Fixing unit and heat roller for fixing unit

摘要

A fixing unit for an image forming device such as a laser printer includes a heat roller and a heating member driving unit to drive the heat roller. The heat roller includes a hollow cylindrical tube and a resistance heating member to selectively heat portions of the tube along the axial length thereof. The resistance heating member includes an insulating layer and a conductive layer. The conductive layer is provided with a plurality of resistance heating patterns arranged along the axial length of the tube and connected to a plurality of electrode portions. The connections between the resistance heating patterns and the electrode portions are arranged such that applying a voltage across selected electrode portions causes selected resistance patterns to generate heat and thus, selectively heat a portion of the tube along the axial length thereof.