JPH0235653A - Disk clamping mechanism - Google Patents

Abstract

PURPOSE:To lower the height of the whole of a disk clamping mechanism and to thin a device by providing a center positioning hole to receive a small diameter part formed at the tip of a center shaft at a clamper. CONSTITUTION:The center shaft 3 is provided with a large diameter part 3a at a base side, an inclination part 3b inclined in convergent shape from the large diameter part 3a, and the small diameter part 3c formed at the tip of the inclination part 3b, and the clamper 5 is provided with the center positioning hole to receive the small diameter part 3c. In such a way, it is possible to lower the height from the plane of a turntable 2 to the tip of the center shaft 3, and to thin the disk clamping mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a disk clamp mechanism, and more particularly to a disk clamp mechanism for a recording/reproducing device that uses a disk-shaped medium such as an optical disk device and is capable of replacing the medium. .

[Prior Art] Generally, this type of disk clamp mechanism is required to rotate the disk medium with high precision. Therefore, as shown in FIG. 2, the spindle motor 11 is equipped with a turntable 12 with high positional accuracy, and the disk medium 4
By setting on top of this, you can position it in the vertical direction.

Further, the disk medium 4 has a center hole drilled with precision, and the spindle motor 11 has a center shaft 13 which is a rotating shaft and is extended and protrudes beyond the surface of the turntable surface 2. By fitting the center shaft 13 into the center hole of the disk medium 4, the disk medium 4 rotates around the rotation axis of the spindle motor 11 without lateral wobbling.

If the disk medium 4 is simply placed on the turntable 12, the disk medium 4 may spring up and fall off the spindle motor 11 during rotation, or may slip between the turntable 12 and the spindle motor 11 may not rotate properly. 4, there is a high possibility that the recording/reproducing process will be hindered, and it is necessary to press the disk medium 4 against the turntable 12 in some way. The clamper 15 performs this role, and rotates together with the disk medium 4 while pressing the disk medium 4 against the turntable 12. The clamper 15 must not have large rotational resistance, and the bearing 16 is essential.

The clamper 15 is biased by the clamp arm 19 and spring 1.
This is done via 7.

There is also a method of rigidly fixing the clamp arm 19 to the clamp shaft 18 and urging the clamper 15 downward, but due to the clamp arm drive mechanism, there is a large error in the vertical same position n of the clamp arm 19, and therefore the pressing force is Since the variation becomes large, the engagement relationship between the clamp arm 19 and the clamp shaft 18 is eliminated, and the pressing force is obtained by the spring 17.

Since the clamper 15 rotates together with the disk medium 4 as described above, positioning is required to prevent it from whirling around. For this purpose, a structure is adopted in which the center shaft 13 of the spindle motor 11 is made to protrude further from the disk medium 4 so that the center hole 15a of the clamper 15 fits therein.

The tip of the center shaft 13 is rounded so that the center hole 4a of the disk medium 4 or the center hole 15a of the clamper 15 is smoothly guided to the straight portion of the center shaft 13 when it starts to fit into the center hole 4a.

[Problem to be solved by the invention l In the conventional disk clamp mechanism described above.

The lower limit of the diameter of the center hole 4a of the disk medium 4 is determined due to the material properties of the disk medium 4, and the outer diameter of the center shaft 13 of the spindle motor 11 is required to have a certain thickness. Mama disk medium 4
The spindle motor 11 protrudes to the top surface, and the tip is machined into a spherical shape according to the radius of the center shaft 13.
The height from the surface of the turntable surface 2 to the tip of the center shaft 13 has to be increased, which ultimately increases the height of the entire disc clamping mechanism, which becomes a major obstacle in making the device thinner. There was a drawback that there was.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and as a means for solving the problems, the present invention provides a turntable for vertically positioning a disk medium, and a turntable for vertically positioning a disk medium. A disk clamp comprising: a spindle motor having a center shaft that protrudes above the turntable surface and rotates the disk medium correctly around the center of rotation; and a clamper that presses the disk medium against the turntable of the spindle motor with a spring force. In Iaa,
The center shaft that protrudes above the turntable surface has a large diameter portion on the base end side, an inclined portion tapering from the large diameter portion, and a small diameter portion formed at the tip of the inclined portion. , the clamper has a center positioning hole for receiving the small diameter portion.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a disk clamp mechanism according to an embodiment of the present invention.

In the figure, 1 is a spindle motor, which rotates the disk body 4 correctly around the rotation center of the center shaft 3.To the north of the main body of the spindle motor 1, a turntable 2 made with precision is placed on the center shaft. It is attached to 3.

The turntable 2 positions the disk medium 4 in the vertical direction, and a clamper 5 can come into contact with the turntable 2 from above. This clamper 5 includes a clamp arm 9, a clamper shaft 8. spring 9
, and rotates on bearings 6 and the like to hold the disk medium 4.

The outer diameter of the large diameter portion 3a on the base end side of the center shaft 3 that protrudes from the upper surface of the turntable 2 is the diameter of the disk medium 4.
The inner diameter of the center hole 4a is slightly smaller than the inner diameter of the center hole 4a, so that the disk medium 4 can be smoothly fitted into the center shaft 3 during sushi. The straight portion of the large diameter portion 3a ends at a point protruding from the turntable surface by 1 to 2 mm, and the inclined portion 3b begins from there. Even if the large KM 3a does not protrude enough to cover the thickness of the disk medium 4, it is sufficient to position the disk medium 4 with this degree of protrusion.

The inclined portion 3b is provided to allow the center hole 4a of the disk medium 4 to fit smoothly into the large diameter portion 3a of the center shaft 3. The leading edge of the center shaft 3 is machined to be even thinner to form a small diameter portion 3C. This small diameter part 3
C is for positioning the clamper 5, and is adapted to be received in a center positioning hole 5a having an inner diameter slightly larger than the outer diameter of the small diameter portion 3C formed in the clamper 5.

[Effects of the Invention] As described above, the present invention provides a turntable for vertically positioning a disk medium, a rotation center that protrudes above the turntable surface, and a turntable that positions the disk medium in the correct rotation center 123. A disk clamping mechanism comprising: a spindle motor having a center shaft that rotates the spindle motor; and a clamper that presses a disk medium against a turntable of the spindle motor with a spring force.

The center shaft that protrudes above the turntable surface has a large diameter portion on the base end side, an inclined portion tapering from the large diameter portion, and a small diameter portion formed at the tip of the inclined portion. Since the clamper has a center positioning hole that receives the small diameter portion, the height from the turntable surface to the tip of the center shaft can be reduced, and the disc clamping mechanism can be made thinner.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a disk clamp mechanism according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional disk clamp mechanism. 1 spindle motor 2: turntable 3: center shaft 3a: large diameter section 3b: inclined section 3c: small diameter section 4: disk medium 5: clamper

Claims (1)

[Scope of Claims] A spindle motor having a turntable that positions a disk medium in the vertical direction, and a center shaft that is a center of rotation and projects above the surface of the turntable, and that rotates the disk medium correctly around the center of rotation. and a clamper that presses the disk medium against the turntable of the spindle motor using a spring force, the center shaft protruding above the turntable surface has a large diameter portion on the base end side, and a clamper that presses the disk medium against the turntable of the spindle motor. 1. A disk clamping mechanism comprising: an inclined portion tapering from a large diameter portion; and a small diameter portion formed at the tip of the inclined portion; and wherein the clamper has a center positioning hole for receiving the small diameter portion.