JPH0756722B2 - Disk clamp device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a disc clamp device incorporated in a part of a recording / reproducing device for a disc such as a compact disc.

2. Description of the Related Art In recent years, a disk clamp device has been widely used in a system that uses an attractive force of a magnet.

Hereinafter, an example of the above-described conventional disc clamp device will be described with reference to the drawings.

FIG. 3 is a perspective view of a CD player incorporating a conventional disc clamp device, and FIG. 4 is a sectional view of the conventional disc clamp device. In FIG. 4, 1 is a turntable, 2 is a turntable shaft, 3 is a centering ring, 4 is a centering ring retainer, 5 is a preload spring, 6 is a disk, 7 is a sheet and 8 is a magnet. Reference numeral 9 denotes a magnet holder which also serves as a back yoke for fixing the magnet 8 and forming a magnetic circuit of the magnet 8. The sheet 7 is adhered to the magnet 8 and is provided to maintain the adhesion between the disk 6 and the magnet 8. A center pin 20 fixes the magnet holder 9 and the flange plate 21.
The flange plate 21 is to be held inside the lid of the CD player without falling off, but it is necessary to allow the flange plate 21 to rotate freely without contact with surrounding members during rotation.

The operation of the disc clamp device configured as described above will be described below.

When the magnet 8 fixed integrally with the magnet holder 9, the flange plate 21, and the center pin 20 is brought near the center hole of the disk 6 with the disk 6 placed on the turntable 1 manually or automatically, Are attracted to the turntable 1 by magnetic attraction. At this time, the tip spherical portion 20a of the center pin 20 enters the inverted conical recess 4a of the centering ring retainer 4, and the magnet 8 attaches the disk 6 to the turntable 1 substantially coaxially with the turntable shaft 2.

Problems to be Solved by the Invention However, in the above-described configuration, the position of the magnet 8 is separated from the turntable 1 as the thickness of the disk 6 increases, and as a result, the inverted conical recess 4a of the centering ring retainer 4 is formed. Since the tip spherical portion 20a of the center pin 20 separates, play play increases and the concentricity with the turntable shaft 2 deteriorates, it is necessary to secure a large clearance between the magnet holder 9 and the flange plate 21. There is a problem in that miniaturization is hindered and the dynamic balance of rotation of the turntable 1 is lost.

In view of the above problems, the present invention provides a disk clamp device that attracts a magnet 8 coaxially to a turntable 1 and clamps a disk 6 without disturbing the dynamic balance.

Means for Solving the Problems In order to solve the above problems, the disk clamp device of the present invention is such that a center pin is slidably fitted in a center hole of a magnet holder, and the center pin is inserted from the magnet holder side. A plate spring is urged in the direction of abutting against the disc, and the center pin is fitted into a part of the turntable shaft while abutting against the disc.

The present invention has the above-described structure, and even when a thick disc is held by a turntable and a magnet, the center pin is urged in the disc contacting direction by the leaf spring, and the center pin is placed in the inverted conical recess of the centering ring retainer. The spherical end of the pin abuts, and the magnet is guided coaxially with the turntable shaft to sandwich the disc and attract it to the turntable.

Embodiment A disk clamp device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of a disc clamp device according to an embodiment of the present invention. 1 and 2, 1 is a turntable, 2 is a turntable shaft, 3 is a centering ring, 4 is a centering ring retainer, and 5 is a centering ring 3 pushed up from the turntable 1 by a preload spring. Has stopped. Reference numeral 6 denotes a disk, which is attached to the turntable 1 through the sheet 7 by utilizing the magnetic attraction force to the turntable 1. A magnet holder 9 functions as a back yoke that forms a magnetic circuit of the magnet 8, and a center pin 9 is slidably engaged with a center hole 9a. Reference numeral 11 is a leaf spring that urges the center pin 10 from the magnet holder 9 in the disc contact direction. A flange plate 12 is fixed to the center pin 10.

The operation of mounting the disc clamp configured as described above will be described below.

A center pin 10 slidably engaged with a center hole 9a of the magnet holder 9 is biased by a leaf spring 11 and locked by a flange plate 12. In this state, when the magnet 8 is brought close to the disk 6 placed on the turntable 1, the turntable
It is attracted by the magnetic attraction force to 11. At this time, the tip spherical portion 10a of the center pin 10 abuts on the inverted conical recess 4a of the centering ring retainer 4 and resists the biasing force of the leaf spring 11 to further bring the magnet 8 closer to the disk 6 via the sheet 7. Cling to.

FIG. 2B shows a state in which a disk thicker than the disk in FIG.
The magnet 8 holds the disk 6 coaxially with the turntable shaft 2 by contacting the tip spherical portion 10a of 10 or the inverted conical recess 4a of the centering ring holder 4.

As described above, according to this embodiment, the center pin 10 is biased in the attraction direction of the magnet 8 by the leaf spring 11 so that the magnet 8 is coaxially mounted on the turntable shaft 2 regardless of the thickness of the disk. It can be sandwiched and attached to a turntable.

As described above, according to the present invention, the center pin is slidably fitted in the center hole of the magnet holder, the leaf spring biases the center pin in the disc contact direction, and the turntable shaft that drives the disc to rotate. By providing an engaging part where the center pin abuts while abutting, the magnet can be mounted on the turntable coaxially with the turntable shaft regardless of the thickness of the disc. In addition, since the flange plate always holds the disc at the same height, it has an effect that an unnecessary space is not required in the space for storing the flange plate.

[Brief description of drawings]

FIG. 1 is an exploded view of a main part of a disc clamp device according to an embodiment of the present invention, FIGS. 2A and 2B are sectional views of the disc clamp device according to an embodiment of the present invention, and FIG. Is a perspective view of a CD player incorporating a conventional disc clamp device, and FIG. 4 is a sectional view of a conventional disc clamp device. 7 ... Sheet, 8 ... Magnet, 9 ... Magnet holder, 10 ... Center pin, 11 ... Leaf spring, 12 ... Flange plate.

Claims (1)

[Claims] 1. A magnet, a magnet holder that serves as a back yoke to which the magnet is fixed, a sheet provided on the magnet surface and in contact with a disk, and a center pin slidably fitted in a center hole of the magnet holder. A flange plate fixed to the center pin,
A leaf spring for urging the center pin from the side of the magnet holder in the direction of abutting the disc, and an engaging portion for fitting the center pin in abutment with a part of a turntable shaft for rotationally driving the disc. A disc clamp device characterized in that