JPH02273366A - Disk clamping mechanism - Google Patents

Abstract

PURPOSE:To obtain an extremely thin clamping mechanism by sticking a ring on a disk medium and fitting a clamper to the outside of the ring to position the clamper. CONSTITUTION:The main body of a clamper 5 can turn separately with the effect of a bearing 6. One of both ends of a spring 7 is engaged to a spring holder stage 22 with the other end engaged to a spring holding plate 24 respectively. The plate 24 aligns the upper end position of the spring 7. The rings 25 have the diameters slightly smaller than the inner diameter of the pressing surface of the clamper 5 and are stuck on both sides of a disk medium 4. A slanting surface 25a is formed at the entire outer periphery of each ring 25. The clamper 5 is fitted to the outside of the ring 25 and presses the medium 4. Consequently, the approximate coincidence is obtained between a spindle motor 1 and the axial line of the clamper 5. Thus the clamper 5 does not swing despite the rotation of the medium 4. Furthermore no extension of a center shaft 3 of the motor 1 is required and therefore the distance between the upper surface of a turntable 2 and the tip of the shaft 3 can be reduced. Thus a thin disk clamping mechanism is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk clamping mechanism for a recording and reproducing device that uses a disk-shaped medium such as an optical disk device and allows the medium to be replaced.

[Conventional technology]

This type of disk clamp mechanism is required to rotate the disk medium with high precision. Therefore, as shown in FIG. 2, the spindle motor 11 is equipped with a turntable 12 with high positional accuracy, and by setting the disk medium 4 thereon, it is possible to position the disk medium 4 in the vertical direction. Further, the disk medium 4 has a center hole formed with high precision, and the spindle motor 11 has a center shaft B, which is a rotating shaft, that is extended and protrudes beyond the turntable surface. By fitting the center shirt 13 into the center hole of the disk medium 4, the disk medium 4 rotates around the rotation axis of the motor without lateral wobbling.

If the disk medium 4 is simply placed on the turntable 12, the disk medium 4 will spring up during rotation, fall off the spindle motor 11, or slip between the turntable 12 and the spindle motor 11 may not rotate properly. There is a high possibility that the information will not be transmitted and the recording/reproducing process will be hindered, so it is necessary to press the disk medium 4 against the turntable 12 in some way. The clamper 15 performs this role, and moves the disk medium 4 onto the turntable 1.
2 while rotating together with the disk medium 4. The clamper 15 must not have a large rotational resistance, and the bearing 16 is essential.

The clamper 15 is biased by the clamp arm 19 to the spring 17.
It is done via. There is also a method of rigidly fixing the clamp arm 19 to the clamp shaft 18 and energizing the clamper 15, but there is a large error in the vertical position of the clamp arm 19 due to the ramp arm drive mechanism, and therefore the variation in the pressing force becomes large. The engagement relationship between the clamp arm 19 and the tarmb shaft 18 is eliminated, and the pressing force is obtained by the spring. As described above, since the clamper 15 rotates together with the disk medium 4, positioning is required to prevent it from whirling around. For this purpose, the spindle motor 11
The center shaft 13 is made to protrude from the disk medium 4 so that the center hole of the clamper 15 fits therein. The tip of the center shaft is rounded so that the center hole of the disk medium 4 or the center hole of the clamper 15 can be smoothly guided to the straight portion of the center shaft when it starts to fit into the center hole.

[Problem to be solved by the invention]

In the spindle motor of the above-described conventional disk clamp mechanism, the center shaft protrudes above the upper surface of the disk medium with a certain size, and its straight portion is used to determine the center position of the clamp. Moreover, since the tip of the spindle motor had a spherical surface corresponding to the radius of the center shaft, the height from the turntable surface of the spindle motor to the tip of the center shaft had to be high.

[Means to solve the problem]

The present invention has been made in order to solve the above-mentioned conventional problems, and as a means for solving the problem, the present invention has a turntable that positions the disk medium in the vertical direction and gives it rotation, and also serves as the center of rotation of the turntable. A spindle motor that protrudes above the table surface and includes a center shaft that correctly positions the disk medium around the center of rotation, a clamp arm that moves up and down, and a portion that passes through the hole drilled in the clamp arm and protrudes above the clamp arm. A clamp shaft is provided with a stopper to prevent it from being pulled out downwards, and a spring holder and a bearing are attached to the other end of the clamp shaft, and a clamper is attached to the clamp shaft via the bearing attached to the clamp shaft. A clamp shaft with a spring cradle and hair ring attached to the clamp shaft on one end and a clamp shaft attached to the clamp shaft on the other end, a clamper attached via a bearing attached to the clamp shaft, one end on the clamp arm and a clamp on the other end. In a disk clamping mechanism that includes a spring that is locked to a spring holder on a shaft, rings having an inner diameter slightly smaller than the inner diameter of the suppressing surface of the clamper are attached to the front and back surfaces of the disk medium, and the clamper is set on a turntable. When pressing the disk medium, the clamper fits into the outside of the ring of the disk medium, so that the central axis of rotation of the disk medium and the central axis of rotation of the clamper can be substantially aligned.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a cross-sectional view of a disk clamp mechanism according to an embodiment of the present invention, taken from above from a turntable.

On the main body of the spindle motor 1, a turntable 2 made with high precision is mounted on a center shaft 3 with high precision. The tip of the center shaft 3 is divided into an inclined part 3a and a straight part 3b, and it is the straight part 3b that projects 1 to 2 B above the turntable surface that positions the disk medium 4.

Even if this linear portion 3b does not protrude enough to cover the thickness of the disk medium 4, the disk medium 4 can be
The positioning can be performed satisfactorily. The inclined portion 3a at the tip of the center shaft 3 is for smoothly fitting the center hole of the disk medium 4 into the straight portion of the center shaft 3. A hole is made in the clamp arm 9, and the clamp shaft 8 passes through the hole. Clamp arm 9
A stopper 10 for preventing the clamp shaft 8 from coming off and falling from the hole of the clamp arm 9 is attached to a portion projecting upward from the clamp arm 9. The inner ring of the bearing 6 and a spring holder 22 are superimposed on the other end of the clamp shaft 8 by a subshaft 21 . The outer ring of the bearing 6 is fixed to the housing of the clamper 5 by a plate 23.

Therefore, the clamper 5 main body can rotate smoothly by itself due to the effect of the bearing 6.

The spring 7 has one end secured to a spring holder and the other end secured to a spring holding plate 24. The spring holding plate 24 is for aligning the upper end position of the spring 7. A ring 25 with an outer diameter slightly smaller than the inner diameter of the suppressing surface of the clamper 5 is attached to the front and back surfaces of the disk medium 4. Moreover, the outer peripheral side of the ring 25 is
A slope 25a is provided over the entire circumference.

In FIG. 1, the disc medium 4 is being subjected to recording and reproducing processing, and the clamper 5 is fitted onto the outside of the ring 25 attached to the disc medium 4 and presses against the disc medium 4. As a result, the axis of the spindle motor 1 and the axis of the clamper 5 are substantially aligned, and the clamper 5 does not swing around even if the disk medium 4 begins to rotate. The slope 25a on the outside of the ring 25 is for smoothly dropping the clamper 5, which descends with a positional error, to the outside of the ring.

〔Effect of the invention〕

As explained above, in the disk clamping mechanism of the present invention, the clamper can be positioned by attaching a ring to the disk medium and fitting the clamper to the outside of the ring, and without having to extend the center shaft of the spindle motor upward. This allows the height from the turntable surface to the tip of the center shaft to be lowered, making it possible to realize an extremely thin disc clamping mechanism.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a disk clamp mechanism according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of a conventional disk clamp mechanism. 1... Spindle motor, 2... Turntable, 3... Center shaft, 4...
...Disk medium, 5...Clamper, 6...
...Bearing, 7...Spring, 8...
...Clamp shaft, 9...Clamp arm, 25...Ring. Agent Patent Attorney Susumu Uchihara＼9!

Claims (1)

[Claims] A disc medium having a first fitting means capable of specifying the center of rotation of a disc-shaped disk medium having a center hole and storing information is used, and a second fitting means is rotatable and capable of specifying the center of rotation of the disk medium. A clamper, a spindle motor that rotates a center shaft at a constant rotation speed, and a turntable that rotates together with the center shaft, the disk medium being fitted into the center shaft at the center hole, and the clamper and the turntable A disk clamp mechanism, characterized in that the disk medium is supported by fitting the first fitting means and the second fitting means together.