Projection optical system and projection image display apparatus
US8107163B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 2007 |
| Grant date | Jan 31, 2012 |
| Priority date | — |
| Expiry date | Nov 30, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/28
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection optical system for magnifying an image on a primary imaging plane onto a secondary imaging plane includes a first optical system for forming an intermediate image and a second optical system including a concave reflecting surface disposed between the intermediate image and the secondary plane. The first optical system includes first and second groups respectively having negative and positive power, an aperture, and a third group having positive power from the intermediate image. The surfaces of the first and second optical systems have rotational symmetry about a light axis. A ray traveling from the center of the primary plane to the center of the secondary plane intersects the light axis, is reflected off the reflecting surface, intersects the light axis again, and reaches the secondary plane. The following conditions are satisfied: 0.5<φ1/φ2<3, 1<AST/ASS<5,|AST|/L12<1, and −3<K_rel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.