Projector
US6443576B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2000 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Jan 13, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention achieves a reduction in size of a projector by shortening a length of an optical path of an illuminating optical system in a projector using an emitting direction control-type optical modulation device as compared to that of a conventional illuminating optical system, and thus, improves the illumination efficiencies of the illuminating optical system. An illuminating optical system includes a light source, a first lens array having a plurality of first small lenses for dividing light emitted from the light source into a plurality of partial light beam fluxes, and a second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses. In addition, the illuminating optical system includes an optical element such that an outline shape of an emitting surface is a quadrilateral having first and second diagonal lines of different lengths. The quadrilateral of the optical element is set so that the ratio of two diagonal lines of a quadrilateral illumination region to which the illumination light is applied comes closer to 1 than the ratio of the lengths of the first and second diagonal lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.