| 主权项 |
1. An image forming apparatus comprising:
an image carrier; a charging unit that charges the image carrier with electricity; an exposure unit that exposes the image carrier charged with the electricity by the charging unit to light, and forms an electrostatic latent image on the image carrier; a developing unit that develops the electrostatic latent image formed on the image carrier by the exposure to the light by the exposure unit; and a transfer unit that transfers the developed image on a transfer material, wherein at least one of the charging unit and the developing unit uses an electric field in which alternating current and direct current are superposed, the electric field being generated by a bias power supply, the bias power supply including
a transformer that includes a first winding and a second winding, and outputs an alternating-current output signal from the second winding when the first winding is supplied with current,a switch circuit that includes a switching element, and supplies the first winding of the transformer with the current by switching the switching element in accordance with a received modulation output signal, anda modulation circuit that receives a frequency setting signal of setting a frequency of the alternating-current output signal and a modulation signal, and generates the modulation output signal having a modulated pulse width, and wherein a frequency of the modulation signal and a frequency of the alternating-current output signal are set to cause an interval of stripes with different densities generated on the transfer material by interference between the modulation signal and a harmonic of the alternating-current output signal to be smaller than a predetermined interval. |
