Developing apparatus including means for collecting used developing agent

A developing apparatus for developing a latent image on an image carrier, using a one-component developing agent, comprising:

• a developing/cleaning roller, in contact with the image carrier, for supplying the developing agent to the latent image on the image carrier so as to develop the latent image, while simultaneously removing the developing agent remaining on the image carrier;
• storing means for storing the developing agent;
• a transfer roller, in contact with the developing/cleaning roller, for transferring the developing agent from the storing means to the developing/cleaning roller and for collecting the developing agent remaining on the developing/cleaning roller;
• voltage applying means for applying a higher bias voltage to the transfer roller than to the developing/cleaning roller by 50-200 V at a development time, thereby to permit the developing/cleaning roller to receive a developing agent, and applying a lower bias voltage to the transfer roller than to the developing/cleaning roller by 0-100 V at a non-development time, thereby to permit the transfer roller to collect the developing agent remaining on the developing/cleaning roller;
• and
• removing means for removing the developing agent, which has been recovered from the developing/cleaning roller to the transfer roller, from the transfer roller, and returning the removed developing agent to the storing means.