Non-magnetic mono-component impression developing process with polymerized toner of positive polarity

The process used in HL-1240 was developed in optimizing the fine fluidity and the fine tribo-electric charging ability of polymerized toner of positive polarity. These advantages made the combination of the non-magnetic mono-component impression developing process and the cleaner-less developing process possible. Optimization of the materials used for the developing roller and the toner-regulating blade enabled both the fog image and the residual toner on the photoreceptor to become almost nothing. The cleaning roller is unnecessary for HL-1240 under this condition. As the printing speed becomes faster, the residual toner on the photoreceptor increases. When it is up to 25 ppm, the cleaning roller becomes necessary to prevent the ghost image. Furthermore, the cleaning roller improves the durability of the photoreceptor with grinding it moderately. The laser printers produced by Brother Industries, Ltd. are classified into the process with cleaning roller and the process without cleaning roller. These processes are used for the office and workgroup laser printer and the personal laser printer, respectively.