Patent ID: 6195180
Filing Date: 2001-02-27
Classification: H04N

Abstract:
An image forming apparatus comprising:an illuminating means for illuminating a draft image;a photoelectric converting means for receiving reflected light from a draft image obtained by illuminating the draft image and photoelectrically converting the reflected light;an amplifying means for amplifying an output signal from said photoelectric converting means;a digital converting means for converting an analog signal from said amplifying means to a digital signal;a shading correcting means for executing shading correcting to said digital signal; anda scanner control means for providing controls so that first white reference data after power turn ON is fetched by said shading correcting means in a stable region for said illuminating means, said white reference data is used when an image is formed first time, and the shading-corrected white data is fetched for a second sheet of copy in continuous copying operation each time one image is formed; wherein, when fetching white reference data in said stable region or each time one image is formed, if any error is generated in said illuminating means, the white reference data is fetched just before image read is executed.