Rear-projection screen
US5432636A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1994 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | May 31, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a rear-projection screen comprising a Fresnel lens and a light-diffusing member such as a lenticular lens sheet, a rise angle in a central region of the Fresnel lens is smaller than a rise angle in an intermediate region thereof (e.g., the former is not larger than 3.degree. and the latter is larger than 3.degree. ). The rise angles may preferably gradually increase from the central region of the Fresnel lens toward the intermediate region thereof. The central region of the Fresnel lens may preferably be a region extending within the range of from 1/4 to 1/3 from the middle point of a diagonal of the rear-projection screen. Such a Fresnel lens is effective for improving white uniformity in the intermediate region of the rear-projection screen and eliminating color corn in the central region thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.