# US 11,029,730 B2 · System for discharging heat out of head-mounted display based on hybrid fan > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,730 B2 - Document ID: US11029730B2 - Status: Granted - Kind: B2 - Application number: 16/845,769 - Filed: 2020-04-10 - Published: 2020-07-30 - Granted: 2021-06-08 - Earliest claimed: 2017-04-19 - Assignees: Facebook Technologies, LLC - Applicants: Facebook Technologies, LLC - Inventors: Boyd Drew Allin; Robin Michael Miller - Web page: https://patentgrep.com/patent/US11029730B2 ## CPC - G06F 1/163: {Wearable computers, e.g. on a belt} - G02B 27/0176: {characterised by mechanical features} - G06F 1/20: Cooling means - G06F 1/203: {for portable computers, e.g. for laptops} - G06F 1/206: {comprising thermal management} - F28D 15/02: in which the medium condenses and evaporates, e.g. heat pipes {(heat pipes used in solar heat collectors F24S10/95; in radiators F28D1/0226; in nuclear reactors G21C15/257)} - G02B 7/008: {with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation} - G06F 3/011: {Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00)} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) ## Abstract A head-mounted display (HMD) includes a hybrid fan, a printed circuit board (PCB) with one or more electronic components and a heat pipe to dissipate heat. The hybrid fan has a center axis extending from a rear side of the HMD to a front side of the HMD. The hybrid fan pulls air from a rear side of the HMD. The heat pipe has an end coupled to the PCB. The heat pipe partially surrounds a periphery of the hybrid fan and transfers heat away from at least the PCB. The HMD further includes a side cover and a front cover. The side cover encloses the hybrid fan, the PCB and the heat pipe. The front cover is attached to the side cover with a slit between an outer edge of the front cover and an outer edge of the side cover to discharge air from the hybrid fan. ## Claims ### Claim 1 A head-mounted display (HMD) comprising: a fan having a center axis extending from a rear side of the HMD to a front side of the HMD, the fan configured to push air through a slit between a front cover of the HMD and a side cover of the HMD; a circuit board with at least one processor separated from the fan, the at least one processor generating heat during operation of the HMD; and a metal frame acting as a heat sink that receives the heat and dissipates the heat, the circuit board directly mounted onto a side of the metal frame. ### Claim 2 (depends on 1) The HMD of claim 1, wherein the front cover is attached to the side cover with the slit between an outer edge of the front cover and an outer edge of the side cover to discharge the heat out of the HMD. ### Claim 3 (depends on 1) The HMD of claim 1, wherein the air is pushed to flow at least partially along an inner surface of the front cover and out of the HMD through the slit. ### Claim 4 (depends on 1) The HMD of claim 1, wherein the metal frame is enclosed within the side cover. ### Claim 5 (depends on 1) The HMD of claim 1, wherein the side cover encloses the fan and the at least one processor. ### Claim 6 (depends on 1) The HMD of claim 1, wherein the fan is further configured to pull the air from a cavity between a face of a user wearing the HMD and the front side to cool down a temperature in the cavity. ### Claim 7 (depends on 1) The HMD of claim 1, wherein the fan is further configured to pull air from the rear side of the HMD to cool the at least one processor. ### Claim 8 (depends on 1) The HMD of claim 1, wherein the fan is further configured to exhaust air to flow over the at least one processor for cooling the at least one processor. ### Claim 9 (depends on 1) The HMD of claim 1, wherein the metal frame spreads the heat to facilitate discharging the heat out of the HMD through the slit. ### Claim 10 (depends on 1) The HMD of claim 1, wherein the metal frame has edges shaped with contours that at least partially match an internal contour of the side cover to support the side cover. ### Claim 11 (depends on 1) The HMD of claim 1, further comprising: a heat pipe in an interior space, the heat pipe at least partially surrounding a periphery of the fan and transferring the heat away from the at least one processor. ### Claim 12 (depends on 11) The HMD of claim 11, wherein an end of the heat pipe is coupled to the at least one processor via a thermal interface material, and the heat pipe transfers the heat away from the at least one processor into the metal frame. ### Claim 13 (depends on 11) The HMD of claim 11, wherein the heat pipe is horseshoe shaped with a first member coupled to the at least one processor, a second member extending parallel to the first member and a third member connecting the first member and the second member. ### Claim 14 (depends on 1) The HMD of claim 1, wherein the fan is a hybrid fan that exhausts the air at sides of the fan after pulling the air from the rear side of the HMD. ### Claim 15 A head-mounted display (HMD) comprising: a circuit board with at least one processor in an interior space defined by a front cover of the HMD and a side cover of the HMD, the at least one processor generating heat during operation of the HMD; a fan having a center axis extending from a rear side of the HMD to a front side of the HMD, the fan configured to push air through a slit between the front cover and the side cover to discharge the air and the heat out of the HMD; and a metal frame in the interior space acting as a heat sink that dissipates the heat generated by the at least one processor, the circuit board directly mounted onto a side of the metal frame. ### Claim 16 (depends on 15) The HMD of claim 15, wherein the front cover is attached to the side cover with the slit between an outer edge of the front cover and an outer edge of the side cover to discharge the heat out of the HMD. ### Claim 17 (depends on 15) The HMD of claim 15, wherein the fan is further configured to pull the air from a cavity between a face of a user wearing the HMD and the HMD front side to cool down a temperature in the cavity. ### Claim 18 (depends on 15) The HMD of claim 15, wherein the metal frame spreads the heat to facilitate discharging the heat out of the HMD through the slit. ### Claim 19 (depends on 15) The HMD of claim 15, wherein the fan is further configured to exhaust air to flow over the at least one processor for cooling the at least one processor. ### Claim 20 (depends on 15) The HMD of claim 15, wherein the air is pushed to flow at least partially along an inner surface of the front cover and out of the HMD through the slit.