Temperature sensing and control of a fusing roll

Abstract From the Canadian patent

Apparatus for controlling the surface temperature of a fusing roller of the type having a heat-insulative release surface over a thermally conductive core by (1), internally heating the core, (2) sensing the temperature of the core rather than of the external release surface (3), providing different temperature control settings for the core sensor and (4) selectively switching the internal heating means into operative relation with a predetermined control setting in anticipation of changes in heat loss from the external surface. The core of the fusing roll is thereby controlled toward the different temperature control settings one at the "copy run" condition, another at the "idle" …