| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image reading device provided with light sources at different positions in a main scanning direction that performs shading correction with high accuracy even when the light amounts of the light sources fluctuate. <P>SOLUTION: A reference illuminance distribution curve f1 and a reference illuminance distribution curve f2 are respectively prestored in a shading correction memory 35. Prior to shading correction, light is emitted from a light emission unit 25, and white reference plates 28R and 28L are read. Since an increase/decrease in the intensity of light emitted from a LED equally affects each position in a main scanning direction, if reading results of the white reference plates 28R and 28L are compared with the reference illuminance distribution curve f1 and the reference illuminance distribution curve f2, it can be specified what larger or smaller value actual illuminance distribution curves have than the reference illuminance distribution curves f1 and f2. If the illuminance distribution curves are added to each other, a composite illuminance distribution curve F of a LED 251R and a LED 251L is specified, and shading correction is performed based thereon. <P>COPYRIGHT: (C)2012,JPO&INPIT |
