Camera viewfinder
US5229808A · kind A · utility
3Cited by
12References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1992 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Jan 22, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B13/24
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a photographic camera, a neutral density or other light reducing filter in the viewfinder obscures details of a subject viewed through the viewfinder in low light to provide a warning that ambient light is insufficient for a proper daylight exposure. The filter has little or no light reducing capability at a central portion and along a peripheral portion to serve as aiming and framing features, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.