Charging device and image forming apparatus incorporating same

摘要

A charging device includes a charger and a power supply circuit. The charger is disposed opposing a latent image bearer. The power supply circuit applies to the charger an alternating voltage obtained by superimposing a pulsating voltage on a direct-current voltage. The alternating voltage generates normal discharge from the charger to a surface of the latent image bearer and reverse discharge from the surface of the latent image bearer to the charger. A pulse ON time of a voltage component toward a reverse discharge side relative to a desired surface potential Vde of the latent image bearer is shorter than a pulse ON time of a voltage component toward a normal discharge side relative to the desired surface potential Vde of the latent image bearer.

主权项

1. A charging device, comprising:
a charger configured to contact a latent image bearer; and a power supply circuit configured to apply to the charger an alternating voltage obtained by superimposing a pulsating voltage on a direct-current voltage, wherein
the alternating voltage generates normal discharge from the charger to a surface of the latent image bearer and reverse discharge from the surface of the latent image bearer to the charger,a pulse ON time of a voltage component toward a reverse discharge side relative to a desired surface potential Vde of the latent image bearer is shorter than a pulse ON time of a voltage component toward a normal discharge side relative to the desired surface potential Vde of the latent image bearer, andthe alternating voltage has a waveform in which a falling time of a voltage component generating the normal discharge is 0.282/f[s] or greater, where f represents a frequency of the alternating voltage applied to the charger.