| abstract |
An image forming apparatus of the present invention comprises: a latent image carrier; and a developing means for charging a toner into a negative polarity by triboelectric charging, for converting an electrostatic latent image on said latent image carrier to a visible image with said toner and is characterized in that (1) the work function (Φ t ) of said toner is set to be larger than the work function (Φ OPC ) of the surface of said latent image carrier, or (2) in case that the apparatus is of a type transferring the visible image to an intermediate transfer medium, the apparatus is characterized in that the work function (Φ t ) of said toner is set to be larger than the work function (Φ TM ) of the surface of said intermediate transfer medium or (3) the work function (Φ OPC ) of the surface of said latent image carrier, the work function (Φ t ) of said toner, and the work function (Φ TM ) of the surface of said intermediate transfer medium are set to satisfy a relation Φ t >Φ OPC >Φ TM . According to this apparatus, during development, the amount of fog can be reduced and the transfer efficiency can be improved. Since the transfer efficiency from the latent image carrier to the intermediate transfer medium is improved, thereby reducing the consumption of the toner, reducing the cleaning toner amount. Therefore, reduction in running cost and reduction in size of the cleaning toner container can be achieved. |