CONTROLLING METHOD FOR PRINTING PROCESS IN PRINTING DEVICE

PROBLEM TO BE SOLVED: To utilize one optical sensor for further multiple functions, by an electrophotographic device, required to measure large amount of processing parameters by adopting a sensor. SOLUTION: This device is letting an optical sensor 100 to detect toner on a substrate, by letting an image formed on a substrate 141, and returning the substrate to a transfer station by both sides copying method (namely, by letting the substrate reversed). Therefore, the device is made possible to measure one or more optical parameter such as register color, detecting the color/color density, and quality of transferring and fix/processing by applying the output the optical sensor 100.