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US 10,591,813 B2Granted
Illumination apparatus and image projection apparatus
AssigneeCanon Kabushiki Kaisha
InventorTomohiro Nakamura
Life of this patent
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Abstract
An illumination apparatus includes a light source, a polarization conversion element configured to convert light from the light source into polarized light having a specific polarization direction and to emit the polarized light to an illumination surface, and a photosensor configured to receive light emitted from a surface different from an incident surface and an exit surface of the polarization conversion element.
Claims8
An illumination apparatus comprising:
- a light source;
- a polarization conversion element configured to convert light from the light source into polarized light having a specific polarization direction and to emit the polarized light to an illumination surface;
- and
- a photosensor configured to receive light emitted from a detection surface of the polarization conversion element different from an incident surface and an exit surface of the polarization conversion element,
- wherein the polarization conversion element includes:
- a plurality of first polarization separation films arranged in a specific direction,
- a plurality of reflection films arranged in the specific direction between the first polarization separation films, and
- a second polarization separation film disposed closer to an end of the polarization conversion element in the specific direction than the first polarization separation films, and
- wherein the detection surface is a surface of the second polarization separation film or a transmission surface through which light that transmits through the second polarization separation film is emitted.
6 more elements
An image projector apparatus comprising:
- an illumination apparatus including a light source, a polarization conversion element configured to convert light from the light source into polarized light having a specific polarization direction and to emit the polarized light to an illumination surface, and a photosensor configured to receive light emitted from a detection surface of the polarization conversion element that is a different from an incident surface and an exit surface of the polarization conversion element,
- wherein the polarization conversion element includes:
- a plurality of first polarization separation films arranged in a specific direction;
- a plurality of reflection films arranged in the specific direction between the first polarization separation films, and
- a second polarization separation film disposed closer to an end of the polarization conversion element in the specific direction than the first polarization separation films, and
- wherein the detection surface is a surface of the second polarization separation film or a transmission surface through which light that transmits through the second polarization separation film is emitted.
3 more elements
Dependencies are inferred from the claim text.