JP2001266439A - Disk clamping mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk clamping mechanism which is simple in structure and with which an always stable clamping effect may be assured. SOLUTION: A disk loading surface (2a) of a turntable (2) fixed to a shaft (1) of the disk clamping mechanism for fixing a recording disk (4) by placing the recording disk on the turntable and holding down the recording disk by means of a clamper (8) from above is provided with an annular groove 10 formed with a step part (10c) constituted by forming the inner diameter near the bottom smaller than in an upper part (10a) and the bottom (10b). An annular back yoke (11) formed with the inner diameter slightly larger than the inner diameter of the upper part of the annular groove and an annular magnet (7) are successively laminated within the annular groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turntable suction mechanism for sucking a disk holding clamper in a disk clamp mechanism.

[0002]

2. Description of the Related Art Conventionally, various disk clamp mechanisms have been proposed in which a medium such as a CD-ROM is placed on a turntable of a spindle motor, and the recording disk is held down from above by a clamper.

FIG. 2 is a view showing a conventional disk clamp mechanism. In FIG. 1, reference numeral 1 denotes a shaft of a spindle motor. Reference numeral 2 denotes a turntable fixed to the shaft 1, 2a denotes a disk mounting surface of the turntable 2, and 2b denotes a hub. Reference numeral 3 denotes a friction material fixed to the vicinity of the outer periphery of the disk mounting surface 2a by adhesion or the like. The friction material 3 is for transmitting a driving force to the recording disk 4, and has a surface friction such as a sponge or urethane rubber. Any material having a large elasticity may be used. Reference numeral 5 denotes an annular groove provided near the center of the hub 2b on the disk mounting surface 2a side. Reference numeral 6 denotes a back yoke accommodated in the annular groove 5 and fixed to the bottom of the annular groove 5 by bonding or the like. Numeral denotes an annular magnet which is superimposed on and adhered to the back yoke 6 and accommodated in the annular groove 5. Reference numeral 8 denotes a clamper attached to, for example, a lid of a CD drive device, and reference numeral 9 denotes a magnetic clamping plate fixed to the center of the clamper 8 by fitting or bonding. The disk clamp mechanism configured as described above fits the center hole of the recording disk 4 into the hub 2b of the turntable 2 and mounts it on the disk mounting surface 2a, and then manually lowers the clamper 8, Alternatively, when the recording disk 4 is automatically detected inside the disk drive device (or the disk mounting surface 2a) and the clamper 8 is automatically lowered, the clamping plate 9 is attracted to the annular magnet 7, and the recording is performed. The disk 4 is pressed by the clamper 8 and fixed on the disk mounting surface 2a.

[0004]

However, in the disk clamp mechanism configured as described above, when the spindle motor rotates at a high speed, depending on the bonding conditions such as the amount of the adhesive, the curing time, the processing pressure, the temperature, etc. There was a danger that the back yoke 6 fixed to the bottom of the groove 5 would come off from the bottom of the annular groove 5. As described above, when the back yoke 6 or the annular magnet 7 is peeled off from the annular groove 5 of the turntable 2, the clamping function becomes incomplete and data cannot be read from the recording disk 4, or the recording disk 4 is There were drawbacks such as being unable to be taken out. Furthermore, due to the incomplete rotation of the clamp,
There was a disadvantage that the recording disk 4 was damaged.

The present invention has been made to solve the above-mentioned drawbacks, and to provide a disk clamping mechanism which has a simple structure and can always secure a stable clamping force.

[0006]

According to a first aspect of the present invention, a recording disk is mounted on a turntable, and the recording disk is fixed from above with a clamper. In the clamp mechanism, an annular groove is formed on the upper surface of the turntable fixed to the rotating shaft, and a stepped portion is formed by forming a small diameter in the vicinity of the bottom between the top and bottom, and the inside diameter of the annular groove is set to the inside diameter. This can be achieved by sequentially laminating an annular back yoke and an annular magnet having a diameter slightly larger than the inner diameter of the upper part of the annular groove. Further, the gap (radius difference) between the inner periphery near the bottom of the annular groove and the inner periphery of the annular back yoke is 2 μm (micrometer) to 5 μm.
This can be achieved by setting the range to 0 μm (micrometer).

[0007]

FIG. 1 is a sectional view of a turntable according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a shaft of a spindle motor. Reference numeral 2 denotes a turntable fixed to the shaft 1, 2a denotes a disk mounting surface of the turntable 2, and 2b denotes a hub.
Numeral 3 is for transmitting the driving force to the disk.
a friction material fixed around the outer periphery of a by adhesion or the like;
May be made of a material having a large surface friction and elasticity, such as sponge or urethane rubber. Reference numeral 10 denotes an annular groove provided near the center of the hub 2b on the side of the disk mounting surface 2a. The inner diameter of the annular groove 10 is divided into an upper part and a lower part. In the vicinity of the bottom, the inner diameter 10b is formed to have a small diameter to form a step 10c.
Reference numeral 11 denotes a ring-shaped back yoke which is housed in the annular groove 10 and is fixed to the bottom of the annular groove 10 by bonding or the like. The inner diameter (diameter of the center hole) of the back yoke 11 is formed to have a radius D2. And the radius D2 of the inner diameter,
The difference from the radius D1 of the inner diameter 10a at the top of the annular groove 10 is 2 μm.
m (micrometer) to 50 μm (micrometer), which is very small. Further, the distance of the stepped portion 10 c from the bottom of the annular groove 10 is provided at a position slightly higher than the thickness of the back yoke 11. Reference numeral 7 denotes an annular magnet fixed on the back yoke 11 by bonding and magnetic attraction. When the annular magnet 7 is stacked on the back yoke 11, the total thickness of the annular magnet 7 and the back yoke 11 is formed to be slightly smaller than the depth of the annular groove 10. Reference numeral 8 denotes a clamper, which is attached to, for example, a lid of a CD drive device, and when the recording disk 4 is placed on the disk loading surface 2a, the clamper 8 is manually lowered, or the disk is detected by another detecting means. Upon detecting that the recording disk 4 is loaded inside the drive device (or the disk loading surface 2a), the clamper 8 is automatically lowered. Reference numeral 9 denotes a magnetic clamping plate fixed to the center of the clamper 8 by fitting or bonding. As described above, when the clamper 8 is lowered, the clamping plate 9 is attracted to the annular magnet 7 and firmly fixes the recording disk 4. Depending on the drive device, the clamper 8 may be of a type that can be lowered from above, a type that can be pressed from the side, or the like, but any type may be selected.

In use, a switch (not shown) is turned on.
It is turned off, the spindle motor is driven or stopped, and the turntable is repeatedly rotated at high speed and suddenly stopped via the shaft 1. Bottom of annular groove 10 and back yoke 11
If there is a variation in the bonding state (poor bonding), the back yoke 11 bonded to the bottom of the annular groove 10 is peeled off by vibration or the like caused by high-speed rotation, and the annular groove 10 is attracted by the annular magnet 7 and the clamping plate 9. At this time, the inner diameter of the back yoke 11 (the diameter of the center hole) (D2 × 2) is equal to the inner diameter 1 of the upper part of the annular groove 10.
Since it is only slightly larger than 0a (D1 × 2), it does not get stuck when jumping out.

[0009]

As described above, the turntable 2
In the disk clamp mechanism for mounting the recording disk 4 on the disk and fixing the recording disk 4 by holding the recording disk 4 from above, the inner diameter of the disk mounting surface 2a of the turntable 2 fixed to the shaft 1 is lower at the upper and lower portions. An annular groove 10 having a small diameter in the vicinity and serving as a step is provided. Inside the annular groove, an annular back yoke 11 and an annular magnet 7 having an inner diameter slightly larger than the inner diameter of the upper part of the annular groove. Are sequentially stacked, even if the spindle motor rotates at high speed and the back yoke 11 comes off from the bottom of the annular groove 10, there is no danger that the annular magnet 7 will scatter around. Further, the adhesive between the back yoke 11 and the annular magnet 7 does not peel off.
In addition, the clamping function will not be incomplete,
The data disk 4 cannot be read from the recording disk 4, the recording disk 4 cannot be removed from the device, or the recording disk 4 is not damaged due to incomplete rotation of the clamp.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a disk clamp mechanism according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional disk clamp mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft 2 Turntable 3 Friction material 4 Disk 5, 10 Annular groove 6, 11 Back yoke 7 Annular magnet 8 Clamper 9 Clamping plate

Claims (2)

[Claims] 1. A disk clamp mechanism for mounting a recording disk on a turntable and fixing the recording disk by holding the recording disk from above with a clamper, wherein the inner diameter of the upper surface of the turntable fixed to the rotating shaft is near the bottom between the top and bottom. The annular back yoke whose inner diameter is slightly larger than the inner diameter of the upper part of the annular groove and the annular magnet are sequentially laminated inside the annular groove. A disk clamp mechanism characterized by comprising: 2. A gap (radius difference) between an inner periphery near the bottom of the annular groove and an inner periphery of the annular back yoke is in a range of 2 μm (micrometer) to 50 μm (micrometer). The spindle motor clamping mechanism according to claim 1, wherein