| 摘要 |
<p>A heat roll for electrophotography of a surface heating type having a heating resistor is arranged such that a bonding layer (3), an insulating layer (4), a resistance layer (5), and a surface insulating layer (8) are consecutively provided on an outer surface of a hollow cylindrical core (2), and a bearing member for fitting with a bearing is fitted at each opposite end of the heat roll. A pipe (1) or a round bar formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like which has a greater coefficient of thermal conductivity than that of mild steel is disposed inside the core (2) to permit a unform distribution of the temperature. In addition, a gap of 0.2 mm or more is provided between the inner surface of the core (2) and an outer peripheral surface of the member formed of the high-temperature conductive material. As a result, effects that are attributable to a difference in the coefficients of thermal conductivity can be alleviated, and a temperature rise of the heat roll up to a predetermined temperature can be accelerated.</p> |
