| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable efficient scanning of a face to be scanned and formation of an image of high quality. <P>SOLUTION: In an image forming apparatus, the light amount of a light beam radiated varies with the height of the image owing to shading characteristics within an effective scanning width D<SB POS="POST">p</SB>. The shading characteristics in the range from start to end of the scanning differ between the forward and return passages. Correction values which show characteristics different between the forward and return passages are applied to compensate the shading characteristics. The correction values are determined for each predetermined segment of the image height in advance and stored as data for a correction value table in the ROM. When the scanning starts, correction values are read out from the correction value table in the ROM sequentially from the value for a low image height toward the one for a high image height in the order of scanning of the forward passage, and the light amount of the light beam is corrected by the read-out correction values. In the return passage of scanning, correction values are read out from the ROM sequentially in the order reverse to that of the forward passage, or from the correction value for a high image height toward the one for a low image height. <P>COPYRIGHT: (C)2012,JPO&INPIT |
