Patent ID: 7142792

Claim:
A fixing apparatus for fixing polymerized toner on transfer material comprising: a) a heating roller having a cylindrical cored bar, a elastic layer and releasing layer provided around said cylindrical cored bar; b) a pressure roller, in contact with the heating roller, having a cylindrical cored bar, a elastic layer and releasing layer provided around said cylindrical cored bar; c) a first guide member provided opposite the pressure roller; and d) a second guide member provided near the heating roller without contacting thereto; wherein the difference in hardness between the heating roller and pressure roller is 5 through 10 degrees in AskerC, the hardness of the pressure roller being higher than that of the heating roller, and a fixing nip portion, convexshaped on the side closest to the heating roller, is formed between the heating roller and pressure roller, and the nip pressure of the fixing nip portion is 24.5 N/cm or more.