Projection zoom lens system and projector apparatus
US6137638A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 28, 1999 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Jul 28, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection zoom lens system of the present invention having telecentric incident side is suitable for a projector apparatus using LCD or DMD with prism. The projection zoom lens system of this invention comprises five lens groups having, from the screen side, negative, positive, positive, negative and positive power. In addition to this arrangement, since the lens located closest to the screen is a screen side convex negative meniscus lens, wide-angled and bright zoom lens system can be realized. Further, by designing the distribution of power of the first lens group located closest to the screen, the projection zoom lens provides further improved aberration correction. As the condition for realizing the aforementioned projection zoom lens system, it is preferable that a focal length f1 of the first lens group and a focal length at a wide-angle end fw satisfy the following condition: EQU -1.9<f1/fw<-0.9 (A).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.