Film-feeding speed controlling device for sound-cinecamera
US4021104A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 10, 1975 |
| Grant date | May 3, 1977 |
| Priority date | — |
| Expiry date | Nov 10, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B31/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A sound-cinecamera comprising a motor for driving a capstan at uniform velocity, a motor for feeding a film intermittently, a detecting switch for detecting any superfluity or insufficiency of the film feed by said film-feeding motor relative to the film feed by said capstan driving motor and generating corresponding sag-signals, a speed-controlling circuit connected to said film-feeding motor and comprising a tachometer generator for maintaining the stability of the speed of said motor, and a sag-detecting circuit comprising said detecting switch, said sag-detecting circuit being connected to the power source of said film-feeding motor and the output thereof is connected to the controlling means of said speed-controlling circuit through a delay circuit, whereby said sag-signals generated by said detecting switch are transmitted to said controlling means independently of said speed-controlling circuit for regularizing fluctuations in the number of revolution of said film-feeding motor arising from fluctuations in voltage of said power source of the film-feeding motor and fluctuations in load of the film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.