Zoom optical system
US6433940B1 · kind B1 · utility
4Cited by
10References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2001 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Apr 24, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B15/143103
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A zoom optical system comprising, in order from the object side, a first lens unit having positive refractive power, a second lens unit having positive refractive power and a third lens unit having negative refractive power, and configured to change a magnification from a wide position to a tele position by moving the lens units on the object side so as to widen an airspace between the first lens unit and the second lens unit and narrow an airspace between the second lens unit and the third lens unit, thereby having a short total length at the tele position in particular and favorable optical performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.