Zoom assembly having an improved cam barrel
US6108146A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1999 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Mar 31, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Briefly summarized, according to one aspect of the present invention, a zoom assembly having a plurality of different zoom positions and focus adjustment for different object distances in each of the zoom positions includes: (i) a zoom lens having a plurality of lens groups defining an optical axis and (ii) a cam barrel centered about the optical axis. The cam barrel has an inner peripheral surface with at least one cam groove for moving one of the lens groups relative to another one of the lens groups. The cam groove includes: (i) a set of primary zoom sections, each corresponding to one of the zoom positions and having a slope with respect to the optical axis, and (ii) a set of intermediate sections corresponding to transitions from one of the plurality of zoom positions to another one of the plurality of zoom positions. Each of the intermediate sections is has a slope with respect to the optical axis. A subset of the set of the primary zoom sections has slopes of one, common sign and the set of primary zoom sections also includes at least one primary zoom section having a slope of opposite sign from the sign of the slopes of the subset of the set of primary zoom sections. The se…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.