Exposure information storage device for a photographic camera
US4363540A · kind A · utility
3Cited by
5References
8Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Jan 26, 1977 |
| Grant date | Dec 14, 1982 |
| Priority date | — |
| Expiry date | Jan 26, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B7/093
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A storage device for storing photographic exposure information employs a closed-loop analog-to-digital (A-D) converter circuit includes a counter and a digital-to-analog (D-A) converter. The influence of erroneous signals which are created at the output of the D-A converter when the exposure information is stored in the counter is eliminated. The D-A converter circuit employs a ladder network of coarse accuracy. The stored exposure value, however, is highly accurate because of the closed-loop nature of the A-D converter circuit. Means responsive to the stored value for operating the exposure system of the camera are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.