Motion picture camera with film marking means
US4339180A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1981 |
| Grant date | Jul 13, 1982 |
| Priority date | — |
| Expiry date | Apr 9, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/246
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A motion picture camera has a rotary shutter driven by a DC motor which is supplied from a battery. The camera also has an arrangement for making light markings for identification purposes on the film in the camera. This arrangement includes a light-emitting diode and a capacitor which is charged by the battery and discharges across the diode. The electrical circuitry is such that the capacitor is connected to the battery only when the motor is disconnected therefrom; inversely, when the motor is to be connected to the battery in order to operate the shutter (and also to advance the film), the capacitor is first disconnected from the battery before the motor is connected to it and then discharges across the diode. The circuit also suppresses afterglowing of the diode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.