International Business Machines Corporation

Jack P Chang

Fred Young Brandon

William D Clark

Marc Lawrence Steinbrecher

Eugene G Stahlberg

An early roll closure method and apparatus associated with an electrophotographic or xerographic device for fixing a toner image onto a copy sheet by application of heat and pressure. A lower closing force is exerted on the fuser rollers during early roll closure than when fixing an image to a copy sheet. The use of a backup roll made of bare metal facilitates this technique. This early roll closure method also allows the temperature of the heated fuser roll to be reduced along the entire circumference. The early roll closure is only allowed to occur on the first sheet of a copy or fusing run.

Early fuser roll closure with reduced force

An electrophotographic copier machine with a roll fuser where one of the mating rolls is comprised of a thin outer shell which takes a variable taper so that a concave shape is produced under high humidity conditions and a relatively straight roller is produced under low humidity conditions. Means for changing the support at the roll ends is provided to produce the variable taper. End plugs can be moved axially inward at high humidity to provide support for the end portions of the normally concave roll and can be moved axially outwardly under low humidity such that no support is provided until the roll ends are flattened under the pressure of a mating roll.

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Boulder, CO, United States of America

Jack P Chang