JPH0415527B2 - - Google Patents

Description

[Detailed Description of the Invention] Object of the Invention The present invention relates to a method for manufacturing a magnetic disk medium,
In particular, it relates to a processing method suitable for coating film finishing.

Prior Art In conventional coating processing of magnetic disk media, the number of revolutions of the magnetic disk and the feeding speed of the tape head were kept constant, so the circumferential speed varied depending on the radial position of the processed surface of the magnetic disk, resulting in a There was a difference in processing time using polishing tape. For this reason, compared to the outer periphery, where the processing time per unit area is shorter, the inner periphery, where the processing time is longer, requires more processing, and the finished coating film is thicker on the outer periphery and less on the inner periphery. The drawback was that it was thin around the edges. It is well known that the difference in the thickness of the coating film affects the coating strength and overwriting characteristics.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a method for processing a coated surface of a magnetic disk, which eliminates the drawbacks of the prior art described above and eliminates the difference in processing amount between the inner and outer peripheral portions of the magnetic disk.

General description of the invention In order to reduce the difference in coating film thickness between the inner and outer peripheries, it is necessary to increase the force pressing the polishing tape against the processed surface in the outer periphery, where the amount of processing is small, or to reduce the difference in coating thickness per unit area. However, since the former method has doubts about the reliability of changing the pressing force and the lifespan of the polishing tape and the rubber roller that presses it, we decided to consider the latter method.

Embodiment of the Invention Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A magnetic disk medium 1 is chucked onto a spindle 2 by a chuck holder 3 and rotated. The polishing tape 4 is wound onto a take-up reel 5 from a brake reel (not shown) and is pressed against the magnetic disk surface by a contact roller 8 that transmits the force of a spring 7 attached to a holding arm 6 for processing. . These tape running systems are collectively referred to as the tape head 17. Further, the base 9 on which the tape head 17 is mounted reciprocates on two rails 12 by the rotation of the read screw 11 of the servo motor 10, and moves the tape head 17 in the direction of the arrow 13 indicating the radial direction of the magnetic disk. ,
Process the entire surface of the magnetic disk.

The rotary encoder 14, which rotates in synchronization with the rotation of the servo motor 10, outputs pulses in accordance with the rotation, and when the pulse counter 15 measures a predetermined pulse, the servo motor drive circuit 16 controls the voltage supplied to the servo motor 10. to change the rotation speed. By arbitrarily setting the relationship between the number of measured pulses and the control voltage, the reciprocating speed of the base 9 can be changed freely.

Effects of the Invention According to the present invention, the amount of processing on the magnetic disk can be arbitrarily controlled by changing the feeding speed of the tape head, so that the difference in coating film thickness after processing between the inner and outer circumferences of the magnetic disk can be greatly reduced. It is highly effective in manufacturing magnetic disks that can be made small and have good coating film strength and overwriting characteristics.

Figures 2 and 3 show the effects of the present invention. Figure 2 shows the relationship between the feeding speed of the tape head in the radial direction of the magnetic disk, and shows the constant speed mode, the conventional method with constant speed, the linear variable speed mode, and the linear speed mode. The curved speed change mode illustrates the method of speed change according to the present invention. Figure 3 shows the coating thickness after processing the magnetic disk in the above-mentioned speed change mode.
It can be seen that the difference in coating thickness between the inner and outer peripheries is the smallest for those processed in curved speed mode.

[Brief explanation of drawings]

FIG. 1 is a top view showing the structure of an embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing the relationship between the speed change mode and the coating film difference, showing the effects of the present invention. 1...Magnetic disk, 2...Spindle, 3...
...Chuck holder, 4...Polishing tape,
5... Take-up reel, 6... Holding arm, 7...
Spring, 8...Contact roller, 9...Base,
10... Servo motor, 11... Lead screw, 12... Rail, 13... Arrow, 14... Rotary encoder, 15... Pulse counter, 16
...Servo motor drive circuit, 17...Tape head.

Claims (1)

[Claims] 1. A method for manufacturing a magnetic disk in which a polishing tape is brought into contact with a rotating magnetic disk and the coating is polished while being moved from the inner circumference to the outer circumference of the magnetic disk by the rotation of a motor, in which a rotary encoder is synchronized with the rotation of the motor. The motor is rotated, the pulses output from the rotary encoder are counted by a pulse counter, and the number of revolutions of the motor is decreased at a predetermined rate until the value counted by the pulse counter reaches a predetermined number. A method for manufacturing a magnetic disk medium, characterized in that when the value counted by the pulse counting section exceeds the predetermined number, the rotational speed of the motor is decreased at a rate smaller than the predetermined rate.