Projection-type display apparatus
US5743610A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 1996 |
| Grant date | Apr 28, 1998 |
| Priority date | — |
| Expiry date | Aug 27, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3182
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection display comprising: a square column dichroic prism composed of four triangle prisms having equal refractive index together whose cross sections are right isosceles triangles such that three light valves are located adjacent to three exterior peripheral surfaces of dichroic prism to receive colored and modulated light beams therefrom and; a filter for absorbing light with a specified wavelength range, leaked from surface of dichroic prism at the opposite side of incident light surface and directed to liquid crystal light valve, the filter being located between liquid crystal light valves and surface of dichroic prism. As for construction of the dichroic prism itself, specifically, of the four aforementioned triangular prisms, the first triangular prism and the aforementioned third triangular prism are mutually affixed in a condition in which there is a first step difference in the vertical direction. The first exposed side is formed on one edge of the affixed side of the first triangular prism. Similarly, the second triangular prism and the fourth triangular prism are attached to each other such that there is a second step difference on the same edge, and a second expos…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.