公开(公告)号：US11340312B2

公开(公告)日：2022-05-24

申请号：US17012483

申请日：2020-09-04

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： James Howard Ellis ,  Keith Bryan Hardin ,  William Pohl Corbett, Jr.

IPC: G01R33/00 ,  G01R33/07 ,  G01R33/02 ,  G06F21/75

Abstract: A magnetic sensor array device is described that is constructed with multiple sensors integrated on a common silicon die, diced and packaged in a wafer level package (WLP). The device comprises an array of multi-axis magnetic sensors that can measure the multi-dimensional magnetic field of an arbitrary sized two-dimensional region with high spatial resolution, reduced sensing distance, higher measurement throughput, tolerance to motion, improved temperature measurement, and improved yield when placed on a circuit card comprises part of an authentication system including a physical unclonable function (“PUF”), a substrate, a plurality of magnetized particles randomly dispersed in the substrate, and a PUF reader constructed using one or more of the magnetic sensor array devices wherein the PUF reader measures the magnetic field 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.

公开(公告)号：US11346903B2

公开(公告)日：2022-05-31

申请号：US17012474

申请日：2020-09-04

Applicant: Lexmark International, Inc.

Inventor： James Howard Ellis ,  Keith Bryan Hardin ,  William Pohl Corbett, Jr.

IPC: H04L9/32 ,  G06K7/08 ,  G01R33/00 ,  G01R33/12 ,  G06V40/13

Abstract: A magnetic sensor array device is described that is constructed with multiple single sensor die, diced out of a wafer as a group and packaged in a wafer level package (WLP). The device comprises an array of multi-axis magnetic sensors that can measure the multi-dimensional magnetic field of an arbitrary sized two-dimensional region with high spatial resolution, reduced sensing distance, higher measurement throughput, tolerance to motion, improved temperature measurement, and improved yield when placed on a circuit card comprises part of an authentication system including a physical unclonable function (“PUF”), a substrate, a plurality of magnetized particles randomly dispersed in the substrate, and a PUF reader constructed using one or more of the magnetic sensor array devices wherein the PUF reader measures the magnetic field 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.

公开(公告)号：US10133205B2

公开(公告)日：2018-11-20

申请号：US15472733

申请日：2017-03-29

Applicant: LEXMARK INTERNATIONAL, INC.

Inventor： John Bruce Berry ,  William Pohl Corbett, Jr. ,  Robert Michael Tulenko

IPC: G03G15/00 ,  G03G15/043 ,  G03G15/04

Abstract: An imaging device has a photoconductor with a surface that is selectively discharged by a light from a laser diode to create a latent electrostatic image for attracting toner for transfer to a media. A circuit drives the laser diode. The circuit has a switch for turning on and off the light, a resistor complementary to the laser diode selectively connectable to the switch, and a passive circuit component coupled to the laser diode. The passive circuit component is a delay line, inductor, choke, coiled wire, or ferrite bead is contemplated. It may also typify a length of copper tracing on a printed circuit board that supports the laser diode. The circuit causes an initial overshoot voltage spike in an on voltage pulse that is about 20% or more than the settled on voltage. The voltage spike dampens out in about one-fourth of a total voltage on time of the pulse.