Lexmark International, Inc.

Xerox Corporation

Gary Allen Denton

Roger Steven Cannon

James Paul Drummond

Kelly Ann Killeen

Katherine Marie Gilliam

William Paul Cook

Cary Patterson Ravitz

Matthew Lee Rogers

David Daniel Dreyfuss

Elliott Vincent Jernigan

Dominique Renee Rowe

James Ronald Booth

Alan Stirling Campbell

Scott Richard Castle

Stanley Coy Tungate, Jr

Robert Dan Bennett, Iii

Randal Scott Williamson

Keith Bryan Hardin

Robert Henry Muyskens

Wilson Morgan Routt, Jr

Samuel Leo Rhodus

Royden Thomas Kern

Courtney Harrison Soale

Erik Christopher Bard

Albert Mann Carter, Jr

Michael Craig Leemhuis

Carl Edmond Sullivan

Jorge Antonio Alvarez

Henry R Till

Francisco Zirilli

Brant Dennis Nystrom

Eric Wayne Westerfield

Graydon Randall Dodson

Michael Brian Bacelieri

Daniel Enrique Alonzo

Damodar M Pai

James R Larson

Michael Jon Levy

John F Knapp

James Edward Williams

James Harold Powers

Gregory Alan Cavill

Gregory Lawrence Ream

Robert Wilson Cornell

David Anthony Schneider

Michael David Maul

Keith Seaman

Anthony R Lubinsky

Paul F Sawicki

James M Pacer

Jarrett Clark Gayne

Thomas Allen Henderson

Paul Windsor Morehouse, Jr

John William Kietzman

Nancy Beth Goodman

Julie Ann Gordon Whitney

Lawrence R Benedict

Tao Yu

John Melvin Olson

Mark Doerre

Douglas A Kreckel

Trent Duane Peter

Brian Anthony Reichert

Paul D Keller

William Pohl Corbett, Jr

David Kurt Klaffenbach

Kurt Matthew Korfhage

Albert Munn Carter, Jr

George F Bergen

Joseph Edward Johnson

Jason Edward Gordon

Thomas George Twardeck

Peter J McGuire

Richard H Dennie

Robert Christopher Sbert

David R Jenkins

John M Simpson, Iii

William Corbett

Robert Dan Iii Bennett

The use of a magnetic particle based 'PUF' (Physically Unclonable Function) disk, when read by magnetic sensor(s), as a positional encoder is described. It is often necessary to include a linear or rotary encoder within a device for tracking motor movements, or to enable a closed-loop control algorithm on the motor system. These randomly dispersed magnetic particle disks can be used as a positional encoder, where the speed of movement and the direction of movement may be monitored.

Physical unclonable function encoder

A physical unclonable function ('PUF') object can be used to encode the geography or region in which device to which the PUF is attached may operate. Disclosed are two potential ways to regionalize a device using a PUF disk: placing the magnetic sensor at a different radius depending on the region or geography intended for sale; and altering the magnetic structure of the disk to magnetically encode the region into the sensor data.

Physical unclonable function (PUF) alters disk structure to encode region

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

Magnetic PUFs (Physical Unclonable Function) may utilizes a single 3-axis Hall-effect sensor for enrollment. When a PUF is manufactured, a Hall-effect sensor is used to model the PUF disk and store that data where it may be accessed. This process is called 'enrollment.' This invention improves upon the PUF implementation by introducing controlled variability into the enrollment, the reading of the PUF data from the Hall-effect sensors (the number and position of read sensors), the sampling method of the read sensor(s), and the processing of the PUF data.

Physical unclonable function variable read sensor

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 toner level detection assembly for an electrophotographic image forming device according to one example embodiment includes a magnet connected to a rotatable shaft and rotatable with the shaft around an axis of rotation of the shaft. The magnet is pivotable independent of the shaft about a pivot axis that is spaced radially from the axis of rotation. A magnetic sensor is positioned to sense a magnetic field of the magnet at a point in a rotational path of the magnet and is configured to measure an orientation of the magnetic field of the magnet at the point in the rotational path of the magnet. Processing circuitry in communication with the magnetic sensor is configured to determine an estimate of an amount of toner in a toner reservoir correlating with the measured orientation of the magnetic field of the magnet at the point in the rotational path of the magnet.

Toner level detection measuring an orientation of a rotatable magnet having a varying orientation relative to a pivot axis

Toner level detection measuring an orientation of a rotatable magnet having a varying radius

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

Magnetic keys having a plurality of magnetic plates are disclosed. The location and orientation of the magnetic plates are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Magnetic keys having a plurality of magnetic plates

Magnetic keys having a plurality of magnetic layers having holes are disclosed. The location and orientation of the holes are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Magnetic keys having a plurality of magnet layers with holes

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 developer roll according to one example embodiment includes a core including at least one permanent magnet forming a magnetized portion of the core. A cylindrical sleeve positioned around the core is rotatable relative to the core about an axis of rotation in an operative rotational direction. A release pole of the permanent magnet is positioned to magnetically attract developer mix to an outer circumferential surface of the sleeve to transport developer mix on the surface of the sleeve in the operative rotational direction when the sleeve rotates relative to the core to a release point where a magnetic field of the permanent magnet is insufficient to retain developer mix against the surface of the sleeve. An axial length of the magnetized portion of the core decreases at both axial ends of the core as the magnetized portion of the core approaches the release point in the operative rotational direction.

Developer roll having magnetic zones of varying axial length for a dual component development electrophotographic image forming device

Growing community of inventors

Lexington, KY, United States of America

Gary Allen Denton