JP2002208201A - Clamping device, spindle motor, and information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamping device in which the flipping of a clamper or the wear due to irregular contact of the contact part of the clamper with a turntable is prevented with a simple configuration even when a disk is not loaded on the turntable at the time of starting a spindle motor, and to provide a spindle motor and an information reproducing device. SOLUTION: An information reproducing device is provided with a spindle motor which is provided with a clamping device for holding a detachable disk. The clamping device is provided with a turntable 3 which detachably mounts a disk D, a disk guidance means 6 which is provided on the turntable 3 for guiding the disk D to the position where the center of the disk D coincides with the center of the turntable 3 when mounting the disk, a clamper C which presses the disk D on the turntable 3, and a magnetic attraction means 8 formed on the turntable 3 for magnetically attracting the clamper C on the turntable 3. Contact resistance in the contact part when the clamper C comes in direct contact with the turntable 3 is magnified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CD-ROM and a DVD.
The present invention relates to a clamp device for holding a recording disk, a spindle motor having the same, and an information reproducing device having the same, which is provided in a drive device for reproducing or writing information on the recording disk, such as the above.

[0002]

2. Description of the Related Art Usually, a recording disk such as a CD-ROM or a DVD (hereinafter simply referred to as a disk) is mounted on an information reproducing apparatus for reproducing the recorded information (some of them have an information writing function). It is used by replacing various discs according to information to be reproduced. Therefore, the apparatus is provided with a clamp device for detachably holding the disk in a motor (hereinafter, referred to as a spindle motor) for rotating the recording disk.

Various types of clamp devices are known. For example, as shown in FIG. 5, a turntable 3 provided on a rotating shaft 5 of a spindle motor M provided on a housing B of an information reproducing apparatus. And a clamper C presses the disk D toward the turntable 3. The spindle motor M has an axial center line in the vertical direction, and this rotor rotates together with the clamp device. The clamper C has a dish shape made of a resin material, and has a pressing portion C1 for pressing the disk D all around and a suction portion C2 in which a magnetic material is embedded. The turntable 3 has a disk shape, and a sheet-like rubber member 4 is provided on an outer peripheral portion thereof for preventing the disk D from slipping and ensuring stable holding.
And a magnetic attraction means 8 for magnetically attracting the attraction section C2 of the clamper C. The disk guide means 6 has an inclined wall surface 6a whose outer wall surface is reduced in diameter in the axial direction upward with the inner diameter of the center hole of the disk D as a maximum diameter, and the inclined wall surface 6a
The disk D is guided to a position where the center of the disk D and the center of the turntable 3 coincide with each other. The magnetic attracting means 8 is arranged such that an annular magnet 10 is superimposed on an annular yoke 9 made of a magnetic material and accommodated in an annular concave portion 11 which extends annularly inward in the radial direction of the disk guide means 6. Is magnetically attracted. In this way, the disk D is mounted on the turntable 2
The magnetic attraction means 8 magnetically attracts the suction part C2, and the clamper C presses the disk D to be fixed to the turntable 3. At this time, the clamper C is positioned at the axial position p where the pressing portion C1 only comes into contact with the disk D and otherwise does not come into contact with the turntable 2 and the disk D.
Stop at 1.

Some information reproducing apparatuses having such a clamp device have a mechanism in which a spindle motor is temporarily rotated to check the operation of the information reproducing apparatus when the power is turned on. Then, when the spindle motor rotates, it starts on the premise that the disk D is loaded, so that the clamper C descends to a position where the clamper C presses the disk D.

There are two types of use in the reproducing apparatus: a case where the power is turned on with the disk D used after the previous use being mounted, and a case where the power is turned on without the disk D mounted by removing the disk D after the previous use. There is. In the former case, there is no problem in the structure of the information reproducing apparatus, but in the latter case, since there is no disk D, the rotational inertia around the axis of the spindle motor is small, so that the spindle motor has the same torque as the former. When added, it starts to spin rapidly. On the other hand, as shown in FIG. 6, the clamper C moves beyond the axial position p1 pressing the disk D and further contacts the upper end surface of the disk guide means 6.
Descent to 2. At this time, the clamper C comes into contact with the turntable 2 in an unstable state because there is no disc D to be pressed, and in some cases, the damper C is flipped and may damage the clamper C itself or a peripheral part. In particular,
When the vibration of the rotating motor M is large, the vibration is transmitted to the clamper C through the turntable 2 and the motor M is easily flipped off. Further, there is also a problem that the contact portion between the clamper C and the turntable 2 is abnormally contacted to cause abrasion. In recent years, in information reproducing apparatuses, the spindle motor M tends to rotate at high speed due to high performance, and such a problem is likely to occur.

As a countermeasure against such a phenomenon, a disk D
If the device is not mounted, a method of controlling the clamper C so as not to be mounted on the turntable 3 can be considered. However, this method is used for design reasons such as a complicated control circuit of the information reproducing apparatus and an increase in cost. It may not be possible.

Therefore, the present invention is to solve the above-mentioned problem, and even if a disk is not mounted on the turntable at the time of starting the spindle motor, the clamper can be blown off by a simple configuration, An object of the present invention is to provide a clamp device, a spindle motor, and an information reproducing device that do not generate wear due to abnormal contact of a contact portion with a turntable.

[0008]

SUMMARY OF THE INVENTION A clamp device for solving the present invention is a clamp device for holding a detachable disk, which includes a turntable on which a disk can be detachably mounted, and a turntable for mounting the disk. A disc guide means formed on the turntable for guiding the disc to a position where the center of the disc coincides with the center of the turntable; a disc holding means for pressing the disc against the turntable; and the disc holding means. A magnetic attraction means provided on the turntable for magnetic attraction to the turntable, wherein when the disc holding means and the turntable are in direct contact, the contact resistance at the contact portion is reduced. It is characterized by being large.

In such a clamp device, when the disk holding means comes into direct contact with the disk guiding means, the disk holding means is integrally fixed to the disk guiding means. Therefore, even if the turntable rotates without mounting a disk, the disk holding means rotates integrally with the turntable, thereby preventing the disk holding means from being flipped or abrasion due to abnormal contact at the contact portion.

[0010] The configuration in which the contact resistance at the contact portion is large means that a convex shape protruding in the axial direction is provided on one surface constituting the contact portion, and a concave shape fitted to the convex shape is provided on the other surface. There are things. By doing so, the convex shape and the concave shape are fitted to each other, so that the contact area at the contact portion is widened, and the contact resistance can be increased by a simple configuration.

Another configuration is to provide a rubber layer on at least one surface constituting the contact portion. With this configuration, the contact resistance of the contact portion can be made larger than that of the simple configuration by utilizing the characteristics of the rubber.

Further, as another configuration, at least one surface constituting the contact portion has a large surface roughness. In this case, the surface itself of the disk holding means or the disk guide means constituting the contact portion only needs to be roughly formed, and the contact resistance of the contact portion can be made larger than in the simple configuration.

In the above-mentioned configuration, each of the above-mentioned configurations may be used in combination. For example, one surface forming the contact portion is provided with a convex shape protruding in the axial direction, and the other surface is formed in the convex shape. Are provided, and a rubber layer is provided on those surfaces, or the surface roughness of those surfaces is increased.

Further, the above-mentioned clamper device can be provided in a spindle motor, and further, an information reproducing device provided with the spindle motor can be provided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a clamp device, a spindle motor and an information reproducing device according to the present invention will be described with reference to sectional views shown in FIGS. 1 and 2 correspond to FIG.
6 has substantially the same structure as that of the conventional clamp device, spindle motor and information reproducing device shown in FIG. 6, and the following description will focus on the differences, and the same reference numerals indicate the same parts.

The difference in FIG. 1 is the shape of the lower surface of a clamper (disk holding means) C which faces the disk guiding means 6 and the magnetic attraction means 8 of the turntable 3 in the axial direction. That is, on the lower surface of the clamper C, the upper end portion of the inner cylindrical portion 11a and the upper end portion of the outer cylindrical portion 11b (which constitutes a part of the disk guide means 6) are defined. Are formed with an inner concave portion 21 and an outer concave portion 22, respectively. That is, as shown in FIG. 2, the contact portion between the clamper C and the turntable 3 is such that the upper end of the inner cylindrical portion 11a protruding in the axial direction meshes with the horizontal plane and the outer wall surface defining the inner concave portion 21 without any gap. Outer cylindrical portion 1 which abuts against
The upper end of 1b is brought into contact with the horizontal surface defining the outer concave portion 22 and the inner wall surface so as to mesh without gap.

This is a configuration in which the contact resistance at the contact portion between the clamper C and the turntable 3 is large.
One of the surfaces (turntable 3) constituting the contact portion between the clamper C and the turntable 3 is provided with a convex shape (inner cylindrical portion 11a and outer cylindrical portion 11b) protruding in the axial direction, and the surface of the other (clamper C) is provided. Are provided with concave shapes (the inner concave portion 21 and the outer concave portion 22) fitted to the convex shape, and the convex shape and the concave shape are fitted to each other to increase the contact area at the contact portion.

Thus, even if the clamper C descends and comes into contact with the turntable 3 without mounting the disk D, the contact does not occur only on the horizontal surface as in the conventional case, but in addition to the horizontal surface, the vertical surface (in the axial direction) (A surface to be formed), and the contact area between the clamper C and the turntable 3 is increased to increase the contact resistance. Therefore, the clamper C is surely integrated with the turntable 3. To rotate with the turntable 3.

Further, since the contact portion forms a contact surface on a vertical surface which is different from the horizontal surface, the contact portion has a vertical surface and a vertical surface against a force acting in an arbitrary direction when the clamper C is flipped. The function of the plurality of surfaces to restrict the movement of the clamper C also contributes to the rotation of the clamper C integrally with the turntable 3. Therefore, even if the spindle motor rotates and the clamper C descends to the axial position p2 without loading a disk as in the conventional case, the clamper C rotates integrally with the turntable 3, so that the clamper C may be flipped off. In addition, problems such as wear due to abnormal contact can be prevented.

The spindle motor provided with such a clamp device can safely rotate regardless of the presence or absence of the disk D because the clamper C is not flipped even when the disk is not mounted. The information reproducing apparatus provided has a small number of failures in which the clamper C is hardly flipped in the apparatus.

Next, a second embodiment of the spindle motor provided with the clamping device according to the present invention will be described with reference to a sectional view shown in FIG. 3, which is different from the first embodiment or the conventional example shown in FIGS. This will be mainly described. The difference in FIG.
The clamper C is the same as the conventional one, and the annular recess 1 in which the magnetic attraction means 8 in the turntable 3 is disposed
1 is that the opening is attached so as to seal the opening with a sheet-like rubber member 24. The rubber member 24 is provided on each of the upper end surface of the inner cylindrical portion 11a and the outer cylindrical portion 11b, is accommodated in the step portion, and is provided so as to protrude somewhat from the upper end surfaces.

Therefore, when the clamper C is lowered without loading the disk C (not shown), the rubber member 2
By slightly shrinking 4 and improving the adhesion, the contact resistance between the contact portions increases, and the same effect as above can be obtained. Note that the rubber member 24 may form a thin rubber layer by spraying a spray rubber or the like.

Next, a third embodiment of the spindle motor provided with the clamping device according to the present invention will be described with reference to the cross-sectional view of FIG. 4, which differs from the first and second embodiments or the conventional example shown in FIGS. The following description focuses on the differences. The difference in FIG. 4 is that the turntable 3 is the same as the conventional one. 26 is attached.

Therefore, when the clamper C is lowered (not shown) without the disk C being mounted, the rubber member 2
4, when it comes into contact with the upper end of each of the inner cylindrical portion 11a and the outer cylindrical portion 11b as in the second embodiment, the shrinkage somewhat improves the adhesion, thereby increasing the contact resistance of the contact portions with each other, The same effects as above can be obtained. The rubber member 2
6 may form a thin rubber layer by spraying a spray rubber.

As described above, the clamper device, the spindle motor and the information reproducing device according to the present invention have been described, but the scope of the present invention is not limited thereto. For example, the convex shape and the concave shape provided on the clamper C and the turntable 3 in the first embodiment may be provided opposite to each other. Alternatively, in the second and third embodiments, the rubber members 24 and 26 may be provided on both the clamper C and the turntable 3. Alternatively, the rubber members 24 and 26 of the second and third embodiments are combined with the first embodiment, so that one of the convex shapes of the clamper C and the turntable 3 is fitted to the other concave shape. A rubber member may be provided. Alternatively, in each embodiment including the conventional configuration, it is also effective to increase the surface roughness of the surface forming the contact portion between the clamper C and the turntable. Further, the magnetic attraction means is composed of the yoke 9 and the magnet 10, but it is also possible to use only the yoke and embed the magnet in the clamper C.

[0026]

According to the first aspect of the present invention, even if the turntable rotates without mounting a disk, the disk holding means rotates integrally with the turntable, and the disk holding means is flipped or contacted. Wear due to abnormal contact in the part is prevented.

In the clamp device according to the second to fourth aspects, the contact resistance of the contact portion between the disk holding means and the turntable can be increased by a simple configuration.

In the spindle motor according to the fifth aspect and the information reproducing apparatus according to the sixth aspect, the disk holding means can be prevented from being flipped even when the disk is not mounted by a simple configuration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment according to the present invention, showing a state where a disk is mounted.

FIG. 2 shows a state in which a disc is not mounted and a clamper contacts a turntable in FIG.

FIG. 3 is a sectional view showing a second embodiment according to the present invention, showing a state where a disk is mounted.

FIG. 4 is a sectional view showing a third embodiment according to the present invention, showing a state where a disk is mounted.

FIG. 5 is a cross-sectional view showing a conventional configuration, showing a state where a disk is mounted.

FIG. 6 shows a state in which the disc is not mounted and the clamper contacts the turntable in FIG. 5;

[Explanation of symbols]

 B case C clamper C1 pressing part C2 suction part D disk M spindle motor 3 turntable 4 rubber member 5 rotating shaft 6 disk guide means 6a inclined wall 6b cylindrical wall 8 magnetic suction means 9 yoke 10 magnet 11 annular concave 11a inner cylinder 11b Outer cylindrical portion 21 Inner concave portion 22 Outer concave portion 24 Rubber member 26 Rubber member

Claims (6)

[Claims] 1. A clamp device for holding a removable disk, comprising: a turntable on which the disk can be removably mounted; and a disk at a position where the center of the disk coincides with the center of the turntable when the disk is mounted. A disk guide means provided on the turntable for guiding; a disk holding means for pressing a disk against the turntable; and a disk holding means formed on the turntable for magnetically attracting the disk holding means to the turntable. A magnetic attracting means, comprising: a contact device that, when the disc holding device and the turntable come into direct contact with each other, has a large contact resistance at a contact portion thereof. 2. The clamping device according to claim 1, wherein a convex shape protruding in the axial direction is provided on one surface constituting the contact portion, and a concave shape is provided on the other surface to be fitted with the convex shape. 3. The clamp device according to claim 1, wherein a rubber layer is provided on at least one surface of the contact portion. 4. The clamping device according to claim 1, wherein at least one surface constituting said contact portion has a large surface roughness. 5. A spindle motor provided with the clamp device according to claim 1. 6. An information reproducing apparatus comprising the spindle motor according to claim 5.