Lexmark International, Inc.

James Paul Drummond

Gary Allen Denton

Kelly Ann Killeen

Roger Steven Cannon

James Ronald Booth

Jon Brock Whitney

Randal Scott Williamson

Jeanne Marie Saldanha Singh

Matthew Joe Russell

Ganesh Vinayak Phatak

Trevor Daniel Gray

Timothy Lorn Howard

John Richard Fowler

Kin-Ming Kwan

Frank Edward Anderson

James Daniel Anderson, Jr

Keith Bryan Hardin

Carl Edmond Sullivan

David Emerson Greer

Michael John Dixon

Bryan McKinley

Kin Ming Kwan

Stephen Francis DeFosse

Brian Anthony Reichert

William Pohl Corbett, Jr

George Nelson Woolcott

Christina Allison Cullins

Amanda Kay Plakosh-Angeles

Julie Ann Whitney

James D Anderson

Jerry Randall Reed

Steve R Komplin

William Corbett

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

An elongate physical unclonable function (PUF) is disclosed. The PUF has a longitudinal axis and contains a plurality of small magnetic particles. A much larger magnet is positioned on the longitudinal axis to indicate a home position. A low-cost linear translation mechanism may be used to read the PUF by referencing position information to the home position. Other devices are disclosed.

Elongated physical unclonable function

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

This invention addresses how an end user can create an electroluminescent device () using basic components obtained by the end user as retail items. The layers or subassemblies () are created first. Then the layers are assembled to form a completed device customized as selected by the end user. The subassemblies may be created layer-by-layer by thermal inkjet. Elements used typically will be made by manufacturers and sold commercially separately. This encompasses the printing of conductive patterns for electroluminescence on paper. In one aspect a display has a main body that may be permanent and useful indefinitely, while a part carrying the conductive pattern defining the display is readily removed and is replaced by another such part on which a new conductive pattern is printed. For tight contact with the main body, the display provides releasable pressure. Air pockets are minimized with a thin layer of highly viscous dielectric liquid.

Customizable electroluminescent displays

In a system for laser welding work pieces along a collapsing weld interface, methods and apparatus include providing welding pads and/or stop projections on either or both of the work pieces to control the manner or amount of collapse. Preferably, the stop projections exist a separation distance from the weld interface while the welding pads exist at and form a portion of the weld interface. Buffers are taught between the weld interface and stop projection. The work pieces may comprise inkjet printhead lids and bodies. In another aspect, the invention teaches methods of laser welding inkjet printhead lids and bodies according to whether the inkjet printhead body embodies a mono or color ink body type and especially includes selective control of one or more laser light sources to illuminate the inkjet printhead lid in a specific pattern of light.

Laser welding methods and structures and control therefor including welded inkjet printheads

Some embodiments of the present invention provide a waveguide apparatus for transferring light to a weld area. The waveguide apparatus can include a waveguide comprising a material having a first index of refraction and having at least one wall defining at least one cavity. The assembly can also include a filler material positioned within the at least one cavity and having a second index of refraction less than the first index of refraction. Also, some embodiments of the present invention provide a laser welding assembly in which a waveguide apparatus is used to weld materials, a method of laser welding materials using a waveguide, and a method of manufacturing such a waveguide.

Waveguide apparatus and method for laser welding

In a system for laser welding upper and lower work pieces along a weld interface, the upper work piece being transparent to laser light and having a non-uniformly thick dimension, compensation plates and compliant members are taught that mate or otherwise contact the upper work piece such that a combined thickness of the upper work piece and the compensation plate or compliant member is substantially uniform in a region at least above the weld interface. In this manner, substantially consistent amounts of laser light reach the weld interface. The upper work piece may include positive projections, negative voids, contoured profiles, surface imperfections or other that cause the non-uniformity. In one embodiment, the compensation plate is fashioned together with a compliant member. In another embodiment, the upper and lower work pieces comprise inkjet printhead lids and bodies, respectively.

Compensation plates and compliant members for laser welding a non-uniformly thick work piece including inkjet printheads with non-uniformly thick printhead lids

A regulator adapted to regulate the throughput of an ink between an ink source and a print head includes: (a) a pressurized chamber including an ink inlet in fluid communication with the ink source, an ink outlet in fluid communication with the print head, and at least one flexible wall; and (b) a lever including a flexible arm extending along a portion of the flexible wall and an opposing arm operatively coupled to a seal biased to close the ink inlet when the lever is in a first position and to open the ink inlet to allow fluid communication between the ink inlet and the pressurized chamber when the lever is pivoted to a second position; where a lower pressure differential across the flexible wall causes the flexible wall to actuate the flexible arm, pivoting the lever to the first position (inlet closed), where a higher pressure differential across the flexible wall causes the flexible wall to actuate the flexible arm to pivot the lever to the second position (inlet open), and where a pressure change from the lower pressure differential to the higher pressure differential across the flexible wall causes the flexible wall to actuate and flex the flexible arm without causing the lever to pivot.

Growing community of inventors

Georgetown, KY, United States of America

James Paul Drummond