JPH0626054U - Chucking mechanism in disc player - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a chucking mechanism in a disc player, and in a disc player in which a pickup is arranged below the disc, the level of natural vibration when the disc is clamped from above using air pressure and rotated. The purpose is to suppress signal deterioration and prevent signal deterioration. [Structure] A chucking table 3 which contacts the disc 2 on the turntable 1 and clamps the disc from above.
The chucking table 3 is configured to include a recessed portion 11 that is located on the disc in a portion protruding from the turntable 1 and that is open to the disc side, and a plurality of holes 12 that communicate with the recessed portion 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chucking mechanism in a disc player, and more particularly to a mechanism for chucking a CD on a turntable in a player such as a compact disc (CD).

[0002]

[Prior art]

 In the conventional disc player such as a CD, there are the following two types of systems for reproducing the signal of the disc. (B) A CD mounted on a turntable like a record board, and a signal is detected by a downward optical pickup arranged above. (B) A CD that is placed on a small-diameter turntable and clamped, and a signal is detected by an upward optical pickup located below.

[0003]

[Problems to be solved by the device]

 However, among the above-mentioned conventional disc players, in the player of (a), since the pit surface of the disc faces upward, dust and the like are apt to accumulate and cause malfunction, and also the optical pickup. Since the lens is normally designed to face upward, there is a problem in that there are various restrictions in the design of the structure that hangs downward.

On the other hand, in the player of the above (b), such a problem is solved, but since the part of the disc protruding from the turntable is not clamped, vibration occurs on the disc when the disc rotates. Therefore, there is a problem that the level of the natural vibration of the disk rises and the signal is easily deteriorated.

The present invention has been made in view of such conventional problems, and in a disc player in which an optical pick-up is arranged below the disc, the disc is clamped from the upper side by utilizing a change in air pressure. An object of the present invention is to provide a chucking mechanism that suppresses the deterioration of signals by suppressing the level of natural vibration during rotation.

[0006]

[Means for Solving the Problems]

 The present invention is provided with a chucking table that contacts a disc on a turntable and clamps the disc from above, and the chucking table is located on the disc outside the turntable and is opened to the disc side. It is characterized in that it is provided with a recess and a plurality of holes communicating with the recess.

[0007]

[Action]

 In the present invention, when the disk on the turntable is clamped by the chucking table, the recess becomes a hollow part whose lower surface is closed by the disk, and when the disk rotates in this state, the air pressure in the recess (cavity) becomes smaller than the atmospheric pressure. Therefore, the disc is attracted to the chucking table, and the part of the disc protruding from the turntable is clamped, and the level of natural vibration when the disc rotates can be suppressed.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of a chucking mechanism according to the present invention.

First, the configuration will be described. 1 to 3, the chucking mechanism includes a chuck table 3 that clamps a disc 2 on a turntable 1. The turntable 3 is fixed to the shaft 5 of the disc motor 4, a boss 6 is provided on the upper surface of the turntable 3, and a protrusion 7 is formed around the boss 6. The chucking table 3 has a fitting hole 8 that fits into the boss 6 at the center, and a taper that fits between the protrusion 7 and the boss 6 at the lower end edge of the fitting hole 8. The protrusion 9 is formed.

The chucking table 3 is provided with a convex portion 10 which is located at a portion where the disk 2 is protruded from the turntable 1 and which protrudes upward. The recess 11 is formed. Further, holes 12 are formed at a plurality of circumferential locations on the upper surface of the convex portion 10.

Next, the operation will be described. First, the center hole of the disk 2 is fitted into the protrusion 7 of the turntable 1, and the chucking table 3 is clamped from above. That is, by fitting the fitting hole 8 into the boss 6 and fitting the tapered protrusion 9 between the boss 6 and the protrusion 7, the disc 2 is clamped on the turntable 1 and at the same time. The back surface of the chucking table 3 also comes into close contact with the part of the disk 2 that protrudes from the turntable 1. As a result, the concave portion 11 on the lower surface of the convex portion 10 becomes a hollow portion closed by the disc 2. When the turntable 1 rotates in this state, the disk 2 and the chucking table 3 also rotate at the same time, and at this time, the air pressure in the recess 11 (cavity) becomes smaller than the outside atmospheric pressure, and as shown by the arrow in FIG. Further, a force acts so that the disc 2 is attracted from the back surface of the chucking table 3, and the portion of the disc 2 protruding from the turntable 1 is also securely clamped by the chucking table 3. Therefore, the level of natural vibration when the disk rotates can be suppressed, and signal deterioration can be prevented.

[0012]

[Effect of device]

 As described above, according to the present invention, since the chucking table is formed with the concave portion located in the portion of the disc protruding from the turntable and the air hole communicating with this concave portion, the concave portion (cavity portion) due to the rotation of the disc is formed. As the internal air pressure decreases, the disc is pressed against the chucking table, which suppresses the level of natural vibration of the disc and effectively prevents signal deterioration due to vibration during disc rotation.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a chucking mechanism according to the present invention.

FIG. 2 is a central sectional view of FIG.

FIG. 3 is an enlarged view of a main part of FIG.

[Explanation of symbols]

 1 turntable 2 disc 3 chucking table 11 recess 12 hole

Claims (1)

[Scope of utility model registration request] 1. A chucking table that contacts a disc on a turntable and clamps the disc from above is provided, and the chucking table is located on the disc at a portion protruding from the turntable and opens to the disc side. A chucking mechanism in a disk player, comprising a recess and a plurality of holes communicating with the recess.