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US 4,958,195 AGranted
Method and apparatus for fusing envelopes
AssigneeInternational Business Machines Corporation
InventorsRowland V. D. Firth, III, Quay C. Hunter, Jr., Ronald A. Kohlin, William W. Sitton
Life of this patent
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Abstract
An electrophotographic printer is disclosed wherein the fusing of a toner image to an envelope by the use of a roll fuser causes the fusing nip to open early, i.e. the fusing nip opens a predetermined and controlled time/distance before the trailing edge of the envelope exits the fusing nip. As a result, creasing, wrinkling and the like of the envelope is minimized.
Claims26
In an electrophotographic reproduction device having a roll fuser that is formed by a pair of generally circular cylinder rolls supported in pressure contact to form a fusing nip, a method for fusing multiple-ply transfer material, comprising the steps of,
- feeding toner bearing multiple-ply transfer material to said fusing nip for fusing of toner to the transfer material,
- determining the position of said transfer material as said transfer material moves toward said fusing nip, and
- controlling said fusing nip as a function of said position, to open said fusing nip, and thereby release roll pressure from said transfer material, before said trailing edge exits said fusing nip.
A method for fusing xerographic toner to the flat surface of paper or paper-like envelopes by the use of an electrophotographic reproduction device having a pressure fuser, said envelopes being fed through said reproduction device in a manner to have a leading edge and a trailing edge, comprising the steps of
- determining if toner images are to be reproduced on envelopes by operation of said reproduction device, and
- if toner images to be reproduced on envelopes, releasing the pressure of said pressure fuser after the majority of said envelope extending from said leading edge to said trailing edge has passed through said pressure fuser, but before the trailing edge of said envelope has passed through said pressure fuser, to thereby release pressure from said envelope before said trailing edge exits said pressure fuser.
An electrophotographic printer comprising,
- a photoconductor element movable through a transfer station to selectively transfer a toner image carried thereby either to sheet transfer material or to envelope transfer material,
- a pressure fuser operable to receive transfer material from said transfer station as said transfer material is fed through a path so as to have a leading end and a trailing end, said pressure fuser being operable to fuse toner thereto, and
- control means sensitive to the selection of envelope transfer material, and operable to control said pressure fuser to release fusing pressure prior to the trailing end of said envelope transfer material entering said pressure fuser.
A pressure fuser comprising,
- a pair of circular cylinder rotatable rolls mounted in substantially parallel axes configuration, and compliantly force biased together to form a pressure fusing nip for fusing moving toner-carrying transfer material,
- a nip opening mechanism comprising a roll powered, roll separating cam member mounted to rotate about the axis of one of said rolls, said cam member being mounted at one end of said one roll in friction contact with the cylindrical surface of said one roll, and at an axial position thereof so as not to extend into said fusing nip,
- a cam release member having a catch portion operable to hold said cam member against rotation and in a position that is rotationally upstream of said fusing nip, and
- control means to momentarily operate said cam release member, to thereby allow said cam member to be driven through said fusing nip by rotation of said one roll, thereby opening said fusing nip,
- said cam member thereupon being driven by said one roll back to said rotationally upstream position, where movement of said cam member is again held by operation of said cam release member.
2 more elements
A pressure fuser comprising,
- a pair of circular cylinder rotatable rolls mounted in substantially parallel axes configuration, and compliantly force biased together to form a pressure fusing nip for fusing moving toner-carrying transfer material,
- a nip opening mechanism comprising an eccentric, roll separating cam member mounted to rotate about the axis of one of said rolls, such rotation being independent of rotation of said one roll, said eccentric cam member being mounted at one end of said one roll, and being force biased for rotation in the direction of rotation of said one roll,
- a cam release member operable to hold said eccentric cam member against rotation,
- a drive disk member mounted to rotate with and about the axis of the other of said rolls and in the same plane of rotation of said eccentric cam member, the position of said eccentric cam member when held by said cam release member being such that no engagement exist between said eccentric cam member and said drive disk member, said pair of rolls at this time being in fusing engagement, and
- control means to operate said cam release member and thereby allow said eccentric cam member to rotate under said bias force, to thereby bring the surface of said eccentric cam member into engagement with said drive disk means, whereupon the axis of said one roll is moved away from the axis of said other roll by operation of said eccentric cam member as said eccentric cam means is driven by said drive disk means.
2 more elements
An electrophotographic reproduction device comprising,
- a photoconductor element movable in sequence through a charging station whereat said photoconductor element receives a charge, an imaging station whereat said photoconductor element is selectively discharged to form a latent electrostatic image, a developing station whereat toner is selectively applied to said latent electrostatic image to form a toner image, and a transfer station whereat said toner image is transferred either to sheet transfer material or to envelope transfer material,
- a pressure fuser operable to receive transfer material from said transfer station as said transfer material is fed through a path so as to have a leading end and a trailing end, said pressure fuser being operable to fuse toner thereto, and
- control means sensitive to the selection of envelope transfer material, and operable to control said pressure fuser to release fusing pressure prior to the trailing end of said envelope transfer material entering said pressure fuser.
Dependencies are inferred from the claim text.