JP2957686B

PURPOSE:To enable a high fidelity image equivalent to an initial image to be obtained by causing toner to contain at least polyester resin as binder resin, and the predetermined quarternary ammonium salt compound containing fluorine as a polarity control agent. CONSTITUTION:A carrier has a silicone resin coat containing a conductive powdered silane coupling agent, and toner is made to contain at least polyester resin as binder resin, and the predetermined quarternary ammonium salt compound containing fluorine as expressed by the equation I, as a polarity control material. In the equation I, R1 to R4 stand for a lower alkyl group having carbon atoms between 1 and 10 and an aryl group, (n) for a negative integer, (m) for a positive integer and X stands for -CO, and -SO2, respectively. According to the aforesaid constitution, an image displaying quality equivalent to an initial image can be obtained, even after a continuous copying process.