| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To adjust the focus of an optical writing device irrespective of a binary image and a multilevel image. <P>SOLUTION: During the work for adjusting the focus, an image G' is formed on a sheet P based on a pattern image G including a plurality of patterns G1-G9 having a different density and information of adjusting value attached to each pattern G1-G9. As the position of an LED 227 shifts from the focus position for a photosensitive drum 222, density of each pattern G1'-G9' of the image G' on the sheet P decreases. From the numerical value attached to a pattern of lowest density among such patterns as the image is not formed on the sheet P, r.p.m. of a screw 22 for adjusting th position of the LED head 227 appropriately is recognized. <P>COPYRIGHT: (C)2004,JPO</p> |
