# US 9,517,022 B2 · Finger biometric sensor including magnetic field finger biometric sensing pixels and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,022 B2 - Document ID: US9517022B2 - Status: Granted - Kind: B2 - Application number: 13/944,326 - Filed: 2013-07-17 - Published: 2014-01-23 - Granted: 2016-12-13 - Earliest claimed: 2012-07-20 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Dale R. Setlak - Web page: https://patentgrep.com/patent/US9517022B2 ## CPC - G06V 40/1394: {using acquisition arrangements} - G06V 40/12: Fingerprints or palmprints - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A finger biometric sensor may include a substrate and an array of magnetic field finger biometric sensing pixels carried by the substrate. The finger biometric sensor may also include processing circuitry coupled to the array of magnetic field finger biometric sensing pixels and capable of generating a magnetic field extending into a finger positioned adjacent the array of magnetic field finger biometric sensing pixels to cause eddy currents in the finger. The processing circuitry may also be capable of sensing a counter magnetic field caused by the eddy currents representative of at least one finger biometric characteristic. ## Claims ### Claim 1 A finger biometric sensor comprising: a substrate; an array of magnetic field finger biometric sensing pixels carried by the substrate; and processing circuitry coupled to the array of magnetic field finger biometric sensing pixels and capable of generating, via at least one magnetic field finger biometric sensing pixel of the array thereof, a magnetic field extending into a finger positioned adjacent the array of magnetic field finger biometric sensing pixels to cause eddy currents in the finger, and sensing, via at least one magnetic field finger biometric sensing pixel of the array thereof, a counter magnetic field caused by the eddy currents based upon ridges and valleys of the finger for performing at least one authentication function. ### Claim 2 (depends on 1) The finger biometric sensor of claim 1, wherein the array of magnetic field sensing finger biometric pixels each comprises at least one electrically conductive coil. ### Claim 3 (depends on 2) The finger biometric sensor of claim 2, wherein the at least one electrically conductive coil comprises a driving coil; and wherein the processing circuitry is capable of generating the magnetic field via the driving coil. ### Claim 4 (depends on 2) The finger biometric sensor of claim 2, wherein the at least one electrically conductive coil comprises a sensing coil; and wherein the processing circuitry is capable of sensing the counter magnetic field via the sensing coil. ### Claim 5 (depends on 2) The finger biometric sensor of claim 2, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetic shield associated with the at least one coil. ### Claim 6 (depends on 2) The finger biometric sensor of claim 2, wherein the processing circuitry comprises: an alternating current generator capable of generating an alternating current in the at least one coil; and a sensing device capable of sensing a phase difference between the alternating current and a voltage of the at least one coil. ### Claim 7 (depends on 1) The finger biometric sensor of claim 1, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetoresistive sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the magnetoresistive sensor. ### Claim 8 (depends on 1) The finger biometric sensor of claim 1, wherein the array of magnetic field sensing finger biometric pixels each comprises a Hall effect sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the Hall effect sensor. ### Claim 9 (depends on 1) The finger biometric sensor of claim 1, further comprising a non-magnetic, dielectric material layer over the array of magnetic field sensing finger biometric pixels. ### Claim 10 A finger biometric sensor comprising: a substrate; an array of magnetic field finger biometric sensing pixels carried by the substrate, each of the magnetic field finger biometric sensing pixels comprising at least one electrically conductive coil; a non-magnetic, dielectric material layer over the array of magnetic field sensing finger biometric pixels; and processing circuitry coupled to the array of magnetic field finger biometric sensing pixels and capable of generating, via at least one magnetic field finger biometric sensing pixel of the array thereof, a magnetic field extending into a finger positioned adjacent the array of magnetic field finger biometric sensing pixels to cause eddy currents in the finger, and sensing, via at least one magnetic field finger biometric sensing pixel of the array thereof, a counter magnetic field caused by the eddy currents based upon ridges and valleys of the finger for performing at least one authentication function. ### Claim 11 (depends on 10) The finger biometric sensor of claim 10, wherein the at least one electrically conductive coil comprises a driving coil; and wherein the processing circuitry is capable of generating the magnetic field via the driving coil. ### Claim 12 (depends on 10) The finger biometric sensor of claim 10, wherein the at least one electrically conductive coil comprises a sensing coil; and wherein the processing circuitry is capable of sensing the counter magnetic field via the sensing coil. ### Claim 13 (depends on 10) The finger biometric sensor of claim 10, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetic shield associated with the at least one coil. ### Claim 14 (depends on 10) The finger biometric sensor of claim 10, wherein the processing circuitry comprises: an alternating current generator capable of generating an alternating current in the at least one coil; and a sensing device capable of sensing a phase difference between the alternating current and a voltage of the at least one coil. ### Claim 15 (depends on 10) The finger biometric sensor of claim 10, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetoresistive sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the magnetoresistive sensor. ### Claim 16 (depends on 10) The finger biometric sensor of claim 10, wherein the array of magnetic field sensing finger biometric pixels each comprises a Hall effect sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the Hall effect sensor. ### Claim 17 An electronic device comprising: a portable housing; a wireless transceiver carried by the portable housing; a finger biometric sensor carried by the portable housing and comprising a substrate, an array of magnetic field finger biometric sensing pixels carried by the substrate, and processing circuitry coupled to the array of magnetic field finger biometric sensing pixels and capable of generating, via at least one magnetic field finger biometric sensing pixel of the array thereof, a magnetic field extending into a finger positioned adjacent the array of magnetic field finger biometric sensing pixels to cause eddy currents in the finger, and sensing, via at least one magnetic field finger biometric sensing pixel of the array thereof, a counter magnetic field caused by the eddy currents based upon ridges and valleys of the finger for performing at least one authentication function. ### Claim 18 (depends on 17) The electronic device of claim 17, wherein the array of magnetic field sensing finger biometric pixels each comprises at least one electrically conductive coil. ### Claim 19 (depends on 18) The electronic device of claim 18, wherein the at least one electrically conductive coil comprises a driving coil; and wherein the processing circuitry is capable of generating the magnetic field via the driving coil. ### Claim 20 (depends on 18) The electronic device of claim 18, wherein the at least one electrically conductive coil comprises a sensing coil; and wherein the processing circuitry is capable of sensing the counter magnetic field via the sensing coil. ### Claim 21 (depends on 18) The electronic device of claim 18, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetic shield associated with the at least one coil. ### Claim 22 (depends on 17) The electronic device of claim 17, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetoresistive sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the magnetoresistive sensor. ### Claim 23 (depends on 17) The electronic device of claim 17, wherein the array of magnetic field sensing finger biometric pixels each comprises a Hall effect sensor; and wherein the processing circuitry is capable of sensing the counter magnetic field via the Hall effect sensor. ### Claim 24 (depends on 17) The electronic device of claim 17, further comprising a non-magnetic, dielectric material layer over the array of magnetic field sensing finger biometric pixels. ### Claim 25 (depends on 17) The electronic device of claim 17, further comprising at least one input device carried by the portable housing and carrying the array of magnetic field finger biometric sensing pixels. ### Claim 26 (depends on 25) The electronic device of claim 25, wherein the at least one input device comprises a pushbutton switch. ### Claim 27 A method of sensing a finger comprising: generating, using processing circuitry via at least one magnetic field finger biometric sensing pixel of the array thereof, a magnetic field extending into the finger positioned adjacent an array of magnetic field finger biometric sensing pixels to cause eddy currents in the finger; and sensing, using the processing circuitry via at least one magnetic field finger biometric sensing pixel of the array thereof, a counter magnetic field caused by the eddy currents based upon ridges and valleys of the finger for performing at least one authentication function. ### Claim 28 (depends on 27) The method of claim 27, wherein the array of magnetic field sensing finger biometric pixels each comprises at least one electrically conductive coil. ### Claim 29 (depends on 28) The method of claim 28, wherein the at least one electrically conductive coil comprises a driving coil; and wherein generating the magnetic field comprises generating the magnetic field via the driving coil. ### Claim 30 (depends on 28) The method of claim 28, wherein the at least one electrically conductive coil comprises a sensing coil; and wherein sensing the counter magnetic field comprises sensing the counter magnetic field via the sensing coil. ### Claim 31 (depends on 28) The method of claim 28, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetic shield associated with the at least one coil. ### Claim 32 (depends on 28) The method of claim 28, wherein using the processing circuitry comprises: generating an alternating current, using an alternating current generator, in the at least one coil; and sensing a phase difference, between the alternating current and a voltage of the at least one coil. ### Claim 33 (depends on 27) The method of claim 27, wherein the array of magnetic field sensing finger biometric pixels each comprises a magnetoresistive sensor; and wherein sensing the counter magnetic field comprises sensing the counter magnetic field via the magnetoresistive sensor. ### Claim 34 (depends on 27) The method of claim 27, wherein the array of magnetic field sensing finger biometric pixels each comprises a Hall effect sensor; and wherein sensing the counter magnetic field comprises sensing the counter magnetic field via the Hall effect sensor.