1. Field of the Invention
The present invention relates to an apparatus for clamping optical discs.
2. Discussion of the Related Art
In general, as shown in
As shown in
The clamper 15 comprises a magnetic clamper yoke 16 for making a disc and a turntable 100 of the spindle motor 10 kept to be close to each other; and the spindle motor 10 incorporates a clamper magnet 101 assembled as a single unit together with the turntable 100.
As shown in
Meanwhile, if the spindle motor 10 rotates with high speed, air turbulence around the optical disc 20 generates a levitation force which pushes the optical disc 20 toward the clamper. Since the clamper 15 and the rotor of the spindle motor 10 operate as a single unit due to the clamper magnet 101, the levitation force generates a force which makes the entire rotor of the spindle motor 10 float from the stator of the spindle motor 10 toward the rotor shaft 105.
Therefore, an absorption magnet 107 is installed at the rotor of the spindle motor in order to generate an attractive force between the rotator and the stator of the spindle motor 10; thus, a magnetic force is made to be exerted between the absorption magnet 107 and the ferrous metal bearing housing 106 installed at the stator of the spindle motor to attract each other.
Accordingly, even if the air turbulence generated due to high speed rotation of an optical disc acts as a levitation force to push the optical disc 20 loaded into the turntable 100 toward the clamper, the optical disc 20 is kept to be close firmly to the turntable 100 of the spindle motor 10 by a magnetic force exerted between the clamper yoke 16 and the clamper magnet 101 as described above; due to a magnetic force exerted between the absorption magnet 107 installed at the rotor of the spindle motor 10 and the bearing housing 106 installed at the stator, the rotor of the spindle motor 10 is allowed to rotate safely at a fixed position without rising in an upward direction.
However, since the clamper yoke 16, clamper magnet 101, and absorption magnet 107 employ a costly magnet but with a strong magnetic force, manufacturing costs of optical disc drives rise. On the other hand, if a low cost magnet with a weak magnetic force is employed, a levitation force due to air turbulence cannot be completely removed; therefore, a critical error such as damage to an optical disc may occur, not to mention the noise generated.
To solve the problem described above, the present invention has been made in an effort to provide an apparatus for clamping an optical disc to enable optical disc clamping operation and rotational operation of a spindle motor in a normal manner without employing an expensive magnet such as a clamper yoke, clamper magnet, and absorption magnet.
An apparatus for clamping an optical disc according to one embodiment of the present invention comprises a turntable into which an optical disc is loaded; a clamper for clamping the optical disc; and an elastic member being installed in an upper part of the clamper and making contact with the clamper, thereby providing an elastic force for clamping the optical disc.
In one embodiment, the elastic member can be installed directly at a chassis or a clamper cover adhered to the chassis.
In one embodiment, a protrusion for making contact with the elastic member can be formed in an upper surface of the clamper.
In one embodiment, the elastic member can include a plate spring, one side of which is fixed and the other side of which is left free.
In one embodiment, installed at the chassis or clamper cover can be a stopper which restricts the operation range of the other side of the elastic member left free.
In one embodiment, the elastic member can comprise the plate spring and coil springs for pushing or pulling the plate spring in a direction toward the clamper.
In one embodiment, the coil spring can be installed between the middle part of the plate spring and the other side thereof which is left free.
An optical disc drive according to another embodiment of the present invention comprises an optical pick-up for recording data into an optical disc or reading out data from the optical disc; a spindle motor for rotating the optical disc; a turntable being formed above the spindle motor, where the optical disc is loaded; a clamper for clamping the optical disc; and an elastic member being installed in an upper part of the clamper and providing an elastic force for clamping the optical disc to the turntable by making contact with the clamper when the clamper clamps the optical disc as the turntable approaches.
An apparatus for clamping an optical disc according to the present invention enables optical disc clamping operation and rotational operation of a spindle motor in a normal manner without employing an expensive magnet such as a clamper yoke, clamper magnet, and absorption magnet and therefore efficiently reduces manufacturing costs of optical disc drives.
The accompany drawings, which are included to provide a further understanding of this document and are incorporated on and constitute a part of this specification illustrate embodiments of this document and together with the description serve to explain the principles of this document.
[0027]In what follows, preferred embodiments of an apparatus for clamping an optical disc according to the present invention will be described in detail with reference to appended drawings.
First, an apparatus for clamping an optical disc according to the present invention can be applied to various types of optical disc drives (ODDs) for recording data to or playing data from an optical disc such as a CD, DVD, or BD.
As shown in
The clamper cover 34, for example, may be bonded to the chassis 33 forming an upper side external shape of the optical disc drive by an adhesive after the clamper cover 34 is manufactured as a separate, independent apparatus or manufactured as a single unit together with the chassis 33.
Also installed at the clamper cover 34 is an elastic member for keeping a turntable of the spindle motor 30 and the clamper 35 to be closer to each other by pushing the clamper 35 from an upper direction to a lower direction.
For example, as shown in
As shown in
In other words, the clamper cover 34 is additionally equipped with the clamper plate spring 36, one end part of which is fixed whereas the other end part of which is left free being limited for a predetermined distance by the plate stopper 37. The central part of the clamper plate spring 36 makes contact with the projection 350 projected in an upper, central part of the clamper 35 and delivers an appropriate force to the clamper 35. Since the clamper 35 should rotate while it makes contact with the central part of the clamper plate spring 36, the projection may assume the shape of a circle or triangular pyramid to minimize a contact area.
As shown in
And since the clamper plate spring 36 has been designed to provide an appropriate contact force according to a displacement generated by optical disc thickness, the clamper plate spring 36 pushes the projection 350 of the clamper in a downward direction, thereby making the clamper and the turntable of the spindle motor kept close to each other.
Therefore, even if air turbulence generated due to high speed rotation of an optical disc acts as a levitation force pushing the optical disc 20 loaded into the turntable of the spindle motor in an upward direction toward the clamper 35, the optical disc 20 can be made to be kept close firmly to the turntable of the spindle motor by using an elastic force of the clamper plate spring 36 as described above.
In other words, optical disc clamping operation can be carried out in a normal manner within the optical disc drive without employing an expensive clamper yoke or clamper magnet. Furthermore, the rotor of a spindle motor can be prevented from being pushed in an upward direction without employing an expensive absorption magnet; therefore, rotational operation of the spindle motor can be carried out in a normal manner.
As shown in
And the clamper cover 34 can be manufactured as a single unit together with the chassis 43. In this case, the clamper plate spring, plate stopper, and clamper coil spring can be installed directly at the chassis 43.
Preferred embodiments of the present invention have been introduced for the illustration purpose only. Therefore, it should be noted that various improvements, modifications, substitutions of, or additions to the present invention are possible without departing from the technical principles and scope of the present invention.
Number | Date | Country | Kind |
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10-2011-0067658 | Jul 2011 | KR | national |