Automatic disc-changing apparatus, disc-chucking apparatus, disc apparatus and position-detecting apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsYoshinori Kakuta, Akira Sakuta, Masami Tomita, Kunihiko Nakagawa
Life of this patent
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Abstract
A disc apparatus for recording information to and reproducing information from a disc includes a turntable with a magnetized surface; an excitation coil disposed opposite the magnetized surface of the turntable; a drive circuit driving a focus actuator; a detector detecting focusing error; and a control circuit. The control circuit controls energization of the excitation coil in accordance with the detector so as to move the turntable in the axial direction via the magnetic force between the excitation coil and the magnetized turntable.
Claims8
A disc apparatus for recording and reproducing signals using light or magnetism, comprising:
- a turntable supported rotatably and also supported slidably in an axial direction with respect to a base, said turntable having a first surface for holding a disc and a second surface on an opposite side, and in part magnetized with a magnetized surface formed on said opposite side;
- an excitation coil mounted on said base and disposed oppositely to said magnetized surface of said turntable;
- a drive circuit driving a focus actuator;
- a detector detecting focusing error of an optical pickup;
- and
- a control circuit controlling the energization of said excitation coil in accordance with the output of said detector and moving said turntable in said axial direction by means of the magnetic force between said excitation coil and said magnetized turntable.
A disc apparatus, comprising:
- a base;
- a turntable that rotates and is slidably supported in an axial direction relative to said base, said turntable having a first surface for holding a disc and a magnetized second surface opposite said first surface;
- an excitation coil mounted on said base, opposite said magnetized second surface of said turntable;
- and
- a control circuit controlling energization of said excitation coil in accordance with a focusing error of said disc apparatus to alter a magnetic force between said excitation coil and said magnetized second surface of said turntable and thereby move said turntable in said axial direction.
A method of correcting a focus error of a disc apparatus that includes a base;
- a turntable that rotates and is slidably supported in an axial direction relative to said base, said turntable having a first surface for holding a disc and a magnetized second surface opposite said first surface;
- and an excitation coil mounted on said base, opposite said magnetized second surface of said turntable, said method comprising:
- detecting a focusing error of said disc apparatus;
- and
- controlling energization of said excitation coil in accordance with the detected focusing error to alter a magnetic force between said excitation coil and said magnetized second surface of said turntable and thereby move said turntable in said axial direction.
Dependencies are inferred from the claim text.