JP2500451B2 - Magnetic head feeding mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head feeding mechanism, and more particularly to a magnetic head feeding mechanism used in a servo track writer.

[0002]

2. Description of the Related Art A conventional magnetic head feeding mechanism is, for example,
There is a description in the Technical Bulletin published by the Institute of Invention (Kogi No. 91-8603). As shown in the perspective view of FIG. 2 and the sectional view of FIG. 3, this magnetic head feeding mechanism includes a fan-shaped positioner arm 11 having a shaft 13 serving as a rotation center of a spindle 18 and an arc surface 11a, and this positioner arm. 1
Magnetic head 1 held at one end of holder 1 via holder 15a
5, a rotary encoder 14 connected to the shaft 13 of the positioner arm 11 via a coupling 19 to measure the rotation angle of the positioner arm 11, and an output shaft 1 installed outside the arc surface 11a of the positioner arm 11.
7 is arranged with a predetermined gap from the circular arc surface 11a of the positioner arm 11, and the output shaft 17 of the pulse motor 16 is wound around the circular arc surface 11a a plurality of times. A thin plate-shaped belt 12a fixed to the end surface of the arm 11
And a thin plate-shaped belt 12b that is wound around the output shaft 17 of the pulse motor 16 a plurality of times in the opposite direction to the belt 12a and stretches in the opposite direction to the belt 12a along the arc surface 11a of the positioner arm 11, and the rotation center of the positioner arm 11. A bearing 20 having an arcuate track along the arcuate surface 11a as a center and a bearing support 20a for supporting the bearing 20 are provided.

The arc surface 1 of the positioner arm 11
1a, the belts 12a and 12b, and the output shaft 17 are arranged with no space therebetween so that vibration does not occur.

Next, the feeding operation of the magnetic head 15 in the above-mentioned conventional magnetic head feeding mechanism will be described.
First, a control circuit (not shown) operates the pulse motor 16 to rotate the output shaft 17. As the output shaft 17 rotates, the belt 12a and the belt 12b are wound around and unwound around the output shaft 17, and the positioner arm 11 rotates in a circular arc direction around the shaft 13, which is a rotating shaft.

The rotary encoder 14 measures the rotation angle at the rotation center of the positioner arm 11. Then, the control circuit positions the magnetic head 15 at a predetermined position based on the measured rotation angle.

[0006]

In the above-mentioned conventional magnetic head feeding mechanism, the output shaft has a small diameter in order to improve the feeding accuracy of the magnetic head. Therefore, when the magnetic head moves largely, it is necessary to wind the belt many times. However, if the magnetic head is wound many times, the winding amount changes and the diameter of the output shaft up to the belt outer circumference increases or decreases.

When the belt is attached to the circular arc surface without any gap,
A force that expands between the rotation center of the positioner arm and the output shaft works, and a radial force is applied to the positioner arm and the output shaft.If a gap is installed, the belt will vibrate during operation and the magnetic head feeds. Has the drawback of becoming unstable.

[0008]

According to the present invention, there is provided a positioner arm having a first shaft serving as a center of rotation and a first arc surface forming an arc around the first shaft, and a positioner arm serving as a center of rotation. And a second arcuate surface that forms an arc around the second shaft, and the second arcuate surface and the first arcuate surface of the positioner arm face each other at a predetermined interval. A guide arm to be arranged, a magnetic head for writing data held at one end of the positioner arm, a rotary encoder connected to the first shaft for measuring a rotation angle of the positioner arm, the positioner arm and the A pulse motor having an output shaft disposed between the guide arm and the first and second arc surfaces with a predetermined gap, and a thin plate-shaped one end A first arm which is fixed to a positioner arm and extends along the first circular arc surface to half-circulate the output shaft of the pulse motor and which extends along the second circular arc surface of the guide arm and fixes the other end to the guide arm; The belt and the thin plate-shaped one end are fixed to the positioner arm in the opposite direction to the first belt and are stretched along the first arc surface to half-circulate the output shaft of the pulse motor and the second arm of the guide arm. And a second belt which is stretched along the arc surface and whose other end is fixed to the guide arm.

The first circular arc surface of the positioner arm and the second circular arc surface of the guide arm may be the circular arc surface of the fan-shaped member.

[0010]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention. As shown in FIG. 1, the magnetic head feeding mechanism of this embodiment includes a positioner arm 1 having a shaft 3 made of a fan-shaped member and serving as a center of rotation and an arcuate surface 1a, and a fan-shaped member similar to the positioner arm 1. A shaft 8 made of a member and having a center of rotation and a circular arc surface 6a; a positioner arm 1; and a guide arm 6 in which the two circular arc surfaces 1a and 6a are arranged so as to face each other at a predetermined interval; The magnetic head 5 held by the shaft 3, the rotary encoder 4 connected to the shaft 3 for measuring the rotation angle of the positioner arm 1, and the output shaft 10 between the positioner arm 1 and the guide arm 6 from the circular arc surfaces 1a and 6a. Driving pulse motor 9 arranged so as to have a gap
And a thin plate shape, one end is fixed to the positioner arm 1, the output shaft 10 of the pulse motor 9 is half-circled along the arc surface 1a, and the other end is fixed to the guide arm 6 along the arc surface 6a of the guide arm 6. Similarly to the belt 2, one end of the belt 2 is fixed to the positioner arm 1 in a direction opposite to the belt 2 and is stretched along the arc surface 1a.
And a belt 7 for fixing the other end to the guide arm 6 along a circular arc surface 6a of the guide arm 6.

The belt 2 and the belt 7 are each given a predetermined tension so as to prevent slack.
Further, there are no gaps between the constituent members so that vibration does not occur between the circular arc surface 1a of the positioner arm 1, the circular arc surface 6a of the guide arm 6, the output shaft 10 of the pulse motor 9, and the belts 2 and 7. It is set up.

Next, the feeding operation of the magnetic head 5 in this embodiment will be described. First, a control circuit (not shown)
Operates the pulse motor 9 to rotate the output shaft 10.
As the output shaft 10 rotates, the driving force of the belts 2 and 7 increases.
And the positioner arm 1 is rotated. The guide arm 6 makes the rotation of the positioner arm 1 smooth, and the shaft 8 rotates in the opposite direction following the rotation of the positioner arm 1 so that the slack of the belts 2 and 7 does not occur.

The rotary encoder 4 measures the rotation angle at the rotation center of the positioner arm 1. Then, the control circuit positions the magnetic head 5 at a predetermined position based on the measured rotation angle. At this time, FIG.
As shown in Fig. 2, the belts 2 and 7 are always half the circumference of the output shaft 10.
Positioner arm 1 and output shaft 10
And the distance is constant without changing. In addition, the belts 2 and 7 do not generate slack and rotate the positioner arm 1. As a result, the magnetic head 5 can be accurately and stably positioned and data can be written.

[0015]

As described above, in the magnetic head feeding mechanism of the present invention, the guide arm is provided, and the belt is not wound around the output shaft of the pulse motor but is always in contact with the output shaft of the pulse motor for half a turn. The distance between the circular arc surface and the output shaft can be kept constant. Therefore, there is an effect that the magnetic head is precisely and stably fed without applying an extra load (a force in the radial direction) to the positioner arm and the output shaft.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional example.

3 is a cross-sectional view of FIG.

[Explanation of symbols]

 1 Positioner Arm 1a Arc Surface 2 Belt 3 Shaft 4 Rotary Encoder 5 Magnetic Head 6 Guide Arm 6a Arc Surface 7 Belt 8 Shaft 9 Pulse Motor 10 Output Shaft 11 Positioner Arm 11a Arc Surface 12a Belt 12b Belt 13 Shaft 14 Rotary Encoder 15 Magnetic Head 15a Holder 16 Pulse motor 17 Output shaft 18 Spindle 19 Coupling 20 Bearing 20a Bearing support

Claims (2)

(57) [Claims] 1. A positioner arm having a first shaft that serves as a center of rotation and a first arc surface that forms an arc about the first shaft, a second shaft that serves as a center of rotation, and a second shaft that serves as a center of rotation. A guide arm having a second arc surface that forms an arc about the shaft, and the second arc surface and the first arc surface of the positioner arm are arranged to face each other at a predetermined interval; A magnetic head for writing data held at one end of the positioner arm,
A rotary encoder that is connected to the first shaft and measures a rotation angle of the positioner arm, and an output shaft between the positioner arm and the guide arm has a predetermined gap from the first and second arc surfaces. And a thin plate-shaped one end fixed to the positioner arm and extending along the first arc surface so as to half-circulate the output shaft of the pulse motor and to the second arc surface of the guide arm. A first belt having the other end stretched and fixed to the guide arm, and a thin plate-shaped belt having one end fixed to the positioner arm in the opposite direction to the first belt and stretched along the first arc surface. A second belt that extends around the output shaft of the motor and extends along the second arc surface of the guide arm and fixes the other end to the guide arm. Magnetic head feed mechanism to be. 2. The magnetic head feeding mechanism according to claim 1, wherein the first circular arc surface of the positioner arm and the second circular arc surface of the guide arm are circular arc surfaces of a fan-shaped member.