Apparatus for the reduction of image intensity variations in a continuously variable reducing copier

Abstract

Image transferring apparatus for a continuously variable reduction electrostatic copier. A single fixed aperture is employed, adjacent the object plane, to: (1) reduce image intensity variations caused by non-uniform illumination across the object plane; (2) correct for lens cos.sup.4 losses for one mode of reduction; (3) reduce image distortions due to photoconductor drum curvature, particularly at edges; and (4) reduce image illuminance variations due to changes in reduction mode throughout a continuous range of reduction modes. In accordance with preferred embodiments, the foregoing functions are achieved notwithstanding movement in image or optical center line as a function of reduction to compensate for corner referencing objects to be copied. The single fixed aperture provides for adequate reduction in intensity variations, i.e., in an embodiment of the invention, image intensity varies plus or minus 6% from nominal levels across the image plane as reduction mode is varied throughout the range of reduction modes.

Dependencies are inferred from the claim text.