| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of detecting the entire gradation characteristics of toner density against the input gradation accurately with uniform accuracy. <P>SOLUTION: The image forming apparatus is equipped with a density detection means 21 or the like for optically detecting the density of a toner gradation pattern formed by a toner gradation pattern forming means. The density output of the toner gradation pattern detected by the density detection means is held in a density output holding means 41, and a difference between the density output held by the density output holding means and the density output of the toner gradation pattern detected by the density detection means next is amplified by a differential amplification means 42 and output from the differential amplification means is arithmetically calculated by an arithmetic means 43. Above-mentioned operation is repeated until the service of the toner gradation pattern is finished, and the toner density to the input gradation is detected, then an image forming condition is controlled in accordance with the toner density. <P>COPYRIGHT: (C)2008,JPO&INPIT |
