Variable power optical system and image pickup apparatus
US7375900B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2006 |
| Grant date | May 20, 2008 |
| Priority date | — |
| Expiry date | Aug 31, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144507
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An object of the present invention is to provide a compact size variable power optical system capable of producing a high quality image. The variable power optical system comprises a plurality of lens groups for forming an optical image on an image surface of an image pickup device. Among the plurality of lens groups, the first lens group, which is disposed in the most subject side has a negative refraction power, includes at least a lens having a negative refraction power and a reflective optical element for bending the optical axis. When varying the variable power, the axial distance between the first lens group and the image surface varies. When Nd denotes the refraction power of the lens having negative refraction power at d-line, the refraction power satisfies the conditional formula Nd>1.81.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.