US 4,907,214 AGranted

Eccentricity correction apparatus for an optical disk device

AssigneeKabushiki Kaisha Toshiba

InventorsKatsumi Nagano, Hiroshi Watanabe

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Abstract

An optical disc apparatus includes a tracking device which positions the beam light on the recording track of an optical disc in order to carry out at least recording or reproducing of information by moving the beam light in the radial direction of the optical disc, and a detection device for obtaining a position deviation signal of the beam light by receiving reflected light from the surface of the optical disc. In addition, the apparatus includes an optical head which carries out recording or reproducing of information for the recording track of the optical disc, a control device which controls the tracking device in response to the position deviation signal obtained from the detection device, a first device which reads, prior to an actual operation of recording or reproducing, a position deviation signal from the detection device, and stores the resulting data in a memory as eccentricity correction data for the recording track, and a second device which transfers, when actually carrying out recording or reproducing operation, the eccentricity correction data memorized in the memory to the D/A converter and gives the output of the D/A converter to the tracking control device. The D/A converter converts the digital quantity read from the memory to an analog signal, and the analog signal may be applied to a device for driving the optical head.

Claims12

Dependent claims

An eccentricity correction apparatus for an optical disc device, said apparatus comprising:

optical means for recording or reproducing information on a recording track of an optical disc using a light beam, said optical means including an optical head and driving means for positioning the light beam;
detecting means optically coupled to said optical means for converting portions of the light beam reflected from the optical disc into a position deviation signal;
comparing means operatively coupled to said detecting means for generating a reference signal and for comparing the position deviation signal with the reference signal to produce a difference signal;
storage means for storing an externally supplied first digital quantity;
calculating means operatively coupled to said comparing means and to said storage means for calculating a second digital quantity based on the difference signal and the first digital quantity and transferring the second digital quantity to said storage means for storage as the first digital quantity, the second digital quantity being a binary signal with a least significant bit and having a weight corresponding to the difference signal, and for repeating said calculation and transferring of the second digital quantity until the value of the least significant bit of the second digital quantity becomes smaller than the value of said reference signal;
and
converting means operatively coupled to said storing means and to said driving means for converting the first digital quantity to an analog signal for driving said driving means.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/942,706Filed 17 Dec 1986
Priority: JP 60-28276418 Dec 1985
Granted: 6 Mar 1990
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G11B 7/0953
Specially adapted for discs, e.g. for compensation of eccentricity or wobble: to compensate for eccentricity of the disc or disc tracks
G11B 7/08505
With provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing…: methods…
G05B 2219/49177
Nc machine tool, till multiple: runout, eccentricity, imbalance of tool or workpiece
G11B
Information storage based on relative movement between record carrier and transducer