Lexmark International, Inc.

Kelly Ann Killeen

Gary Allen Denton

James Paul Drummond

Roger Steven Cannon

Johnny Dale Massie, Ii

Bhaskar Gopalanarayanan

Ronald Lloyd Roe

James Ronald Booth

Bradley Leonard Beach

Donald Wayne Stafford

James Joseph Semler

Jing X Sun

Robert Francis Soto

Bart Mansdorf

Randal Scott Williamson

Keith Bryan Hardin

Sean Terrance Weaver

Carl Edmond Sullivan

James F Feeman

Xiaoming Wu

Terence E Franey

David Christopher Graham

Mark Duane Foster

Martin Victor DiGirolamo

David Starling MacMillan

Craig Michael Bertelsen

Jean Marie Massie

Christopher Allen Craft

Bryan Michael Blair

Kathryn Dowlen Mullins

Mark Stephen Weisman, Jr

William Pohl Corbett, Jr

Bryan Thomas Fannin

Mark William Johnson

Kurt Daniel Lambert

Kevin Scott Kennedy

Billie Jo Enciu

Scott Alan Searls

William Corbett

Liam Ruan De Paor

Jane Elece Barcelo

Chao Li

Richard Nicholas Schrantz, Jr

A physical unclonable function is disclosed. A highly random distribution of magnetic particles within a thermoplastic polymer is created by magnetizing magnetizable particles in solid pellet feed material before feeding the solid pellets into an injection molding machine. Other devices and processes are disclosed.

Injection-molded physical unclonable function

A system for use in authentication processes is described comprising a physical unclonable function ('PUF'), a substrate, a plurality of magnetized particles randomly dispersed in the substrate, a PUF reader constructed using multiple discrete magnetometer chips that have magnetic field sensors, placed on a circuit card in an array with a sufficient center to center spacing between sensing elements of adjacent magnetometer chips, wherein the PUF reader measures the magnetic field data at multiple locations in close proximity to the magnetized particles. The measured magnetic field data may be compared to previously enrolled data to assess authenticity.

Magnetometer chip sensor array for reading a magnetic PUF, including a magnetic PUF film or tape, and systems incorporating the reader

In the invention described, magnetic field characteristics of randomly placed magnetized particles are exploited by using the magnetic field fluctuations produced by the particles as measured by a sensor. The magnetized particles generate a complex magnetic field near the surface of an integrated circuit chip on a bank card or identification card that can be used as a 'fingerprint.' The positioning and orientation of the magnetized particles is an uncontrolled process, and thus the interaction between the sensor and the particles is complex. The randomness of the magnetic field magnitude and direction near the surface of the material containing the magnetic particles can be used to obtain a unique identifier for an item such as an integrated circuit chip on a bank card or identification card carrying the PUF.

Physical unclonable functions in bank cards or identification cards for security

A method of making a physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other methods are disclosed.

Methods of making physical unclonable functions having magnetic and non-magnetic particles

A rotating magnetic physical unclonable function (PUF) is disclosed. Rotating the PUF enables robust low cost PUF readers. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

Rotating magnetic measurements of physical unclonable functions

A physical unclonable function (PUF) imaged through two faces is disclosed. The PUF is difficult to counterfeit because the view through both faces must be duplicated for a successful counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

Physical unclonable function imaged through two faces

A method for forming a roll core for use in an electrophotographic image forming device according to one example embodiment includes shaping the roll core from a mixture of an uncured elastomer and hollow microparticles. The elastomer of the shaped roll core is cured without permanently expanding hollow microparticles positioned near the outer surface of the shaped roll core. After curing, the hollow microparticles positioned near the outer surface of the shaped roll core are permanently expanded to form the roll core having compressible and resiliently recoverable hollow microparticles extending beyond an outer circumference of the roll core and providing a surface texture to the roll core.

Elastomeric roll for an electrophotographic image forming device having compressive hollow microparticles defining a surface texture of the roll

A physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

Physical unclonable functions having magnetic and non-magnetic particles

A toner adder roll according to one example embodiment includes an electrically conductive shaft defining an axis of rotation of the toner adder roll. A foam member is cylindrically disposed about the shaft and forms an outer circumferential surface of the toner adder roll. The foam member is composed of a polymeric open-cell foam material. An abrasive agent is dispersed on the outer circumferential surface of the toner adder roll.

Toner adder roll having an abrasive agent additive

A method for making a developer roll by molding a metal shaft with a conductive or semi-conductive soft rubber forming a rubber core and a coating deposited on the soft rubber core wherein the coating has a conductive agent. The outer surface of the soft rubber core is modified to form an &#x2014;OH rich surface layer before the coating is deposited onto the outer surface of the rubber core to chemically bond therein.

Developer rolls having a tuned resistivity method for making

An endless electrophotographic member, such as a developer roller, which indicates an improved resistance to nip banding. The improvement to nip banding may be provided by the use of an organic salt within a roller surface region. The roller may provide, at a nip location, a resistive surface layer having an electrical resistance that avoids the development of nip banding and relatively dark regions on printed media.

Electrophotographic roller with resistance to nip banding

Developer roll having a conductive or semi-conductive soft rubber core and a coating deposited in the soft rubber core wherein the coating has a conductive agent. The outer surface of the soft rubber core is modified before the coating is deposited onto the outer surface of the soft rubber core. Methods for making the same.

Developer rolls having a tuned resistivity

The present disclosure relates to the use of radiation cured coatings that may be used in a device within an image forming apparatus. The coating composition may include a reactive oligomer capable of radiation curing having a number average molecular weight (Mn) of greater than 1500. A reactive diluent may then be combined with the reactive oligomer, which diluent is also capable of radiation curing and which has a Mn of less than or equal to 1500. The reactive diluent may be present at a level of less than fifty percent by weight of the coating composition. The coating composition may be present at a solids level of 90-100%.

Radiation cured coatings for image forming device components

A nozzle plate for a micro-fluid ejection head, a method of making a hydrophobic nozzle plate, and a method for improving the resiliency of a nozzle plate. The nozzle has a photoimageable hydrophobic polycyclic polyolefin layer derived from an epoxy functionalized polynorbornene.

Hydrophobic nozzle plate structures for micro-fluid ejection heads

Growing community of inventors

Lexington, KY, United States of America

Kelly Ann Killeen