# US 2025/0060426 A1 · Electronic Devices With Optical Assembly Position Sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0060426 A1 - Document ID: US20250060426A1 - Status: Published application - Kind: A1 - Application number: 18/755,068 - Filed: 2024-06-26 - Published: 2025-02-20 - Earliest claimed: 2023-08-15 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Aaron D Johnson; Matin Seadat Beheshti - Web page: https://patentgrep.com/patent/US20250060426A1 ## CPC - G01R 33/032: using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} - G02B 7/005: {Motorised alignment} - G02B 7/12: Adjusting pupillary distance of binocular pairs - G02B 27/0176: {characterised by mechanical features} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A head-mounted device may include optical assemblies for presenting images to a user. Each optical assembly may have a support configured to support a display, a lens through which an image from the display is presented to an eye box for viewing, and a sensor. Each support may have an opening configured to receive a guide rod along which the support slides to adjust where the optical assembly is positioned along that guide rod. Each guide rod may include a position index such as a strip-shaped index formed from alternating magnetic poles or alternating light and dark regions. A magnetic sensor or optical sensor may monitor the position index as the support slides along the guide rod to determine the position of the support and optical assembly along the guide rod. ## Claims ### Claim 1 A head-mounted device, comprising: a head-mounted housing; guide rods coupled to the head-mounted housing, each guide rod including a respective position index; and optical assemblies, wherein each optical assembly includes: a lens; a display that is configured to provide an image to an eye box through the lens; a sensor; and a support for the lens, display, and sensor, wherein the support of each optical assembly is configured to slide along a respective one of the guide rods while the sensor of that optical assembly makes position measurements on the respective position index of that guide rod. ### Claim 2 (depends on 1) The head-mounted device defined in claim 1 wherein the respective position index of each guide rod has regions with different magnetic poles. ### Claim 3 (depends on 2) The head-mounted device defined in claim 2 wherein the sensor of each optical assembly comprises a magnetic sensor. ### Claim 4 (depends on 3) The head-mounted device defined in claim 3 wherein each guide rod comprises a tube and wherein the respective position index of that guide rod comprises a magnetic position index that extends along an exterior surface of the tube. ### Claim 5 (depends on 3) The head-mounted device defined in claim 3 wherein each guide rod comprises a tube having a wall and wherein the respective position index of that guide rod comprises a magnetic position index embedded in the wall. ### Claim 6 (depends on 3) The head-mounted device defined in claim 3 wherein each guide rod comprises a tube having a wall and wherein the respective position index of that guide rod compromises a magnetic position index on an inner surface of the wall. ### Claim 7 (depends on 3) The head-mounted device defined in claim 3 wherein each guide rod has a groove and wherein the respective position index of that guide rod is formed in the groove and extends along that guide rod. ### Claim 8 (depends on 3) The head-mounted device defined in claim 3 wherein each guide rod has a wall formed at least partly from polymer and wherein the respective position index of that guide rod comprises a strip of magnetic particles embedded in the polymer. ### Claim 9 (depends on 3) The head-mounted device defined in claim 3 wherein the support of each optical assembly has an opening configured to receive a respective one of the guide rods and wherein the sensor of that optical assembly is mounted in the opening facing the respective position index. ### Claim 10 (depends on 1) The head-mounted device defined in claim 1 wherein each position index comprises a relative position index that the sensor is configured to monitor to determine a relative position of the sensor along that relative position index. ### Claim 11 (depends on 1) The head-mounted device defined in claim 1 wherein each position index comprises an absolute position index containing coded absolute position information that the sensor is configured to monitor to determine an absolute position of the sensor along the respective one of the guide rods. ### Claim 12 (depends on 1) The head-mounted device defined in claim 1 wherein each position index comprises relative position index regions and absolute position index portions interspersed among the relative position index regions. ### Claim 13 (depends on 1) The head-mounted device defined in claim 1 wherein the respective position index of each guide rod has alternating light and dark regions and wherein the sensor comprises an optical sensor configured to make the position measurements by measuring the alternating light and dark regions. ### Claim 14 (depends on 13) The head-mounted device defined in claim 13 wherein each guide rod has fibers that are configured to form at least part of the light and dark regions of that guide rod. ### Claim 15 (depends on 1) The head-mounted device defined in claim 1 wherein the respective position index of each guide rod has multiple tracks and wherein the sensor of the optical assembly that slides along that guide rod has multiple sensor elements each of which measures a respective one of the multiple tracks. ### Claim 16 A head-mounted device, comprising: a head-mounted housing; a guide rod coupled to the head-mounted housing, wherein the guide rod has a magnetic strip that extends along the guide rod; a support having an opening configured to receive the guide rod and allow the support to slide along the guide rod; a display supported by the support; a lens supported by the support; and a magnetic sensor supported by the support, wherein the magnetic sensor is configured to measure the magnetic strip to determine where the support is positioned along the guide rod. ### Claim 17 (depends on 16) The head-mounted device defined in claim 16 wherein the magnetic strip comprises a series of regions with alternating north and south magnetic poles and wherein the series of regions extends along the magnetic strip. ### Claim 18 (depends on 17) The head-mounted device defined in claim 17 wherein the magnetic sensor is mounted within the opening. ### Claim 19 A head-mounted device, comprising: a head-mounted housing; a guide rod coupled to the head-mounted housing, wherein the guide rod has light and dark regions; a support having an opening configured to receive the guide rod and allow the support to slide along the guide rod; a display supported by the support; a lens supported by the support; and an optical sensor configured to measure the light and dark regions to determine where the support is positioned along the guide rod. ### Claim 20 (depends on 19) The head-mounted device defined in claim 19 wherein the light and dark regions alternate in a strip along the guide rod.