The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1993
Filed:
Jul. 30, 1992
Hirosi Ando, Nishikasugai, JP;
Shinji Namba, Kariya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A light-guiding device having a light-incident surface and a light-outgoing surface for guiding light incident from the light-incident surface from the light-outgoing surface toward a light-receiving surface of a photodetector for generating an electric signal corresponding to a quantity of the received light. The device comprises a hologram layer having an interference pattern which acts as a diffraction grating to diffract and reflect the light, incident from the light-incident surface, in a predetermined direction. The hologram layer is interposed between first and second total reflection layers. The first total reflection layer has a first total reflection surface disposed in opposed relation to one of the longitudinal surfaces of the hologram layer so that the light diffracted and reflected by the hologram layer is incident on the first total reflection surface at a predetermined angle larger than the critical angle so as to be total-reflected thereon, and the second total reflection layer has a second total reflection surface disposed in opposed relation to the other longitudinal surface of the hologram layer so that the incident light passing through the hologram layer is incident on the second total reflection surface at a predetermined angle greater than the critical angle so as to be total-reflected thereon. This arrangement improves the light-receiving performance concurrently with reducing the thickness of the device.