Apparatus for varying picture size before or after film advance
US4180314A · kind A · utility
Inventors
Key dates
| Filing date | Feb 2, 1978 |
| Grant date | Dec 25, 1979 |
| Priority date | — |
| Expiry date | Feb 2, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B17/28
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The apparatus includes an image field limiting frame and at least one movable mask for the purpose of varying picture size in a line parallel to the direction of film travel and means to control film transport steps proportional to the picture window left open by the mask. It also includes means to directly transport the film in either the forward or reverse direction during picture size adjustment so that the forward edge of the film matches the forward edge of the picture window. In this manner, it is possible to execute picture size changes at anytime, even after operation of the film transport, without waste of film or overlap of sequential pictures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.