Retinal scanning display device and beam width expander
AssigneeSeiko Epson Corporation
InventorsMitsutaka Ide, Masatoshi Yonekubo
Life of this patent
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Abstract
In a retinal scanning display device, a scanning section scans a light beam emitted from a light source to form a scanned image. The light beam emitted from the scanning section is expanded in beam width of the light beam in a first direction by a first beam width expander. The first beam width expander includes alternately stacked first partially reflective layers and first light-transmissive layers disposed between a pair of first reflection faces that face each other in the first direction. The plural partially reflective layers include a partially reflective layer having a transmittance exceeding 50%. This enables the light intensity distribution to be appropriately adjusted in the first direction for a light beam expanded in the first direction.
Claims13
A retinal scanning display device comprising:
- a light source that emits a light beam;
- a scanning section that scans the light beam emitted from the light source to form a scanned image;
- a first beam width expander that expands a beam width of the light beam emitted from the scanning section by expanding in a first direction;
- and
- an optical system that makes the light beam, expanded in beam width by the first beam width expander, incident on an eye of a user;
- the first beam width expander including
- a pair of first reflection faces facing each other along the first direction,
- a plurality of first partially reflective layers disposed between the pair of first reflection faces and stacked along the first direction;
- and
- a plurality of first light-transmissive layers disposed so as to be interposed between each of the pair of first reflection faces and an adjacent first partially reflective layer of the plurality of first partially reflective layers and interposed between adjacent first partially reflective layers of the plurality of first partially reflective layers;
- the first beam width expander including a first incident face disposed at an end face of the first beam width expander at one side in a first length direction intersecting the first direction, and a first emission face disposed at an end face of the first beam width expander at the other side in the first length direction;
- and
- at least one first partially reflective layer from out of the plurality of first partially reflective layers being a partially reflective layer having a transmittance exceeding 50%.
A beam width expander that expands a beam width of an incident light beam by expanding in one direction, the beam width expander comprising:
- a pair of first reflection faces facing each other along the one direction,
- a plurality of partially reflective layers disposed between the pair of reflection faces and stacked along the one direction;
- and
- a plurality of light-transmissive layers disposed so as to be interposed between each of the pair of reflection faces and an adjacent partially reflective layer of the plurality of first partially reflective layers and so as to be interposed between adjacent first partially reflective layers of the plurality of first partially reflective layers;
- wherein
- a stacked body configured by the pair of reflection faces, the plurality of partially reflective layers, and the plurality of light-transmissive layers includes an incident face disposed at an end face of the stacked body at one side in a length direction intersecting the one direction, and an emission face disposed at an end face of the stacked body at the other side along the length direction;
- and
- at least one partially reflective layer from out of the plurality of partially reflective layers is a partially reflective layer having a transmittance exceeding 50%.
Dependencies are inferred from the claim text.