Lightguide optical combiner for head wearable display

Abstract

An eyepiece for a head wearable display includes a lightguide component for guiding display light and emitting the display light along at a viewing region. The light guide component includes an input surface oriented to receive the display light into the lightguide component at the peripheral location, a first folding surface disposed to reflect the display light received through the input surface, a second folding surface disposed to reflect the display light received from the first folding surface, an eye-ward facing surface disposed opposite to the second folding surface to reflect the display light received from the second folding surface, and a curved reflective surface having reflective optical power disposed at the viewing region to receive the display light reflected from the eye-ward facing surface and to reflect the display light for emission out through the eye-ward facing surface.

1 . An eyepiece assembly for a wearable display, the eyepiece assembly comprising:
 a lightguide component configured to guide display light received from a display source and to emit the display light and an ambient light scene to a user of the wearable display along a viewing region, the light guide component including:
 an input surface oriented to receive the display light into the lightguide component from the display source; 
 a first folding surface disposed to receive the display light from the input surface without reflection and to reflect the received display light; 
 a second folding surface disposed to receive the reflected display light directly from the first folding surface and to generate a secondary reflection of the reflected display light, the second folding surface being a planar surface; and 
 an eye-ward facing surface disposed to face the second folding surface to receive light from the secondary reflection, wherein the eye-ward facing surface includes the viewing region, the viewing region being positioned to emit the received light and the ambient light scene out of the lightguide component toward an eye of the user; and 
   a camera module having a lens facing outward from the lightguide component away from the eye-ward facing surface, the camera module being disposed adjacent to at least one of the input surface and the second folding surface.   
     
     
         2 . The eyepiece assembly of  claim 1 , wherein the lightguide component further includes:
 a first notch surface that interfaces by contact with the input surface; and   a second notch surface that interfaces by contact with the second folding surface, the second notch surface being non-coplanar with the first notch surface;   wherein the first and second notch surfaces form an alcove in the lightguide component adjacent to the input surface, and the camera module is disposed in the alcove.   
     
     
         3 . The eyepiece assembly of  claim 1 , further comprising the display source. 
     
     
         4 . The eyepiece assembly of  claim 3 , further comprising a frame assembly to support the lightguide component and the camera module for wearing on a head of the user so that the viewing region is positioned in front of the eye of the user. 
     
     
         5 . The eyepiece assembly of  claim 3 , further comprising a frame assembly to support the lightguide component, the camera module and the display source for wearing on a head of the user so that the viewing region is positioned in front of the eye of the user,
 wherein the frame assembly is configured to position the display source peripherally to the user's central vision.   
     
     
         6 . The eyepiece assembly of  claim 1 , wherein the viewing region is positioned to emit the received light and the ambient light scene out of the lightguide component so that the received light is presented as a virtual image superimposed over the ambient light scene as an augmented reality scene. 
     
     
         7 . The eyepiece assembly of  claim 6 , wherein the eyepiece assembly is configured to increase contrast of the received light by fully, partially or selectively blocking the ambient light scene. 
     
     
         8 . The eyepiece assembly of  claim 1 , further comprising:
 a curved reflective surface having reflective optical power, the curved reflective surface disposed to receive the light from the secondary reflection, to collimate the received light and to direct the collimated light to the viewing region of the eye-ward facing surface;   wherein the eye-ward facing surface is disposed to receive the collimated light from the secondary reflection and the viewing region is positioned to emit the collimated light and the ambient light scene out of the lightguide component toward the eye of the user.   
     
     
         9 . The eyepiece assembly of  claim 8 , wherein the curved reflective surface comprises a partially reflective surface that is configured to partially reflect the light received from the secondary reflection, to transmit the ambient scene light through the viewing region, and to optically combine the ambient scene light with the light received from the secondary reflection. 
     
     
         10 . The eyepiece assembly of  claim 8 , further comprising:
 a see-through add-on component mounted to the lightguide component along the curved reflective surface, the see-through add-on component being formed of a material having an index of refraction substantially equivalent to that of the lightguide component,   wherein the see-through add-on component is at least partially transparent to the ambient scene.   
     
     
         11 . The eyepiece assembly of  claim 10 , wherein the see-through add-on component includes:
 an interface surface having a size and a curvature that mates to and complements the curved reflective surface of the lightguide component; and   an external scene facing surface having an alignment such that the ambient scene light that passes through the see-through add-on component and the lightguide in the viewing region experiences substantially no optical power.   
     
     
         12 . The eyepiece assembly of  claim 1 , wherein the first folding surface, the second folding surface, and the eye-ward facing surface are clear surfaces that are oriented relative to each other to reflect the display light via total internal reflection. 
     
     
         13 . A wearable display system configured to display imagery to a user, the wearable display comprising:
 a display source configured to generate display light;   a lightguide component configured to guide the display light received from the display source and to emit the display light and an ambient light scene to a user of the wearable display system along a viewing region, the light guide component including:
 an input surface oriented to receive the display light into the lightguide component from the display source; 
 a first folding surface disposed to receive the display light from the input surface without reflection and to reflect the received display light; 
 a second folding surface disposed to receive the reflected display light directly from the first folding surface and to generate a secondary reflection of the reflected display light, the second folding surface being a planar surface; and 
 an eye-ward facing surface disposed to face the second folding surface to receive light from the secondary reflection, wherein the eye-ward facing surface includes the viewing region, the viewing region being positioned to emit the received light and the ambient light scene out of the lightguide component toward an eye of the user; 
   a camera module having a lens facing outward from the lightguide component away from the eye-ward facing surface, the camera module being disposed adjacent to at least one of the input surface and the second folding surface; and   a housing receiving the camera module and at least a portion of the lightguide component therein, the housing being configured for wearing on a head of the user.   
     
     
         14 . The wearable display system of  claim 13 , wherein the housing further includes at least one of a microprocessor, a wireless transceiver, a battery, or a speaker. 
     
     
         15 . The wearable display system of  claim 13 , wherein the lens of the camera module is arranged to view the ambient light scene. 
     
     
         16 . The wearable display system of  claim 13 , wherein a front surface of the lens of the camera module is coplanar with the second folding surface. 
     
     
         17 . The wearable display system of  claim 13 , wherein:
 the wearable display system is a monocular wearable display system; and   the viewing region of the monocular wearable display system is positioned to emit the received light and the ambient light scene so that the received light is presented as a virtual image superimposed over the ambient light scene as an augmented reality scene.   
     
     
         18 . The wearable display system of  claim 13 , wherein:
 the wearable display system is a binocular wearable display system having a pair of lightguide components; and   the viewing region of each lightguide component is positioned to emit the received light and the ambient light scene out toward a respective eye of the user so that the received light is presented as a virtual image superimposed over the ambient light scene as an augmented reality scene.   
     
     
         19 . The wearable display system of  claim 13 , wherein the camera module is disposed in an alcove of the lightguide component. 
     
     
         20 . The wearable display system of  claim 19 , wherein the alcove is formed by a first notch surface that interfaces by contact with the input surface and a second notch surface that interfaces by contact with the second folding surface, the second notch surface being non-coplanar with the first notch surface.