Optical information processing apparatus incorporating diffraction grating with non-grating light receiving area
AssigneeFujitsu Limited
InventorsKoichi Tezuka, Kyoko Tadaki
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Abstract
An optical information processing apparatus is designed to generate a tracking error signal based on reflected light from a storage medium. The apparatus is a 3-beam type, in which the storage medium is irradiated by a main beam and two sub-beams offset from the main beam in the tracking direction of the storage medium. Each of the two sub-beams is, as viewed on the storage medium, smaller in size in the tracking direction than the main beam.
Claims5
An optical information processing apparatus designed to generate a tracking error signal based on reflected light from a storage medium, the apparatus comprising a main beam that irradiate the storage medium and two sub-beams that irradiate the storage medium and are offset from the main beam in a tracking direction,
- wherein each of the two sub-beams is, as viewed on the storage medium, smaller in size in the tracking direction than the main beam.
Dependencies are inferred from the claim text.