JPS6342347B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic disk device positioned by a servo head, and particularly to a base and cover structure suitable for downsizing the magnetic disk device.

[Field of application of the invention]

FIG. 1 is a partial sectional view of a conventional magnetic disk device. In the figure, a plurality of disks 1 are attached to a spindle 5 that is rotationally driven. 3 is a servo head for positioning, 4 is a data head,
Both are connected to an actuator 6, which moves them in the direction of arrow 11 to exchange information with the disk surface. The spindle 5 and actuator 6 are attached to a base housing 7 and surrounded by a cover 8 and a shield material 9. The structure of the conventional base housing 7 is flat, and when the cover 8 is removed, the disk 1 protrudes from the base housing surface 12. The performance required of the base housing 7 is rigidity that can hold the attached parts and the information recording position recorded on the disk surface with an accuracy of several microns, and for this purpose, the thickness dimension 13
is required, and the height dimension 14 of the device becomes large.
The servo information surface 2 corresponding to the positioning servo head 3 needs to have the information used for its positioning control written in advance with high accuracy, and this can be done by writing the information to the servo information writing device from outside the device with the cover 8 removed. Servo information surface 2 for writing
A distance 15 between the base housing surface 12 and the base housing surface 12 is required.

As the recording density of disk devices improves, the disk diameter size has been reduced from 14 inches to 8 inches and then to 5 inches. The lateral dimensions of the device are becoming smaller due to the reduction in disk size, and the height dimension is also required to be smaller, which requires reducing the thickness of the base housing. There was a drawback that it could not be made thinner.

[Purpose of the invention]

An object of the present invention is to provide a base housing structure that can reduce the height of the device while maintaining positioning accuracy.

[Summary of the invention]

In order to achieve this object, the present invention is characterized in that the edges of the base housing are raised up from the flat plate shape to provide rigidity, and the dividing plane between the cover and the base housing is located approximately at the center of the plurality of disks. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In general, the positioning deviation caused by the servo head 3 is due to a mere lack of structural rigidity of the base housing 7 and thermal displacement with respect to the servo information surface 2. When the center axis of the spindle motor is tilted again by 16, a deviation 18 occurs from the data position 17 before tilting. It's for a reason. This deviation amount 18 becomes larger as the disk surface is farther away from the servo information surface 2.

In order to reduce the positioning deviation, it is necessary to improve the base rigidity to reduce the inclination, and also to consider means to reduce the deviation due to the inclination caused by thermal displacement.

Furthermore, with respect to the thermal displacement inclination, by placing the servo information surface 2 at the center of the plurality of disks 1, the distance from the servo information surface 2 to the farthest disk can be reduced, thereby reducing misalignment.

In consideration of the above, in this implementation, the servo information surface 2 is located at the center of the plurality of disks 1, the dimensional interval 15 is set such that servo information can be written by the servo information writing device, and the base housing 7 is A rigid structure is achieved by increasing the upright dimension 19. In addition, in order to reduce the lateral dimensions of the device, the gap between the disk 1 and the base housing 7 and cover 8 is required to be small, and the width of the airtight shield material 9 is as small as 1 to 2 mm. It needs to be brought into the room. By placing the dividing surface of the base housing 7 and cover 8 between the disks, there is an advantage that the protruding shield material 9 does not touch the disk 1.

〔Effect of the invention〕

According to the present invention, by raising the edges of the base housing, it is possible to make the base housing about 50% thicker than a flat base without sacrificing rigidity.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a conventional magnetic disk device, FIG. 2 is a partial sectional view of a magnetic disk device of the present invention, and FIG. 3 is a principle diagram showing the deviation between servo information position and data position with respect to spindle axis tilt. . Explanation of symbols 1...disk, 2...servo information surface, 3
... Servo head, 4... Data head, 5... Spindle, 6... Actuator, 7... Base housing, 8... Cover, 9... Shield material, 10... Gap (gap between base or cover and disk), 11
...arrow, 12...base housing surface, 13...thickness dimension, 14...height dimension, 15...interval, 16...angle, 17...data position before tilt, 18...displacement, 1
9...Starting dimensions.

Claims (1)

[Claims] 1. In a magnetic disk device consisting of an actuator consisting of a servo head that performs positioning with a plurality of data heads, a plurality of discs, a spindle that rotates them, and a base housing and cover that house these, the base housing and cover are separated. A magnetism characterized in that the surface is one plane, the dividing surface is provided at a disk surface approximately in the middle of a plurality of disks, and the center of the disk surface, and a servo disk is provided at a position near the center of the plurality of disks. disk device.