# US 2021/0278675 A1 · Eye imaging with an off-axis imager > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278675 A1 - Document ID: US20210278675A1 - Status: Published application - Kind: A1 - Application number: 17/326,920 - Filed: 2021-05-21 - Published: 2021-09-09 - Earliest claimed: 2015-09-23 - Assignees: Magic Leap, Inc. - Applicants: Magic Leap, Inc. - Inventors: Michael Anthony Klug; Adrian Kaehler - Web page: https://patentgrep.com/patent/US20210278675A1 ## CPC - G02B 27/0172: {characterised by optical features} - A61B 3/10: Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions - A61B 3/113: for determining or recording eye movement - A61B 3/12: for looking at the eye fundus, e.g. ophthalmoscopes (A61B3/13 takes precedence) - A61B 3/14: Arrangements specially adapted for eye photography - A61B 5/1122: {of movement trajectories} - A61B 5/163: {by tracking eye movement, gaze, or pupil change} - A61B 5/742: {using visual displays (displays for heart-related electrical signals, e.g. ECG, A61B5/339)} - G02B 27/0093: {with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking} - A61B 5/117: Identification of persons (methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00) - G02B 2027/0138: {comprising image capture systems, e.g. camera} - G02B 2027/0178: {Eyeglass type (eyeglass details G02C)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Examples of an imaging system for use with a head mounted display (HMD) are disclosed. The imaging system can include a forward-facing imaging camera and a surface of a display of the HMD can include an off-axis diffractive optical element (DOE) or hot mirror configured to reflect light to the imaging camera. The DOE or hot mirror can be segmented. The imaging system can be used for eye tracking, biometric identification, multiscopic reconstruction of the three-dimensional shape of the eye, etc. ## Claims ### Claim 1 An imaging system comprising: a reflective element that reflects light in a first wavelength range; and an imager sensitive to light in a non-empty subset of less than all of the first wavelength range, wherein the imager is configured to be oriented to capture light reflected by the reflective element. ### Claim 2 (depends on 1) The imaging system of claim 1, wherein the reflective element comprises a hot mirror, a holographic optical element (HOE), an off-axis holographic mirror (OAHM), or an off-axis volumetric diffractive optical element (OAVDOE). ### Claim 3 (depends on 1) The imaging system of claim 1, wherein the first wavelength range comprises an infrared wavelength range. ### Claim 4 (depends on 1) The imaging system of claim 1, wherein the imaging system comprises an optical element, wherein the optical element comprises the reflected element, and wherein the optical element is transmissive to at least 50% of visible light incident on the optical element. ### Claim 5 (depends on 1) The imaging system of claim 1, wherein the reflective element comprises a plurality of segments. ### Claim 6 (depends on 5) The imaging system of claim 5, wherein a first segment in the plurality of segments has an optical property that is different from an optical property of a second segment in the plurality of segments. ### Claim 7 (depends on 6) The imaging system of claim 6, wherein the optical property of the first segment in the plurality of segments or the optical property of the second segment in the plurality of segments comprises a reflection angle or an optical power. ### Claim 8 (depends on 5) The imaging system of claim 5, wherein two of the plurality of segments are arranged horizontally. ### Claim 9 (depends on 5) The imaging system of claim 5, wherein two of the plurality of segments are arranged vertically. ### Claim 10 (depends on 1) The imaging system of claim 1, wherein the imager further comprises a perspective control lens assembly comprising a shift lens, a tilt lens, or a shift-tilt lens. ### Claim 11 An imaging system comprising: a reflective element that reflects light in a first wavelength range, wherein the reflective element comprises an off-axis holographic mirror (OAHM) or an off-axis volumetric diffractive optical element (OAVDOE), and wherein the reflective element is oriented to reflect light propagating from an eye of a user when the imaging system is placed in front of the eye of the user; and an imager sensitive to light in a non-empty subset of less than all of the first wavelength range, wherein the imager is oriented to image an image of the eye of the user by capturing light propagating from the eye of the user reflected by the reflective element. ### Claim 12 (depends on 11) The imaging system of claim 11, wherein an effective location of the camera placed in front of the eye of the user is at infinity. ### Claim 13 (depends on 11) The imaging system of claim 11, wherein the first wavelength range comprises an infrared wavelength range. ### Claim 14 (depends on 11) The imaging system of claim 11, wherein the imaging system comprises an optical element, wherein the optical element comprises the reflected element, and wherein the optical element is transmissive to at least 50% of visible light incident on the optical element. ### Claim 15 (depends on 11) The imaging system of claim 11, wherein the reflective element comprises a plurality of segments. ### Claim 16 (depends on 15) The imaging system of claim 15, wherein a first segment in the plurality of segments has an optical property that is different from an optical property of a second segment in the plurality of segments. ### Claim 17 (depends on 16) The imaging system of claim 16, wherein the optical property of the first segment in the plurality of segments or the optical property of the second segment in the plurality of segments comprises a reflection angle or an optical power. ### Claim 18 (depends on 11) The imaging system of claim 11, wherein the imager further comprises a perspective control lens assembly. ### Claim 19 (depends on 18) The imaging system of claim 18, wherein the perspective control lens assembly comprises a shift lens, a tilt lens, or a shift-tilt lens. ### Claim 20 An imaging system comprising: a display comprising a reflective element that reflects light in a first wavelength range, wherein the reflective element comprises a hot mirror, an off-axis holographic mirror (OAHM), or an off-axis volumetric diffractive optical element (OAVDOE); and an imager sensitive to light in the first wavelength range, wherein the imager is configured to be oriented to capture at least light reflected by the reflective element.