Patent ID: 7162175

Claim:
A fixing device for an image forming apparatus, comprising: a heating roller; a press roller pressed against the heating roller, wherein the heating roller and the press roller operate to fix an image on a document; a heat source that heats the heating roller, wherein the heat source is configured to activate to heat the heating roller before or substantially when the heating roller and the press roller start to rotate, independent of a temperature of the heating roller; and a sensor that detects the temperature of the heating roller, wherein a sensing position of the sensor is disposed a fixed rotational angle from a nip position of the heating roller and press roller, wherein the heat source is configured to stay activated for at least a time period that the heating roller rotates by the fixed rotational angle, and wherein, after the heating roller rotates by the fixed rotational angle, the heat source is configured to activate or deactivate based on the temperature detected by the sensor.