Method and apparatus for regulation of the amount of printing light in photographic enlarging or printing devices
US5365306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1993 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | Oct 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/73
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
According to a process for regulating the amount of copying light in a closed control loop of a photographic color photocopier equipped with color filters, the copying light influenced by the color filters is selectively measured in the primary colors, red, green and blue. A deviation resulting from the comparison of the real values with predeterminable set values is subdivided into a color deviation and a brightness deviation. The color deviation is compensated by regulating the color filters, whereas the brightness deviation is converted into a correction factor for the lighting time, so that for each primary color the product of the light intensity real value by the effective lighting time is constant and identical to the product of the light intensity set value by the lighting time set value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.