| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading apparatus which uses a frequency spread clock, reduces an EMI noise level, can make an optical irradiation time from an object constant, can acquire a proper image, and can make an optical irradiation time constant with no influence from the spread clock by matching the modulation period of the spread clock with the optical irradiation time. SOLUTION: The image reading apparatus comprises a photoelectric conversion means for synchronizing with a frequency-spread spread clock signal to convert reflected light from an object into potential and an AD conversion means for converting an analog output from the photoelectric conversion means into a digital signal, and performs image processing for the converted digital value. A light irradiation time of the reflected light from the object to the photoelectric conversion means is matched with a modulation period of a clock signal spread means. COPYRIGHT: (C)2007,JPO&INPIT
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