Transparent rear projection screen
US4509822A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1983 |
| Grant date | Apr 9, 1985 |
| Priority date | — |
| Expiry date | Aug 2, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A transparent rear projection screen has a lense system for paralleling light arriving from behind. On the front side of the screen rectilinear lenses extending in the vertical direction in the position of use of the screen are provided the sides of which form a small angle of inclination with respect to the normal to the screen. The sides are totally reflecting to light arriving from behind and between the reflecting lenses further lenses are arranged. In order to compensate for color shading by the projection of differently colored television images upon the rear side of the screen, the tops of the reflecting lenses are so shaped and their totally reflecting sides have such an inclination with respect to the normal to the screen, and moreover have such a width that at the most 80% of the light which from behind enters the reflecting lenses is emitted through the tops of the lenses, and that at least 20% of said entering light is emitted through the sides of the lenses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.