Measuring device for selecting the filter in photographic enlarging or copying apparatuses
US4678319A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 24, 1986 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Feb 24, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/735
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A measuring device for selecting the color composition of the copying light when copying a film frame original in a photographic enlarging or copying apparatus has two groups of red-, green- and blue-sensitized measuring cells of which one group receives measuring light entering into the film frame original and the other group receives measuring light coming out of the film frame original. The measuring signals of each color from both groups of measuring cells are combined with one another and from the combination signals, ratios are formed of the color parts with respect to one another. As a result of the combination of measuring signals of the copying light before and after the flow through the film frame original to be copied, an undercompensation of the color deviation of individual originals with respect to a reference original is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.