Roll fuser apparatus and system therefor

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring now to the FIGURE, it can be seen that the invention is directed to a roll fuser apparatus generally indicated 10.
The fuser apparatus comprises a heated roll structure 12 cooperating with a non-heated backup roll structure 14 to form a nip 16 through which a copy substrate 18 passes with toner images 20 formed thereon in a well known manner.
The toner images 20 contact the heated roll structure while a force is applied between the roll structures in a well known manner to create pressure therebetween resulting in the deformation of the heated roll structure by the backup roll structure to thereby form the nip 16.
As the substrate passes out of the nip, it is stripped or guided from the backup roll structure by a plurality (only one shown) of stripping devices 22 after which it is free to move along a predetermined path toward the exit of the machine (not shown) in which the fuser apparatus 10 is to be utilized.
A contact temperature sensor 24 is provided for sensing the surface temperature of the roll structure 12 to maintain the surface temperature at a predetermined set-point value, for example, on the order of 330.
degree.
-400.
degree.
F.
.
+-.
15.
degree.
F.
The heated roll structure 12 comprises a hollow cylinder 26 having a radiant quartz heater 28 disposed in the hollow thereof.
When suitably energized via a power supply and controller 29, the heating element radiates heat to the cylinder which is then conducted to the outer surface of an outer deformable layer 30 of insulative material of the structure 12 which preferably comprises silicone rubber having a thickness of between 10-150 mils.
Other elastomeric materials may be employed, for example, Viton (trademark of E.
I.
duPont).
In accordance with the invention the heater 28 serves to elevate the roll structure 12 only during the standby mode of operation such that its outer surface is at approximately the setpoint temperature which will be dictated by the particular machine configuration in which the fuser is employed