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公开(公告)号:US20250116860A1
公开(公告)日:2025-04-10
申请号:US18983957
申请日:2024-12-17
Inventor: Kazuhiro MINAMI , Satoshi KUZUHARA , Ken'ichi KASAZUMI , Kosuke IMAWAKA
Abstract: A light guide includes an exit extension region including a diffraction structure dividing an image light ray propagating in a first direction intersecting a thickness direction of a body, into image light rays propagating in a second direction intersecting the first direction, in the first direction, and allowing them to emerge therefrom. At least one part of the region satisfies that when refractive indices of media on individual incident and exit sides of a ray relative to the region are assumed to be equal to each other, an exit angle θ_out of a ray emerging from the region at the highest diffraction efficiency in a plane including a normal line of the region is not smaller than 15° and is not greater than 45°, and an incident angle θ_in of a ray incident on the region in the plane is greater than θ_out by 14° or more.
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公开(公告)号:US20220244177A1
公开(公告)日:2022-08-04
申请号:US17726697
申请日:2022-04-22
Inventor: Akira KUROZUKA , Tatsuo ITOH , Kosuke IMAWAKA , Hiroyuki FURUYA
IPC: G01N21/3554 , G01N21/47 , G01N21/359 , G08G1/00
Abstract: An optical device includes: a light source part configured to project illumination light toward a sensing region; a photodetector configured to receive reflected light of the illumination light reflected on the sensing region; and a condenser mirror. The condenser mirror has a through hole through which the illumination light from the light source part passes and an optical axis of the light source part and an optical axis of the condenser mirror are aligned with each other. A reflection surface of the condenser mirror has a shape obtained by cutting out a columnar body extending in a projection direction of the illumination light, with a spheroid whose rotation axis is a major axis. The photodetector is disposed in a direction toward a first focal position of the condenser mirror. The sensing region is set in a direction toward a second focal position of the condenser mirror.
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公开(公告)号:US20220196545A1
公开(公告)日:2022-06-23
申请号:US17690836
申请日:2022-03-09
Inventor: Kosuke IMAWAKA , Hiroyuki FURUYA , Akira KUROZUKA
Abstract: A moisture sensing device includes: a light source part; a projection optical system configured to project illumination light emitted from the light source part, onto a road surface; a photodetector configured to receive reflected light of the illumination light reflected by the road surface; a light-receiving optical system configured to condense the reflected light onto the photodetector; and an optical element configured to align the optical axis of the projection optical system and the optical axis of the light-receiving optical system with each other in a range on the road surface side.
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