Optical-pick-up device achieving accurate positioning of objective lens and solid-immersion lens and method of forming same
AssigneeRicoh Company, Ltd.
InventorsHironobu Mifune, Kouichi Ohtaka
Life of this patent
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Abstract
An optical-pick-up device focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to the optical recording medium. The optical-pick-up device includes a substrate and an objective lens which is provided on one side of the substrate and focuses the coherent light beam at an exposed surface situated on another side of the substrate.
Claims27
An optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- a substrate;
- an objective lens formed on one side of said substrate and configured to focus said coherent light beam at a surface of no contact situated on another side of said substrate;
- and
- a layer having a refractive index higher than that of said substrate and provided on said another side of said substrate to form said exposed surface.
An optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- a substrate;
- an objective lens formed on one side of said substrate and configured to focus said coherent light beam at a surface of no contact situated on another side of said substrate;
- and
- a solid-immersion lens having a refractive index higher than that of said substrate and provided on said another side of said substrate, said solid-immersion lens being aligned to said objective lens in terms of an optical axis.
A method of creating an optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said method comprising the steps of:
- a) forming an objective lens on one side of a substrate, said objective lens focusing said coherent light beam;
- b) forming a recess having a curved surface in a surface of another side of said substrate;
- and
- c) filling in said recess with a material having a refractive index higher than that of said substrate so as to form a solid-immersion lens.
An optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- an objective lens formed on a first substrate and configured to focus said coherent light beam;
- and
- a solid-immersion lens formed in a second substrate and having a refractive index higher than that of said first substrate,
- wherein said first substrate and said second substrate are connected together to form a single composite.
A method of creating an optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said method comprising the steps of:
- a) forming a first substrate with an objective lens for focusing said coherent light beam;
- b) forming a second substrate with a solid-immersion lens;
- and
- c) connecting said first substrate and said second substrate together such that said objective lens and said solid-immersion lens are aligned in terms of an optical axis thereof.
An optical-pick-up device which focuses at least one coherent light beam to form at least one spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- a plurality of objective lenses formed on a first substrate and configured to focus said at least one coherent light beam;
- and
- a plurality of solid-immersion lenses formed in a second substrate and having a refractive index higher than that of said first substrate,
- wherein said first substrate and said second substrate are connected together to form a single composite, and said plurality of objective lenses and said plurality of solid-immersion lenses are arranged in an array form, respectively.
An optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- an objective lens configured to focus said coherent light beam;
- a solid-immersion lens having a first refractive index and having an optical axis aligned to that of said objective lens;
- a beam deviating unit provided over said objective lens and configured to change a direction in which said coherent light beam travels;
- a polarization unit provided between said beam deviating unit and said objective lens and configured to change a polarization of said coherent light beam;
- and
- a substrate formed with said objective lens, said solid-immersion lens, said beam deviating unit, and said polarization unit, and having a second refractive index lower than said first refractive index.
An optical-pick-up assembly which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up assembly comprising:
- an objective lens configured to focus said coherent light beam;
- a solid-immersion lens having a first refractive index and having an optical axis aligned to that of said objective lens;
- a beam deviating unit provided over said objective lens and configured to change a direction in which said coherent light beam travels;
- a polarization unit provided between said beam deviating unit and said objective lens and configured to change a polarization of said coherent light beam;
- a light emitting unit configured to emit said coherent light beam;
- a light detecting unit configured to detect a reflected light beam returning from said optical recording medium;
- and
- a substrate formed with said objective lens, said solid-immersion lens, said beam deviating unit, said polarization unit, said light emitting unit, and said light detecting unit, and having a second refractive index lower than said first refractive index.
An optical-pick-up assembly which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up assembly comprising:
- an objective lens configured to focus said coherent light beam;
- a solid-immersion lens having a first refractive index and having an optical axis aligned to that of said objective lens;
- a beam deviating unit provided over said objective lens and configured to change a direction in which said coherent light beam travels;
- a polarization unit provided between said beam deviating unit and said objective lens and configured to change a polarization of said coherent light beam;
- a light emitting unit configured to emit said coherent light beam;
- a light detecting unit configured to detect a reflected light beam returning from said optical recording medium;
- and
- a plurality of substrates which are combined together and formed with said objective lens, said solid-immersion lens, said beam deviating unit, and said polarization unit, said light emitting unit, and said light detecting unit, and one of said substrates formed with said solid-immersion lens has a second refractive index lower than said first refractive index.
A method of creating an optical-pick-up device based on photolithography, said method comprising the steps of:
- a) applying a photosensitive resin on a substrate such that said photosensitive resin has a predetermined thickness;
- b) casting light on said photosensitive resin after said light passes through a diffusing plate and a pattern mask provided over said photosensitive resin;
- c) applying a development process so as to create a recess having a concave surface in said photosensitive resin, said concave surface representing an intensity distribution of said light;
- d) applying dry etching so as to create a lens shape from said recess;
- and
- e) filling in the lens shape with a material having a refractive index higher than that of said substrate so as to create a first lens.
An optical-pick-up device which focuses a coherent light beam to form a spot on an optical recording medium, and performs recording/reproducing of information with respect to said optical recording medium, said optical-pick-up device comprising:
- a substrate;
- an objective lens formed on one side of said substrate;
- and
- a solid-immersion lens having a refractive index higher than that of said substrate and provided on another side of said substrate, said solid-immersion lens being aligned to said objective lens in terms of an optical axis.
Dependencies are inferred from the claim text.