Belt fixing system and method therefor

摘要

A belt fixing system includes a rotatably supported belt, a heating member for heating the belt, a pressure member which contacts with a circumference of the belt to form a nipping region therewith where a toner image supported on a sheet member is fixed onto the sheet member. The system further includes a first detector for detecting a portion of the belt where it has touched with the sheet member at the nipping region, and a controller for controlling the heating member so that an amount of heat supply to the belt is changed in response to an detecting result of the first detector.