JPH04341980A - Actuator arm for disk device - Google Patents

Abstract

PURPOSE:To enable high speed access of a head by omitting a wing for fitting a scale, arranging an arm, a voice coil and the scale in series, making the whole arm easily balanced and reducing its weight. CONSTITUTION:The wing is omitted by fitting the scale 9 of the actuator arm direct to the opposite side of the arm 2 to the voice coil 6. Then, the arm 2, a load beam 3, a magnetic head slider 4, the coil 6 and the scale 9 are arranged in series on a center line P, and the whole arm is made to be easily balanced, so that a counter weight is omitted. Consequently, the arm 2 is light in weight as a whole, and hence inertia can be reduced, thus having an advantage of high speed access of the magnetic head slider 4. Moreover, the scale 9 is disposed on the opposite side of the slider 4 and the arm 2, and the scale 9 is separated from an arm shaft 1, and a radius R is made to be large, so that an advantage against thermal off-track is obtained, and also a high output of an optical encoder 8 is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator arm for a disk device, which is most suitable for application to, for example, a hard disk device.

0002

2. Description of the Related Art Conventionally, as shown in FIG. 4, an actuator arm for a hard disk drive includes an arm 2 that swings around an arm shaft 1, and a load beam 3 attached to the tip of the arm 2. A magnetic head slider 4 which is a magnetic head, a voice coil 6 of a voice coil motor 5 attached to the opposite side of the arm 2 from the magnetic head slider 4, and a substantially V-shaped head on one side of the arm 2 on the load beam 3 side It includes a wing 7 attached in the shape of a shape, and a scale 9 of an optical encoder 8 attached to the tip of the wing 7. Note that the voice coil motor 5
The magnet and yoke, the optical means (light emitting element and light receiving element) of the optical encoder 8, and the reticle are mounted on the chassis 10.
Fixed on top.

[0003] Then, a hard disk 11, which is a disk-shaped recording medium, is transferred to a turntable 12 of a spindle motor.
For example, the arm 2 is driven to rotate in the direction of the arrow a, for example, and the arm 2 is driven to swing in the direction of the arrow b by the voice coil motor 5 activated by energizing the voice coil 6, so that the magnetic head slider 4 is moved approximately in the radial direction of the hard disk 11. At the same time, the scale 9 is swung together with the arm 2 by the wing 7 in the direction of arrow b, and the optical encoder 8 tracks the magnetic head slider 4 while recording and/or reproducing the hard disk 11. is configured to do so.

[0004]The conventional actuator arm is
Since the scale 9 was attached to one side of the arm 2 via the wing 7, a counterweight 13 was attached to the side of the voice coil 6 on the side of the above point B so that the balance point was at the point B in Fig. 3. .

[0005]

[Problems to be Solved by the Invention] However, in the conventional actuator arm, the wing 7 and the counterweight 13 are attached to the arm 2, and the entire arm 2 is heavy, so the inertia of the entire arm 2 is large, and the magnetic head This was disadvantageous for high-speed access of the slider 4. Also,
Since the scale 9 is attached to a position shifted to one side from the center of the arm 2, there is a problem in that it is disadvantageous against thermal off-track.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide an actuator arm for a disk device that does not require the use of wings or counterweights.

[0007]

[Means for Solving the Problems] An actuator arm of a disk device of the present invention for achieving the above object has the following features:
an arm that swings around an arm axis; a head that is attached to the tip of the arm for recording and/or reproducing a disk-shaped recording medium; and a voice coil that is attached to the opposite side of the arm from the head. The motor includes a voice coil and an optical encoder scale attached to the side of the voice coil opposite to the arm.

[0008]

[Operation] In the actuator arm of the disk device of the present invention configured as described above, the optical encoder scale is attached to the side opposite to the voice coil arm, so the wing for attaching the scale can be omitted. . Furthermore, since the arm, voice coil, and scale can be arranged in series, it is easy to balance the entire arm, and a counterweight can be omitted.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an actuator arm of a hard disk drive to which the present invention is applied will be described below with reference to FIGS. 1 and 2. Note that the same reference numerals are given to the same structural parts as in FIGS. 3 and 4, and redundant explanation will be omitted.

This actuator arm has a scale 9 attached to the opposite side of the voice coil 6 from the arm 2 by direct adhesive or the like. The load beam 3, magnetic head slider 4, voice coil 6, and scale 9 are arranged in a straight line on the center line P of the arm 2 passing through the center of the arm shaft 1. The slit pattern 9a of the scale 9 is formed in an arc shape with a sufficiently large radius R relative to the center of the arm shaft 1.

[0011] This actuator arm has a scale of 9
Since the voice coil 6 is directly attached to the side opposite to the arm 2, the wing 7 shown in FIG. 4 can be omitted. Also,
The arm 2, load beam 3, magnetic head slider 4, voice coil 6, and scale 9 are arranged in series and placed on the center line P of the arm 2, making it easy to balance the entire arm. The counterweight 13 shown in 4 can be omitted.

Therefore, in this actuator arm, the entire arm 2 is lightweight and the inertia can be reduced, which is advantageous for high-speed access of the magnetic head slider 4. Furthermore, since the scale 9 is disposed directly opposite the magnetic head slider 4 with the arm shaft 1 in between, this is advantageous against thermal off-track. Furthermore, the scale 9 is placed on the opposite side of the voice coil 6 from the arm 2, and the scale 9 is
Since it is separated from the arm axis 1 by a sufficient distance, the radius R of the slit pattern 9a of the scale 9 can be made sufficiently large, and a high output of the optical encoder 8 can be obtained.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made based on the technical idea of the present invention. Further, the present invention is not limited to the actuator arm of a hard disk device, but can be applied to the actuator arm of a disk device that records and/or reproduces various disk-shaped recording media.

[0014]

[Effects of the Invention] Since the actuator arm of the disk device of the present invention is constructed as described above, it has the following effects.

[0015] The scale of the optical encoder is attached to the opposite side of the voice coil arm, so that the wing for attaching the scale can be omitted, and the arm, voice coil, and scale can be arranged in series. This makes it easier to balance the entire arm and eliminates the counterweight, which makes the entire arm lightweight and reduces the inertia of the entire arm, which is advantageous for high-speed head access.

The scale of the optical encoder can be placed on the opposite side of the head across the arm axis, which is advantageous for thermal off-track.

Since the scale of the optical encoder can be arranged at a sufficient distance from the arm axis, the radius of the slit pattern of this scale can be made sufficiently large, and a high output of the optical encoder can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating an actuator arm of a hard disk drive according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating the overall balance of the actuator arm according to the above.

FIG. 3 is a diagram illustrating the balance of the entire arm of a conventional actuator arm.

FIG. 4 is a plan view illustrating an actuator arm of a conventional hard disk device.

[Explanation of symbols]

1 Arm shaft 2 Arm 4 Magnetic head slider (head) 5
Voice coil motor 6 Voice coil 7 Wing 8 Optical encoder 9 Scale 11 Hard disk (disc-shaped recording medium) 1
3 Counterweight

Claims (1)

[Claims] Claims: 1. An arm that swings around an arm axis; a head that is attached to the tip of the arm for recording and/or reproducing a disk-shaped recording medium; An actuator arm for a disk device, comprising a voice coil of a voice coil motor attached thereto, and a scale of an optical encoder attached to a side of the voice coil opposite to the arm.