| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect toner residual amount without influencing image density. SOLUTION: Developing bias is outputted in specified timing (1) from starting recording operation. At such a time, the duty of AC bias is set to 50% being a specified value at the time of detecting the toner residual amount without depending on the setting of the image density. By outputting the developing bias, the detected value of the toner residual amount is changed according to the toner residual amount in a toner container and is saturated in timing (2). Furthermore, the duty of the AC bias is set to a value (duty 70%) in accordance with the setting of the image density in timing (3). Thereafter, the leading edge of first recording paper reaches a cartridge part, and developing processing is performed with the specified image density. Processing for detecting the toner residual amount at the time of starting the recording operation is performed between the timing (2) and the timing (3). |
