INTERCHANGEABLE LENS ADAPTABLE TO A CAMERA OR PHOTOGRAPHIC SHUTTER, WITH BUILT-IN SECTOR SYSTEM
US3935581A · kind A · utility
Inventor
Key dates
| Filing date | Feb 9, 1973 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Feb 9, 1993 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B17/14
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is related to a sector system capable of providing lens elements of different aperture held in different support means. Exposure of a film through the lens is determined by the opening and closing of a sector plate system and the time and extent of opening and closing is appropriately controlled by changing the position of the drive means relative to the lens forming means. In this way the sector plates for exposing the camera film to light passing through the lens travel different distances which depend upon the light aperture required in order that the exposure shall be consistent with the lens aperture and its speed and at least approximately equal to the overlap and overswing phases of the sector system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.