Optical pick-up device using diffraction grating element having

Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system

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369112, 369122, 369 4412, 369 4414, 359571, 359569, G11B 700, G11B 7013

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active

051114496

ABSTRACT:
An optical pick-up device for focusing a laser beam emitted from a light emitting element through an optical system onto a recording medium. The beam is reflected from the recording medium and redirected through the same optical system on to a photodetector. A tracking error signal and a focusing error signal are produced from the output signals of the photo-detector. A diffracting element positioned before the light emitting element and the photo-detector and produces two sub-spots in two directions for applying the so-called 3-spots method from the laser beams that were projected from the light emitting element toward the recording medium. The diffracting element is divided into a first sub-region and a second sub-region formed in the same place and defined by a parting line aligned substantially perpendicular to the track direction. The first sub-region includes a diffraction grating for diffracting three beams that comprise a main beam toward the recording medium. The second sub-region includes a diffraction grating for diffracting the reflected beams of the three beams from the recording medium in the direction where the photo-detecting element is installed.

REFERENCES:
patent: 4665310 (1987-05-01), Heemskerk
patent: 4753513 (1988-06-01), Shikama
patent: 4771411 (1988-09-01), Greve
patent: 4794585 (1988-12-01), Lee
patent: 4817072 (1989-03-01), Toide et al.
patent: 4835378 (1989-05-01), Coops
patent: 4839506 (1989-05-01), Bressers et al.
patent: 4847478 (1989-07-01), Sugiura
patent: 4904856 (1990-02-01), Nagahama et al.
patent: 4945529 (1990-07-01), Ono et al.
patent: 4983002 (1991-01-01), Shikama et al.

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