The present invention relates to a conductive polymer composition for a PTC element with decreased NTC characteristics, using carbon nanotubes, a PTC binder resin, and a cellulose-based or polyester-based resin for fixing the carbon nanotubes and the PTC binder, and to a PTC element, a circuit and a sheet heating element using the same. The electric power head includes an AC motor with a drive shaft configured to mechanically couple with the proximal end of the auger assembly. Considering this, when a forced monochrome mode is selected, even if the user’s setting for the copy-forgery-inhibited pattern is color, the color is changed to monochrome before output. Other methods and apparatuses are also described.