JPH0223055A - Actuator device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an actuator device for moving a magnetic head in the track direction of a disk memory.

BACKGROUND OF THE INVENTION Some hard disk drive devices are provided with a head feeding mechanism for positioning a magnetic head on a desired track on a disk, and a voice coil motor is used as an actuator for the head feeding mechanism. Generally, a voice coil motor consists of a voice coil and a magnetic field generator for applying a magnetic field to the voice coil, and the voice coil is usually fixed to a movable carriage that supports a magnetic head assembly. The conventional hard disk drive actuator device as described above will be explained with reference to FIG.

FIG. 3 is a sectional view of a head carriage and a voice coil motor that constitute a conventional actuator device. The head carriage 31 is movable by rollers 36 along a round bar-shaped rail 35 fixed to the outside. Reference numeral 32 denotes a voice coil wound in a rectangular shape, and the two windings are fixed to the helad carriage 31 on the negative side, respectively, with the upper and lower sides passing between the gap parts, and the rectangle surrounded by the voice coil 32. The surface of head carriage 3
It is facing the direction of movement of 1. Further, 34 is a plate-shaped magnet attached to the magnetic core 33, and the magnetic flux generated by the magnet 34 passes through this magnetic core 33 to form a magnetic circuit, generating a magnetic field in the gap between the magnetic cores 33. . A conventional actuator device has the above-described structure, and by passing a current through the coil, the coil receives a force from a magnetic field in a direction perpendicular to the surface surrounding the coil, thereby making it possible to move the carriage.

Problems to be Solved by the Invention In the actuator device as described above, the weight of the moving part is large (this results in a long movement time), and the lowest resonance frequency in the resonance of a part of the actuator of the hard disk drive. The resonant frequency of the voice coil becomes lower due to the shape of the voice coil, resulting in poor response characteristics.

Means for Solving the Problems In order to solve this problem, the present invention provides a voice coil attached to a carriage with a shape in which the width of the coil becomes gradually narrower in the direction away from the carriage.

Effects With the above-described configuration, the shape of the coil winding becomes tapered as it moves away from the carriage mounting portion, so that the resonant frequency of the coil also increases.

Embodiment Hereinafter, an actuator device which is an embodiment of the present invention will be described based on the drawings. In FIG. 1, reference numeral 11 denotes a carriage with a fixed head assembly, which is fixed on a movable table 12. On the movable table 12, rollers 16 sandwich two rails 17 on both sides and move along the rails. It's free. Voice coils 13 are fixed to both sides of the carriage 11, and are shaped like an isosceles triangle with the mounting portion as the base. Further, a magnetic core 14 is provided to surround this shape from the inside and outside, and the magnetic core 1
The magnetic flux generated by the magnet 15 attached to the voice coil 13 is configured to perpendicularly cross the isosceles of the voice coil 13.

The operation will be explained below. In FIG. 1, when a current is passed through the voice coil 13, a magnetic field perpendicular to the direction of current flow is generated in the winding portion of the voice coil 13 surrounded by the magnet 15 and the magnetic core 14. A force parallel to the direction acts, and the carriage 11 moves in the direction in which the force is received.

The force generated by this coil current and magnetic field is proportional to the amount of coil current, so by controlling the amount of current, the moving speed of the carriage 11 can be controlled, and the magnetic head can be moved to a desired position. is possible.

This actuator device must instantaneously position the magnetic head with accuracy on the order of submicrons. However, since the natural vibration frequency of the actuator device is the lowest (the part with the largest amplitude is the coil winding part), it is necessary to increase the strength of the coil winding part and raise the resonance frequency.Here, Comparing Figures 2 and 3, the coil section of the actuator device in Figure 2 has a tapered shape as it moves away from the carriage, so the weight is reduced and the strength is increased. The resonant frequency becomes higher.

Effects of the Invention As explained above, in the actuator device of the present invention, the voice coil attached to the carriage has a width in the direction surrounding the voice coil that gradually narrows in the direction away from the carriage.
In other words, since the shape of the voice coil tapers away from the carriage mounting portion, the resonant frequency of the coil portion can be increased, and an actuator device with good followability can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an actuator device according to an embodiment of the present invention, FIG. 2 is a sectional view of the actuator device shown in FIG. 1, and FIG. 3 is a sectional view of a conventional actuator device. 11... Carriage 13... Voice coil 14... Magnetic core 5... Magnet

Claims (1)

[Scope of Claims] A magnetic field forming means for forming a magnetic field, a voice coil movable in a direction to cut the magnetic flux of the magnetic field formed by the magnetic field forming means, and a movable carriage holding the voice coil. An actuator device comprising: a shape of a portion of the voice coil that cuts the magnetic flux of the magnetic field such that a width surrounded by the coil gradually becomes narrower in a direction away from the carriage.