

That is, a data magnetic head that performs at least one of recording and reproducing information on a rotating storage medium;
A magnetic disk cover comprising: a servo magnetic head that moves together with the data magnetic head and determines the relative position of the data head with respect to the storage medium by reading position information recorded in advance on the storage medium; The servo magnetic head is composed of a thin film magnetic head, and the adjacent data magnetic head and the servo magnetic head are arranged offset in the plane direction of the storage medium, so that there is no space between the data magnetic head and the servo magnetic head. There is no need to provide extra parts such as magnetic shielding material, which simplifies the structure.

Furthermore, since the servo magnetic head is composed of a thin-film magnetic head that is less susceptible to external magnetic influences, the amount of positional deviation between the data magnetic head and the servo magnetic head can be minimized, resulting in head floating characteristics. It is possible to realize a stable positioning operation of the data magnetic head based on the position information from the servo magnetic head without damaging the data.

Further, by forming a plurality of data magnetic heads other than the servo magnetic head with inexpensive Mn-Zn ferrite, etc., the cost of the magnetic disk device can be reduced.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a plan view and a side view showing an example of a main part of a magnetic disk device, which is an embodiment of the present invention, respectively; FIG. 2 is a magnetic disk drive, which is an embodiment of the present invention. FIG. 2 is a side view schematically showing the device. DESCRIPTION OF SYMBOLS 1... Base, 2... Motor, 3... Spindle, 4... Magnetic disk (storage medium), 4a... Recording surface, 5... Bearing, 6... Actuator, 7
, 7a...head arm, 8.8a... gimbal,
9... Data magnetic head, 10... Servo magnetic head, 10a... Thin film magnetic head, d... Positional deviation amount between the data magnetic head and the servo magnetic head. Figure 1 Figure 2

Claims (1)

[Claims] 1. A data magnetic head that performs at least one of recording and reproducing information to and from a rotating storage medium; A magnetic disk device comprising a servo magnetic head that grasps a relative position with respect to a storage medium,
A magnetic disk device characterized in that the servo magnetic head is a thin film magnetic head, and the adjacent data magnetic head and the servo magnetic head are arranged offset in a plane direction of the storage medium.