IMAGE READER, IMAGE PROCESSOR, IMAGE FORMING DEVICE AND COPYING DEVICE

摘要

PROBLEM TO BE SOLVED: To shorten adjusting time of an image signal amplification gain for a plurality of reading periods and to improve reliability. SOLUTION: An image reader having a plurality of the reading periods is provided with a gain setting means for setting a first amplification gain of image signal amplification for a first period so that image data of standard level reading at the first period (color mode) becomes a level of a setting range and setting a second amplification gain for a second period (monochrome mode) based on the first amplification gain and a means for verifying whether image data of standard level reading using the second amplification gain at the second period is in the level of the setting range or not. The verification means adjusts the second amplification gain so that data is within the setting range when it is out of the setting range. When an image reading instruction is received, the gain setting means sets the first or second amplification gain in an amplification circuit of a variable gain in accordance with color or monochrome reading designation. COPYRIGHT: (C)2006,JPO&NCIPI