IMAGE FORMING SYSTEM

摘要

PROBLEM TO BE SOLVED: To eliminate the error of scanning length color registering in all of color-on-color lines. SOLUTION: This image forming system 10 is equipped with a raster output scanner 28 reflecting modulation beams from a plurality of the facets 25 of a rotary polygon 26 and forming a plurality of scanning lines in a lateral direction over the width of a photoconductive belt 12 and a control processor 30 detecting the start of scanning to provide a scanning start(SOS) signal showing the detection. The control processor 30 detects the first SOS signal to the first scanning line of the first image exposing frame I1 on the belt and correlates the first SOS signal of the first image exposing frame with the predetermined facet of the rotary polygon. The control processor 30 further detects the second SOS signal to the first scanning line of the second image exposing frame I2 superimposed on the first image exposing frame on the belt and correlates the second SOS signal with the predetermined facet of the rotary polygon in order to minimize the error of color registering.