Fresnel lens, screen, image display device, lens mold manufacturing method and lens manufacturing method
US6726859B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2002 |
| Grant date | Apr 27, 2004 |
| Priority date | — |
| Expiry date | May 29, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A Fresnel lens has a plurality of pitch areas in which a plurality of hybrid type prism portions are arranged. Each hybrid type prism portion has a refraction type prism portion and a total reflection type prism portion. In the refraction type prism portion, a ray of incident light Li1 of an incident angle “an” is refracted twice and goes out as a ray of outgoing light Lo1 of an outgoing angle “f”. In the total reflection type prism portion, a ray of incident light Li2 of the incident angle “a” is refracted, totally reflected and refracted in that order and goes out as a ray of outgoing light Lo2 parallel to the ray of outgoing light Lo1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.