Fresnel lens sheet
US6407860B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1999 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Dec 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/60
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Provided is a Fresnel lens sheet having the advantage of reducing unnecessary rays of light that may go out around the center area of the concentrically-configured Fresnel lens of the sheet. When it is combined with a lenticular lens sheet to construct a viewing screen, the screen has the advantage of preventing white spots from appearing around its center area. The Fresnel lens sheet is for screens for rear projection image displays, and is characterized in that the lens pitch in the center area of the concentrically-configured Fresnel lens of the sheet differs from that in the peripheral area thereof, and that the lens pitch in the center area is larger than that in the peripheral area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.