Vibration and noise induced by electrostatic force on a contact charger roller of electrophotography

Electromechanical dynamics of a contact charging subsystem of electrophotography was investigated to clarify fundamental characteristics of vibration and noise induced by electrostatic force on a contact charger roller. The following conclusions were deduced from the modeling and experiments. (1) Alternative electrostatic force is yielded in the vicinity of the nip between the charger roller and a photoreceptor drum, because ac voltage applied between the roller and the drum induces a high alternative electrostatic field in the vicinity of the nip. Noise is mainly caused by the resonance vibration of a cartridge cover, which contains the roller and the photoreceptor drum, but noise due to gas discharge and pipe resonance of the drum are minor. (2) The frequency of the electrostatic force is twice that of the ac applied voltage. The magnitude of the electrostatic force is large under high ac applied voltage operation. Therefore, resonance frequency of the cartridge cover should be designed to be apart from twice of the ac voltage frequency and it is preferable to set the ac voltage as low as possible.