Fusing roller for an electrophotographic image forming apparatus having quick warm up time and uniform temperature distribution

A fusing roller for an electrophotographic image forming apparatus, said fusing roller having two end portions and a center portion disposed in between said two end portions, said heating roller comprising:

• a hermetically sealed internal pipe having a working fluid therein along a length of the fusing roller;
• a resistive heater wrapped in a spiral around the pipe, a distance between adjacent windings of the resistive heater being smaller at said two end portions than at said center portion of the fusing roller;
• and
• a fusing portion disposed around the resistive heater.

A fusing roller for an electrophotographic image forming apparatus, comprising:

• an internal pipe being hermetically sealed and having a working fluid stored within;
• a fusing portion installed to surround the internal pipe;
• and
• a heating portion comprised of a helical resistance heating coil which is installed between the fusing portion and the internal pipe to generate heat, said heating portion generating more heat per unit length of said fusing roller at two end portions of said fusing roller than at a center portion of said fusing roller.