# US 12,008,835 B2 · Biometric imaging arrangement for infrared imaging comprising a waveguide formed on an image sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,008,835 B2 - Document ID: US12008835B2 - Status: Granted - Kind: B2 - Application number: 18/028,912 - Filed: 2021-09-29 - Published: 2023-10-19 - Granted: 2024-06-11 - Earliest claimed: 2020-10-01 - Assignees: Fingerprint Cards Anacatum IP AB - Applicants: Fingerprint Cards Anacatum IP AB - Inventors: Johan Hammersberg; Pontus Jägemalm - Web page: https://patentgrep.com/patent/US12008835B2 ## CPC - G06V 40/1318: {using electro-optical elements or layers, e.g. electroluminescent sensing} - G06V 10/145: Illumination specially adapted for pattern recognition, e.g. using gratings - H10F 39/184: {Infrared image sensors} - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces} - G02F 1/29: for the control of the position or the direction of light beams, i.e. deflection - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract The present invention relates to a biometric imaging arrangement comprising: an image sensor comprising a detector pixel array configured to detect infrared radiation transmitted from an object for capturing an image, a waveguide structure arranged on the image sensor to cover the detector pixel array, the waveguide structure comprising optical decoupling areas configured to orthogonally redirect infrared light received from a side of the waveguide structure towards the object when being placed for imaging. ## Claims ### Claim 1 A biometric imaging arrangement comprising: an image sensor comprising a detector pixel array configured to detect infrared radiation transmitted from an object for capturing an image, the detector pixel array being arranged on a first side of the image sensor, a waveguide structure attached directly on the detector pixel array side of the image sensor to cover the detector pixel array, the waveguide structure comprising optical decoupling areas configured to orthogonally redirect infrared light received from a side of the waveguide structure towards the object when being placed for imaging, wherein the biometric imaging arrangement is configured (i) to be arranged under a display panel of an electronic device comprising a display, and to acquire an image of the object located on an opposite side of the display panel, and wherein the waveguide structure comprises a grating pattern adapted to form the optical decoupling areas for redirecting the infrared light through openings in the display and towards the object. ### Claim 2 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the waveguide structure is a thin film covering the detector pixel array. ### Claim 3 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the waveguide structure is manufactured directly on the image sensor. ### Claim 4 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the decoupling areas of the waveguide structure are arranged to be aligned with the openings in the display. ### Claim 5 (depends on 1) The biometric imaging arrangement according to claim 1, wherein a dimension of the grating pattern is substantially the same as a wavelength of light exceeding the visible spectrum. ### Claim 6 (depends on 1) The biometric imaging arrangement according to claim 1, comprising at least one lens arranged between the waveguide structure and the display panel, the lens being configured to redirect infrared light transmitted from the object onto the photodetector pixel array. ### Claim 7 (depends on 1) The biometric imaging arrangement according to claim 1, comprising an infrared light source for producing the infrared light. ### Claim 8 (depends on 7) The biometric imaging arrangement according to claim 7, wherein the infrared light source is arranged adjacent to the waveguide structure. ### Claim 9 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the waveguide structure is a film formed on the image sensor, the film comprising a main surface facing away from the image sensor, and at least one side surface, wherein the film is adapted to receive the infrared light at the side surface, guide the infrared light through the waveguide parallel to a main plane of the film, and orthogonally redirect the infrared light at the decoupling areas. ### Claim 10 (depends on 9) The biometric imaging arrangement according to claim 9, wherein the at least one side surface is adapted to receive infrared light from the infrared light source. ### Claim 11 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the waveguide comprises a nanoimprinted material. ### Claim 12 (depends on 1) The biometric imaging arrangement according to claim 1, wherein the infrared light is narrow linewidth light. ### Claim 13 (depends on 1) An electronic device comprising: an at least partly transparent display panel, the biometric imaging arrangement according to claim 1, and processing circuitry configured to: receive a signal from the biometric imaging arrangement indicative of a biometric object touching the transparent display panel, perform a biometric authentication procedure based on the detected fingerprint. ### Claim 14 (depends on 13) The electronic device according to claim 13, wherein the electronic device is a mobile device. ### Claim 15 A method for manufacturing a biometric imaging arrangement comprising an image sensor having a detector pixel array, the method comprising: depositing a waveguide structure material on the detector pixel array of the image sensor; patterning the waveguide structure material to form decoupling areas configured to orthogonally redirect infrared light away from a plane of the detector pixel array; and producing the image sensor in a single production flow as the deposition and patterning of the waveguide structure material. ### Claim 16 (depends on 15) The method according to claim 15, wherein depositing comprises depositing a thin film of waveguide material on the detector pixel array. ### Claim 17 (depends on 15) The method according to claim 15, wherein the waveguide structure is a thin film covering the detector pixel array.