Apparatus for making test exposures on marginal portions of photographic films or the like
US4260245A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 22, 1979 |
| Grant date | Apr 7, 1981 |
| Priority date | — |
| Expiry date | Jan 22, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/243
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Apparatus for exposing a gray sample onto the unexposed perforated marginal portion of a web of photographic film has a drum over which the web is trained while moving lengthwise, and a device which monitors the web and generates a signal on detection of successive or selected perforations. Such signals are delayed for an interval of time which insures that a field which is to be provided with a test exposure and is located at a predetermined distance from the perforation which has caused the generation of a signal is located in the range of an imaging system operating with a flash unit to expose the sample onto the aforementioned field. The delay can be effected by a computer which receives the aforementioned signals and which further receives signals denoting incremental advances of the web through distances of selected unit length. The test exposures are used in the copying machine for comparison with a color chart to insure proper selection of intervals during which the film frames are exposed to light of various colors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.