# US 2019/0317320 A1 · Multi-focal augmented reality device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0317320 A1 - Document ID: US20190317320A1 - Status: Published application - Kind: A1 - Application number: 16/129,636 - Filed: 2018-09-12 - Published: 2019-10-17 - Earliest claimed: 2018-04-11 - Assignees: Korea Institute of Science and Technology - Applicants: Korea Institute of Science and Technology - Inventors: Soongi PARK; Minkoo KANG; Sungkyu KIM - Web page: https://patentgrep.com/patent/US20190317320A1 ## CPC - G02B 27/0101: {characterised by optical features (G02B27/0172 takes precedence)} - G02B 27/0093: {with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking} - G02B 27/14: operating by reflection only - G02B 27/144: {using partially transparent surfaces without spectral selectivity (G02B27/147 takes precedence)} - G06T 19/006: {Mixed reality (object pose determination, tracking or camera calibration for mixed reality G06T7/00)} - G02B 2027/0127: {comprising devices increasing the depth of field} - G02B 2027/013: {comprising a combiner of particular shape, e.g. curvature} - G02B 2027/0134: {of stereoscopic type} - G02B 2027/0185: {Displaying image at variable distance} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A multi-focal augmented reality device may include a multi-focal display that provides a plurality of images output from a plurality of image-providing devices and located at different depths and an augmented reality image synthesis device that synthesizes the plurality of images provided by the multi-focal display and an external image. ## Claims ### Claim 1 A multi-focal augmented reality device comprising: a multi-focal display configured to provide a plurality of images output from a plurality of image-providing devices and located at different depths; and an augmented reality image synthesis device configured to synthesize the plurality of images provided by the multi-focal display and an external image. ### Claim 2 (depends on 1) The multi-focal augmented reality device of claim 1, wherein the plurality of image-providing devices are disposed at different distances from a lens disposed between the multi-focal display and the augmented reality image synthesis device to provide the plurality of images located at the different depths. ### Claim 3 (depends on 1) The multi-focal augmented reality device of claim 1, wherein the multi-focal display comprises a beam splitter configured to match travelling directions of the plurality of images by passing some of the plurality of images and reflecting the other images, such that the plurality of images provided from the plurality of image-providing devices are viewed at the same position by a user. ### Claim 4 (depends on 3) The multi-focal augmented reality device of claim 3, wherein the number of beam splitters is one less than the number of image-providing devices. ### Claim 5 (depends on 1) The multi-focal augmented reality device of claim 1, wherein the augmented reality image synthesis device comprises a beam splitter configured to synthesize the images provided by the multi-focal display and the external image, and wherein the beam splitter is disposed to reflect the images provided by the multi-focal display and to pass the external image, and an image synthesized through the beam splitter is provided in a stereoscopic 3D manner. ### Claim 6 (depends on 1) The multi-focal augmented reality device of claim 1, wherein the augmented reality image synthesis device comprises a beam splitter and a concave mirror that are configured to synthesize the images provided by the multi-focal display and the external image, and wherein the beam splitter is disposed to reflect an image provided by the multi-focal display and then reflected by the concave mirror after passing through the beam splitter and to pass the external image. ### Claim 7 (depends on 1) The multi-focal augmented reality device of claim 1, further comprising: a controller configured to process the images provided by the plurality of image-providing devices, such that an image output through the augmented reality image synthesis device is viewed at a predetermined specific depth. ### Claim 8 (depends on 7) The multi-focal augmented reality device of claim 7, wherein the controller applies a depth-fused 3D method for adjusting luminance ratios of the images provided by the plurality of image-providing devices or a compressive light field display method for representing rays of light constituting the images as the sum or product of pixels located at the specific depth. ### Claim 9 (depends on 1) The multi-focal augmented reality device of claim 1, further comprising: an eye tracking sensor configured to track eyes of a user that views an image output from the augmented reality image synthesis device; and a controller configured to operate in conjunction with the eye tracking sensor to selectively drive only some of the plurality of image-providing devices, based on information received from the eye tracking sensor. ### Claim 10 (depends on 9) The multi-focal augmented reality device of claim 9, wherein the controller measures a fixation depth of the user, based on an interpupillary distance and a binocular vergence angle obtained from the eye tracking sensor, and drives only an image-providing device that provides an image closest to the fixation depth, among the plurality of image-providing devices. ### Claim 11 (depends on 1) The multi-focal augmented reality device of claim 1, wherein the plurality of image-providing devices correspond to an organic light emitting diode (OLED), a liquid crystal display (LCD), a liquid crystal on silicon (LCoS), a digital micro-mirror device (DMD), or a micro-electro-mechanical system (MEMS) scanning mirror.