Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
143 words
A heated fuser roll for use in a fusing apparatus for fixing toner images to a support surface, said fuser roll comprising: an electrically conductive core member including a plurality of axially disposed longitudinal channels lying along the outer surface of said core member; a heating element formed of a semiconducting ceramic material having a positive temperature coefficient of resistivity and exhibiting a Curie temperature transition point at which the resistance of said material increases with increasing temperature positioned in each of said channels; a layer of a thermally conductive material covering the outer exposed surfaces of both said core member and said heating elements; and a sleeve member positioned around said thermally conductive material, said thermally conductive material being in a resilient form to withstand repeated thermal cycles and remain in contiguous contact with said core member, heating elements and sleeve member.
Claim 2
Dependent Claim
143 words
A heated fuser roll for use in a fusing apparatus for fixing toner images to a support surface, said fuser roll comprising: an electrically conductive core member including a plurality of axially disposed longitudinal channels lying along the outer surface of said core member; a heating element formed of a semiconducting ceramic material having a positive temperature coefficient of resistivity and exhibiting a Curie temperature transition point at which the resistance of said material increases with increasing temperature positioned in each of said channels; a layer of a thermally conductive material covering the outer exposed surfaces of both said core member and said heating elements; and a sleeve member positioned around said thermally conductive material, said thermally conductive material being in a resilient form to withstand repeated thermal cycles and remain in contiguous contact with said core member, heating elements and sleeve member.
Claim 3
Dependent Claim
24 words
A roll according to claim 1 wherein both the upper and lower surfaces of each of said heating elements are coated with a metal.
Claim 4
Dependent Claim
18 words
A roll according to claim 2 wherein said metal coated on said heating elements is silver or aluminum.
Claim 5
Dependent Claim
15 words
A roll according to claim 1 wherein said heating elements have a rectangular cross section.
Claim 6
Dependent Claim
15 words
A roll according to claim 1 wherein each channel contains a plurality of heating elements.
Claim 7
Dependent Claim
23 words
A roll according to claim 1 wherein said ceramic material exhibits a Curie temperature ranging from about 150° C. to about 220° C.
Claim 8
Dependent Claim
20 words
A roll according to claim 6 wherein said ceramic material comprises barium titanate, strontium titanate and/or lead titanate, and lanthanum.
Claim 9
Dependent Claim
27 words
A roll according to claim 1 wherein the upper surface of said heating element is at a higher radial elevation than the upper surface of said core.
Claim 10
Dependent Claim
15 words
A roll according to claim 8 wherein said thermally conductive material is a metallic foil.
Claim 11
Dependent Claim
12 words
A roll according to claim 9 wherein said metallic foil is corrugated.
Claim 12
Dependent Claim
23 words
A roll according to claim 9 wherein the thickness of said metallic foil is in the range of about 0.001" to about 0.003".
Claim 13
Dependent Claim
16 words
A roll according to claim 9 wherein said metallic foil is made of copper or brass.
Claim 14
Dependent Claim
16 words
A roll according to claim 1 wherein said core is made of aluminum, copper, or brass.
Claim 15
Dependent Claim
16 words
A roll according to claim 1 wherein said sleeve is made of aluminum, copper or brass.
Claim 16
Dependent Claim
17 words
A roll according to claim 1 further comprising an outer layer of silicone rubber covering said sleeve.
Claim 17
Dependent Claim
16 words
A roll according to claim 1 further comprising an outer layer of polytetra-fluoroethylene covering said sleeve.