JPS6436261A - Picture data reader - Google Patents

Abstract

PURPOSE:To obtain a picture data with high sharpness by controlling the radiated luminous quantity to an original from a light source in response to a reflected luminous quantity from an original face so as to obtain an optimum picture contrast regardless of the color of original. CONSTITUTION:A read signal of a voltage level in response to the picture density outputted from a linear image sensor 57 is given to a binarization circuit 109 and an A/D converter 116. In this case, only at the reading of a white level picture data, the digital data subject to A/D conversion is given to the control section 101. When the transfer processing by one line by the linear image sensor 57 is finished, the mean value of the entire digital data to be transferred is calculated to obtain the degree of white level of the original (a). The digital data for read density adjustment is outputted to a D/A converter 117. Thus, a threshold level VREF to the binarization circuit 109 and the drive voltage to the LED array 16 are set in the D/A conversion section 117 in response to the degree of white level of the original (a).