Film cassette
US4875637A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 12, 1989 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | Jan 12, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/266
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A film cassette is disclosed wherein a film spool having a filmstrip coiled about it is rotatable in an unwinding direction to automatically advance a leader portion of the filmstrip along a film passage slit to the outside of the cassette shell, preparatory to initial film exposure, and is rotatable in a rewinding direction to wind the leader portion to the inside of the shell, following complete film exposure, at least until a leading end of the leader portion is positioned inward of the slit. The cassette shell includes first integral guide means, protruding from an inner circumferential wall of the shell to a predetermined location proximate the film passage slit and an outermost convolution of the filmstrip, for guiding the leading end of the leader portion between the inner wall and the outermost convolution to prevent the leading end from entering the slit. Second integral guide means is formed at the inner wall of the cassette shell for guiding the leading end of the leader portion directly to the first integral guide means in response to rotation of the film spool in the unwinding direction anytime after the leading end has been wound inward of the film passage slit. Thus,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.