3-Dimensional electro-optical see-through displays

Abstract

An exemplary display is placed in an optical pathway extending from an entrance pupil of a person's eye to a real-world scene beyond the eye. The display includes at least one 2-D added-image source that is addressable to produce a light pattern corresponding to a virtual object. The source is situated to direct the light pattern toward the person's eye to superimpose the virtual object on an image of the real-world scene as perceived by the eye via the optical pathway. An active-optical element is situated between the eye and the added-image source at a location that is optically conjugate to the entrance pupil and at which the active-optical element forms an intermediate image of the light pattern from the added-image source. The active-optical element has variable optical power and is addressable to change its optical power to produce a corresponding change in perceived distance at which the intermediate image is formed, as an added image to the real-world scene, relative to the eye.

1 . A see-through display for placement in an optical pathway extending from an entrance pupil of a person's eye to a real-world scene beyond the eye, the display comprising;
 at least one 2-D added-image source that is addressable to produce a light pattern corresponding to a virtual object and that is situated to direct the light pattern toward the person's eye to superimpose the virtual object on an image of the real-world scene as perceived by the eye via the optical pathway; and   an active-optical element situated between the eye and the added-image source at a location that is optically conjugate to the entrance pupil and at which the active-optical element forms an intermediate image of the light pattern from the added-image source, the active-optical element having variable optical power and being addressable to change its optical power to produce a corresponding change in perceived distance at which the intermediate image is formed, as an added image to the real-world scene, relative to the eye.   
     
     
         2 . The display of  claim 1 , wherein the added-image source is a micro-display comprising a 2-D array of light-producing pixels. 
     
     
         3 . The display of  claim 1 , wherein the active-optical element comprises a refractive active-optical element. 
     
     
         4 . The display of  claim 3 , wherein the refractive active-optical element comprises a liquid lens. 
     
     
         5 . The display of  claim 4 , wherein:
 the active-optical element and added-image source are situated on an optical axis that intersects the optical pathway; and   the refractive active-optical element further comprises a fixed-power objective lens situated on the optical axis.   
     
     
         6 . The display of  claim 1 , further comprising:
 a beam-splitter situated in the optical pathway to receive light of the intermediate image from the active-optical element along an optical axis that intersects the optical pathway at the beam-splitter such that the active-optical element is on a first side of the beam-splitter; and   a mirror located on the axis on a second side of the beam-splitter to reflect light back to the beam-splitter that has passed through the beam-splitter from the active-optical element.   
     
     
         7 . The display of  claim 6 , wherein the mirror is a condensing mirror. 
     
     
         8 . The display of  claim 7 , wherein:
 the mirror has a center of curvature and a focal plane; and   the active-optical element is situated at the center of curvature to produce a conjugate exit pupil through the beam-splitter.   
     
     
         9 . The display of  claim 7 , wherein, as the active-optical element addressably changes its optical power, the intermediate image is correspondingly moved relative to the focal plane to produce a corresponding change in distance of the added image relative to the eye. 
     
     
         10 . The display of  claim 9 , wherein the distance at which the added image is formed serves as an accommodation cue for the person with respect to the intermediate image. 
     
     
         11 . The display of  claim 6 , wherein the beam-splitter is further situated to reflect light reflected from the mirror to the person's eye. 
     
     
         12 . The display of  claim 1 , wherein the display is mountable on the person's head whenever the person is using the display. 
     
     
         13 . The display of  claim 1 , wherein the display is binocular and comprises first and a second optical pathways extending from respective eyes of the person to the real-world scene, first and second added-image sources associated with the respective optical pathways, and first and second active-optical elements, the first and second added-image sources and active-optical elements being situated relative to respective eyes of the person. 
     
     
         14 . The display of  claim 1 , wherein the display is addressably operable in at least one of a variable-single-focal-plane mode and a multi-focal-plane mode. 
     
     
         15 . The display of  claim 14 , wherein:
 for operation in the variable-single-focal-plane mode the display further comprises a user interface coupled to the active-optical element; and   the active-optical element is addressable to change its power in response to feedback produced by and received from the user interface being operated by the person.   
     
     
         16 . The display of  claim 15 , wherein:
 the user interface is configured to received, from the person, respective responses to accommodation and/or convergence cues perceived and interpreted by the person; and   the accommodation and/or convergence cues are provided by the display to the person interpreting a user-perceived distance of the intermediate image in the real-world view.   
     
     
         17 . The display of  claim 14 , wherein:
 for operation in the variable-single-focal-plane mode, the display further comprises an eye-tracker situated relative to the eye to detect and track a parameter of the eye related to accommodation and/or convergence; and   the active-optical element is addressable to change its power in response to feedback produced by and received from the eye-tracker.   
     
     
         18 . The display of  claim 17 , wherein:
 the display further comprises a controller connected to the eye-tracker and to the active-optical element; and   the controller receives data from the eye-tracker, interprets the data, and delivers corresponding address commands to the active-optical element to provide an accommodation and/or convergence cue regarding the virtual object as view by the person.   
     
     
         19 . The display of  claim 18 , wherein the controller delivers address commands to the active-optical element in real-time as the person perceives the intermediate image. 
     
     
         20 . The display of  claim 14 , wherein:
 for operation in the multi-focal-plane mode, the display further comprises a controller connected to the active-optical element; and   the active-optical element is addressable by the controller to change its optical power in response to a respective command received by the active-optical element from the controller.   
     
     
         21 . The display of  claim 20 , wherein the controller is configured to address the active-optical element in a time-multiplexed manner to cause the active-optical element to exhibit multiple respective discrete optical powers that form multiple respective discrete distances of the virtual object as perceived by the person. 
     
     
         22 . The display of  claim 21 , wherein:
 the controller is further connected to the added-image source to address the added-image source; and   the controller is configured to address the added-image source to cause the added-image source to produce respective light patterns at selected respective distances as perceived by the person.   
     
     
         23 . The display of  claim 22 , further comprising multiple added-image sources each being connected to and addressable by the controller to produce respective light patterns and to direct the light patterns, at respective distances and at respective times to the person's eye. 
     
     
         24 . The display of  claim 23 , wherein the respective light patterns produced by each added-image source are coordinated by the controller to respective focal distances exhibited by the active-optical element in response to respective addresses delivered to the active-optical element from the controller. 
     
     
         25 . The display of  claim 18 , wherein:
 the display is a binocular display comprising a respective eye-tracker for each eye; and   the controller is configured to interpret data and generate corresponding address commands for the active-optical element according to a variable-focus gaze-contingent algorithm comprising integrated convergence tracking of the person's eyes to provide the person with real-time focus cues regarding the virtual object.   
     
     
         26 . The display of  claim 21 , wherein the controller is configured to establish the discrete powers according to a depth-fused 3-D algorithm. 
     
     
         27 . The display of  claim 14 , wherein:
 the display is a binocular display comprising a respective active-optical element for each eye;   for operation in the variable-single-focal-plane mode, the display further comprises a respective eye-tracker for each eye;   the display further comprises a controller connected to the active-optical elements and to the eye-trackers; and   the controller is configured to receive point-of-gaze data from the eye-trackers and to address the active-optical elements to match the person's perceived convergence distances in real-time based on a variable-focus gaze-contingent display algorithm.   
     
     
         28 . The display of  claim 1 , further comprising:
 a condensing mirror; and   a beam-splitter;   wherein the active-optical element is configured to form an intermediate image of the light pattern;   the mirror is configured to relay light from the intermediate image to the beam-splitter; and   the beam-splitter is configured to direct the light toward the eye.   
     
     
         29 . The display of  claim 6 , wherein:
 the condensing mirror has a center of curvature; and   the active-optical element is situated at the center of curvature.   
     
     
         30 . The display of  claim 14 , wherein:
 for operation in the variable-single-focal-plane mode, the display further comprises a feedback device; and   the active-optical element is addressable to change its power in response to feedback provided by the feedback device.   
     
     
         31 . The display of  claim 14 , wherein, for operation in the multi-focal-plane mode, the display further comprises a controller connected to the active-optical element, the controller being programmed to address the active-optical element in a time-multiplexed manner to produce multiple intermediate images in the real-world view at different respective distances as perceived by the person. 
     
     
         32 . A method for producing an image of a virtual object in a view of a real-world scene as provide to at least one eye of a person, the method comprising:
 from a source other than the real-world scene, producing a light pattern corresponding to the virtual object;   directing the light pattern to an active-optical element, located optically conjugate to an entrance pupil of the eye to enable the active-optical element to form an intermediate image of the light pattern;   directing the intermediate image to the person's eye;   as the person is viewing the real-world scene and the intermediate image, addressing the active-optical element to provide a selected optical power, from a selectable range of optical powers, to produce a corresponding perceived distance at which the intermediate image is formed relative to the person's eye in the real-world scene.   
     
     
         33 . The method of  claim 32 , further comprising:
 producing the light pattern from an addressable source; and   addressing the source to impart a change in the light pattern.   
     
     
         34 . The method of  claim 32 , wherein the addressed change in the light pattern is coordinated with an addressed optical power provided by the active-optical element. 
     
     
         35 . The method of  claim 32 , further comprising:
 forming the intermediate image along a second axis intersecting the first axis;   at an intersection of the first and second axes, combining light of the intermediate image with light from the real-world scene such that the intermediate image is perceived by the person as being in the real-world scene at a distance corresponding to the selected optical power.   
     
     
         36 . The method of  claim 36 , wherein the active optical element is addressed according to a mode selected from a variable-single-focal-plane mode and a multi-focal-plane mode. 
     
     
         37 . The method of  claim 36 , further comprising, in the variable-single-focal-plane mode, addressing the active-optical element based on feedback data concerning at least one of accommodation and convergence exhibited by the person's eye. 
     
     
         38 . The method of  claim 37 , wherein the feedback data is produced by the person. 
     
     
         39 . The method of  claim 37 , wherein the feedback data is produced by monitoring an action of the eye as the eye views the intermediate image. 
     
     
         40 . The method of  claim 39 , wherein monitoring of the eye is performed by VF-GCD tracking of the person's point of gaze, the method further comprising computing a convergence distance of the eye from tracking of the person's point of gaze, and using the computed convergence distance to address the active-optical element to provide an updated focus cue to the person's eye. 
     
     
         41 . The method of  claim 36 , further comprising:
 in the variable-focal-plane mode, producing the light pattern from an addressable source;   controllably addressing the source and the active-optical element to provide intermediate images at respective distances from the person's eye, as perceived by the person.   
     
     
         42 . The method of  claim 41 , wherein the source and active-optical element are addressed according to a depth-fused 3-D algorithm in a time-multiplexed manner. 
     
     
         43 . The method of  claim 41 , wherein the active-optical element is addressed using a square-wave addressing command, in which discrete peaks of the square wave correspond to respective optical powers of the active-optical element. 
     
     
         44 . The method of  claim 43 , wherein the square-wave addressing command includes at least one null portion.