AUGMENTED AND VIRTUAL REALITY DISPLAY SYSTEMS WITH SHARED DISPLAY FOR LEFT AND RIGHT EYES
A wearable display system includes a light projection system having one or more emissive micro-displays, e.g., micro-LED displays. The light projection system projects time-multiplexed left-eye and right-eye images, which pass through an optical router having a polarizer and a switchable polarization rotator. The optical router is synchronized with the generation of images by the light projection system to impart a first polarization to left-eye images and a second different polarization to right-eye images. Light of the first polarization is incoupled into an eyepiece having one or more waveguides for outputting light to one of the left and right eyes, while light of the second polarization may be incoupled into another eyepiece having one or more waveguides for outputting light to the other of the left and right eyes. Each eyepiece may output incoupled light with variable amounts of wavefront divergence, to elicit different accommodation responses from the user's eyes.
1 . A method, comprising:
outputting image light from a light projection system of a head-mounted display, the image light comprising left-eye image light for forming left-eye images time-multiplexed with right-eye image light for forming right-eye images;
receiving, by a polarizer of an optical router, the image light from the light projection system and only outputting image light with a first polarization state;
receiving, by a switchable polarization rotator of the optical router, the image light with the first polarization state and selectively changing a polarization state of the received image light to a second polarization state;
receiving, by a polarization-sensitive reflector of the optical router, the image light from the switchable polarization rotator and reflecting image light having the first polarization state and transmitting image light having the second polarization state; and
providing, by the optical router, at different times, the left-eye image light to a left eyepiece of the head-mounted display and the right-eye image light to a right eyepiece of the head-mounted display.
2 . The method of claim 1 , wherein receiving the image light with the first polarization state and selectively changing the polarization state of the received image light includes selectively changing the polarization state via a switchable half-wave plate (HWP).
3 . The method of claim 1 , further comprising:
synchronizing generation of left-eye image images by the light projection system and routing of the left-eye image light to the left eyepiece by the optical router with generation of the right-eye images by the light projection system and routing of the right-eye image light to the right eyepiece by the optical router, and
synchronizing the switchable polarization rotator with the light projection system to output left-eye image light with a first polarization state and to output right-eye image light with a second polarization different from the first polarization state.
4 . The method of claim 1 , wherein providing, at different times, the left-eye image light to the left eyepiece of the head-mounted display and the right-eye image light to the right eyepiece of the head-mounted display includes:
directing, by the polarization-sensitive reflector, left-eye image light having one of the first and second polarization states towards the left eyepiece; and
directing, by the polarization-sensitive reflector, right-eye image light having the other of the first and second polarization states towards the right eyepiece.
5 . The method of claim 1 , wherein receiving the image light from the switchable polarization rotator and reflecting image light having the first polarization state and transmitting image light having the second polarization state includes reflecting image light having the first polarization state and transmitting image light having the second polarization via a polarization beam splitter.
6 . The method of claim 1 , further comprising:
in-coupling, by a left-eye in-coupling optical element, image light into a left-eye waveguide of the left eyepiece;
out-coupling, by a left-eye out-coupling optical element, in-coupled image light out of the left-eye waveguide;
in-coupling, by a right-eye in-coupling optical element, image light into a right-eye waveguide of the right eyepiece; and
out-coupling, by a right-eye out-coupling optical element, in-coupled image light out of the right-eye waveguide.
7 . The method of claim 6 , further comprising:
outputting light with variable amounts of wavefront divergence corresponding to a plurality of depth planes from the left eyepiece; and
outputting light with variable amounts of wavefront divergence corresponding to a plurality of depth planes from the right eyepiece.
8 . The method of claim 6 , further comprising:
outputting light of a plurality of component colors, and wherein each of the left eyepiece and the right eyepiece includes a respective waveguide assembly comprising at least one dedicated waveguide for light of each component color.
9 . A method, comprising:
outputting image light from a light projection system of a head-mounted display, the image light comprising left-eye image light for forming left-eye images time-multiplexed with right-eye image light for forming right-eye images; and
receiving, by an optical router, the image light from the light projection system and providing, at different times, the left-eye image light to a left eyepiece of the head-mounted display and the right-eye image light to a right eyepiece of the head-mounted display,
wherein the left eyepiece comprises one or more left-eye waveguides, each left-eye waveguide comprising:
a left-eye polarization-sensitive in-coupling optical element configured to in-couple light having the first polarization state into the left-eye waveguide; and
a left-eye out-coupling optical element configured to out-couple in-coupled light out of the left-eye waveguide,
wherein the right eyepiece comprises one or more right-eye waveguides, each right-eye waveguide comprising:
a right-eye polarization-sensitive in-coupling optical element configured to in-couple light having the second polarization state into the right-eye waveguide; and
a right-eye out-coupling optical element configured to out-couple in-coupled light out of the right-eye waveguide, and
wherein the left-eye polarization-sensitive in-coupling optical element and the right-eye polarization-sensitive in-coupling optical element are disposed in a same image light path.
10 . The method of claim 9 , wherein a cleanup polarizer is disposed between the left-eye polarization-sensitive in-coupling optical element and the right-eye polarization-sensitive in-coupling optical element, and wherein the method further comprises:
blocking, by the cleanup polarizer, light not having a polarization for which the downstream polarization-sensitive in-coupling optical element is configured sensitive.
11 . The method of claim 9 , wherein providing, at the different times, the left-eye image light to the left eyepiece of the head-mounted display and the right-eye image light to the right eyepiece of the head-mounted display includes receiving, by a polarizer of the optical router, the image light from the light projection system and only outputting image light with a first polarization state.
12 . The method of claim 11 , wherein providing, at the different times, the left-eye image light to the left eyepiece of the head-mounted display and the right-eye image light to the right eyepiece of the head-mounted display includes receiving, by a switchable polarization rotator of the optical router, the image light from the polarizer with the first polarization state and selectively changing a polarization state of the received image light to a second polarization state.