Patent ID: 7221896

Claim:
A fixing device, comprising: a fixing roller, where the fixing roller is a heat roller having a heat source; and at least two pressure rollers providing respective nip portions by pressing the fixing roller, wherein the fixing roller and the pressure rollers rotate, thereby transporting a recording medium to the nip portions and fixing a developing agent on the recording medium, the at least two pressure rollers including: a first pressure roller which provides a first nip portion by pressing the fixing roller and delivers, to the first nip portion, the recording medium having been externally transported; and a second pressure roller which provides a second nip portion by pressing the fixing roller and peels the recording medium having passed though the second nip portion from the fixing roller, and the first pressure roller being disposed upstream to the second pressure roller in a transport direction of the recording medium, wherein the heat roller, the first pressure roller, and the second pressure roller satisfy the following relationship; an outer diameter of the heat roller>an outer diameter of the first pressure roller>an outer diameter of the second pressure roller, and wherein the heat roller is made up of (a) a hollow cylinder having a wall thickness of 3 mm or less with thermal conductivity and (b) a heat-roller-side elastic layer having a thickness of 1 mm or less with elasticity, the heat-roller-side elastic layer being formed around the hollow cylinder.