| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of highly accurately detecting paper position in a paper feed direction even when transporting paper at a high speed and capable of realizing an accurate printing-position. <P>SOLUTION: A CIS 204 is disposed in a paper passage area so that readable pixels are arranged perpendicular to the paper transport direction of the image forming apparatus of an electrophotographic system. Parts of readable pixels, (1000 pixels), which corresponds to 1/7 of the total readable pixels, are repeatedly read at short time interval TS, and the position of the leading end of the transported sheet is detected. Based upon the timing of the detected position of the leading end of the sheet, writing on a photoreceptor drum 31 in the sub-scanning direction of a laser emitted to the drum 31 is started after a predetermined length of standby period. In addition, readable pixels (6000 pixels) which corresponds to 6/7 of the total readable pixels are read at a long time intervals TL, and the position of the lateral end of the transported sheet is detected. Based upon the detected position of the lateral end of the paper, an amount of misalignment is calculated to correct a writing position on the paper in the main scanning direction. <P>COPYRIGHT: (C)2003,JPO |
