| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of improving image quality of a read image while inexpensively preventing discharge of electromagnetic energy. SOLUTION: The image reading apparatus 1 is provided with a CCD image sensor 8 for photoelectrically converting a reflection light from a light source at an operation clock generated by a timing generator 23 on the basis of a reference clock generated by a PLL circuit 26, and allows an ADC 22 to perform an operation of converting an output signal from the CCD image sensor 8 into a digital signal. In this case, the apparatus 1 allows the PLL circuit 26 to change the frequency division ratio of a first programmable frequency divider, according to the variable width of the frequency division ratio, to change the frequency of a signal to be inputted into a phase frequency detector, and to change a changing time of a VCO when a frequency division ratio of a second programmable frequency divider is changed stepwise. COPYRIGHT: (C)2005,JPO&NCIPI
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