| 摘要 |
PROBLEM TO BE SOLVED: To suitably set environmental conditions without spoiling economical efficiency.SOLUTION: Solid patches having toner stuck uniformly in predetermined regions and non-solid patches having toner sticking parts and non-sticking parts mixedly in predetermined regions are both formed on a photoreceptor drum with a plurality of different developing bias voltages, respectively, and an IDC sensor 41Y detect toner amounts of the respective patches. A patch selection part 42d selects a patch for determining development characteristics between a solid patch and a non-solid patch formed with the same developing bias voltage based upon a preset effective range of an output voltage of the IDC sensor 41Y. A toner sticking amount calculation part 42e calculates the toner sticking amount of the selected patch from an output voltage of the patch, and a development characteristics determination part 42g determines development characteristics based upon the relation between the calculated toner sticking amount and developing bias voltage. |
