Rear projection type image display device
US6124969A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1998 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Aug 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/74
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A rear projection type image display device includes a single projection lens, a Fresnel lens sheet, and a lenticular lens sheet 4 having black stripes in an area where when the light entered through the Fresnel lens sheet is transmitted, the outgoing light does not pass. When the angle (deg) of incidence to the lenticular lens sheet 4 is taken to be .theta., the total light transmittance (%) of the lenticular lens sheet to the light with the angle .theta. of incidence is taken to be Tt(.theta.), and the light transmittance loss by a light absorbent contained in the lenticular lens sheet is taken to be .alpha., as shown by (b), (c) in FIG. 4, in the central part of the lenticular lens sheet, if .vertline..theta..vertline.=5, the expression Tt(.theta.)>70.times.(1-.alpha.) is satisfied, and if .vertline..theta..vertline.=20, the expression Tt(.theta.)<50.times.(1-.alpha.) is satisfied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.