JPH09320158A - Disk-chucking mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk-chucking mechanism, capable of chucking a disk by a constant clamping force regardless of the disk thickness. SOLUTION: In a fitting part 3 provided on a turntable 1 and fitted in the hollow hole of a CD 2, a holding catch 7 pressed by a spring 4 is disposed to be slightly projected from the fitting part 3. A contact surface 7a formed in the holding catch 7 to be contacted with the hollow hole inner end O of the CD 2 is shaped, such that an angle between the contact surface 7a and the base surface 1a of the turntable 1 is a fixed acute angle.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a CD (Compact Di
The present invention relates to the technical field of a mechanism for chucking a disk-shaped recording medium such as sk).

[0002]

2. Description of the Related Art Conventionally, a so-called one-touch clamp system is known as a system for simply clamping a disc-shaped recording medium such as a CD. Among these one-touch clamp systems, a ball clamp system and an O-ring system are known. ing.

FIGS. 6 (A) and 6 (B) show a ball clamp type chuck mechanism. As shown in FIGS. 6 (A) and 6 (B), a central portion of the turntable 1 as a mounting portion is provided. Is provided with a fitting portion 3 that fits into the center hole of a CD 2 as a disc-shaped recording medium, and the fitting portion 3 is biased in the radial direction of the CD 2 by a spring 4 as an elastic member. A steel ball 5 is supported. Therefore, when the CD 2 is fitted into the fitting portion 3, the steel ball 5 is pushed by the end surface of the center hole of the CD 2 and is once pushed into the fitting portion 3, but as shown in FIGS. As shown in B), when the CD 2 is moved until it comes into contact with the support portion 6 formed on the turntable 1 by a rubber sheet or rubber printing, the inner edge portion P of the center hole is located closer to the center position of the steel ball 5. Is also located below, and the CD 2 is clamped by the biasing force of the spring 4.

Further, as an application example of this ball clamp system, a resin member having a spherical convex portion instead of the steel ball 5 is provided in the fitting portion 3, and the curved surface portion of the resin member is used as described above. There is one that clamps CD2 in the same manner as.

Further, what is called an O-ring system is
An O-ring formed of an elastic member such as rubber is attached to the fitting portion 3 on the outer periphery of the fitting portion, and the CD 2 is clamped by the elastic force of the O-ring.

[0006]

However, the CD2
In the Red Book (CD standard), the thickness is 1.1 to 1.5 mm on the recording surface on which information is recorded, and
The clamp area in the center of the disc where no information is recorded is regulated to 1.2 to 1.5 mm, and in some commercially available discs, the thickness of the clamp area is 1.1 mm. Since there are discs of about the same size, in the above-described conventional clamping method, the clamping force may differ depending on the thickness of the disc.

For example, in the above-described ball clamp system, the contact position of the inner edge portion P of the center hole of the disk with respect to the steel ball 5 is as shown in FIG. As shown in FIG. 6 (B), the clamping force B of the spring force A represented by the sin component with respect to the cos component, which is the force for pushing the disk by the steel ball 5, is Larger than a thick disc.

As a result, when the strength of the spring is set so that the 1.5 mm disk is clamped accurately, it is 1.1
When a disc of mm is mounted, the clamping force becomes large, and the outer peripheral portion of the disc may be warped with the supporting portion 6 rubber-printed so as to contact the disc as a fulcrum.

In order to prevent this, it is conceivable to provide the supporting portion 6 on the entire base surface 1a of the turntable 1, but
Since the thickness of the clamp area of the disc is not specified, it may be thicker than the area where the information is recorded. In this case, the disc can be brought into contact with the support portion 6 in the clamp area, but the information is recorded. Since a non-contact state with the support portion 6 occurs in the formed area, the resonance of the disk easily occurs and cannot be adopted. After all, the supporting portion 6 has to be provided in a part outside the clamp area of the disc as shown in FIGS. 6 (A) and 6 (B), and the above-mentioned warp of the disc cannot be avoided.

When a warp occurs in the outer peripheral portion of the disc as described above, it is necessary to cause the optical pickup to follow both the inner peripheral portion of the disc with less warp and the outer peripheral portion of the disc with a large amount of warp. growing. Further, since the follow-up range of the optical pickup in the focus direction is set within a predetermined range above and below the reference position in the case where there is no warp, the initial position of the optical pickup is set from the reference position in accordance with the warp. Also, if the above is changed to the upper direction, the tracking range of the optical pickup with respect to the upward direction of the focus direction may be narrowed.

Therefore, in view of the above problems, it is an object of the present invention to provide a disc chuck mechanism capable of chucking a disc with a constant clamping force regardless of the thickness of the disc.

[0012]

In order to solve the above-mentioned problems, a disk chuck mechanism according to a first aspect of the present invention has a support shaft that is rotatably provided and a base surface that is supported by the support shaft. A mounting unit for mounting a disc-shaped recording medium,
A support part for contacting and supporting the disk-shaped recording medium substantially parallel to the base surface is provided on a mounting part provided on the base surface, and a center part of the mounting part with the support shaft as a center, A fitting portion that fits in the center hole of the recording medium, and a plurality of holding claws that are arranged in the fitting portion so as to slightly project in the radial direction of rotation of the mounting portion from the fitting portion. And a contact surface that contacts the inner edge of the center hole on the surface side opposite to the contact surface of the disk-shaped recording medium, and the contact surface on the side that contacts the inner edge of the center hole. The holding claw on which the contact surface is formed so that the angle formed with the base surface of the mounting portion is a constant acute angle, and the holding claw,
And an elastic member for elastically holding the disc-shaped recording medium in an elastically contacting state.

According to the disc chuck mechanism of the first aspect, when the disc-shaped recording medium is mounted so that the center hole of the disc-shaped recording medium and the fitting portion are fitted, the disc-shaped recording medium is placed from the fitting portion. The plurality of holding claws slightly protruding in the radial direction of rotation of the portion contact the peripheral portion of the central hole of the disk-shaped recording medium, and the holding pawl is pushed by the peripheral portion of the central hole to temporarily hold the fitting portion. It moves inward against the biasing force of the elastic member. Then, when the disc-shaped recording medium is mounted up to the position where the surface of the disc-shaped recording medium comes into contact with the supporting portion provided on the base surface of the mounting portion, the contact surface of the holding claw is The inner edge of the central hole on the surface side opposite to the contact surface with the inner edge of the central hole receives a pressing force from the holding claw according to the urging force of the elastic member. The pressing force is a force in a direction perpendicular to the contact surface, that is, a cos component of the biasing force in the protruding direction, and the pressing force is a force in a direction perpendicular to the contact surface between the supporting portion and the disk-shaped recording medium. , Ie, the pressing force sin
The component acts as a clamping force on the disc-shaped recording medium. Therefore, the clamping force becomes a sin component of the cos component of the biasing force in the protruding direction, and the magnitude of the clamping force is the angle formed between the surface of the disk-shaped recording medium and the contact surface of the holding claw. Depends on However, the angle formed between the contact surface and the base surface of the mounting portion on the side in contact with the inner edge of the center hole on the surface side of the disk-shaped recording medium is a constant acute angle. The angle formed between the surface of the disk-shaped recording medium that is supported substantially parallel to the contact surface and the contact surface is also a constant acute angle, and the central hole on the surface side due to the difference in the thickness of the disk-shaped recording medium. Even when the contact position between the inner edge and the contact surface is different, the angle formed between the contact surface and the surface of the disk-shaped recording medium is a constant acute angle, so that the thickness of the disk-shaped recording medium is large. The clamping force is constant even if the difference is present.

In order to solve the above-mentioned problems, the disc chuck mechanism according to a second aspect of the present invention is the disc chuck mechanism according to the above-mentioned first aspect, in which the holding claw has a certain angle with the contact surface. It is characterized by having a smoothly continuous guide surface for a disc-shaped recording medium.

According to the disc chuck mechanism of the second aspect, when the disc-shaped recording medium is mounted so as to be fitted in the fitting portion, the peripheral portion of the center hole of the disc-shaped recording medium contacts the guide surface of the holding claw. It touches and moves along the guide surface.
Since the guide surface and the contact surface are smoothly continuous with each other at a certain angle, the inner edge of the center hole of the surface of the disk-shaped recording medium is smoothly positioned at the contact position with the contact surface. Thus, the disc-shaped recording medium can be fitted smoothly.

In order to solve the above-mentioned problems, a disk chuck mechanism according to a third aspect of the present invention is the disk chuck mechanism according to the above-mentioned second aspect, in which the abutting surface of the holding claw and the base of the mounting portion are the same. The angle formed with the surface is 6
It is characterized by being set at 0 °.

According to the disc chuck mechanism of the third aspect, the angle formed between the contact surface of the holding claw and the base surface of the mounting portion is set to 60 °. , The height of the fitting portion in the support axis direction is kept low, and
The biasing force of the elastic member is set to an appropriate value. That is, 6
When the angle is set to be smaller than 0 °, as described above, in order to keep the angle of the guide surface and the contact surface constant and to smoothly continue the guide surface, the guide surface is moved from a high position in the support axis direction. Inevitably, it is necessary to form the holding claws, and as a result, the height of the holding claws increases, and the height of the fitting portion in the support axis direction increases. Further, when the angle is set to be larger than 60 °, the clamping force becomes small as described above, so that the biasing force of the elastic member needs to be increased. However, according to the disc chuck mechanism of the third aspect, since the angle is 60 °, the height of the fitting portion can be kept low and the biasing force of the elastic member can be set to an appropriate value.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
Explanation will be made based on FIG. FIG. 1 is a plan view of a turntable device equipped with a disc chuck mechanism of the present embodiment, FIG. 2A is a half sectional view of the turntable device of FIG. FIG. 2 is a partial cross-sectional view of the turntable device of FIG. 1 viewed from the direction of arrow B.
As shown in these figures, the turntable 1 as a mounting portion is rotatably supported by a rotation shaft 11 of a spindle motor 10 as a rotation means as a supporting shaft, and is provided on the outer peripheral portion of the base surface 1a of the turntable 1. A support portion 6 formed by a rubber sheet or rubber printing is provided in a predetermined range. Further, a fitting portion 3 into which the central hole of the disc is fitted is provided at the center of the turntable 1, and the fitting portion 3 is made of resin or the like in a removable chuck case. Three holding claws 7 are provided. The holding claw 7 is biased by a spring 4 as an elastic member, and is arranged so as to slightly project from the fitting portion 3 in the radial direction of the turntable 1. In FIG. 1, 12 is a spring receiving member, and the spring receiving member 12 is the spring 4
Holds and holds the holding claw 7 stable.

3 (A) and 3 (B) are sectional views around the holding claws when the turntable device of FIG. 1 is viewed from the direction of arrow A. FIG. 3 (A) shows a state in which the CD 2 is mounted, Figure 3
(B) shows a state in which the CD2 is not attached. As can be seen from FIG. 3, the shape of the holding claw 7 of this embodiment is
An abutment surface 7a of the disc with the inner edge P of the hollow hole is formed in a planar shape having a constant acute angle with respect to the base surface 1a of the turntable 1. Further, an upper surface of the holding claw 7 which is continuous with the contact surface is formed with a guide surface 7b as a guide surface which is smoothly continuous with the contact surface 7a at a certain angle. Therefore, when the CD 2 is fitted into the fitting portion 3 from above, the inner edge portion Q of the central hole of the lower surface of the CD 2 is smoothly fitted along the inviting surface 7b, and as shown in FIG. The contact surface 7a and the inner edge P of the central hole on the upper surface of the CD 2 contact each other, and the clamping force B is generated based on the spring force A.

The angle between the contact surface 7a and the attracting surface 7b is C
Since a certain size is required for smooth fitting of D2 and the angle is set to a certain angle based on experiments and the like, if the angle between the contact surface 7a and the base surface 1a is reduced, Since it is necessary to form the inviting surface 7b having a gentle slope while maintaining the angle with the invoking surface 7b, the height of the holding claw 7 becomes high, and accordingly, the fitting portion 3 also needs to be made high. As a result, the device becomes large. On the other hand, when the angle of the contact surface 7a is increased, the clamping force B is decreased, so that the spring force A needs to be increased.

Therefore, in the present embodiment, as a result of experiments, the angle of the contact surface 7a is set to 60 ° with respect to the CD surface when the CD is fitted. By thus forming the contact surface 7a as a plane having a constant angle with respect to the base surface 1a, as shown in FIG. 4, the angle of the contact surface 7a with respect to the surface of the CD2 is the thickness of the CD2. The spring force A is constant and therefore the clamping force B expressed as a sin component of the cos component of the spring force A is also substantially constant.

In FIG. 4A, the disc thickness is 1.
The case of 2 mm, the case of a disk thickness of 1.5 mm in FIG. 4 (B), and the case of a disk thickness of 1.1 mm in FIG. 4 (C) are shown. It can be seen that the force B is Asin 60 ° cos 60 ° and is almost constant.

Further, FIG. 5 shows the change of the clamping force with respect to the thickness of the disk when the holding claw 7 having the flat abutment surface 7a of the present embodiment is used and the conventional steel ball is used. It is shown in comparison with the case of the ball clamp method. In this measurement, the diameter of the steel ball was 2.1 mm, the spring force applied to the steel ball was 100 gf, and the spring constant was 40 gf / mm when the disk thickness was 1.1 mm. A similar spring was used for the device of this embodiment.

As can be seen from FIG. 5, the conventional steel balls have a large difference in the clamping force depending on the thickness of the disc.
In the case of the holding claw 7 of this embodiment, the difference is small. Even in the case of this embodiment, the clamping force differs depending on the thickness of the disc because the spring force A changes depending on the thickness of the disc.

The contact surface 7a of the holding claw 7 may have a linear cross section, and the plan view as seen from the rotation axis direction as shown in FIG. 1 may be curved. Although making the cross-sectional shape of the contact surface 7a linear can also be realized by using a steel ball having a large diameter, there is a disadvantage that the device becomes large as a result of increasing the diameter of the steel ball, Not preferable.

In the present embodiment, the case where a CD is used as the disc-shaped recording medium has been described.
The present invention is not limited to this, and can be applied to the case of using another disc-shaped recording medium such as a DVD.

Further, although the case where the coil spring is used as the elastic member has been described in the present embodiment, the present invention is not limited to this, and a leaf spring or a column spring can be used.

[0028]

As described above, according to the disc chuck mechanism of the first aspect, the contact surface of the holding claw is on the side of contact with the inner edge of the center hole of the disk-shaped recording medium. Since the angle formed between the base and the base surface of the mounting portion is a constant acute angle, the difference in the clamping force due to the variation in the thickness of the disk-shaped recording medium is the difference in the biasing force of the elastic member. Since it is small by itself, it is possible to easily set the clamp load. Further, as a result of the clamping force becoming substantially constant, even when the thickness of the disc-shaped recording medium is thin, it is possible to suppress the warp of the outer peripheral portion of the disc-shaped recording medium, reduce the load of the optical pickup, and Since the follow-up range in the focus direction can be set large, good focus servo control can be performed.

According to the disc chuck mechanism of the second aspect, in the disc chuck mechanism of the first aspect, the guide surface and the contact surface of the disc-shaped recording medium in the holding claw have a certain angle and are smooth. As described above, not only can the occurrence of warpage of the disc-shaped outer peripheral portion be suppressed as described above, but the inner edge of the center hole of the surface of the disc-shaped recording medium can be smoothly brought into contact with the contact surface. Thus, the disc-shaped recording medium can be fitted smoothly.

Further, according to the disk chuck mechanism of the third aspect, in the disk chuck mechanism of the third aspect, the angle of the contact surface with respect to the base surface is set to 60 °. It is possible to suppress the occurrence of warpage of the outer peripheral portion of the disc-shaped recording medium, to smoothly fit the disc-shaped recording medium, and to provide an appropriate clamping force without increasing the biasing force of the elastic member. Obtainable. Further, since the height of the holding claw can be reduced, the height of the device can be suppressed to be low.

[Brief description of drawings]

FIG. 1 is a plan view of a turntable device including a disc chuck mechanism according to an embodiment of the present invention.

2A is a half cross-sectional view seen from the direction of arrow A in FIG.
(B) is a partial cross-sectional view as seen from the direction of arrow B in FIG. 1.

3A is a cross-sectional view of the periphery of a holding claw when a CD is mounted as viewed in the direction of arrow A in FIG. 1, and FIG. 3B is an arrow A in FIG.
FIG. 6 is a cross-sectional view of the periphery of the holding claw when the CD is not mounted, as viewed from the direction.

FIG. 4A shows the turntable device of FIG.
Sectional view around the holding claw when a 2 mm CD is attached,
(B) is a cross-sectional view of the holding claws when a CD with a thickness of 1.5 mm is mounted on the turntable device of FIG. 1, and (C) is a CD with a thickness of 1.1 mm mounted on the turntable device of FIG. 1. FIG. 6 is a cross-sectional view of the periphery of the holding claw in the case of performing

5 is a graph showing the relationship between the thickness of the disc and the clamping force when the turntable device of FIG. 1 is used and when the conventional ball clamp system is used.

FIG. 6 is a side view showing a schematic configuration of a conventional ball clamp system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Turntable 1a ... Base surface 2 ... CD 3 ... Fitting part 4 ... Spring 6 ... Support part 7 ... Holding claw 7a ... Abutment surface 7b ... Invitation surface 11 ... Rotating shaft P ... CD hollow hole inner edge part

Claims (3)

[Claims] 1. A support shaft that is rotatably provided, and a mounting portion that has a base surface and is supported by the support shaft, and that mounts a disk-shaped recording medium. A supporting portion that is contacted and supported substantially parallel to the surface is provided on the mounting portion provided on the base surface, and is provided in the central portion of the mounting portion with the support shaft as a center, and is provided in the center hole of the disc-shaped recording medium. A disc-shaped recording medium comprising: a mating part to be mated, and a plurality of holding claws arranged in the mating part so as to slightly project in the rotation radius direction of the placing part from the mating part. Has a contact surface that contacts the inner edge of the center hole on the surface side opposite to the contact surface with the support portion, and the contact surface and the base of the mounting portion on the side that contacts the inner edge of the center hole. A holding claw formed with the contact surface so that an angle formed between the contact surface and the surface is a constant acute angle; Disc chucking mechanism nails, and urged in the direction of the protruding, characterized in that the disc-shaped recording medium and a resilient member for elastic contact retention. 2. The disk according to claim 1, wherein the holding claw has a guide surface of the disk-shaped recording medium that is smoothly continuous at an angle with the contact surface. Chuck mechanism. 3. The disc according to claim 2, wherein an angle formed between the abutting surface of the holding claw and the base surface of the mounting portion is set to 60 °. Chuck mechanism.