Transparent rear projection screen
US4636035A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 1985 |
| Grant date | Jan 13, 1987 |
| Priority date | — |
| Expiry date | Nov 26, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A rear projection screen consists of a Fresnel lens and a picture-forming screen placed in front of it. The picture-forming screen has vertical backward convex lenses on its back and vertical masking strips on its front and strip-shaped sections situated between the masking strips and opposite the backward convex lenses. Each of these is designed to refract light rays coming from behind so that they are directed towards the strip-shaped sections. In order to increase the picture resolution or definition capability of the screen and to avoid notch sensitivity between the backward convex lenses an intermediate lens is provided between every two of the backward convex lenses. Every intermediate lens has two sides shaped in such a way that the rays which hit one side of each intermediate lens are refracted so that they are directed towards the strip-shaped section which is situated opposite to the backward convex lens which is adjacent to the other side of the intermediate lens concerned, and that the rays which hit the other side of the intermediate lens concerned are refracted so that they are directed towards the strip-shaped section with is situated opposite to the backward convex …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.