Objective system with zoom lens for photographic apparatus
US3969018A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1974 |
| Grant date | Jul 13, 1976 |
| Priority date | — |
| Expiry date | Sep 12, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B19/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An objective system for motion picture cameras wherein a zoom lens is installed in a barrel and the barrel is surrounded by two ring-shaped selectors. The rear selector is rotatable to change the focal length of the lens by moving the optical elements of the rear group of optical elements of the lens with and relative to each other in the direction of the optical axis. The front selector is rotatable within a first angle to focus the image of a subject which is located at a distance of 5 ft. or more from the barrel, and within a second angle to focus the image of a subject prior to the making of close-up shots. The front selector moves the optical elements of the front group of optical elements of the lens during rotation within the first angle and the optical elements of the second group during rotation within the second angle. The focussing for close-up shots can be made after the focal length of the lens is reduced to a minimum value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.