Camera having means for correcting shutter time by measuring the actual exposure time
US5532785A · kind A · utility
12Cited by
3References
32Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 10, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A shutter operation detection device comprising a light emitting diode and a photo transistor is provided in proximity to the shutter curtains to measure the actual exposure time. The difference between the control exposure time, which is based upon the brightness value of the subject to be photographed and the film sensitivity, and the actual exposure time is determined. The control exposure time for the next session is corrected based upon this difference. The amount of correction for increasing the control exposure time is differentiated from the amount correction for decreasing the control exposure time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.