Diagnosis system for an electrostatic recording apparatus

摘要

A potential of a reference potential measure section (6) is set to the desired value of potential for a drum surface (charge receptive surface (29)) such that the potential of the reference potential measure section (6) and the potential of the charge receptive surface are detected by a surface potential detecting device (7) during a rotation of the drum to obtain the difference between the values of the measured potentials, so that operation of a charger (8) is controlled in the way that the difference is reduced to zero, thereby changing the potential of the charge receptive surface (29). This enables the surface potential to be precisely controlled without necessiting a frequent calibration of the surface potential detecting device (7). In addition, the potential of the reference potential measure section (6) is appropriately set depending on a developing condition so as to prevent toner (from being fixed thereonto), when the reference portion passes at a developing unit (10).