| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that accurately adjusts writing timing of each light emission part by exactly recognizing the density of evaluation patterns. <P>SOLUTION: The image forming apparatus comprises: an exposure control unit which outputs evaluation patterns PT1-PT10 having different writing timings and comparison patterns PTcom around each of the patterns; a density correction unit which makes a density sensor measure the density of each evaluation pattern to calculate the density of the evaluation pattern PT based on the result of measurement, similarly makes the density sensor measure the density of the comparison patterns PTcom outputted in the vicinity of each evaluation pattern to calculate an average and specifies the value determined by subtracting the average density of the comparison patterns PTcom from the density of the evaluation pattern as the correction density for the evaluation pattern; and a writing timing determination unit which extracts the evaluation pattern having the lowest density or the highest density of the correction density among the evaluation patterns and determines the writing timing when drawing the extracted evaluation pattern as a writing timing of a laser diode. <P>COPYRIGHT: (C)2012,JPO&INPIT |
