| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress variations in reading values of a white roller, and to raise precision of shading correction without increasing the number of blocks when shading correction data is generated based on white reference data obtained by reading the white roller. Ž<P>SOLUTION: A CPU 138 of an ADF control part 133 which functions as a shading data generation means receives a detection signal of a white roller rotation position detection sensor 170 and a line synchronization signal from a CIS unit 135 by a CPU interruption input. Upon receiving the detection signal of the sensor 170, the white reference data read by the CIS 135 is fetched in one rotation period of the white roller 137 by an XSLEAD signal indicating a fetching range. Timings of roller division areas A, B, C, D are counted for the number of times set as count values from the detection signal of the sensor 170, an XSSCAN signal indicating a reading range in timing of each area is generated, the white reference data is fetched, and shading data is generated by average value and peak value processing. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
