Motion-picture camera with diaphragm control system having fadeover capability
US4106864A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 25, 1977 |
| Grant date | Aug 15, 1978 |
| Priority date | — |
| Expiry date | Aug 25, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B19/26
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The user selects a fadeover duration by selecting the number of pulses in a reference pulse packet registered by a reference counter. During film transport in either direction, a frame-pulse counter counts up a number of frame pulses equal to the number of pulses in the reference pulse packet, and then performs another frame-pulse counting cycle. Each frame-pulse counting cycle advances a program-step counter. Logic circuitry is responsive to the count on the program-step counter and, during the successive program steps, causes fade-out, film-rewind, and fade-in operations to be performed. The adjusting motor for the diaphragm operates at a speed inversely related to the number of pulses in the reference pulse packet, and the amount by which the adjusting motor changes the diaphragm setting during each frame-pulse counting cycle is always the same.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.