# US 2019/0174124 A1 · Near-eye display system including a modulation stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174124 A1 - Document ID: US20190174124A1 - Status: Published application - Kind: A1 - Application number: 16/253,140 - Filed: 2019-01-21 - Published: 2019-06-06 - Earliest claimed: 2016-08-12 - Assignees: Avegant Corp. - Applicants: Avegant Corp. - Inventors: Aaron Matthew Eash; Allan Thomas Evans; Andrew John Gross; D. Scott Dewald; Eamon Han O'Connor; Forrest Foust; Warren Cornelius Welch, III - Web page: https://patentgrep.com/patent/US20190174124A1 ## CPC - G02B 7/06: Focusing binocular pairs - G02B 17/023: {for extending or folding an optical path, e.g. delay lines} - G02B 30/52: the three-dimensional [3D] volume being constructed from a stack or sequence of two-dimensional [2D] planes, e.g. depth sampling systems - G02F 1/0136: {for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence)} - H04N 13/383: for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes - G02B 2027/0127: {comprising devices increasing the depth of field} - G02B 2207/117: Adjustment of the optical path length - H04N 13/344: with head-mounted left-right displays - 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 - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A near-eye display system comprising an image source, a modulation stack, and an imaging assembly. The modulation stack, in one embodiment, comprises one or more digital light path length modulators. ## Claims ### Claim 1 A near-eye display system to display an image to a user comprising: an image source to provide light; a modulation stack comprising one or more digital light path length modulators, a digital light path length modulator comprising: a polarization modulator to receive light and to selectively modulate a polarization of the light; and a unitary optical path length extender (OPLE) to direct the light having a first polarization through a first light path through the OPLE, and to direct the light having a second polarization through a second light path through the OPLE, the first and second light paths having different light path lengths; and an imaging assembly to create a plurality of image portions at a plurality of virtual object distances, from the light output by the modulation stack, wherein a number of perceived virtual object distances depends on the number of the one or more digital light path length modulators. ### Claim 2 (depends on 1) The near-eye display system of claim 1, wherein the modulation stack adjusts the path length of the light by altering the polarization of the light between the one or more digital light path length modulators. ### Claim 3 (depends on 1) The near-eye display system of claim 1, wherein a farthest virtual object distance is infinity, and the image portions are moved to different virtual object distances. ### Claim 4 (depends on 1) The near-eye display system of claim 1, wherein the polarization modulator alters the path length of the light on a time sequential basis, creating a time sequential series of subframes at a plurality of virtual object distances, to create a discretized multi-focal light display. ### Claim 5 (depends on 1) The near-eye display system of claim 1, wherein the polarization modulator alters the path length of the light on a per pixel basis, to create a plurality of simultaneous image elements at a plurality of virtual object distances. ### Claim 6 (depends on 1) The near-eye display system of claim 1, further comprising: an eye tracking mechanism to track the user's eye; and the near-eye display system to automatically adjust the light path length to place a selected image portion at a determined virtual object distance, based on the data from the eye tracking mechanism. ### Claim 7 (depends on 6) The near-eye display system of claim 6, further comprising: a focal point selector to select an image portion and selectively focus or blur image elements outside the selected image portion. ### Claim 8 (depends on 1) The near-eye display system of claim 1, further comprising: binocular elements for a second eye of the user, the near-eye display system providing a binocular display, the binocular display providing both focus and vergence distance cues to create a realistic three dimensional image. ### Claim 9 (depends on 1) The near-eye display system of claim 1, wherein the plurality of virtual object distances are created based on one or more of: per pixel adjustment of the light path length, time sequential adjustment of the light path length, and variable adjustment of the light path length. ### Claim 10 (depends on 1) The near-eye display system of claim 1, wherein the image source comprises one or more of: a light source and a digital correction system, and an external image source. ### Claim 11 A near-eye display system to display an image to a user comprising: an image source to provide light; and a modulation stack to output light via a first light path and a second light path, the first light path and the second light path having different light path lengths, the light path lengths modulated by a digital signal; an imaging assembly to display a plurality of image portions at a plurality of virtual object distances, from the light output by the modulation stack. ### Claim 12 (depends on 11) The near-eye display system of claim 11, wherein the adjusting of the light path length enables adjustment in controlled diopter steps, without moving parts. ### Claim 13 (depends on 11) The near-eye display system of claim 11, wherein the modulation stack adjusts the light path length utilizing one or more digital light path length modulators, each digital light path length modulator including an optical path length extender (OPLE). ### Claim 14 (depends on 13) The near-eye display system of claim 13, further comprising: each of the digital light path length modulators comprising a polarization modulator, the polarization modulator being digitally controlled, and enabling a change of focus, based on adjusting the virtual object distances of the image portions in biological real time. ### Claim 15 (depends on 11) The near-eye display system of claim 11, further comprising: an eye tracking mechanism to track a user's eye; and the near-eye display system to automatically adjust the light path lengths to place a selected image portion in focus, based on data from the eye tracking mechanism. ### Claim 16 (depends on 11) The near-eye display system of claim 11, wherein the system creates a time series of virtual object distances, to create a multi-focal display. ### Claim 17 (depends on 11) The near-eye display system of claim 11, further comprising: a focal point selector to select an image portion and selectively focus or blur image portions outside the selected image portion. ### Claim 18 (depends on 11) The near-eye display system of claim 11, wherein the near-eye display system comprises one of: a virtual reality headset, an augmented reality headset, a camera, a microscope a display, focal assist in the microscope, a telescope, a digital scope, a medical display system, a rifle scope, and a range finder. ### Claim 19 A near-eye display system comprising: a first display subsystem comprising: a first image source to provide light; and a first modulation stack comprising a plurality of digital light path length modulators, each of the digital light path length modulators comprising: a digitally controlled polarization modulator to receive polarized light and to selectively modulate a polarization of the light; and a unitary optical path length extender (OPLE) to direct the light having a first polarization through a first light path through the OPLE, and to direct the light having a second polarization through a second light path through the OPLE, the first and second light paths having different light path lengths; a first imaging assembly to create a plurality of image portions at a plurality of focal lengths for display to a first eye of the user, from the light output by the modulation stack; a binocular elements display subsystem to provide binocular elements, the second display subsystem providing a second plurality of image portions at the plurality of focal lengths for display to a second eye; an auxiliary data system to receive external data and use the external data to adjust the virtual object distance of one or more image elements; the near-eye display system providing a binocular display providing both focus and vergence distance cues to create a realistic three dimensional image. ### Claim 20 (depends on 19) The near-eye display system of claim 19, wherein the plurality of image portions at a plurality of focal lengths are created based on one or more of: per pixel adjustment of the light path length, time sequential adjustment of the light path length, and variable adjustment of the light path length.