| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image reader that can normally correct shading in the case of eliminating a background of an image by using a peak level of read data from an original for a reference voltage of an A/D converter. SOLUTION: An analog image signal is applied to a peak hold amplifier 12b and an A/D converter 13 and a CPU 15 applies a gain G depending on a degree of background elimination instructed via an operation section 14 to the peak hold amplifier 12b via a D/A converter 16. The peak hold amplifier 12b holds the peak of the analog image signal depending on the gain G and a reference voltage Vref in response to the peak is applied to the A/D converter 13.
|
