Optical information storage apparatus and optical device including a beam splitting surface with a convex surface side and a concave surface side
AssigneeFujitsu Limited
InventorsShinya Hasegawa, Nobuhide Aoyama, Wataru Odajima
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Abstract
There is disclosed a small lightweight optical information storage apparatus which can obtain a sufficient writing light quantity, and an optical device which can realize the optical information storage apparatus. The optical device for use in the optical information storage apparatus has a splitting surface constituted of a part of a cylindrical surface. A light emitted from a light source is passed via the optical device and directed to an optical information storage medium, and a signal light is split from a return light from the optical information storage medium by the optical device.
Claims20
An optical information storage apparatus comprising:
- a light source for emitting a divergent light;
- an objective optical system for focusing the light emitted from said light source upon an optical information storage medium to generate a return light at least partially including a signal light corresponding to stored information, and for converting the return light from the optical information storage medium to convergent light and directing the light toward said light source;
- and
- an optical device, positioned between said light source and said objective optical system, for passing and guiding the light emitted from said light source to said objective optical system, and for splitting the signal light from the return light reflected by said optical information storage medium and returned via said objective optical system,
- said optical device comprising a splitting surface formed of a part of a cylindrical surface, passing and guiding the light emitted from said light source via a concave surface side of the splitting surface to said objective optical system, and splitting, by said splitting surface, said signal light from the return light which returns via the same route as the route when guided to the objective optical system and which is incident upon a convex surface side of the splitting surface.
The optical information storage apparatus according to 5, further comprising a signal detector, constituted of two optical detectors, for detecting said signal light, wherein:
- said optical device comprises a reflecting surface formed of a part of a cylindrical surface, reflects the signal light split by said splitting surface on a concave surface side of the reflecting surface to converge the signal light, and further splits the signal light converged by the reflecting surface into the ordinary beam and the extraordinary beam by said birefringence part for differential outputs of said two optical detectors.
An optical information storage apparatus comprising:
- a light source for emitting a divergent light;
- an objective optical system for focusing the light emitted from said light source upon an optical information storage medium to generate a return light at least partially including a signal light corresponding to stored information, and for converting the return light from the optical information storage medium to convergent light and directing the light toward said light source;
- and
- an optical device, positioned between said light source and said objective optical system, for passing and guiding the light emitted from said light source to said objective optical system, and for splitting the signal light from the return light reflected by said optical information storage medium and returned via said objective optical system,
- said optical device comprising a splitting surface formed of a part of a cylindrical surface, passing and guiding the light emitted from said light source via a concave surface side of the splitting surface to said objective optical system, and splitting, by said splitting surface, said signal light from the return light which returns via the same route as the route when guided to the objective optical system and which is incident upon a convex surface side of the splitting surface,
- wherein said optical device has, as said splitting surface, a surface which can split said signal light from the return light incident at an incidence angle of 45°.
An optical device, disposed between an objective optical system for focusing a light emitted from a light source for emitting a divergent light upon an optical information storage medium to generate a return light at least partially including a signal light corresponding to stored information and for converting the return light from the optical information storage medium to a convergent light and directing the convergent light toward said light source and said light source, for passing and % guiding the emitted light from said light source to said objective optical system, and for splitting the signal light from the return light reflected by said optical information storage medium and returned via said objective optical system, the optical device comprising a splitting surface constituted of a part of a cylindrical surface, the optical device passing and guiding the emitted light from said light source to said objective optical system via the concave surface side of the splitting surface, and splitting, by said splitting surface, said signal light from the return light which returns via the same route as the route when guided to the objective optical system and which is incident on the convex surface side of the splitting surface.
An optical information storage apparatus comprising:
- a light source for emitting a divergent light;
- an objective optical system for focusing the light emitted from said light source upon an optical information storage medium to generate a return light at least partially including a signal light corresponding to stored information, and for converting the return light from the optical information storage medium to convergent light and directing the light toward said light source;
- and
- an optical device, positioned between said light source and said objective optical system, for passing and guiding the light emitted from said light source to said objective optical system, and for splitting the signal light from the return light reflected by said optical information storage medium and returned via said objective optical system,
- wherein said optical device comprises:
- a splitting surface formed of a part of a cylindrical surface, passing and guiding the light emitted from said light source via a concave surface side of the splitting surface to said objective optical system, and splitting said signal light from the return light incident upon a convex surface side of the splitting surface by the splitting surface;
- and
- a birefringence part for further splitting the signal light split by said splitting surface into an ordinary beam and an extraordinary beam.
An optical device, disposed between an objective optical system for focusing a light emitted from a light source for emitting a divergent light upon an optical information storage medium to generate a return light at least partially including a signal light corresponding to stored information and for converting the return light from the optical information storage medium to a convergent light and directing the convergent light toward said light source and said light source, for passing and guiding the emitted light from said light source to said objective optical system, and for splitting the signal light from the return light reflected by said optical information storage medium and returned via said objective optical system, the optical device comprising a splitting surface constituted of a part of a cylindrical surface, the optical device passing and guiding the emitted light from said light source to said objective optical system via the concave surface side of the splitting surface, and splitting said signal light from the return light incident on the convex surface side of the splitting surface by the splitting surface,
- wherein the optical device further comprises:
- a reflecting surface formed of a part of the cylindrical surface;
- and
- a birefringence part for further splitting the signal light by said splitting surface to an ordinary beam and an extraordinary beam,
- which reflects the signal light split by said splitting surface on the concave surface side of said reflecting surface to converge the signal light, and further splits the signal light converged by the reflecting surface into an ordinary beam and an extraordinary beam by said birefringence part for differential outputs of two optical detectors.
Dependencies are inferred from the claim text.