Toner-image fixing device for image forming device

摘要

To quickly raise a surface temperature of a roller to a target temperature, maintaining the boundary temperature of a roller core below a temperature at which its rubber lining may strip off. ÄConstructionÜ A roller 50 containing heating means 51 and a roller 60 to be pressed against the roller 60 are provided to fix an unfixed toner image by heat onto a recording medium 40 while the latter passes through the rollers. The toner 41 is fused on to the recording medium by the contacting therewith roller 50 that is heated by the internal heater 51 therein and a heater 71 in an external heating means 70 disposed outside the roller 50. The roller 50 may be heated to two preset values of its surface temperature, at respective values of which the heater 51 in the roller 51 and the external heater 71 are switched ON or OFF.