Optical information processor with prismatic correction of laser beam shape
AssigneeHitachi, Ltd.
InventorsSeiji Yonezawa, Toshio Sugiyama, Masahiro Ojima
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Abstract
An optical information processor comprising a semiconductor laser device which has a rectangular light emitting region, a disk, and an optical system which includes a prism for converting a non-circular beam emergent from the laser device into a circular beam, the circular beam being projected onto the disk by the optical system thereby to record or play back predetermined information.
Claims29
An optical information processor comprising a light source formed by a semiconductor laser having a rectangular light emitting region which emits a beam of light having a substantially-elliptical cross section, an information storage medium, an optical system which focuses the beam of light emitted by the semiconductor laser onto the information storage medium, and means for detecting variations in the amount of light emergent from the information storage medium;
- wherein said optical system includes means in the form of at least one prism for converting the elliptical light beam emitted by said semiconductor laser device into a beam of circular cross section.
An optical information processor comprising
- a light source formed by a semiconductor laser having a rectangular light emitting region,
- an information storage medium,
- an optical system for projecting a non-circular light beam emitted by said laser as a circular light spot onto said medium, the optical system comprising first lens means for converting said non-circular light beam into a collimated non-circular light beam, prism means for converting said collimated non-circular light beam into a collimated circular light beam, and second lens means for focusing said collimated circular light beam onto said medium, and
- detection means for detecting variations in the amount of said light beam emergent from said medium.
Dependencies are inferred from the claim text.