Film cassette having film-exposure status indicator
US4978985A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1989 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Jul 24, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/266
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A film cassette is disclosed wherein a filmstrip is advanced to the outside of a light-tight cassette shell in order to expose successive imaging areas of the filmstrip and can be returned to the inside of the cassette shell before all of the imaging areas have been exposed or after the filmstrip has been substantially completely exposed. According to the invention, a film-exposure status indicator is supported on the cassette shell for movement relative to the shell from a normal first position to successive second and third positions for providing respective visible indications that the filmstrip is generally unexposed, the filmstrip has been returned to the inside of the shell before all of its imaging areas have been exposed, and the filmstrip is substantially completely exposed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.