Zoom lens system and imaging device
US7535657B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 15, 2006 |
| Grant date | May 19, 2009 |
| Priority date | — |
| Expiry date | Apr 30, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/1461
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is provided a zoom lens system including at least a first lens group GR1 having a positive refractive power, a second lens group GR2 having a negative refractive power, a third lens group GR3 having a positive refractive power, a fourth lens group GR4 having a negative refractive power, a fifth lens group GR5 having a positive refractive power, and a sixth lens group GR6 having a negative refractive power, arranged sequentially from the object side. Zoom ratio is varied by changing the distance between the adjacent lens groups. The distance, taken as DW(i-j), between the i- and j-th lens groups at the wide angle end during at-infinity imaging and that, taken as DT(i-j), between the i- and j-th lens groups at the telephoto end during at-infinity imaging meet the following conditions (1), (2), (3), (4) and (5)DW(1-2)<DT(1-2) (1)DW(2-3)>DT(2-3) (2)DW(3-4)>DT(3-4) (3)DW(4-5)<DT(4-5) (4)DW(5-6)<DT(5-6) (5)and focusing is made by moving the fourth lens group GR4 axially of the lenses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.