Projection optical system and image projection apparatus
US7116498B2 · kind B2 · utility
2Cited by
3References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 7, 2005 |
| Grant date | Oct 3, 2006 |
| Priority date | — |
| Expiry date | Jun 17, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection optical system and an image projection apparatus that are small in size and can achieve projection with a wide angle while a good image forming performance is assured includes a first lens group having a negative refracting power and a second lens group also having a negative refracting power. The first and second lens groups are arranged in order from the projection side. The first lens group includes a negative meniscus lens that has a concave surface directed to the projection side and formed as an aspherical reflecting surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.