Projection-type display apparatus
US5777804A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/7441
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection-type display apparatus including an elliptical condenser mirror having a concave reflecting surface consisting of part of a substantially elliptical surface, a light source arranged near a first focal point of the elliptical surface, a collimator lens having a focal point near a second focal point of the elliptical surface, an optical modulation element array having a lens array on the collimator lens side, in which optical modulation elements each having an area S are two-dimensionally arranged, and a projection lens, wherein the following relations are satisfied: ##EQU1## (when said light source is arranged perpendicular to the elliptical condenser mirror) ##EQU2## (when said light source is arranged parallel to the elliptical condenser mirror) PA1 .mu.=(B/A).sup.2 (A: major axis, B: minor axis) where L is the length of a light-emitting portion of the light source, .mu. is the square of a ratio of the minor axis to the major axis of an ellipse of the elliptical condenser mirror, f is the focal length of the collimator lens, m is the distance between the lens array and an opening portion of the modulation element, and n is the refractive index between the lens array a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.