Front projection screen made from a transparent material
US3938876A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1974 |
| Grant date | Feb 17, 1976 |
| Priority date | — |
| Expiry date | Dec 19, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/60
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A front projection screen is disclosed which is made from a transparent material. Prism-like elements are formed on the backside thereof so that light incident upon the screen from a preferred direction will be totally reflected by the screen while light incident upon the screen from other directions will pass therethrough. Sides of the prism-like elements are curved for dispersion in the horizontal plane while the front surface of the projection screen has segments of cylindrical columns formed thereon perpendicular to the prism-like elements to provide an angular spread in the vertical plane. The thickness of the screen is between 30 percent and 70 percent of the focal length of the cylindrical columns to allow the screen to be tilted in the vertical plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.