JPH01169771A - Spindle mechanism for optical disk - Google Patents

Abstract

PURPOSE:To securely load an optical disk by providing a circular hole at the edge face central part of the rotational spindle of a spindle motor and clearance- fitting a steel ball in a circular hole part. CONSTITUTION:A circular hole 2b is provided in a spindle direction at the central part of an edge face 2a of a rotational spindle 2 of a spindle motor 1. A coil spring 6 and a steel ball 7 are provided inside the circular hole 2b, the inside diameter part of an optical disk 4 and the steel ball are engaged, and the centering of the disk 4 is performed. A clamper 8 is arranged rotatably, and the disk 4 is compress-fixed on a turntable 5. Since the steel ball 7 is installed with clearance-fitting inside the circular hole 2b, when force deviated from the spindle direction acts, it point-contacts with the inside diameter part. Thus, frictional force between both is small, the steel ball 7 moves smoothly in the spindle direction, and the disk 4 can be loaded stably and precisely. Beside, the steel ball 7 is possible to rotate in an arbitrary direction, and the centering is performed easily and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spindle mechanism for an optical disk, and more particularly to a spindle mechanism with improved centering and centering of an optical disk.

[Conventional technology]

Conventionally, as shown in FIG. 2, the spindle mechanism of this type of optical disk is an axially movable spindle mechanism that is mounted on the rotating shaft 2 with clearance fitting to the outer diameter of the rotating shaft 2 of the spindle motor 1 and has a cone-shaped outer diameter surface 3a. The slide member 3 is provided on the rotating shaft 2, and the optical disc 4 is centered by engaging the inner diameter surface 4a of the optical disc 4 with the cone-shaped outer diameter surface 3a.

[Problem that the invention seeks to solve]

The conventional optical disk spindle mechanism described above has a drawback that the sliding member has a complicated shape and requires extremely high precision, resulting in high component costs.

Furthermore, when a force is applied to the slide member in a direction slightly deviated from the axial direction between the outer diameter of the rotating shaft of the spindle motor and the inner diameter portion where the slide member fits, when an optical disk is mounted, the frictional force becomes large. The slide member becomes unable to slide in the axial direction, making it impossible to properly mount the optical disc, and in the worst case, galling occurs between the slide member and the rotating shaft, impairing the function of the slide member. Ta.

[Means for solving problems]

An optical disc spindle mechanism of the present invention includes a spindle motor, a turntable fixed to a rotating shaft of the spindle motor, and a rotatable clamper that presses an optical disc onto the turntable in the axial direction. The present invention is characterized in that a round hole is provided in the axial direction at the center of the end surface of the rotating shaft of the spindle motor, and a coil spring and a steel ball having a clearance fitting diameter and a diameter of the round hole are provided in the round hole.

〔Example〕

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

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

Referring to FIG. 1, a turntable 5 is fixed to a rotating shaft 2 of a spindle motor 1, and a round hole 2b is provided in the center of an end surface 2a of the rotating shaft 2 in the axial direction. A coil spring 6 and a steel ball 7 are provided in the round hole 2b, and the inner diameter portion of the optical disc 4 and the steel ball 7 engage to center the optical disc 4. The clamper 8 is rotatably arranged, and presses and fixes the optical disc 4 onto the turntable 5. The steel ball 7 is a steel ball 7 placed on the end face of the rotating shaft 2.
Movement of the axial force is suppressed by the stopper ring 9 having a diameter smaller than the diameter.

The steel ball 7 is fitted into the inner diameter portion of the round hole 2b of the rotating shaft 2 with a gap fit. Even if a force in a direction deviating from the axial direction is applied to the steel ball 7 when the optical disc 4 is mounted, the inner diameter portion of the round hole 2b and the steel ball 7 come into point contact. Therefore, the frictional force between the two is small, the steel ball 7 moves smoothly in the axial direction, and the optical disc can be mounted stably and accurately. Note that since the steel ball 7 can be rotated not only in the axial direction but also in any direction, centering and centering can be easily and accurately performed.

〔Effect of the invention〕

As explained above, the present invention is simple in that a round hole is provided in the axial direction at the center of the end face of the rotating shaft of a spindle motor, and a coil spring and a steel ball having a diameter of the round hole and a clearance fitting diameter are provided in the round hole. This configuration has the effect of centering and centering the optical disc with high precision and reliable mounting.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional spindle mechanism. 2...Rotating shaft, 4...Optical disc, 6
...Coil spring, 7... Steel ball,
8... Clamper. Agent Patent Attorney Oto Uchihara

Claims (1)

[Claims] In an optical disc spindle mechanism that includes a spindle motor, a turntable fixed to a rotating shaft of the spindle motor, and a rotatable clamper that presses an optical disc onto the turntable in the axial direction, the rotation of the spindle motor 1. A spindle mechanism for an optical disc, characterized in that a round hole is provided in the axial direction at the center of an end face of the shaft, and a steel ball having a coil spring and fitting with a gap in the diameter of the round hole is provided in the round hole.