Motion-picture camera
US4150884A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 1977 |
| Grant date | Apr 24, 1979 |
| Priority date | — |
| Expiry date | Apr 27, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B31/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A motion-picture camera optionally loadable with silent-film and sound-film cassettes has a reversible film-feeding mechanism including a reciprocable transport claw and a catch engageable with a takeup reel through a coupling within the cassette including a rewind stop. A spring-loaded stud close to the catch enables the rewind stop to be disengaged in a sound-film camera whereby the film can be transported backward for trick cinematography such as superposition of scenes. During the first run of such a double exposure, a step-down transmission can be activated to slow the windup of the film within its cassette if the latter is of the silent-film type, thereby creating a reserve length of film that can be rewound on the supply reel. In the presence of a sound-film cassette, as determined by a sensor which could be the aforementioned stud, this stepdown transmission is disabled inasmuch as the disengagement of the rewind stop allows the film to be reverse-driven without such reserve length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.