| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image reading device having a level correction function of a sensor signal. <P>SOLUTION: The image reading device 10 according to the present invention includes an analogue circuit part (140-144) which samples an electric signal input from a photoelectric conversion element, and outputs it after amplifying with an amplifier, and a converter 146 which converts the signal input from the analogue circuit part to a digital signal. The image reading device 10 further includes gain adjustment control means 160 which adjusts the gain of an amplifier 142 so that a peak reference level for an off-set level of the digital signal output from the converter 146 converges within a target range, timing specifying means 120 which, at the time of gain adjustment, outputs the timing signal that specifies an off-set correction period of the duration different from at the time of standby or image reading, and off-set correction means 148 which, upon receiving an input of the timing signal, applies an analogue correction amount so that the off-set level of the digital signal converges to a target value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
