JPH04232678A - Head positioning mechanism - Google Patents

Abstract

PURPOSE:To enable a head positioning mechanism for positioning a head to a prescribed track position on a recording disk of a magnetic disk device, etc., to highly accurately and quickly correct the positional deviation of the head after the head makes access to the prescribed track position of the recording disk. CONSTITUTION:The fixing section 12 of supporting springs 13 supporting a head 14 on a head arm 11 coupled with a main actuator is constituted in such a way that the front end section of the section 12 is coupled to the main body of the head arm 11 through at least one beam-like hinge sections 15 and 16 which can be displaced in the radial direction of a disk and the rear end section is coupled to the arm main body through two displacement elements 18 and 19 which can extend and contract under electric control on both side of a supporting section 17. In addition, the supporting springs 13 fixed to the supporting spring fixing section 12 are constituted so that the springs 13 can be finely displaced in the radial direction independently from the actuator by the differential movement between extension and contraction of the two displacement elements 18 and 19.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head positioning mechanism for positioning a recording/reproducing head to a recording track of a disk in a magnetic disk device, an optical disk device, or the like. In recent years, in magnetic disk drives and the like, as the track density of disks has increased, it has been required to position recording/reproducing heads with higher precision with respect to recording tracks of the disks.

0002

2. Description of the Related Art Conventionally, for example, in a magnetic disk drive, a plurality of magnetic disks 2 are mounted at predetermined intervals on a spindle 1 connected to a rotating mechanism, as shown in FIG. A magnetic head 6 for servo and a magnetic head 7 for servo are respectively supported by a head arm 4 attached to a head positioning mechanism shown in FIG. There is.

[0003] In order to position each data magnetic head 6 on a target recording track of each rotating magnetic disk 2, for example, the magnetic disk 2
Using a dedicated servo disk surface on which servo information is pre-recorded, the servo information is read by a servo magnetic head 7, and the swinging actuator 3 is driven based on the read servo information to control positioning. A servo surface servo method is generally used.

0004

[Problems to be Solved by the Invention] However, in head positioning control using such a servo surface servo method, with the increase in recording density, the precision of the data magnetic head 6 relative to the recording track of each magnetic disk 2 has become more difficult. Misalignment has become a problem. That is, the temperature inside the magnetic disk device during operation rises due to changes in the installed environment temperature, high-speed rotation of each of the magnetic disks 2, and heat generated when the oscillating actuator 3 drives access to the magnetic head. The head arm 4 and the like that support the magnetic head 6 and the servo magnetic head 7 tend to thermally expand or deform.

In addition, since the temperature distribution within the magnetic disk device is not constant, for example, the distance between the servo magnetic head 7 and the data magnetic head 6 whose position is controlled by the servo magnetic head 7 is There is a problem in that so-called thermal off-track occurs, in which there is a slight deviation (on the order of several micrometers) at each radial position, causing a positional deviation of the data magnetic head 6 with respect to the target recording track.

Furthermore, in order to reduce such thermal off-track, it is necessary to select a material with less thermal expansion or deformation for the head support member, or to improve the mechanical design, such as a structure that absorbs thermal distortion and thermal deformation. Although various studies have been made above, although they are extremely complex, sufficient effects have not been obtained. Therefore, there is a drawback that reliability in recording and reproducing information is reduced.

[0007] In view of the above-mentioned conventional problems, the present invention has been developed to increase minute positional deviations by independently slightly displacing the head after positioning, in addition to the main actuator that positions the head at a predetermined track position on a recording disk. It is an object of the present invention to provide a novel head positioning mechanism that enables accurate and high-speed correction.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides head positioning in which the head is supported via a support spring on a head arm fixed to an actuator movable in the radial direction of a recording disk. The support spring fixing portion of the head arm is connected to the head arm main body via at least one beam-shaped hinge portion whose front end portion is movable slightly in the radial direction of the recording disk, The rear end is connected to the arm body via two displacement elements that can be extended and contracted by electrical control on both sides of the support part, and fixed to the support spring fixing part by differential expansion and contraction of the two displacement elements. The supporting spring is configured to be able to be slightly displaced in the radial direction of the recording disk independently of the actuator.

[0009]

[Operation] In the present invention, in addition to the main actuator that positions the head at a predetermined track position on the recording disk, the support spring fixing portion of the head arm that fixes the support spring that supported the head is attached to the head arm main body. The front end is connected via at least one beam-like hinge part that allows minute displacement in the radial direction of the recording disk, and the rear end has two displacement elements on both sides of the support part that can be expanded and contracted by electrical control. , for example, is connected to the head arm main body via two laminated electrostrictive elements, and a minute displacement actuator is configured between the arm main body and the support spring fixing part.

With this configuration, for example, the main actuator positions the head at a predetermined track position on a rotating recording disk, and a predetermined signal voltage is applied to the electrostrictive element in the minute displacement actuator to cause it to expand and contract differentially, By slightly oscillating the support spring fixing part of the head arm in the left-right direction about the beam-like hinge part, the head supported by the support spring fixed to the support spring fixing part can be independently moved. Furthermore, it becomes possible to position at a predetermined track position with high precision.

Therefore, even if the data magnetic head, which is positioned by the main actuator on the basis of position information from the servo magnetic head, thermally off-tracks to a predetermined track position of the rotating recording disk, the minute displacement actuator quickly moves to the target position. It becomes possible to accurately correct the track position.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a plan view of essential parts showing an embodiment of a head positioning mechanism according to the present invention. In the figure, 11
is a frame-shaped head arm attached to a main actuator consisting of a swing type actuator (not shown), and the magnetic head 14 is supported on the support spring fixing portion 12 of the head arm 11 via a gimbal (not shown), for example, in an in-line type. A support spring 13 is fixed.

Further, the support spring fixing portion 12 of the head arm 11 has two parallel beams at its front portion that are capable of minute rocking displacement with respect to the head arm 11 within the frame of the head arm 11. The rear part of the support member 17 is connected to the support member 17 through the hinge parts 15 and 16, and the rear part thereof includes a support member 17 and displacement elements attached to both sides of the other end of the support member 17 that can be expanded and contracted by electrical control, such as laminated electrostrictive elements (piezoelectric elements). elements, etc.) 18,
The head arm 1 is connected in a T-shape via 19.
1 and the support spring fixing part 12 constitute a minute displacement actuator.

Therefore, when recording/reproducing information in a magnetic disk device using such a head positioning mechanism, a main actuator consisting of the swing type actuator or the like is driven based on servo information, for example, to drive a plurality of rotating disks. After simultaneously positioning all the data magnetic heads 14 corresponding to respective predetermined track positions on the magnetic disk and supported by the support springs 13, a head positioning mechanism was installed that supported each of the data magnetic heads 14. By independently applying a servo position shift signal voltage to the two electrostrictive elements (piezo elements, etc.) 18 and 19 in the minute displacement actuator to cause them to expand and contract differentially, the two parallel beam-shaped hinge parts 15 are and 16 are bent to slightly swing and displace the support spring fixing portion 12 in the left-right direction.

By controlling this oscillating displacement, each of the magnetic heads 14, that is, each data magnetic head, can independently accurately and quickly follow the target track position, or easily correct minute positional deviations due to thermal off-track, etc. It becomes possible to correct the Further, FIG. 2 is a plan view of main parts showing another embodiment of the head positioning mechanism according to the present invention, and FIG.
The same reference numerals are given to parts that have the same function as in the above.

The embodiment shown in this figure is different from the embodiment shown in FIG.
The support spring fixing part 12 is connected to the head arm 11 within the frame of the head arm 11 via a single beam-shaped hinge part 21 that allows minute rocking displacement at its front part, and then Similarly, the section includes one beam-like hinge support section 22 and displacement elements attached to both sides of the other end of the beam-like hinge support section 22 that can be expanded and contracted by electrical control, such as laminated electrostrictive elements (piezo elements, etc.). ) 23, 24 to connect the head arm 11 and the support spring fixing part 12 in a T-shape.
A minute displacement actuator is configured in between.

[0017] With such a configuration, by independently applying a servo position shift signal voltage to the two electrostrictive elements (piezo elements, etc.) 23 and 24 in the minute displacement actuator to differentially expand and contract the beam, shaped hinge part 2
1 and the beam-like hinge support part 22 are bent to fix the support spring fixing part 1.
2 undergoes rocking displacement in response to a bending moment in the left-right direction. In particular, in the configuration of this embodiment, the support spring fixing portion 1
There is an advantage that the amount of rocking displacement of No. 2 can be controlled to a greater extent than in the case of the embodiment shown in FIG.

Therefore, by controlling the swing displacement described above, each of the magnetic heads 14, that is, the magnetic heads for each data, can be moved to the target track position independently, accurately and quickly, as in the embodiment of FIG. It becomes possible to easily correct minute positional deviations due to tracking or thermal off-tracking. In the above embodiment, an example was explained in which the present invention was applied to a head positioning mechanism of a magnetic disk device, but the present invention is not limited to such an example. It can also be applied to a head positioning mechanism.

[0019]

As is clear from the above description, according to the head positioning mechanism of the present invention, the support spring fixing portion on the head arm side fixes the support spring that supports the data magnetic head separately from the main actuator. By providing a minute displacement actuator between the head arm and the head arm, it becomes possible to independently and highly accurately position the data head at a predetermined recording track position on a disk with high track density.

Therefore, after accessing a predetermined recording track position on the disk by the main actuator, thermal,
Data heads that have been misaligned due to misalignment or other factors can be quickly and accurately corrected independently using minute displacement actuators. Head positioning accuracy has been significantly improved, and the reliability of disk drives has also been improved. It has excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a plan view of essential parts of an embodiment of a head positioning mechanism according to the present invention.

FIG. 2 is a plan view of main parts showing another embodiment of the head positioning mechanism according to the present invention.

FIG. 3 is a main part configuration diagram for explaining a magnetic disk device.

FIG. 4 is a plan view illustrating an example of a conventional head positioning mechanism.

[Explanation of symbols]

11 Head arm
12 Support spring fixing part 13 Support spring
14 Magnetic head 15, 16, 21
Beam-shaped hinge part 17 Support part 1
8, 19, 23, 24 electrostrictive element
22 Beam hinge support part

Claims (1)

[Claims] Claim 1: A head arm (11) fixed to an actuator movable in the radial direction of a recording disk.
A head positioning mechanism in which a head (14) is supported via a support spring (13) on the head arm (
The support spring fixing part (12) in the head arm body has at least one beam-shaped hinge part (15) whose front end part can be slightly displaced in the radial direction of the recording disk.
, 16), and the rear end is connected to the support part (17
) is connected to the arm main body via two displacement elements (18, 19) that can be expanded and contracted by electrical control, and the support is A head positioning mechanism characterized in that a support spring (13) fixed to a spring fixing part (12) can be slightly displaced in the radial direction of a recording disk independently of the actuator.