ELECTROSTATIC COPYING MACHINE

摘要

An electrophotographic copier includes an erase device comprising a line of light emitting diodes. Light from the diodes is directed on to a photoconductive imaging element surface (26) through an optical element 111. The entrance end of element 111 comprises a central planar portion 112 with convex upper and lower portions 113. The exit end 114 is convex. The element 111 is effective to direct rays round the central axis 99 up to 20 DEG therefrom towards the outer edges of an erase footprint on the imaging element surface. Less intense rays, from 20 DEG to 40 DEG from axis 99 are directed towards the centre of the footprint.