Taking lens apparatus
US6404561B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 2000 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | Oct 24, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1461
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Taking lens apparatus has zoom lens system, focusing light from object to form optical image, and image-sensing device, converting optical image into electric signal. Lens system has: first lens unit having a positive optical power, composed of three or fewer lens elements including at least one negative lens element and at least one positive lens element; second lens unit having negative optical power and moving to be on image-plane side of its position in shortest-focal-length condition; and one or more succeeding lens units. This system varies magnification by varying distances between lens units, and fulfills 0.92<FW/IH<1.85, ND<1.53, and VD>78, where FW represents focal length of lens system in shortest-focal-length condition, IH represents maximum image height, ND represents refractive index for d line of positive lens element included in first lens unit, and VD represents Abbe number for d line of same positive lens element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.