Browse Prior Art Database

Original Publication Date: 1978-Aug-31
Included in the Prior Art Database: 2004-Mar-31

Publishing Venue

Xerox Disclosure Journal


In a color electrophotographic printing machine, color slides may be reproduced, Hereinbefore, color correction was achieved by employing color filters and neutral density filters during the imaging cycle. In operation, the printing machine forms successive, single color light images by inter-posing successive color filters into the optical light path. These single color light images require color correction due to the characteristics of the slide. This may be achieved by interposing a second color correction filter into the optical light path during the formation of one of the single color light images. Alternatively, color correction may be obtained by cycling an aperture in front of the slide projector lens. A powered aperture may be positioned in the optical light path to provide varying amounts of light depending upon an operator adjustable setting or automatically in response to the amount of light detected by a light detector. A system of this type regulates the amount of light by adjusting the aperture and does not introduce image degradations inherent in the use of neutral density filters. Thus, the overall exposure balance can be optimized.