Zoom assembly having zoom lens with plurality of lens group that move together or differentially for zooming and focusing
US6151171A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1999 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Mar 31, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/102
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
It is an object of the present invention to provide a very compact zoom assembly with a minimum number of parts. Another object of this invention is to provide a zoom assembly which does not require guide rods and utilizes with only one motor for both zooming and focusing. Briefly summarized, according to one aspect of the present invention, a zoom assembly includes a zoom lens defining an optical axis. This zoom lens is capable of operating in a plurality of different zoom positions and of focus adjustment for different object distances in each of the zoom positions. The zoom positions are (i) two extreme zoom positions (a wide angle position and a telephoto position), and (ii) a plurality of intermediate zoom positions. The zoom lens includes at least a first movable lens group and a second movable lens group. These first and second lens group are separated from one another by a variable distance. The first and second movable lens groups move (i) together, at the same speed and direction in order to focus at one of the extreme zoom positions and at an adjacent intermediate zoom position; and (ii) differentially in order to focus at another one of the extreme zoom positions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.