Prism sheet
US5844720A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1995 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Nov 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/045
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A prism sheet having a plurality of substantially triangular prism-shaped lens units with their longitudinal axes almost parallel to each other arranged on one side and having the other side roughened, and with a characteristic value of 100 when said roughned side is smooth, the characterstic values are not less than 50 in glossiness, not more than 70 in internal reflective ability, and not more than 70 in friction coefficient when the plane including the prism peaks is rubbed by the roughened surface. The prism sheet of the present invention is therefrom free from interference fringes, substantially safe from scratching and uniform and high in brightness, being thus useful for liquid crystal devices etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.