| abstract |
It is an object of the present invention to provide a developing apparatus which is less affected by the use environment, has a high developing efficiency during long term use, and can provide a high quality image without image density nonuniformity. According to the present invention, a magnetic toner carrier has a work function value within a specific range on the surface thereof, and a toner regulating portion for regulating the toner carried on the magnetic toner carrier is made of a specific material in contact with the magnetic toner. A magnetic toner relates to a developing apparatus having an average annularity of 0.950 or more, and wherein the magnetic toner has a surface tension index within a specific range. |