Compensation for diaphragm control in SLR camera
US4621918A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1981 |
| Grant date | Nov 11, 1986 |
| Priority date | — |
| Expiry date | Feb 19, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B19/12
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera comprises a camera body and first and second lens assemblies interchangeably insertable into the camera body. Each lens assembly has a displaceable actuator, a diaphragm adjustable between a maximum aperture and a minimum aperture value responsive to displacement of the actuator and a transducer for generating a first signal representative of the displacement of the actuator. In the camera body, there is generated a second signal representative of the desired aperture value of the diaphragm for correct exposure. The first and second signals are compared and the actuator of the lens assembly inserted in the camera body is displaced responsive to the comparison to stop down the diaphragm from the maximum aperture value toward the minimum aperture value until the first and second signals assume a predetermined relationship. The diaphragm of the second lens assembly is maintained at the maximum aperture value during an initial portion of the displacement of the actuator. Preferably, the initial portion of the actuator displacement is sufficient to compensate for the deviation in aperture value, maximum aperture value, and minimum aperture between the first and second lens asse…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.