| 摘要 |
PURPOSE:To attain accurate, stable realization of half tone even if shading distortion becomes big by correcting peak perception of picture signals on a reference surface and by correcting read picture signals based on the correct signals. CONSTITUTION:A light picture for a line formed on a photoelectric conversion array (CCD)6 is converted into charged for every pixel to be outputted as an analog vidoe signal (b) in order. This signal has its DC offset portion removed in a picture background controller (VBC circuit) 8 and original background removal video signals are prepared after a peak voltage out of one line is specified in the reference voltage. A fixed distortion correct signal generator 9 synchronizes the first adverse distortion signal (d) adjusted and fixed beforehand to picture signals for one line to output the signal and multiplies this signal with an output of VBC8 by a multiplier 10 to prepare the first distortion correct picture signal (e). The device addes this signal to a peak hold circuit 11, detects peak values, and A/D conversion of the first distortion correct picture signal (e) with this signal as a reference comparison voltage allows acquisition of a shading corrected digital picture signals.
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