Patent ID: 6642488
Filing Date: 2003-11-04
Classification: G03G,H05B,Y10T

Abstract:
A fixing device using induction heating for causing alternating current to pass through an electromagnetic induction coil, comprising:said electromagnetic induction coil; and a cylindrical core made of non-magnetic material, wherein said coil is arranged close to an endless member having a metal layer of a conductive material, to cause said endless member to generate heat to heat a member to be fixed, wherein said coil is wound around a surface of the cylindrical core, a winding axis of said coil being perpendicular to the longitudinal axis of said core, wherein said core has two core body portions, said coil being wound on sidewalls of said core body portions as spindles, said core body portions being arranged opposed to each other along the diameter direction of said core, each of said core body portions being a protrusion portion on the surface of said core, said core body portions being protruded from the surface of said core toward the outside and away from the longitudinal axis of said core, each of said core body portions having a long structure along the longitudinal direction of said core, and wherein said coil is wound around said core body portions and is also wound around the surface of said core far apart from said core body portions, one of said core body portions being set to face a fixing portion, wherein said coil is not wound on a surface of said core body portion of said core and thereby said coil around said core body portion being a less dense portion of said coil wherein said core body portion forms a weak heating portion.