Cam grooves for displacing lenses
US4627691A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1984 |
| Grant date | Dec 9, 1986 |
| Priority date | — |
| Expiry date | Dec 17, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B7/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Cam grooves for displacing lenses of an optical system in which lenses or lens groups are displaced in parallel to an optical axis by a lens-operating ring mounted on a support barrel rotatable about the optical axis, but not shifted in parallel to the optical axis. The cam grooves are provided by obtaining the maximum lengths of displacement of vari-focal lenses, among the lengths of displacement of the one or more lenses or one more lens groups, in respective equal-difference minute ranges between respective changed focal lengths, over the entire range of a train of varying focal lengths or photographic distance; and by applying lead angles as slope of cam grooves to the respective maximum lengths of displacement of the lenses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.