| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus of high picture quality by improving precision of recording medium discrimination by measuring distribution unevenness with sufficient precision and applying correction to it, while avoiding wastes of a conveyance distance and a conveyance time for recording medium detection and giving a degree of freedom to a recording medium detection sensor installation place when the recording medium is discriminated without being influenced by light emission distribution unevenness or photodetection sensitivity distribution unevenness of a recording medium detection sensor. <P>SOLUTION: A sensor comprising an imaging sensor comprising an area sensor or line sensor and a light emission source is used to discriminate surface property of the recording medium and the recording medium is imaged while moved to detect light quantity distribution unevenness of the light emission source without being influenced by the surface property of the recording medium, thereby correcting the distribution unevenness. With this constitution, a detection live image is photographed first and then correction data are acquired during recording medium conveyance at normal speed to increase the degree of freedom of the recording medium detection sensor installation position while avoiding wastes of the conveyance time and conveyance distance for the recording medium detection. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
