INPUT DEVICE FOR CHARACTER PRINTING QUALITY MANAGEMENT DEVICE

摘要

PURPOSE:To more finely decompose character picture elements of high density into gradations and to give a uniform gradation to paper white picture elements of low density by providing a diode between an operational amplifier and an A/D converter. CONSTITUTION:A diode 44 is provided between an operational amplifier 42 and an A/D converter 43. Consequently, the level of the output signal is restricted to a maximum values of the input level range of the AD converter 43 by the diode 44 if the level of the electric signal which is photoelectrically converted by the photodetector of an input part 41 and is amplified with a high amplification factor by the operational amplifier 42 is higher than the input level range of the A/D converter 43. Thus, character picture elements of high density (low signal level) are more finely decomposed into gradations and paper white picture elements are not subjected to gradation discrimination and are uniformized (set to one gradation).