Photographic copier using copying light for measurement purposes - has photoelectric scanner of original document arranged for exposure to three-colour modulated copying light source

摘要

The device incorporates a source of light (5), a copying filter (10) for spectral modulation of the source (5), a mixer (11) for homogenising the intensity of illumination over the document surface on a table (1), and an imaging lens (12). The photographic copy paper is exposed on a lower table (2). The document (F) and copy paper (P) are driven by pairs of rollers (3,4) with a common control computer (31) responsive to signals from a photoelectric scanner (20). This is arranged in the path (16) of light from the source (5) so that the same light is used for measurement and for the exposure of the photographic paper (P). ADVANTAGE - Image quality fluctuations due to use of light sources with different powers for measurement and illumination as well as supply voltage variations are avoided.