Zoom lens barrel for macrophotographing
US4346967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1980 |
| Grant date | Aug 31, 1982 |
| Priority date | — |
| Expiry date | Jun 17, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/105
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A two-lens group type zoom lens having a high magnification factor and simple structure yet having smooth transfer between normal zooming and macrophotographing positions. The positions of the first and second lens groups are defined by a respective zooming cam slot and lead slot formed in a cam sleeve. For focusing, a focusing operation sleeve is rotated to determine the position of the first lens group along the optical axis. A linear slot is provided extending from a telephoto end position of the zooming cam slot parallel to the optical axis direction of the lens. Additional circumferential slots may be provided extending from the zooming cam slot and lead slot and a click-stop mechanism utilized to stop the zooming operation sleeve at the telephoto end position and macrophotographing range position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.