| 摘要 |
PURPOSE:To provide a developing device properly detecting a residual toner inside via a change in electrostatic capacity, without having a problem such as the void of an image. CONSTITUTION:In the developing device arranged in parallel with a developer carrier and having a residual toner detecting means 20 detecting the residual toner by the change in the electrostatic capacity with respect to the developer carrier, the width L2 of the main detecting part 20a of the residual toner detecting means 20 is set narrower than the maximum paper passing width L1 of a transfer material in a paper passing possible width. The presence of the residual toner inside the developing device is detected by the main detecting part 20a, so that even if an image is consecutively formed on a small sized transfer material, the main detecting part 20a can surely detect the lack of the toner inside the developing device, on the paper passing part of the transfer material. |
