| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately set a developing bias value for image-forming at yielding of an image by more surely forming two toner patches within a sensor detection range. <P>SOLUTION: A plurality of toner patches are formed, and the toner adhesive amount of the toner patch is detected by an optical sensor 20. Based on two detected values within the sensor detection range, the development bias value at which the density of a toner image becomes the aimed one is calculated, thereby forming the image. The calculated development bias value is stored in a storage part 63. In the case of forming the image next, the developing bias value for forming the toner patch is calculated, based on the content of the storage part 63. Then, the calculated development bias value is set to a developing means 13 so as to produce the toner patch. When only one or less detected value exists within the sensor detection range, the development bias value is changed further, in a direction where it exists within the sensor detection range so as to form the toner patch again. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
