IMPROVED TEMPERATURE SENSING DEVICE
Original Publication Date: 1979-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
This disclosure relates generally to a heat transfer device and in particular, to an improved apparatus for sensing the surface temperature of a f user member as conventionally utilized in the xerographic copying art.
XEROX DISCLOSURE JOURNAL
IMPROVED TEMPERATURE Proposed Classification SENSING DEVICE U.S. Cl. 432/36
Donald A, Seanor mt. Cl. F27b 1/26 Joseph A. Swift
This disclosure relates generally to a heat transfer device and in particular, to an improved apparatus for sensing the surface temperature of a f user member as
conventionally utilized in the xerographic copying art.
Temperature-sensing devices for determining and controlling the surface temper~
ature of a xerographic fuser roll are well known. In U.S. Patent 3,888,622, there is disclosed a probe shoe containing at least one temperature-sensing element with the shoe being positioned in close non~contiguousrelation with the moving surface of a heated fuser roll. In the device in U.S. Patent 3,888,622, a magnetic flux field is created within the air gap between the heated roll surface and the probe shoe,
and a magnetic medium, preferably being in fluid form, having a relatively high coefficient of thermal conductivity is placed within the flux field through which a rapid and efficient flow of heat is maintained. However, most prior art heat transfer systems for determining the temperature of a given body have been of the
contact type wherein the sensing element is placed in direct physical contact with the body under investigation. The probe or thermistor tracks on the fuser roll
surface with a convex metal sheet interfacing. When properly lubricated with liquid silicone release agent, the life expectancy of such a probe or thermistor device is approximately 200,000 400,000 copies at which time failure occurs as a scratching of one or usually both components. Scratches on the fuser roll result in
copy quality defects, namely, toner offsetting.
In accordance with the present disclosure, substantial increases in the lives of the probe and/or the thermistor unit, especially those which are used in conjunctio...