Fixing device, image forming system, and fixing temperature control method

A fixing temperature control method comprising:

• providing a fixing member having non-heated regions formed at a first end part and a second end part of the fixing member in a width direction, and a heated region interposed between the non-heated regions;
• scanning the non-heated regions and the heated region of the fixing member in the width direction using a temperature measurement sensor;
• calculating a first movement time for when the temperature measurement sensor is moved between the first end part and the second end part based on a temperature change measured by the temperature measurement sensor due to movement of the temperature measurement sensor;
• calculating a second movement time for when the temperature measurement sensor is moved from the first end part or the second end part to a movement position of the temperature measurement sensor based on a temperature change measured by the temperature measurement sensor due to movement of the temperature measurement sensor;
• calculating the movement position of the temperature measurement sensor on the basis of a ratio of the second movement time to the first movement time;
• and
• performing temperature control on the fixing member on the basis of the calculated movement position, and the temperature measured by the temperature measurement sensor at the movement position.

A fixing device comprising:

• a fixing belt or roller having non-heated regions formed at a first end part and a second end part of the fixing belt or roller, and a heated region interposed between the non-heated regions;
• a temperature measurement sensor configured to measure the temperature of a surface of the fixing belt or roller;
• a guide configured to move the temperature measurement sensor to scan the non-heated regions and the heated region along a width direction of the fixing belt or roller;
• and
• a fixing controller configured to
• calculate a first movement time for when the temperature measurement sensor is moved between the first end part and the second end part based on a temperature change measured by the temperature measurement sensor due to movement of the temperature measurement sensor;
• calculate a second movement time for when the temperature measurement sensor is moved from the first end part or the second end part to a movement position of the temperature measurement sensor based on a temperature change measured by the temperature measurement sensor due to movement of the temperature measurement sensor;
• calculate the movement position of the temperature measurement sensor on the basis of a ratio of the second movement time to the first movement time;
• and
• perform temperature control on the fixing belt or roller on the basis of the calculated movement position and the temperature measured by the temperature measurement sensor at the movement position.