Claims
- 1. A disc apparatus for recording and reproducing signals to/from a disc, which includes a clamping plate, using light or magnetism, comprising:
- a rotatable turntable on which the disc is placed;
- a rotatable spindle firmly fixed to said turntable so that any movement of said spindle in any axial direction of said spindle causes said turntable to move;
- a magnetic material firmly fixed to said turntable, said magnetic material being permeable to magnetic flux and including an arc-shaped surface which contacts said clamping plate, a circumferential length of the arc-shaped surface being greater than a radial width of the arc-shaped surface; and
- a motor for driving said turntable, said motor including a magnet provided on said turntable and generating the magnetic flux and an excitation coil facing said magnet, said magnetic material guiding the magnetic flux toward said clamping plate so that said magnet applies magnetic attractive force to said clamping plate.
- 2. The disc apparatus of claim 1, wherein said magnetic material is provided between said magnet of said motor and said disc clamping plate.
- 3. The disc apparatus of claim 1, wherein said magnetic material is disposed in said turntable.
- 4. The disc apparatus of claim 1, wherein said magnetic material extends through said turntable from a first surface, on a side of said clamping plate, to a second surface, on a side of said magnet of said motor.
- 5. The disc apparatus of claim 1, wherein said magnet of said motor and said turntable are joined to each other, thereby forming single-piece construction.
- 6. The disc apparatus of claim 1, wherein said magnet of said motor forms a part of said turntable.
- 7. The disc apparatus of claim 1, wherein
- said turntable has an alignment surface for aligning a center of the disc with a center of rotation of said spindle, and
- the surface of said magnetic material which contacts said clamping plate is disposed at a position nearer to the center of rotation of said spindle than said alignment surface of said turntable.
- 8. A disc apparatus for recording and reproducing signals to/from a disc, which includes a clamping plate, using light or magnetism, comprising:
- a rotatable turntable on which the disc is placed;
- a rotatable spindle firmly fixed to said turntable;
- a magnetic material firmly fixed to said turntable, said magnetic material being permeable to magnetic flux;
- a motor for driving said turntable, said motor including a magnet provided on said turntable and generating the magnetic flux and an excitation coil facing said magnet, said magnetic material guiding the magnetic flux toward said clamping plate so that said magnet applies magnetic attractive force to said clamping plate; and
- a resilient body for applying a pressing force to said spindle in an axial direction of said spindle against a force applied indirectly to said spindle by said excitation coil, thereby maintaining a gap between said magnet and said excitation coil.
Priority Claims (6)
Number |
Date |
Country |
Kind |
4-220158 |
Aug 1992 |
JPX |
|
4-303648 |
Nov 1992 |
JPX |
|
5-007283 |
Jan 1993 |
JPX |
|
5-011573 |
Jan 1993 |
JPX |
|
5-084533 |
Apr 1993 |
JPX |
|
5-130616 |
Jun 1993 |
JPX |
|
Parent Case Info
This application is a divisional of application Ser. No. 08/522,532, filed on Sep. 5, 1995, the entire contents of which are hereby incorporated by reference, now U.S. Pat. No. 5,726,828, which was a continuation of Ser. No. 08/103,908 filed Aug. 10, 1993, now abandoned.
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Divisions (1)
|
Number |
Date |
Country |
Parent |
522532 |
Sep 1995 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
103908 |
Aug 1993 |
|