| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an image which has asatisfactory graininess for a long period of time and is free from surface stain without causing toner splashing,. <P>SOLUTION: With the predetermined timing of detection, a developing device is driven for a given length of time and a patch image for measurement is developed. Its image density is detected and also toner concentration in the developing device is detected by a toner concentration sensor. Based on the image density and toner concentration detected, development γ is calculated. It is compared with that of known initial developer. When a difference between them is large, carrier or developer is supplied. Thus, even when images are repeatedly formed for a long time, carrier whose ability to charge toner has been degraded is discharged out of the developing device and fresh carrier is supplied to prevent advancement of deterioration of carrier in the developing device. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
