KR20030051203A - Disk clamp device - Google Patents

Abstract

PURPOSE: To provide a disk clamping mechanism which strongly holds a disk on a turntable by a nearly similar and stable holding force even if fluctuation occurs in a thickness dimension of the disk, has a pressing force to prevent the floating of the disk itself even during high-speed rotation, has a small magnetic noise, and deals with a thin motor. CONSTITUTION: A turntable 4 is secured to the end of a rotary shaft 3 of a spindle motor 2 fixed to a motor fixing angle 1 of a recording/reproducing device. A clamper is supported in a suspended state by a support angle 6 of the recording/reproducing device so as to be coaxial to the axis of the rotary shaft 3 by a gap A with the end of the rotary shaft 3 of the spindle motor 2. The support angle 6 is made of a magnetic metal material such as an iron plate, its hole part 6a for inserting the clamper is constituted of a burring, and a ring-shaped magnet 7 having a thickness dimension smaller than the burring height dimension B is secured to its outer periphery 6b by pressure insertion, adhesion, or the like.

Description

Disk clamp mechanism {DISK CLAMP DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording medium, and more particularly, to a disc clamp mechanism used for a recording / reproducing apparatus of an optical disc.

Background Art Conventionally, recording and reproducing apparatus using an optical disc has fixedly attached a turntable to an axis of a spindle motor provided in the apparatus, and puts and rotates the optical disc on the turntable to record or read information on the disc. .

However, if there is a slight discrepancy in the center of gravity or warping of the optical disk on the turntable, the recent optical disk is used at a high speed rotation, so the optical disk slightly moves on the turntable by centrifugal force and rotates the optical disk. There is a problem that the center is displaced or the optical disc itself floats, thereby causing the optical pickup to deviate from the track of the rotating optical disc, making it impossible to read or write information.

Conventionally, in connection with the shift of the rotation center of the optical disk itself described above, a means for keeping the optical disk firmly on the raised surface of the turntable during rotation has always been adopted. As such means, there is provided a ring-shaped hole in the center of the turntable, and a ring-shaped magnet in the hole, and a magnetic metal thin plate such as an iron plate provided in such a manner that the magnet is suspended from the support angle of the recording / reproducing apparatus. The optical disk was firmly held in the direction of the disk raised surface of the turntable by sandwiching the clamper made of magnetic suction and holding the optical disk on which it was placed.

On the other hand, in relation to the floating of the optical disk itself, a suction magnet is attached to the rotor side or the stator side of the spindle motor, and a magnetic member is attached to the stator side or the rotor side facing each other with a gap therebetween. By means of suction, a means has been adopted in which the rotor portion for fixedly attaching the turntable on which the optical disk is placed does not float from the stator portion during rotation.

However, according to the conventional method for preventing misalignment of the rotational center of the optical disk, when a slightly thick optical disk is placed, the magnetic attraction force of the ring-shaped magnet and the clamper to hold the disk is remarkably increased. There exists a case where it may fall, and the problem which the rotation center of an optical disk displaces still occurs.

DESCRIPTION OF RELATED ART Conventionally, the optical disk attaches the stamper manufactured based on the disk to the molding machine, and the transparent disk main body is produced by the resin molding process, such as an acrylic resin.

Then, the disk body is subjected to an aluminum reflective film deposition process and a protective film application process, and finally, the title is displayed by labeling or printing, thereby completing as an optical disk. However, since it is mass-produced through such a manufacturing process, it cannot be avoided that a deviation arises in the size of each manufactured finished product. In particular, the thickness size important for the optical disk is, according to the JIS standard, for example, in the case of the optical disk for CD-ROM, the thickness standard is 1.20 mm and the tolerance is defined as +0.3 mm / -0.1 mm, In the case of an optical disc for DVD, the thickness is 1.20 mm and the tolerance is set to +0.3 mm / -0.06 mm.

Although the thickness size of the optical disk produced by the manufacturing process as mentioned above is managed in JIS standard, between the thing which has the thickness of an upper limit, and the thing of the thickness of a lower limit, the ring-shaped which clamps the disk is supported. In some cases, the holding force due to magnetic attraction of the magnet and the clamper is greatly changed. This is due to the damping characteristic that the force acting on the stimulus in Coulomb's law is inversely proportional to the square of the distance. When the magnetic suction mechanism is set at the place where the change of such characteristic is severe, the rotation of the optical disk The above-mentioned problem which shifts out of center arises remarkably.

On the other hand, according to the above-described method for preventing the injury of the optical disk, there is a problem that the number of parts of the suction magnet or the magnetic body increases, thereby increasing the assembly work.

Moreover, according to such a component structure, there exists a problem that the structure of the spindle motor itself becomes large and it cannot respond to the trend of thinning of the market.

In addition, the addition of a suction magnet, together with a ring magnet, causes a problem of increased leakage magnetic flux and increased magnetic noise.

Accordingly, an object of the present invention is to solve the above problems, and even if the thickness size of the optical disk varies, the shift of the rotation center does not occur, and the optical disk does not float even during high-speed rotation, thereby reducing the magnetic noise as well. An object of the present invention is to provide a disk clamp mechanism capable of responding to a thin motor.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of an essential part showing a state before a disk is mounted in an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part showing an enlarged main part shown in FIG. 1.

3 is a sectional view of an essential part showing a disk mounting state in the embodiment of the present invention.

FIG. 4 is a cross-sectional view of the main part showing an enlarged view of the main part further shown in FIG. 3.

5 is an explanatory view showing the disk holding characteristics of the disk clamp mechanism according to the present invention and the clamp mechanism according to the conventional method.

6 is a perspective view showing a modification of the clamper body according to the present invention.

7 is a cross-sectional view of an essential part showing a modified embodiment of the present invention.

FIG. 8 is a cross-sectional view of a main part showing an enlarged main part shown in FIG. 7.

Description of the main parts of the drawing

1: motor fixed angle 2: spindle motor

3: rotation axis 4: turntable

5: clamper main body 6: support angle

7: magnet 8: spring pressing member

9: coil spring 10: stopper

11: optical disc 12: tray

According to the invention described in claim 1, the object includes a turntable fixed to a rotating shaft of a spindle motor, and a clamper supported and supported by a support angle, wherein the disk is sandwiched between the turntable and the clamper. The disk clamp mechanism, wherein the clamper includes a spring pressing member including a clamper body facing the turntable and a magnetic metal portion, and a spring member extending therefrom, the support angle including a magnetic metal portion, and the spring pressing member. By providing the magnetic suction means at the position of the support angle opposite to the pressure, the disk is pressed against the turntable by the elastic force of the spring member of the clamper that acts against the magnetic suction force of the magnetic suction means during chucking of the disk. By clamping the disk.

Further, as in the invention described in claim 2, in the disc clamp mechanism, the rotating shaft is achieved by being provided on the rotor portion facing an axial gap in the stator portion of the spindle motor.

The magnetic suction means may be a magnet formed in a ring shape fixedly attached to the support angle as in the invention as claimed in claim 3, or fixed to the spring pressing member as in the invention as claimed in claim 5. The magnet is formed in an attached ring shape, and the spring member is formed of a coil spring or a leaf spring, as in the invention according to claim 7, wherein the magnet is held when the turntable is placed on the disk. The disc clamp device is obtained by setting a spring constant so that the suction means is brought into a non-contact suction state.

Next, embodiment of this invention is described, referring drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the principal part which shows the state just before clamping a disk in the disk clamp mechanism which concerns on embodiment of this invention. FIG. 2 is an enlarged cross-sectional view of the main part shown in FIG. 1. FIG. 1 and 2, the turntable 4 is fixedly attached to an end portion of the rotation shaft 3 of the spindle motor 2 fixed to the motor fixing angle 1 of the recording / reproducing apparatus. In addition, the motor fixed angle 1 is attached by a mechanism not shown to the recording / reproducing apparatus so as to be movable in the axial direction of the rotation shaft 3. Further, the clamper is fixed to the recording / reproducing apparatus so that the end of the rotating shaft 3 included in the rotor portion facing the stator portion of the spindle motor 2 and the gap A are coaxial with the axis of the rotating shaft 3. It is hypothesized in the state suspended on the support angle 6 which was made.

The support angle 6 is fixed to a recording / reproducing apparatus, is made of a magnetic metal material such as an iron plate, and the hole portion 6a through which the clamper is inserted is formed by burring, and the outer circumference 6b thereof. Has a thickness size smaller than the height size B of the burring, and the ring-shaped magnet 7 magnetized in the axial direction of the rotating shaft 3 is fixedly attached by pressing or bonding. The support angle 6 may be made of a nonmagnetic member, and the magnet 7 may be mounted using a magnetic material or the like. By doing so, the material properties required for each can be selected appropriately.

In Fig. 2, 4a of the turntable 4 is a hemispherical projection for centering when the disk 11 is placed, and 4b is an anti-slip member of the mounted optical disc 11.

Moreover, the clamper is comprised from the clamper main body 5, the spring press member 8, the coil spring 9, and the stopper 10. As shown in FIG. In addition, the clamper main body 5 is shape | molded with resin etc. which have disk-shaped elasticity. The spring pressing member 8 is made of a magnetic material such as an iron plate, and is inserted into and attached to the outer circumferential portion 5a of the end of the clamper main body 5, and the outer diameter portion of the spring pressing member 8 is the outer circumference of the burring of the support angle 6. 6b) It is larger than the diameter. Further, the spring pressing member 8, the stopper 10 fixedly attached to the end of the clamper 5 so as not to be pulled out, and the optical disk pressurization of the spring pressing member 8 and the clamper main body 5 configured as described above. Between the convex surface 5c on the side opposite to the portion 5b, the inner diameter is larger than the diameter of the outer peripheral portion 5a of the clamper main body 5, and the outer diameter is the hole portion 6a of the support angle 6. It is comprised so that the compression coil spring 9 which has a size smaller than the diameter of ()) may be provided.

In the state where the disc is not clamped, the burring end 6c of the support angle 6 is always in contact with the spring pressing member 8, and the pressing portion 5b of the clamper body 5 is elastic in the axial direction. have. Further, the magnet 7 is set to a thickness size smaller than the burring height size B of the supporting angle 6, and the gap between the spring pressing member 8 and the burring end 6c of the supporting angle 6 is small. It sets to stationary and adjusts the intensity | strength of the magnetic attraction force. In the case where such adjustment of the magnetic attraction force is required, as another method, the height size B of the burring of the support angle 6 is made equal to or less than the thickness size of the magnet 7, and the spring pressing member 8 is A thin nonmagnetic plate may be attached to the upper surface of the magnet 7 to attract and adjust its thickness size.

3 is a sectional view of principal parts showing a state in which a disk is clamped in the disk clamp mechanism according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of a main part showing an enlarged main part shown in FIG. 3. 1, when the turntable 4 approaches the clamper main body 5 side, the optical disk 11 is mounted on the turntable 4, and the press part 5b of the clamper main body 5 is a disk. (11), and as the coil spring (9) begins to compress, the clamper body (5) starts to press to hold the disk (11) together with the turntable (4).

In addition, when the turntable 4 moves to a predetermined position, as shown in FIGS. 3 and 4, the clamper main body 5 compresses the coil spring 9 strongly and the disk 11 placed on the turntable 4. ) Is strongly pressed, and the optical disk 11 is held between the turntable 4 and the clamper main body 5. At this time, the magnetic force of the magnet 7 and the spring constant of the coil spring 9 such that the burring end 6c of the support angle 6 and the magnetic suction portion of the spring member 8 are in contact with each other with a gap C. Is set.

While the optical disk 11 is held, the spring pressing member 8 rotates apart from the burring end 6c of the support angle 6 by a gap C, but with the end 6c and the magnet 7 Since the magnetic attraction force acts between the spring pressing member 8, the turntable 4 and the clamper main body 5 hold the disk 11 firmly, and the clamper main body 5 is the disk 11 and the turntable. Since the rotor part including the rotating shaft 3 is strongly pressed through the direction (4) in the direction of the motor fixing angle 1 of the present apparatus, the rotor part on which the optical disc is placed does not float from the stator part even at high speed rotation.

FIG. 5 is a diagram showing the holding characteristics of the disk 11 sandwiched between the turntable 4 and the clamper. In FIG. 5, the X axis represents the thickness size of the disk, and the Y axis represents the holding force of the disk. In addition, D is the characteristic of the disk clamp mechanism by the magnetic attraction force of the conventional system, and E is the characteristic of the disk clamp mechanism by this invention. The characteristic D of the conventional mechanism has a damping curve characteristic, and even when the thickness of the disk 11 is within the JIS standard, the holding force of the disk varies greatly from (f2-f1) when t1 to t2.

On the other hand, the magnetic attraction force that the burring end 6c and the magnet 7 of the support angle 6 and the magnet 7 act on the spring pressing member 8 in the disk clamp mechanism according to the present invention has a thickness of 0.4 for the optical disk. Since the vicinity of a characteristic that does not change even if a change of about a millimeter (permissible range of the thickness size of the JIS standard) is used, even if the thickness of the disk 11 sandwiched between the turntable 4 and the clamper 5 changes, the holding characteristic is maintained. Is a straight line close to flatness as in the characteristic E.

For example, when the thickness of the disk 11 is changed from t1 to t2 as described above, since the coil spring 9 is further compressed, the deformation amount is increased to (t2-t1), so that the pressing force on the disk 11 is increased. This increase is caused by the increased amount of force, so that the spring pressing member 8, which is in the magnetic attraction relationship with the burring end 6c of the support angle 6 and the magnet 7, is constructed as described above. As a result, it is pushed in a direction further spaced by (t2-t1). That is, the clearance C is increased by (t2-t1), and as a result, the compression increase t2-t1 of the coil spring 9 is canceled so that the deformation amount of the coil spring 9 hardly changes, As the pressing force by the clamper does not change when the thickness of the optical disk 11 is t1 and t2, the holding force of the disk 11 held in the inserted state is hardly changed.

In this state, the tip of the rotary shaft 3 is inserted into the guide hole 5d of the clamper main body 5 so that the center of rotation of the clamper itself is rotated during the rotation of the turntable 4 and the disk 11. No deviation occurs.

In addition, since the ring-shaped magnet 7, the support angle 6, the spring pressing member 8, and the like are assembled in parallel planes, the disk 11 held on the turntable 4 can always correspond in parallel to the optical pickup. .

In addition to the coil spring, a leaf spring may be used as the spring member for pressing the clamper main body 5.

FIG. 6: shows the modification of the clamper which concerns on this invention, and is a perspective view which shows the clamper main body 5 from the press part 5b side of a disk. In FIG. 6, the pressing portion 5b of the clamper main body 5 is divided into a plurality of small portions 5f and a large portion 5g by the slit portion 5h. In such a structure, since each divided part of the clamper main body 5 can be contacted independently when pressing the mounted optical disk 11, the whole mounted optical disk 11 can be contacted without any contact. Can be pressed across the circumference.

7 is a sectional view of an essential part showing a disk clamp mechanism showing a modification of the embodiment of the present invention. FIG. 8 is a cross-sectional view of a main part showing an enlarged main part of FIG. 7. This configuration is basically the same as that in Fig. 1, and differs in that the magnet 17 for pressing the optical disk 11 is fixedly attached to the inner circumferential side of the spring pressing member 18 formed in a cup shape. The function is the same as that described above, but there is an advantage that the size of the magnet 17 for pressing the optical disk 11 can be reduced.

In addition, a fly wheel effect using the inertia of the magnet 17 is also obtained.

As described above, according to the disk clamp mechanism according to the present invention, when the disk is chucked by the clamper, the disk is pressed against the turntable by the elastic force of the clamper acting against the magnetic attraction force of the magnetic attraction means. When the disk is chucked, the rotor portion can be pressed against the stator, so that the center of rotation does not shift even if the thickness of the disk changes, and the disk does not float even at high speed. .

In addition, since there is no need to provide a ring-shaped magnet or a suction magnet between the rotor and the stator at the center of the turntable, leakage magnetic flux is reduced, magnetic noise is reduced, and the thickness including the motor can be reduced. .

Claims (12)

A disk clamp mechanism comprising a turntable fixed to a rotating shaft of a spindle motor and a clamper supported and supported by a support angle, wherein the disk clamp mechanism sandwiches a disk by the turntable and the clamper. The clamper includes a spring pressing member including a clamper body and a magnetic metal part facing the turntable, and a spring member that opens them. The support angle includes a magnetic metal portion, By providing the magnetic suction means at a position of the support angle opposite the spring pressing member, the disk is brought about by the elastic force of the spring member of the clamper that acts against the magnetic suction force of the magnetic suction means when chucking the disk. And clamping the disk by pressing against a turntable. The method of claim 1, The rotating shaft is provided on the rotor portion facing the stator portion of the spindle motor with an axial gap, and when the disk is chucked, the rotor portion is urged to the stator portion by the elastic force of the spring member of the clamper. Disk clamp mechanism. The method of claim 1, And the magnetic suction means is a magnet formed in a ring shape fixedly attached to the support angle. The method of claim 2, And the magnetic suction means is a magnet formed in a ring shape fixedly attached to the support angle. The method of claim 1, And said magnetic suction means is a magnet formed in a ring shape fixedly attached to said spring pressing member. The method of claim 2, And said magnetic suction means is a magnet formed in a ring shape fixedly attached to said spring pressing member. The method of claim 1, And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set such that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk. The method of claim 2, And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set so that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk. The method of claim 3, wherein And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set so that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk. The method of claim 4, wherein And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set so that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk. The method of claim 5, And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set so that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk. The method of claim 6, And the spring member is formed of a coil spring or a leaf spring, and a spring constant is set so that the magnetic suction means is brought into a non-contact suction state when the turntable is kept on the disk.