FIXING DEVICE AND IMAGE FORMING DEVICE USING THIS

摘要

When the rotational speed of rotatable heating means for thermally fixing an image on a recording paper is changed from a first rotational speed of the highest level to a second rotational speed of the lowest level by changing the operation mode of a fixing device, the direct change from the first rotational speed to the second one may increase the overshoot of the temperature of the heating means. This shortens the life of the belt and causes an error of abnormally high temperature. To avoid an excessive overshoot of the temperature of the heating means, after the heating means is rotated for a predetermined time at a third rotational speed between the first and second rotational speeds, the rotational speed is changed to the second one.