Fixing apparatus and fixing method

A fixing apparatus comprising:

• a fixing belt comprising an endless belt configured to heat a recording medium having a developing agent image thereon;
• a pressing roller, configured to fix the developing agent image by catching and conveying the recording medium in cooperation with the fixing belt;
• a heating roller, comprising a roller which comes into contact with the fixing belt, and which is configured to heat the fixing belt to a predetermined temperature;
• a plurality of heater lamps, which are disposed in the heating roller and have different outputs, to heat the heating roller entirely in the longitudinal direction;
• and
• a control device configured to control the plurality of heater lamps;
• wherein the heater lamp having a high output among the plurality of heater lamps is positioned upstream in the conveying direction of the fixing belt in a contact area between the fixing belt and the heating roller.

An image forming apparatus comprising:

• an image carrier on which a developing agent image is formed;
• a fixing belt comprising an endless belt configured to heat a recording medium on which the developing agent image is transferred from the image carrier;
• a pressing roller configured to fix the developing agent image by catching and conveying the recording medium in cooperation with the fixing belt;
• a heating roller comprising a roller which comes into contact with the fixing belt and which is configured to heat the fixing belt to a predetermined temperature;
• a plurality of heater lamps which are disposed in the heating roller, which have different outputs and which heat the heating roller entirely in the longitudinal direction;
• and
• a control device configured to control the plurality of heater lamps;
• wherein a heater lamp having high output among the plurality of heater lamps is positioned upstream in a conveying direction of the fixing belt in a contact area between the fixing belt and the heating roller.

A fixing method for fixing a developing agent image by heating and pressing by conveying a recording medium having the developing agent image while holding it between a fixing belt heated in contact with a heating roller and a pressing roller, comprising the steps of:

• heating the heating roller by selectively controlling to turn ON/OFF a plurality of heater lamps which are disposed in the heating roller, which have different outputs and can heat the heating roller entirely in its longitudinal direction, wherein the heater lamp having high output among the plurality of heater lamps is positioned upstream in the conveying direction of the fixing belt in a contact area between the fixing belt and the heating roller;
• heating the fixing belt by contacting the heating roller to the fixing belt;
• and
• passing the recording medium through a nip section formed between the fixing belt which is separated from the heating roller and the pressing roller which is in pressing contact with he fixing belt.