| 摘要 |
<P>PROBLEM TO BE SOLVED: To form a uniform toner layer on a developing roller with low energy without spoiling accumulation of charged particles having a reverse polarity in a developer in a developing tank when imparting stable toner electrification property to carrier over a long term. <P>SOLUTION: The developer includes a toner and the reverse-polarity particles. The developing device has a first conveying member, and a second conveying member opposed to a photoreceptor. An electric field forming means forms the first electric field between the first conveying member and the second conveying member so as to move the toner in the developer on the first conveying member to the second conveying member and also separate a part of the reverse-polarity particles from the toner and collect it in the developer, and forms the second electric field between the second conveying member and the photoreceptor so as to move the toner on the second conveying member to an electrostatic latent image on the photoreceptor. The first electric field comprises only DC electric field, and the second electric field is composed by superposing the DC electric field and oscillating electric field. The oscillating electric field has voltage waveform equipped with a blank part where the application of pulse voltage is stopped only in a predetermined period. <P>COPYRIGHT: (C)2008,JPO&INPIT |
