| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably maintain images of high quality regardless of passage of time or environmental variances by efficiently detecting the variance in characteristic values of a two-component developer including the degree of deterioration of the developer and optimizing a control value in accordance with the variance of the developer. <P>SOLUTION: An image forming apparatus includes a photoreceptor drum 100, a developing unit 300 which stores a developer G including toner and carrier and develops an electrostatic latent image on the surface of the photoreceptor drum 100 by the toner, and a permeability sensor 350 for detecting toner concentration of the developer G in the developing unit 300, and can execute a plurality of image output modes (a standard linear speed and linear speeds 1 and 2 for thick paper mode). The image forming apparatus is provided with a control part 37 which detects the toner concentration in at least one image output mode and compares an output value from the permeability sensor 350 at the time of an environmental variance with a control reference value, obtains a difference from the comparison result, and updates an image density control parameter for determining the amount a toner T supplied to the developing unit 300. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
