Patent ID: 6096996
Filing Date: 2000-08-01
Classification: G03G

Abstract:
A thermal-fixing-unit temperature control method for an image forming apparatus which includes (a) an interim-image forming section for forming a succession of interim images one at a time onto each of successive record mediums based on a plurality of items of input image data representing various object images, the successive record mediums being fed one after another with staggered timing intervals, and (b) a thermal fixing unit, disposed downstream of the interim-image forming section, for receiving from the interim-image forming section the successive record mediums one at a time and fixing the interim image formed on the individual record medium, the thermal fixing unit including a heat roller, in which a heat source is mounted, and a pressure roller coating with the heat roller for feeding the individual record medium while the interim image is fixed to the individual record medium under heat originated from the heat source, said method being operable to control a temperature of the thermal fixing unit and comprising the steps of:(I) counting how many image forming jobs have been carried out by the image forming apparatus from start-up of the image forming apparatus;(II) detecting the intervals of feeding of the individual record mediums one interval after another;(III) setting a target temperature of the thermal fixing unit based on the then-current total number of image forming jobs counted in said step (I) and the then-current interval detected in said step (II);(IV) detecting a then-current temperature of the thermal fixing unit; and(V) controlling the thermal intensity of the heat source so as to adjust the temperature of the thermal fixing unit to the target temperature set in said step (III) using the then-current temperature detected in said step (IV).