| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manuscript reading device and an image forming apparatus with improved convenience in usage at low cost for detecting a manuscript size by a simpler constitution compared with a conventional one. <P>SOLUTION: The image reading device includes a manuscript conveyance means and a manuscript reading means for scanning a manuscript in a main scanning direction sequentially while the manuscript is carried in a sub-scanning direction and changing it to reading data. Detecting signal strings obtained sequentially from one image reading element which is arranged in an extending way in the main scanning direction at the manuscript reading unit are compared with each other and the manuscript size is detected on the basis of a feature difference of the detected signal corresponding to the manuscript portion and the manuscript exterior portion. <P>COPYRIGHT: (C)2007,JPO&INPIT |
