| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal processing system which is capable of restraining lateral stripe-like noises from occurring even at a low ratio of signal to noise and feeding stable image data, and to provide an image forming device using the same. SOLUTION: The signal processing system of the image forming device subjects photoelectrically-converted signals outputted from a linear image sensor to AC coupling, DC level reproduction, sample holding 1, variable gain amplification 2, and analog/digital conversion 3, compares black level data subjected to the analog/digital conversion 3 with a black level target value, and performs a black level feedback that superimposes offset signals on an analog processing component which is not subjected to analog/digital conversion yet so as to make a difference between the black level data and the black level target value zero. The above DC level reproduction, the black level feedback, or both of them are changed in control in each state wherein the image forming device is kept on standby, a reference is read, or a manuscript is read. COPYRIGHT: (C)2006,JPO&NCIPI
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