JPS6220161A - Disk holding device - Google Patents

Abstract

PURPOSE:To minimize the eccentricity of a disk as much as possible by forming the shaft diameter of a sliding part with the supporting ring in a rotating driving shaft part larger than the shaft diameter of a rotating driving shaft main body. CONSTITUTION:Since a fitting shaft part 27a of a magnetic body disk 27 is inserted and fixed into a rotating driving shaft 23, the shaft diameter of the rotating driving shaft 23 comes to be essentially large, and consequently, the concentricity with the rotating driving shaft 23 can be also processed with a high accuracy. As the result, the play at the section of a disk supporting ring 32 can be minimized as much as possible, the eccentricity at the time or positioning a disk 22 through the disk supporting ring 32 can be minimized as much as possible and the highly accurate positioning-out at the time of fixing and holding the disk can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disc holding device for fixedly holding a disc placed on a turntable and rotated at high speed, such as an optical disc, on the turntable.

[Prior art 1] This type of disc holding device is disclosed in the 60th U.S. Patent Application No.
There is a technique described in the earlier application No.-61947. The structure of such a disk holding device is shown in FIG. 4. In FIG. 4, reference numeral 1 indicates a turntable for mounting and supporting the disk 2, which is fixed to a rotational drive shaft (spindle motor shaft) 3. Reference numeral 4 indicates a disc holding member, and disc holding members 5 and 6 are provided on the disc holding surface. Reference numeral 7 denotes a support ring for positioning the disk 2, which is slidably fitted onto the rotary drive shaft 3 and is always urged upward via a bullet 8. The outer periphery of the support ring 7 is shaped into a spherical surface, and a member 9 made of a magnetic material is fixed to the upper end of the 0-rotation drive shaft 3, which is configured to facilitate positioning of the disk 2. The dome 1 member 9 is configured to be able to be attracted to a permanent magnet 10 fixed to the lower surface of the disk holding member 4.

Reference numerals 11 and 12 indicate a regulating portion for regulating relative slippage between the disk pressing member 4 and the rotational drive shaft 3.

According to the above configuration, when the disc 2 is pressed and held via the disc pressing member 4, the disc 2 is held by the support ring 7.
The concentricity of the disc 2 and the rotary drive shaft 3 can be matched, and the disc 2 can be fixedly held on the turntable 1 in a positioned state.

Problem 1 to be Solved by the Invention However, the above configuration has the following problems. That is, in the means for holding the disc 2,
It is necessary to achieve concentricity between the disk 2 and the rotary drive shaft 3 with high precision, but in the above configuration, this is not possible due to the following reasons, and the amount of eccentricity of the disk 2 increases, causing the disk 2 It was not possible to perform highly accurate positioning when the machine was held fixed. That is, in the above configuration, the support ring 7 for disk positioning is configured to be brought into direct sliding contact with the rotary drive shaft 3, but since the rotary drive shaft 3 has a small diameter, one rotation drive shaft 3 It is difficult to achieve high precision machining of the relative sliding contact between the disk support ring 7 and the disk support ring 7, and as a result, the amount of eccentricity of the disk 2 with respect to the rotational drive shaft 3 axis increases, and the height of the disk 2 increases. Accurate positioning was not possible. Further, since the shaft diameter of the rotary drive shaft 3 is small, the shaft rigidity is also extremely low, and there is also a problem that eccentricity occurs in the disk 2 due to deflection of the shaft.

The present invention has been made in view of the above-mentioned problems of the prior art, and is configured to achieve high machining accuracy of the sliding contact portion between the rotary drive shaft portion and the disk support ring, and to improve shaft rigidity. The purpose is to improve the disc eccentricity and minimize the amount of eccentricity of the disc.

[Means and effects for solving the problem 1] The present invention has a disc pressing member that can be pressed against a disc placed on a turntable fixed to a rotational drive shaft,
A disk holding device configured to fix and hold a disk on a turntable via a support ring for disk positioning that is slidably fitted to the rotational drive shaft portion and the disk pressing member, The shaft diameter of the portion of the rotary drive shaft portion that slides with the support ring is larger than the shaft diameter of the rotary drive shaft body.

According to the above structure a, the shaft diameter of the rotary drive shaft portion that supports the support ring in sliding contact can be increased, the shaft rigidity can be improved, and the sliding contact portion between the rotary drive shaft portion and the support ring can be increased. Machining accuracy can be improved.

[Example] Hereinafter, an example of the present invention will be described in detail using the drawings.

First Embodiment FIG. 1 is a front sectional view showing a first embodiment of a disc holding device 20 according to the present invention.

In the figure, 21 indicates a turntable for supporting the disk 22 as a mounting device, and is fixed to a rotational drive shaft (spindle motor shaft) 23 inserted into the axial center of the turntable. Reference numeral 24 denotes a disk holding member (disk clamping member) for fixing and holding the disk 22, and a disk holding member 26 is provided on the disk holding surface portion 25.

Reference numeral 27 denotes a magnetic disk fixed to the upper end of the one-rotation drive shaft 23, and the shaft portion 27a that engages with the one-rotation drive shaft 23 is
@It is formed on the rotating shaft portion coaxial with the rolling drive shaft 23. 28
2 is a recess for fitting with the rotary drive shaft 23. A fitting portion 27b that fits into the fitting hole 29 provided in the axial center of the disk holding member 24 is protruded from the axial center of the magnetic disc 27, and the fitting portion 27b fits into the fitting hole 29 provided at the axial center of the disk holding member 24. Fitting part 27b
The disc holding member 24 is positioned by fitting into each other. The disc body portion 27'c of the 81-mass body disc 27 is connected to the disc pressing member 24.
The magnetic disc 27 is set to be attracted to a permanent magnet 30 fixedly embedded in the lower surface of the permanent magnet 30.
The holding member 26 presses the upper surface of the disc 22 when the disc 22 is attracted to the turntable 22, and is configured so that the disc 22 can be fixedly held on the turntable 22. Reference numeral 31 indicates a connected bin.

A disk support ring 32 for positioning the disk 22 is fitted into the fitting shaft portion 27a of the magnetic disk 27 so as to be slidable in the axial direction.The disk support ring 32 is fitted with a compression coil spring. It is constantly urged upward via a bullet @33. The outer periphery of the disk support ring 32 is formed into a spherical shape, and is configured to facilitate positioning of the disk 22.

In the above configuration, the operation of this embodiment will be explained.

Before placing the disc 22 on the turntable 21, the disc pressing member 24 is moved upward. Here, the disc 22 is placed i1 on the turntable 21.
! Once placed, the disk 22 is automatically centered and set in position by the outer spherical portion of the disk support ring 32.

Next, when the disk holding member 24 is moved downward, the disk holding member 24 is moved into the fitting hole 29 as shown in FIG. The permanent magnet 30 is set in a predetermined position via the fitting part 27b.
The disk holding member 24 is attracted and held on a magnetic disk 27 fixed to the rotational drive shaft 23 through the magnetic disk 27 . This results in
The holding member 26 of the disk holding surface portion 25 presses the disk 22, and the disk 22 is fixedly held on the turntable 21.

Next, when the rotation drive shaft 23 is driven to start rotating the turntable 21, the disk 22 is also rotated, but the relative slippage between the disk holding member 24 and the magnetic disk 27 causes the connection pin 31 to rotate. regulated through. Therefore, it is possible to reliably prevent a delay in the rise time when the rotation of the disk 22 is started.

In particular, in this embodiment, since the fitting shaft portion 27a of the magnetic disk 27 is fitted and fixed on the rotational drive shaft 23, the shaft diameter of the rotational drive shaft 23 becomes substantially large. Therefore, the concentricity with the one-rotation drive shaft 23 can be processed with high precision.

As a result, the play between the disc support ring 32 and the disc support ring 32 can be minimized, and the amount of eccentricity when positioning the disc 22 via the disc support ring 32 can be minimized. Highly accurate positioning is what makes it possible.

Moreover, since the shaft diameter of the rotary drive shaft 23 becomes substantially large due to the fitting shaft portion 27a, so-called shaft rigidity is improved. Therefore, even if centrifugal force occurs due to a shift in the position of the center of gravity of the disk 22 when the disk 22 rotates, the effect can be minimized, and the amount of eccentricity due to deflection of the rotational drive shaft can be minimized. be.

Second Embodiment FIG. 2 is a front view showing a second embodiment of the disk holding device 20 according to the present invention, with the left half of the axis taken in section.

The feature of this embodiment is that the magnetic disk 27 in the first embodiment is
However, the mating shaft portion 27a is constructed separately from the disc main body portion 27c, and the mating shaft portion 27a and the disc main body portion 27c are integrally connected via the mutual mating portions 40 and 41. This is a fixed point. The rest of the structure is the same as that shown in FIG. 1, so the same members are given the same reference numerals and their explanation will be omitted.

The above configuration also provides the same functions and effects as the first embodiment.

Note that the fitting shaft portion 27a is not directly fixed to the rotation drive shaft 23 as shown in FIG.
Of course, the structure may be such that it is fixed to 1 via a fixture 42 such as a countersunk screw.

[Effect of the Invention J As described above, according to the present invention, the amount of eccentricity of the disk can be minimized, and the axial rigidity of the one-rotation drive shaft portion can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view showing a first embodiment of the device according to the present invention, FIGS. 2 and 3 are partially cutaway front views showing the second embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional explanatory diagram of a conventional technique. 21...Turntable 22...Disk 23...Rotation drive shaft 24...Disk holding member 27a...Fitting shaft portion 27c...Magnetic disk body Patent applicant Olympus Optical Industry Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] It has a disc holding member that can be pressed against a disc placed on a turntable fixed to a rotational drive shaft,
In a disc holding device configured to fixedly hold a disc on the turntable via a support ring for disc positioning that is slidably fitted on the rotational drive shaft and the disc pressing member. 2. A disk holding device, characterized in that a shaft diameter of a sliding portion of the rotary shaft portion that slides with the support ring is larger than a shaft diameter of the rotary shaft main body.