| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable the size detection of a document to be accurately performed in a minimum time. <P>SOLUTION: An image reading device has a light source irradiating a document, an opto/electric conversion element receiving light reflected by a document and converting the light into an electric signal, and a signal processing circuit performing signal processing to an output of the opto/electric conversion element to be outputted. Further, the device is provided with a light source control means for making the light source "ON" before completing the activation of the signal processing circuit, a document size detection means for detecting a size of a document based on an output of the opto/electric conversion element at that time, and a light source lighting detection means which can detect a light source lighting state. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
