Zoom optical system and image pickup apparatus
US7193786B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 2006 |
| Grant date | Mar 20, 2007 |
| Priority date | — |
| Expiry date | May 18, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/144511
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom optical system according to the present invention is provided with, in order from an object side thereof: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; and a fourth lens group having a positive refractive power. The zoom optical system moves at least the second lens group and the third lens group for zooming operation from a wide-angle end to a telephoto end. The zoom optical system moves the third lens group for a focusing operation. The first lens group is provided with, in order from the object side of the zoom optical system, a meniscus lens having a negative refractive power whose concave surface faces an image side of the zoom optical system, a reflective optical element, and at least one lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.