Patent ID: 7664451

Claim:
A fixing device comprising: a magnetic field generating component that generates a magnetic field; a fixing member including a heat generating layer that is electromagnetically induced by the magnetic field to generate heat; a support disposed at an inner side of the fixing member; a pressure rotating body that applies pressure to the fixing member in the direction of the support; a pair of magnetic circuit forming members that are disposed with the fixing member and the magnetic field generating component being placed therebetween and at least one of said magnetic circuit forming members having been shaped either by elastic deformation or plastic deformation applied thereto and wherein a thickness t of the magnetic circuit forming members is thicker than a surface depth δ of the material of the magnetic circuit forming members as defined by the equation δ=503(ρ/γμ r ) 1/2 , wherein ρ represents the intrinsic resistivity of the magnetic circuit forming members, γ represents the frequency of the magnetic field generating component, and μ r represents the relative magnetic permeability at room temperature of the magnetic circuit forming members.