Projection type image display apparatus and projection optical system
US8210693B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 2010 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Jan 6, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/16
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection type image display apparatus includes: a light source; an illumination optical system that uniformly illuminates beams, which are emitted from the light source, on a surface of an image modulation element as a primary image plane; and a projection optical system that projects image information of the primary image plane modulated by the image modulation element on a screen as a secondary image plane in an enlarged manner. The projection optical system includes a first optical system having a positive refractive power and including a plurality of transmissive surfaces, and a second optical system having a positive refractive power and including a concave reflective surface. The first optical system has a first reflective surface disposed between any surfaces of the plurality of transmissive surfaces, and a second reflective surface disposed between the first optical system and second optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.