PRINTING POSITION DETECTOR OF ELECTROPHOTOGRAPHIC APPARATUS, AND METHOD FOR CORRECTING PRINTING POSITION OF ELECTROPHOTOGRAPHIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To correct a printing position deviation due to skew of an optical system, etc., by effectively measuring plotting data by a position-detecting means in an electrophotographic apparatus having a plurality of light sources. SOLUTION: A reflecting light of each of C, M, Y and B colors is generated by illumination of a monochromatic detection light source 43, and a focus is imaged to a CCD element 44 having filters corresponding to each of C, M, Y and B colors. A CCD scan sensor 45 and a SELFOC lens array 46 are scanned only once over all segments of a measurement area of a measurement image 42 in a horizontal scanning direction. In other words, the CCD scan sensor 45 and the SELFOC lens array 46 are scanned once from the front side to the rear side of the paper in the drawing. As a result, the measurement image of each of C, M, Y and B colors is measured at a time by one passing a position detection unit. A printing position can be corrected by means not shown on the basis of measured data of the printing position of each color.