Backlight system for liquid crystal display comprising prism lens having apex angle of 80.degree.-85.degree. and refractive index of 1.57-1.59
US6011601A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1997 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Jul 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/0053
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A liquid crystal display comprises a liquid crystal display device (30), a backlight system (20) provided with a prism lens sheet (10). The lens sheet comprises a transparent base sheet (11), and a lens sheet formed integrally with the base sheet and provided with a plurality of parallel unit lenses (12). Each of the unit lenses (12) has a cross section of a shape of an isosceles triangle having an apex angle (.alpha.) in the range of 80.degree. to 87.degree., and is made of a radiation setting resin having a refractive index in the range of 1.57 to 1.59. The prism lens sheet has a half-brightness viewing angle of 65.degree. or below, and the difference between the half-brightness viewing angle and a brightness-curve inversion angle is 20.degree. or above to prevent information displayed on the screen of the liquid crystal display from being seen sidewise by others.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.