| 摘要 |
PROBLEM TO BE SOLVED: To consecutively detect the residual amount of developer without hindering the circulation of the developer by causing vibration in a developing container and measuring intensity distribution in a specified frequency area. SOLUTION: By impressing bias between a photoreceptor drum 5 and a developing sleeve 10, force by electric field acts and a developing sleeve 10 is vibrated in the developing container 12 in the case of impressing AC bias or in the case of impressing or cutting off DC bias. This vibration is transmitted to a sensor 13 functioning as a detection means attached to the outer wall of the container 12 through the wall of the container 12 and toner, and converted into an electric signal. The sensor 13 has only to measure the vibration of the wall surface of the container 12, and a piezoelectric element detecting an acoustic signal such as a microphone is used as the sensor 13. It is desirable that the sensor 13 comes into contact with the wall surface of the container 12, but it does not necessarily come into contact therewith. In this detecting method, the residual amount of the toner is obtained based on the movement of a maximum value in the intensity distribution in accordance with vibration frequency. |
