Patent ID: 6055071
Filing Date: 2000-04-25
Classification: H04N

Abstract:
An image forming apparatus comprising:a reading means for optically scanning and reading a document image;a means for converting an input image signal from said reading means to an output image signal by referring an image signal conversion table, and outputting the converted signal;a writing means for writing image information on an image carrier according to said output image signal;a means for transfer the image on said image carrier onto a transfer member to form the image;a means for generating a plurality of gradation patterns; anda means for updating and selecting an image signal conversion table according to read values obtained by reading the gradation patterns generated and transferred by said generating means onto transfer paper with said reading means for reading an image; wherein a read signal for said gradation patterns comprises a plurality of signals each having different spectral sensitivity, and a memory for storing therein calibration factors for said plurality of signals each having different spectral sensitivity is provided to correct the read signals for said gradation patterns according to said calibration factor from said memory.