U.S. patent application number 16/215234 was filed with the patent office on 2020-02-20 for transmission improvement for flat lens based ar/vr glasses.
The applicant listed for this patent is Facebook Technologies, LLC. Invention is credited to Ningfeng Huang, Wai Sze Tiffany Lam, Lu Lu, Scott Charles McEldowney, Andrew John Ouderkirk, Barry David Silverstein.
Application Number | 20200057304 16/215234 |
Document ID | / |
Family ID | 69179979 |
Filed Date | 2020-02-20 |
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United States Patent
Application |
20200057304 |
Kind Code |
A1 |
Lu; Lu ; et al. |
February 20, 2020 |
TRANSMISSION IMPROVEMENT FOR FLAT LENS BASED AR/VR GLASSES
Abstract
An artificial-reality display uses an anisotropic material to
circularly-polarize light exiting a waveguide so that the
artificial-reality display is relatively transparent.
Inventors: |
Lu; Lu; (Kirkland, WA)
; Lam; Wai Sze Tiffany; (Redmond, WA) ; Huang;
Ningfeng; (Redmond, WA) ; McEldowney; Scott
Charles; (Redmond, WA) ; Ouderkirk; Andrew John;
(Kirkland, WA) ; Silverstein; Barry David;
(Kirkland, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Facebook Technologies, LLC |
Menlo Park |
CA |
US |
|
|
Family ID: |
69179979 |
Appl. No.: |
16/215234 |
Filed: |
December 10, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62764937 |
Aug 16, 2018 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 27/0172 20130101;
G02B 27/48 20130101; G02B 2027/0125 20130101; G02B 6/0056 20130101;
G02B 2027/0178 20130101 |
International
Class: |
G02B 27/01 20060101
G02B027/01; G02B 27/48 20060101 G02B027/48; F21V 8/00 20060101
F21V008/00 |
Claims
1. (canceled)
2. The system of claim 8, wherein the uniform polarization is
elliptical polarization.
3. The system of claim 8, wherein light is polarized before
entering into the waveguide.
4. The system of claim 8, wherein the geometric-phase lens is a
Pancharatnam Berry Phase (PBP) liquid crystal lens.
5. The system of claim 8, wherein the waveplate has an anisotropic
material that has a birefringence that is uniform across the
waveplate.
6. The system of claim 8, wherein the system comprises a linear
polarizer between the optical source and the coupling element.
7. The system of claim 8, further comprising a frame, wherein: the
frame is part of glasses to be worn by a user; and the waveguide,
the waveplate, and the geometric-phase lens are secured in the
frame.
8. A system comprising: an optical source; a waveguide; a coupling
element, wherein the coupling element is configured to couple light
from the optical source into the waveguide; a decoupling element,
wherein the decoupling element is configured to couple light out of
the waveguide so that light decoupled out of the waveguide has a
uniform polarization; a waveplate, wherein the waveplate is
configured to convert light with the uniform polarization into
circularly-polarized light and a geometric-phase lens configured to
focus circularly-polarized light, wherein the waveplate is between
the decoupling element and the geometric-phase lens, and wherein
the waveplate and the geometric-phase lens are bonded together as
part of a lens stack.
9. The system of claim 8, wherein: the lens stack is a first lens
stack; the system further comprises a second lens stack; the second
lens stack comprises a geometric-phase lens; and the waveguide is
between the first lens stack and the second lens stack.
10. A system comprising: an optical source; a waveguide; a coupling
element, wherein the coupling element is configured to couple light
from the optical source into the waveguide; a decoupling element,
wherein: the decoupling element couples light out of the waveguide;
and light coupled out of the waveguide has a spatially-varying
polarization; a waveplate, wherein the waveplate has a
spatially-varying fast axis configured to convert light with the
spatially-varying polarization into circularly-polarized light; and
a geometric-phase lens configured to focus circularly-polarized
light, wherein the waveplate is between the decoupling element and
the geometric-phase lens.
11. The system of claim 10, wherein: the waveplate is divided into
a plurality of zones; the plurality of zones includes a first zone
and a second zone; and the waveplate comprises an optically
anisotropic material having a fast axis with an orientation that
varies, such that: the orientation of the fast axis in the first
zone is at a first angle; the orientation of the fast axis in the
second zone is at a second angle; and the first angle is not equal
to the second angle.
12. The system of claim 11, wherein the plurality of zones creates
a residual defocus of combined light that is below a threshold
value.
13. The system of claim 11, wherein a number of the plurality of
zones is equal to or greater than 25 and equal to or less than
225.
14. The system of claim 10, further comprising a linear polarizer
between the optical source and the coupling element.
15. The system of claim 10, further comprising a frame, wherein:
the frame is part of glasses to be worn by a user; and the
waveguide, the waveplate, and the geometric-phase lens are secured
in the frame.
16. A system comprising: an optical source; a waveguide; a coupling
element, wherein the coupling element is configured to couple light
from the optical source into the waveguide; a decoupling element,
wherein the decoupling element is configured to couple light out of
the waveguide; a geometric-phase lens configured to focus
circularly-polarized light; and a circular polarizer comprising: a
linear polarizer having a polarization bandwidth, wherein: the
polarization bandwidth is equal to or greater than 5 nm and equal
to or less than 50 nm; and the linear polarizer has a transmission
axis; and a waveplate, wherein a combination of the linear
polarizer and the waveplate is configured to pass one handedness of
circularly-polarized light and block a second handedness of
circularly-polarized light.
17. The system of claim 16, wherein: the linear polarizer is a
first linear polarizer; the polarization bandwidth is a first
polarization bandwidth; the system further comprises a second
linear polarizer; the second linear polarizer has a second
polarization bandwidth, wherein: the second polarization bandwidth
is equal to or greater than 5 nm and equal to or less than 50 nm;
and the second polarization bandwidth is different than the first
polarization bandwidth.
18. The system of claim 17, wherein the first linear polarizer is
configured to polarizes red light and the second linear polarizer
is configured to polarize blue light.
19. The system of claim 17, wherein: the system further comprises a
third linear polarizer; and the first linear polarizer, the second
linear polarizer, and the third linear polarizer are part of the
circular polarizer.
20. The system of claim 16, wherein the geometric-phase lens is
between the decoupling element and the circular polarizer.
21. The system of claim 10, wherein light exiting the waveguide has
spatially-varying, elliptical polarization.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 62/764,937, filed on Aug. 16, 2018, which is
incorporated by reference for all purposes.
BACKGROUND
[0002] This disclosure relates generally to near-eye-display
systems, and more specifically to waveguide displays. Conventional
near-eye displays generally have a display element that generates
image light that passes through one or more lenses before reaching
a user's eye. Additionally, near-eye displays in virtual-reality
(VR) systems and/or augmented-reality (AR) systems have design
criteria to be compact, be light weight, and provide
two-dimensional expansion with a large eye box and a wide
field-of-view (FOV). Traditionally, VR displays are magnifier
optics displays. A computer generates an image, and optics are used
to magnify the image. It is challenging to design near-eye displays
to achieve a small form factor, a large FOV, and/or a large eye
box.
SUMMARY
[0003] The present disclosure relates to artificial-reality
displays. More specifically, and without limitation, an anisotropic
material to circularly-polarize light exiting a waveguide is used
so that an artificial-reality display is relatively
transparent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Illustrative embodiments are described with reference to the
following figures.
[0005] FIG. 1 is a diagram of an embodiment of a near-eye
display.
[0006] FIG. 2 is an embodiment of a cross section of the near-eye
display.
[0007] FIG. 3 illustrates an isometric view of an embodiment of a
waveguide display.
[0008] FIG. 4 illustrates a cross section of an embodiment of the
waveguide display.
[0009] FIG. 5 is a block diagram of an embodiment of a system
including the near-eye display.
[0010] FIG. 6 is an exploded view of an embodiment of a lens system
of a waveguide display assembly.
[0011] FIG. 7 is an exploded view of an embodiment of a lens stack
in the lens system.
[0012] FIG. 8 illustrates a cross section of an embodiment of a
waveguide.
[0013] FIG. 9 illustrates a first example of polarization of light
exiting a waveguide.
[0014] FIG. 10 illustrates an embodiment of a fast axis orientation
for a lens having an anisotropic material.
[0015] FIG. 11 illustrates a second example of polarization of
light exiting a waveguide.
[0016] FIG. 12 illustrates an embodiment of fast axis orientations
for a lens having an anisotropic material with a birefringence
property that varies spatially.
[0017] FIG. 13 is an exploded view of another embodiment of a lens
stack.
[0018] FIG. 14 illustrates an embodiment of a flowchart of a
process for using a lens system.
[0019] FIG. 15 illustrates an embodiment of a flowchart of a
process for creating a lens having an anisotropic material with a
birefringence property that varies spatially.
[0020] The figures depict embodiments of the present disclosure for
purposes of illustration only. One skilled in the art will readily
recognize from the following description that alternative
embodiments of the structures and methods illustrated may be
employed without departing from the principles, or benefits touted,
of this disclosure.
[0021] In the appended figures, similar components and/or features
may have the same reference label. Further, various components of
the same type may be distinguished by following the reference label
by a dash and a second label that distinguishes among the similar
components. If only the first reference label is used in the
specification, the description is applicable to any one of the
similar components having the same first reference label
irrespective of the second reference label.
DETAILED DESCRIPTION
[0022] In the following description, for the purposes of
explanation, specific details are set forth in order to provide a
thorough understanding of certain inventive embodiments. However,
it will be apparent that various embodiments may be practiced
without these specific details. The figures and description are not
intended to be restrictive.
[0023] This disclosure relates to reducing tint in, and/or
increasing efficiency of, an augmented-reality (AR) display. More
specifically, and without limitation, this disclosure relates to
reducing tint for an AR display that uses a Pancharatnam-Berry
Phase (PBP) lens. In U.S. patent application Ser. No. 15/693,846,
filed on Sep. 1, 2017, which is incorporated by reference for all
purposes, a PBP lens is used to change a focal length of an AR
display. The PBP lens is configured specifically to receive
circularly-polarized light. Thus a circular polarizer can be placed
before the PBP lens to provide the PBP lens with
circularly-polarized light. A traditional circular polarizer
comprises a linear polarizer and a quarter-wave plate. The linear
polarizer, of the circular polarizer, attenuates (e.g., reflects or
absorbs) about half of randomly-polarized light. Natural light is
randomly-polarized. Thus natural light is attenuated by about half
by a lens system having a traditional circular polarizer, and the
lens appears darker. A dark lens may not be as socially acceptable
in as many situations as glasses used for AR that look clear.
[0024] Using a circular polarizer can also reduce efficiency of
light from a projector in an AR display. A waveguide can be used in
an AR display as a pupil expander through a variety of methods,
such as pupil replication. Light is emitted from a projector,
coupled into a waveguide, coupled out of the waveguide (e.g., using
a grating), and transmitted to a user's eye. The PBP lens is placed
between the waveguide and the user's eye to change focus of light
emitted from the waveguide, which allows for changing the image
plane of the waveguide. Placing a circular polarizer between the
waveguide and the PBP lens can reduce transmission of display
light, because the linear polarizer of the circular polarizer
attenuates light that is not both linearly polarized and aligned
with a transmission axis of the linear polarizer.
[0025] One way to reduce attenuation by the linear polarizer of the
circular polarizer is to remove the linear polarizer and design the
grating to emit light from the waveguide with uniform polarization.
A waveplate can then be used to change the uniform polarization of
light emitted from the waveguide into circularly-polarized light,
before the light is transmitted to the PBP lens.
[0026] Another way to reduce attenuation by the linear polarizer of
the circular polarizer is to linearly polarize light coupling into
the waveguide, but instead of designing the gratings to output a
uniform polarization, use a non-uniform waveplate that compensates
for non-uniform polarization exiting the waveguide. The light out
coupled from the waveguide may have non-uniform polarization, but
the non-uniformity may be different in a deterministic manner, such
that a non-uniform waveplate can be configured to transform the
light from the waveguide into uniform circularly-polarized light.
The non-uniformity and configuration of the waveplate is dependent
on the deterministic manner in which the non-uniform polarized
light out couples from the waveguide. By determining local
variations of polarizations in light emitted from the waveguide, a
waveplate can be designed with local variations in thickness and/or
optic axis orientation of the birefringent materials (such as
liquid crystals) of the waveplate to convert light emitted from the
waveguide into circularly polarized light, without using a linear
polarizer.
[0027] A further way to reduce attenuation is to use circular
polarizers with limited bandwidths. In some embodiments, the
projector uses sources with limited bandwidths. For example, the
projector could have red, green, and blue light-emitting diodes
(LEDs). Three circular polarizers could be placed between the
waveguide and the PBP lens. A first circular polarizer could have a
first linear polarizer that polarizes a limited bandwidth of red
light corresponding to wavelengths of the red LEDs, a second
circular polarizer could have a second linear polarizer that
polarizers a limited bandwidth of green light corresponding to
wavelengths of the green LEDs, and a third circular polarizer could
have a third linear polarizer that polarizes a limited bandwidth of
blue light corresponding to the blue LEDs. By polarizing only a
portion of the visible spectrum, less natural light is attenuated
by the linear polarizers.
[0028] FIG. 1 is a diagram of an embodiment of a near-eye display
100. The near-eye display 100 presents media to a user. Examples of
media presented by the near-eye display 100 include one or more
images, video, and/or audio. In some embodiments, audio is
presented via an external device (e.g., speakers and/or headphones)
that receives audio information from the near-eye display 100, a
console, or both, and presents audio data based on the audio
information. The near-eye display 100 is generally configured to
operate as a virtual reality (VR) display. In some embodiments, the
near-eye display 100 is modified to operate as an augmented reality
(AR) display and/or a mixed reality (MR) display.
[0029] The near-eye display 100 includes a frame 105 and a display
110. The frame 105 is coupled to one or more optical elements. The
display 110 is configured for the user to see content presented by
the near-eye display 100. In some embodiments, the display 110
comprises a waveguide display assembly for directing light from one
or more images to an eye of the user.
[0030] FIG. 2 is an embodiment of a cross section 200 of the
near-eye display 100 illustrated in FIG. 1. The display 110
includes at least one waveguide display assembly 210. An exit pupil
230 is a location where the eye 220 is positioned in an eye box
region when the user wears the near-eye display 100. For purposes
of illustration, FIG. 2 shows the cross section 200 associated with
an eye 220 and a waveguide display assembly 210; a second waveguide
display assembly is used for a second eye of a user.
[0031] The waveguide display assembly 210 is configured to direct
image light to an eye box located at the exit pupil 230 and to the
eye 220. The waveguide display assembly 210 may be composed of one
or more materials (e.g., plastic, glass, etc.) with one or more
refractive indices. In some embodiments, the near-eye display 100
includes one or more optical elements between the waveguide display
assembly 210 and the eye 220. In some embodiments, the waveguide
display assembly 210 includes one or more waveguide displays to
generate a singular view to a user.
[0032] FIG. 3 illustrates an isometric view of an embodiment of a
waveguide display 300. In some embodiments, the waveguide display
300 is a component of the waveguide display assembly 210 of the
near-eye display 100. In some embodiments, the waveguide display
300 is part of some other near-eye display or other system that
directs image light to a particular location.
[0033] The waveguide display 300 includes a source assembly 310, an
output waveguide 320, and a controller 330. For purposes of
illustration, FIG. 3 shows the waveguide display 300 associated
with a single eye 220, but in some embodiments, another waveguide
displays separate, or partially separate, from the waveguide
display 300 provides image light to another eye of the user.
[0034] The source assembly 310 generates image light 355. The
source assembly 310 generates and outputs the image light 355 to a
coupling element 350 located on a first side 370-1 of the output
waveguide 320. The output waveguide 320 is an optical waveguide
that outputs expanded image light 340 to an eye 220 of a user. The
output waveguide 320 receives the image light 355 at one or more
coupling elements 350 located on the first side 370-1 and guides
received input image light 355. In some embodiments, the coupling
element 350 couples the image light 355 from the source assembly
310 into the output waveguide 320. The coupling element 350 may be,
e.g., a diffraction grating, a holographic grating, one or more
cascaded reflectors, one or more prismatic surface elements, a
metalens, a refractive surface at an angle with or without optical
power, and/or an array of holographic reflectors.
[0035] Light from the output waveguide 320 is coupled out of the
output waveguide 320 using a decoupling element 365. Expanded image
light 340 decoupled from the output waveguide 320 is transmitted to
the eye 220 of a user. In some embodiments, a directing element 360
is used to redirect light in the output waveguide 320 to the
decoupling element 365. The directing element 360 is part of, or
affixed to, the first side 370-1 of the output waveguide 320. The
decoupling element 365 is part of, or affixed to, the second side
370-2 of the output waveguide 320, such that the directing element
360 is opposed to the decoupling element 365. The directing element
360 and/or the decoupling element 365 may be, e.g., a diffraction
grating, a holographic grating, one or more cascaded reflectors,
one or more prismatic surface elements, a Bragg grating, and/or an
array of holographic reflectors.
[0036] The second side 370-2 represents a plane along an
x-dimension and a y-dimension. The output waveguide 320 may be
composed of one or more materials that facilitate total internal
reflection of the image light 355 with a transparency in wavelength
bands of interest. The output waveguide 320 may be composed of
plastic, glass, and/or polymers. The output waveguide 320 has a
relatively small form factor. For example, the output waveguide 320
may be approximately 50 mm wide along an x-dimension; 30 mm long
along a y-dimension; and 0.3 to 5.0 mm thick along a
z-dimension.
[0037] In some embodiments, the waveguide display 300 comprises
multiple output waveguides 320. For example, waveguide display 300
comprises a stacked waveguide display. The stacked waveguide
display is a polychromatic display that can be projected on
multiple planes (e.g. multi-planar colored display; a
red-green-blue (RGB) display created by stacking output waveguides
320 used for different colors). The stacked waveguide display can
comprise three output waveguides 320, one output waveguide 320 for
red light, one output waveguide 320 green light, and one output
waveguide 320 blue light (sometimes referred to as a waveguide
stack). In some configurations, the stacked waveguide display is a
monochromatic display that can be projected on multiple planes
(e.g. multi-planar monochromatic display). In some configurations,
the waveguide display 300 is a varifocal waveguide display. The
varifocal waveguide display is a display that can adjust a focal
position of image light emitted from the waveguide display. In some
embodiments, the waveguide display assembly 210 may include the
stacked waveguide display and the varifocal waveguide display. In
some embodiments, a single output waveguide 320 is used for a wide
spectrum of light. For example, a Bragg grating is used as the
decoupling element 365 and out couples red, green, and blue light
from the output waveguide 320.
[0038] The controller 330 controls light emitted from the source
assembly 310. For example, the controller 330 controls scanning
operations of the source assembly 310 and/or timing of light
sources turning off and on. The controller 330 can determine
scanning instructions for the source assembly 310. The controller
330 can be used to control full-field projector engines. In some
embodiments, the output waveguide 320 outputs expanded image light
340 with a large field of view (FOV) to the user's eye 220. For
example, expanded image light 340 is provided to the user such that
the waveguide display 300 has a field of view equal to or greater
than 60 degrees and equal to or less than 150 degrees in x and/or
y. The output waveguide 320 is configured to provide an eye box
with a length equal to or greater than 10 mm and equal to or less
than 50 mm in x and/or y. The controller 330 can be used in
conjunction with a graphics engine to render image information
based on sensors measuring head and/or eye location.
[0039] FIG. 4 illustrates an embodiment of a cross section 400 of
the waveguide display 300. The cross section 400 includes the
source assembly 310 and the output waveguide 320. The source
assembly 310 generates image light 355 in accordance with scanning
instructions from the controller 330. The source assembly 310
includes a source 410 and an optics system 415. The source 410 is a
light source that generates coherent, partially coherent, and/or
incoherent light. The source 410 may include one or more of a laser
diode, a vertical cavity surface emitting laser, a
liquid-crystal-on-silicon, an organic or inorganic light emitting
diode, and/or a superluminescent diode.
[0040] The optics system 415 includes one or more optical
components that condition the light from the source 410.
Conditioning light from the source 410 may include, e.g.,
expanding, collimating, and/or adjusting orientation in accordance
with instructions from the controller 330. One or more optical
elements in the optics system 415 can be used for despeckling.
Speckle forms from coherent light interference. If all light were
perfectly coherent and perfect plane waves a macro version of
speckle develop: interference fringes. Surface defects essentially
create new sources over optical elements that interfere at a micro
level creating speckle. Speckle cannot be imaged away, but rather
optical elements can be used to decohere or temporally or spatially
mix coherent light. Spectral broadening, increasing and mixing
angular extent, depolarization, temporal diffusion, can help reduce
speckle. Optical elements for despeckling can be placed closer to a
final image plane so that new sources for speckle do not emerge.
The one or more optical components may include one or more lens,
liquid lens, mirror, freeform element, aperture, metamaterials,
and/or grating. Light emitted from the optics system 415 (and also
the source assembly 310) is sometimes referred to as image light
355.
[0041] The output waveguide 320 receives the image light 355. The
coupling element 350 couples the image light 355 from the source
assembly 310 into the output waveguide 320. In embodiments where
the coupling element 350 is diffraction grating, a pitch of the
diffraction grating is chosen such that total internal reflection
occurs in the output waveguide 320, and the image light 355
propagates internally in the output waveguide 320 (e.g., by total
internal reflection), toward the decoupling element 365. The
directing element 360 redirects the image light 355 toward the
decoupling element 365 for decoupling from the output waveguide
320.
[0042] In some embodiments, the directing element 360 and/or the
decoupling element 365 are structurally similar. The expanded image
light 340 exiting the output waveguide 320 is expanded along one or
more dimensions (e.g., may be elongated along x-dimension). In some
embodiments, the waveguide display 300 includes a plurality of
source assemblies 310 and a plurality of output waveguides 320.
Each of the source assemblies 310 emits a monochromatic image light
of a specific band of wavelength corresponding to a primary color
(e.g., red, green, or blue). Each of the output waveguides 320 may
be stacked together with a distance of separation to output an
expanded image light 340 that is multi-colored. In some
embodiments, other color schemes are used (e.g., RGBW)
[0043] FIG. 5 is a block diagram of an embodiment of a system 500
including the near-eye display 100. The system 500 comprises the
near-eye display 100, an imaging device 535, and an input/output
interface 540 that are each coupled to a console 510.
[0044] The near-eye display 100 is a display that presents media to
a user. Examples of media presented by the near-eye display 100
include one or more images, video, and/or audio. In some
embodiments, audio is presented via an external device (e.g.,
speakers and/or headphones) that receives audio information from
the near-eye display 100 and/or the console 510 and presents audio
data based on the audio information to a user. In some embodiments,
the near-eye display 100 may also act as an AR eyewear glass. In
some embodiments, the near-eye display 100 augments views of a
physical, real-world environment, with computer-generated elements
(e.g., images, video, sound, etc.).
[0045] The near-eye display 100 includes a waveguide display
assembly 210, one or more position sensors 525, and/or an inertial
measurement unit (IMU) 530. The waveguide display assembly 210
includes the source assembly 310, the output waveguide 320, and the
controller 330. The IMU 530 is an electronic device that generates
fast calibration data indicating an estimated position of the
near-eye display 100 relative to an initial position of the
near-eye display 100 based on measurement signals received from one
or more of the position sensors 525. The imaging device 535
generates slow calibration data in accordance with calibration
parameters received from the console 510. The imaging device 535
may include one or more cameras and/or one or more video cameras.
The input/output interface 540 is a device that allows a user to
send action requests to the console 510. An action request is a
request to perform a particular action. For example, an action
request may be to start or end an application or to perform a
particular action within the application. The console 510 provides
media to the near-eye display 100 for presentation to the user in
accordance with information received from one or more of: the
imaging device 535, the near-eye display 100, and the input/output
interface 540. In the example shown in FIG. 5, the console 510
includes an application store 545, a tracking module 550, and an
engine 555. The application store 545 stores one or more
applications for execution by the console 510. An application is a
group of instructions, that when executed by a processor, generates
content for presentation to the user. Examples of applications
include: gaming applications, conferencing applications, video
playback application, or other suitable applications. The tracking
module 550 calibrates the system 500 using one or more calibration
parameters and may adjust one or more calibration parameters to
reduce error in determination of the position of the near-eye
display 100. The tracking module 550 tracks movements of the
near-eye display 100 using slow calibration information from the
imaging device 535. The tracking module 550 also determines
positions of a reference point of the near-eye display 100 using
position information from the fast calibration information.
[0046] The engine 555 executes applications within the system 500
and receives position information, acceleration information,
velocity information, and/or predicted future positions of the
near-eye display 100 from the tracking module 550. In some
embodiments, information received by the engine 555 may be used for
producing a signal (e.g., display instructions) to the waveguide
display assembly 210 that determines a type of content presented to
the user.
[0047] FIG. 6 is an exploded view of an embodiment of a lens system
of a waveguide display assembly 210. The lens system comprises one
or more waveguides 604 (e.g., similar to the output waveguide 320)
and one or more lens stacks 608. The lens system in the embodiment
shown in FIG. 6 comprises a first waveguide 604-1, a second
waveguide 604-2, a third waveguide 604-3, a first lens stack 608-1,
a second lens stacks 608-2, and an adaptive dimming element 612.
The lens system is secured in the frame 105. Light from the source
410 is coupled into a waveguide 604 using a coupling element 350.
Light is guided in the waveguide 604 (e.g., using total internal
reflection) and coupled out of the waveguide 604 using a decoupling
element 365. Light coupled out of the waveguide 604 is directed
toward an eye 220 of a user of a near-eye display 100. The
waveguides 604 are part of the near-eye display 100.
[0048] A waveguide 604 and/or a decoupling element 365 for a
waveguide 604 can be built for a specific wavelength, or frequency
band, of light. For example, the decoupling element of the first
waveguide 604-1 is designed to decouple red light; the decoupling
element of the second waveguide 604-2 is designed to decouple green
light; and the decoupling element of the third waveguide 604-3 is
designed to decouple blue light. In some embodiments, the
decoupling element of the first waveguide 604-1 is designed to
decouple blue light; the decoupling element of the second waveguide
604-2 is designed to decouple green light; and the decoupling
element of the third waveguide 604-3 is designed to decouple red
light. In some embodiments, other ordering of colors of waveguides
604 is used and/or more than three or less than three waveguides
604 are used. In some embodiments one waveguide 604 is used, and
the decoupling element is configured to decouple red, green, and
blue light.
[0049] The first lens stack 608-1 is between the waveguides 604 and
the eye 220 of the user. The waveguides 604 are between the second
lens stack 608-2 and the first lens stack 608-1. In some
embodiments, the second lens stack 608-2 is oriented orthogonally
to the first lens stack 608-1. The second lens stack 608-2 can have
similar elements as the first lens stack 608-1, arranged in similar
or different orders; the second lens stack 608-2 can have different
elements than the first lens 608-1. In some embodiments, the second
lens stack 608-2 is not used. The adaptive dimming element 612
provides variable light attenuation (e.g., to make the lens system
darker to a user when the user goes outside on a bright day). The
second lens stack 608-2 can be used to offset focusing power of the
first lens stack 608-1 so that natural light does not appear to
change focus even though focus of light exiting the waveguides 604
is changed by the first lens stack 608-1. For example, the first
lens stack 608-1 and the second lens stack 608-2 each have a
Pancharatnam Berry Phase (PBP) lens and a waveplate. Light from the
real world, having random polarization, passes through the PBP lens
of the second stack 608-2, and half the light is focused and half
the light is defocused, assuming equal amounts of right-handed,
circularly-polarized light and left-handed, circularly-polarized
light; a retardance is added to an axis as light passes through the
waveplate of the second lens stack 608-2; light passes through the
waveguides 604 and does not "see" gratings of the waveguides 604
because of angular selectivity of the gratings; light passes
through the waveguide of the first lens stack 608-1, which undoes
the retardance of the waveplate of the second lens stack 608-2; and
light passes through the PBP lens of the first lens stack 608-1,
which undoes focusing and defocusing of the PBP lens of the second
lens stack 60-2.
[0050] FIG. 7 is an exploded view of an embodiment 700 of the first
lens stack 608-1. The first lens stack 608-1 comprises a waveplate
704, a first Pancharatnam Berry Phase (PBP) lens 708-1, a
switchable half-wave plate 712, and a second PBP lens 708-2. Of
note, a linear polarizer is not between the waveguide 604 and the
PBP lens 708. U.S. application Ser. No. 15/693,846, filed on Sep.
1, 2017, discloses PBP lenses for use in optical compensation. The
'846 application is incorporated by reference for all purposes. The
PBP lens 708 is a type of geometric-phase lens and is specifically
designed to receive circularly polarized light. A geometric-phase
lens can also be referred to as a flat lens. A flat lens is based
on metasurfaces, which can use nano structures to modify light
based on polarization. For example, a flat lens can focus light by
acting as a converging lens for one handedness of
circularly-polarized light (e.g., right-handed circularly-polarized
light) and acting as a diverging lens for an orthogonal handedness
of circularly-polarized light (e.g., left-handed
circularly-polarized light). In another example, a flat lens can
reflect one handedness of circularly-polarized light and transmit
an orthogonal handedness of circularly-polarized light. The
geometric-phase lens can comprise liquid crystal polymers. In some
embodiments, elements of the lens stack 608 are bonded
together.
[0051] A circular polarizer can be placed in front of the PBP lens
708 to provide circularly-polarized light to the PBP lens 708. For
example, if the flat lens focuses right-handed circularly-polarized
light by causing light rays to converge, a right-handed circular
polarizer can be placed in front of the PBP lens 708. However, a
right-handed circular polarizer comprising a linear polarizer will
attenuate light passing through the right-handed circular polarizer
so that the lens system appears darkened because the linear
polarizer attenuates light that is not linearly polarized and
oriented along a transmission axis of the linear polarizer. The
circular polarizer also comprises a quarter-wave plate. The
quarter-wave plate can be made of a birefringent material having a
fast axis and a slow axis. The fast axis of the quarter-wave plate
is aligned at 45 degrees with the transmission axis of the linear
polarizer. Light passing through the linear polarizer will be
polarized along the transmission axis and converted from
linearly-polarized light to circularly-polarized light by passing
through the quarter-wave plate. Because the linear polarizer of the
circular polarizer attenuates randomly-polarized light, the lens
system will appear dark (e.g., like sunglasses). A darkened lens
system may not be as socially acceptable as a lens that is more
transparent. Further, having a linear polarizer between the
waveguide 604 in the PBP lens 708 may require more power
consumption by the source 410 to transmit a brighter image to the
eye 220 of the user because of attention by the linear
polarizer.
[0052] The waveplate 704 is used without a linear polarizer between
the waveguide 604 and the PBP lens to create circularly-polarized
light from light coupled out of the waveguide 604. The waveplate
704 is sometimes referred to as a first lens. The waveplate 704 is
made of an optically anisotropic material. For example, the
waveplate 704 comprises a birefringent material. The PBP lenses 708
and the switchable half-wave plate 712 are used to change a focal
length of the lens system (e.g., as described in the '846
application). The waveplate 704 is configured to convert light
coupled out of one or more waveguides 604 into circularly-polarized
light.
[0053] FIG. 8 illustrates a cross section of an embodiment of a
waveguide 604. Image light 355 is coupled into the waveguide 604 by
the coupling element 350. Light is guided in the waveguide 604 by
total internal reflection. Light is coupled out of the waveguide
604 by the decoupling element 365 as expanded image light 340. The
image light 355 can be polarized (e.g., p or s polarized by placing
a linear polarizer before the coupling element 350 and/or by using
a polarized light source, such as a laser diode). In some
embodiments, the waveguide 604, the coupling element 350, and/or
the decoupling element 365 are designed to output polarized light
(e.g., uniform linearly-polarized light or uniform
elliptically-polarized light). For example, a surface relief
grating or liquid crystal Bragg grating could be used as disclosed
in Gregory P. Crawford, "Electrically Switchable Bragg Gratings,"
Optics & Photonics News 14(4), 54-59 (2003), which is
incorporated by reference. In some embodiments, light coupled out
of the waveguide 604 has non-uniform polarization.
[0054] FIG. 9 illustrates a first example of polarization of light
exiting a waveguide 604, wherein the expanded image light 340 has
uniform polarization. Light exiting the waveguide 604 can have
uniform polarization by designing a grating to decouple light with
uniform polarization (e.g., as described in Gregory P. Crawford,
"Electrically Switchable Bragg Gratings," Optics & Photonics
News 14(4), 54-59 (2003)). Polarization of light coupled out of the
waveguide 604 (e.g., expanded image light 340) is represented by a
line labeled polarization axis P. The polarization axis P makes an
angle .theta. with the x-axis. The polarization axis P can
represent linear polarization and/or a major axis for elliptical
polarization. Since polarization of the expanded image light 340 is
uniform, polarization is constant over an x/y space, P(x,
y)=.theta. (a constant). The waveplate 704 can be designed to
change the expanded image light 340 into circularly-polarized light
(e.g., by making the waveplate 704 a quarter-wave plate and
orienting a fast axis of the quarter-wave plate at 45 degrees to
.theta., as described below).
[0055] FIG. 10 illustrates an embodiment of a fast axis F
orientation for a lens (e.g., waveplate 704) having an anisotropic
material. The anisotropic material is birefringent (i.e.,
displaying two different indices of refraction). The birefringent
material has a fast axis F and a slow axis. The slow axis is
usually orthogonal to the fast axis F, but does not have to be. The
fast axis F of the waveplate 704 is designed to be an angle .PHI.
from the polarization axis P, so that expanded image light 340 is
converted into circularly-polarized light. The fast axis F is at an
angle .beta. from the x-axis, such that .beta.=.theta.+.PHI.. If
the polarization of the expanded image light 340 is linearly
polarized, then .PHI. can equal +/-45.degree. using a quarter-wave
plate for the waveplate 704, depending on which handedness of
circularly-polarized light is desired. For simplicity, this
disclosure will provide examples using positive .PHI. values, and
it is understood that negative .PHI. values can also be used. The
angle .PHI. does not have to be 45.degree.. For converting
elliptically-polarized light into circularly-polarized light, the
angle .PHI. can be different from 45.degree. and/or a thickness of
the waveplate 704 can be changed. For uniform polarization of the
expanded image light 340, the fast axis F(x,y)=.theta.+.PHI. (i.e.,
constant). By using the waveplate 704, without a linear polarizer
between the waveguide 604 and the waveplate 704, light can be
circularly polarized for the PBP lens 708 with less loss compared
to using a linear polarizer with the waveplate 704.
[0056] FIG. 11 illustrates a second example of polarization of
light exiting a waveguide 604, wherein the expanded image light 340
is spatially non-uniform. Polarization of light can change in the
waveguide 604 (e.g., by reflections within the waveguide). Though
polarization of light exiting the waveguide 604 is non-uniform, it
is deterministic. In general, polarization varies spatially and
angularly with wavelength because a grating response is wavelength
and angular dependent. Also, ray paths within a waveguide for each
wavelength are slightly different. Since these variation are
deterministic, a spatially-varying waveplate can be designed to
compensate for variations in polarization. The waveplate can use a
multilayer birefringence film to generate an appropriate angular
response.
[0057] The x/y space of the expanded image light 340 is divided
into m rows and n columns. In FIG. 11, m equals two, and n equals
three, so that there are six quadrants. Quadrants can be referred
to as zones. A zone can be a closed two-dimensional shape (e.g., a
rectangle, a polygon, or a freeform area). In FIG. 11, the zones
are rectangles. In practice, values for m and n are usually higher
than 2 or 3 (e.g., m and/or n is equal to or greater than 5, 7, or
10 and/or equal to or less than 12, 15, or 20). A polarization axis
P of the six different quadrants are shown. A first polarization
axis P-1 has an orientation about .theta.=130.degree. in a first
quadrant. A second polarization axis P-2 has an orientation of
about .theta.=95.degree. in a second quadrant. A third polarization
axis P-3 has an orientation of about .theta.=20.degree. in a third
quadrant. A fourth polarization axis P-4 has an orientation of
about .theta.=70.degree. in a fourth quadrant. A fifth polarization
axis P-3 has an orientation of about .theta.=40.degree. in a fifth
quadrant. A sixth polarization axis P-6 as an orientation of about
.theta.=160.degree. in a sixth quadrant. Thus the angle .theta. is
not constant but is spatially dependent in x and y, .theta. (x,y),
and the polarization axis P is spatially dependent in x and y,
P(x,y)=.theta. (x,y). A waveplate 704 for spatially non-uniform,
linearly-polarized light can be created to change expanded image
light 340 by having a birefringence that varies as a
two-dimensional function of position on the waveplate 704. Thus a
matching retarder (e.g., waveplate 704) can be zoned relative to
the waveguide polarization angle and/or ellipticity in order to
create substantially circular polarization within an tolerance such
that the PBP lens focal positional error is below a threshold that
can be defined by wave front error, point spread function error, or
other image quality metric. A plurality of zones can be determined
such that a residual defocus of combined light is below a threshold
value.
[0058] FIG. 12 illustrates an embodiment a waveplate 704 configured
to convert light that is spatially non-uniform (e.g., light as
described in FIG. 11) into circularly-polarized light. The
waveplate 704 has an anisotropic material with a birefringence that
varies spatially across the lens so that a fast axis F of the
birefringence is a function of x and y. The waveplate 704 is
divided into m rows and n columns, similarly as dividing x/y space
of the expanded image light 340 in FIG. 11, so that there are six
quadrants. The fast axis F of the anisotropic material varies as a
function of x and y to match the polarization axis P (e.g.,
F(x,y)=P(x,y)+.PHI.). In some embodiments, the angle .PHI. also
varies as a function of x and y (e.g., quadrant two could be more
linearly polarized than quadrant one, quadrant one being more
elliptically polarized; thus angle .PHI. could be different in
quadrant two than in quadrant one). In an embodiment with the
polarization of the expanded image light 340 being linearly
polarized and non-uniform, a first fast axis F-1 has an orientation
of about .beta.=175.degree. in the first quadrant; a second fast
axis F-2 has an orientation of about .beta.=140.degree. in the
second quadrant; a third fast axis F-3 has an orientation of about
.beta.=65.degree. in the third quadrant; a fourth fast axis F-4 has
an orientation of about .beta.=115.degree. in the fourth quadrant;
a fifth fast axis F-5 has an orientation of about .beta.=85.degree.
in the fifth quadrant; and a sixth fast axis F-6 has an orientation
of about .beta.=205.degree. in the sixth quadrant. Thus an
orientation of the first fast axis F-1 in the first quadrant is at
a first angle, and the orientation of the second fast axis F-2 in
the second quadrant is at a second angle, wherein the first angle
is not equal to the second angle.
[0059] Since polarization of light exiting the waveguide 604 is
deterministic, the polarization can be characterized. The waveplate
704 is built based on characterizing polarization of light coupled
out of the waveguide 604. For example, output from the waveguide
604 is divided into m x n zones (as described in FIG. 11). A
spatially-varying retarder (e.g., waveplate 704) is constructed by
also dividing the spatially-varying retarder into m x n zones. In
some embodiments, m and/or n are equal to or greater than 7 and
equal to or less than 100 (e.g., m=n=5, 10, or 20). A fast axis F
in each zone is matched (and/or thickness of the spatially-varying
retarder is matched) to the polarization P of light in that zone to
convert light emitted from the waveguide 604 into
circularly-polarized light. By spatially matching the fast axis F
to the polarization axis P in each zone, the waveplate 704 produces
circularly-polarized light for the PBP lens 708 (sometimes referred
to as a second lens) with less loss compared to using a linear
polarizer with the waveplate 704. Thus a linear polarizer is not
used between the waveguide 604 in the PBP lens 708, and the lens
system is more transparent than if the lens system had a linear
polarizer.
[0060] FIG. 13 is an exploded view of another embodiment 1300 of
the first lens stack 608-1. The first lens stack 608-1 in the
embodiment 1300 comprises three circular polarizers 1304. A
circular polarizer can be made by using a linear polarizer and a
quarter-wave plate, wherein a transmission axis of the linear
polarizer is offset from a fast axis of the quarter-wave plate by
45.degree.. The circular polarizers 1304 comprise a linear
polarizer and a waveplate (e.g., a quarter-wave plate). The
circular polarizers 1304 have narrow bandwidths, such that the
linear polarizers of the circular polarizers 1304 polarize light
only within the narrow bandwidth. In some embodiments, narrow
bandwidth is equal to or greater than 5, 10, or 15 nm and equal to
or less than 20, 30, 35, 40, 50, 75, or 80 nm (e.g., as measured
full width, half max). In some embodiments, circular polarizers
1304 have narrow bandwidths centered on different wavelengths
(e.g., to filter red, green, and blue light).
[0061] A first circular polarizer 1304-1 comprises a first linear
polarizer and a first waveplate. The first linear polarizer has a
first polarization bandwidth; the first polarization bandwidth is
equal to or greater than 5 nm and equal to or less than 50 nm; and
the first linear polarizer has a first transmission axis. The first
waveplate is configured to convert light polarized in a direction
of the first transmission axis into circularly-polarized light. A
second circular polarizer 1304-2 comprises a second linear
polarizer and a second waveplate. The second linear polarizer has a
second polarization bandwidth; the second polarization bandwidth is
equal to or greater than 5 nm and equal to or less than 50 nm; and
the second linear polarizer has a second transmission axis. The
second waveplate is configured to convert light polarized in a
direction of the second transmission axis into circularly-polarized
light. A third circular polarizer 1304-3 comprises a third linear
polarizer and a third waveplate. The third linear polarizer has a
third polarization bandwidth; the third polarization bandwidth is
equal to or greater than 5 nm and equal to or less than 50 nm; and
the third linear polarizer has a third transmission axis. The third
waveplate is configured to convert light polarized in a direction
of the third transmission axis into circularly-polarized light.
[0062] The first circular polarizer 1304-1 is used to polarize red
expanded image light 340; the second circular polarizer 1304-2 is
used to polarize green expanded image light 340; and the third
circular polarizer 1304-3 is used to polarize blue expanded image
light 340. By having narrow bands, circular polarizers 1304
attenuate less light than having a broadband linear polarizer as
part of a circular polarizer because only a portion of ambient
light is polarized by linear polarizers of the circular polarizers
1304. Take for example a natural light spectrum from 400 to 700 nm;
a 300 nm spectrum. If a traditional linear polarizer is used, about
half the natural light will be absorbed (or reflected) by the
traditional linear polarizer. But if three circular polarizers 1304
are used, each having a polarization bandwidth of 30 nm, then only
90 nm of the natural light 300 nm spectrum will be polarized.
Assuming 50% loss for each wavelength, and equal magnitudes for
each wavelength of natural light, then loss is closer to 15% (e.g.,
0.5*90/300) instead of close to 50%. Thus natural light is less
attenuated by using circular polarizers having a linear polarizer
with a narrow bandwidth, and the lens system appears more
transparent.
[0063] In some embodiments, a single circular polarizer 1304 is
used. For example, only red light could be used for the source 410
(e.g., for a near-eye display for a pilot of an airplane). Then the
first circular polarizer 1304-1 is the only circular polarizer 1304
used, and not the second circular polarizer 1304-2 or the third
circular polarizer 1304-3, to change the red light into
circularly-polarized light. Similarly, if the source 410 comprises
more than three colors, then more than three circular polarizers
1304 can be used.
[0064] The circular polarizer 1304 can be placed before the PBP
lens 708 (farther from the eye than the PBP lens 708) or after the
PBP lens 708 (e.g., closer to the eye than the PBP lens 708). In
either configuration, the circular polarizer 1304 blocks an
orthogonal polarization of light (e.g., light of un-preferred
polarization passes through the PBP lens 708, is focused oppositely
than light of a preferred polarization, and is then blocked by the
circular polarizer 1304 before reaching the eye). In some
embodiments, the circular polarizer 1304 is placed after the PBP
lens 708 because some displays emit linearly-polarized light. In a
worst case scenario, light emitted by a display could be totally
blocked by the circular polarizer if a linear polarizer of the
circular polarizer is oriented orthogonal to polarization of the
display, and the circular polarizer 1304 is between the display and
the PBP lens 708. Further, by having the circular polarizer 1304
after the PBP lens 708, then a quarter-wave plate is not used in
the second lens stack 608-2 to compensate for retardance of the
circular polarizer 1304. Light from the real world passes through a
PBP lens of the second lens stack 608-2 and is reversed by the PBP
lens 708 of the first lens stack 608-1. The circular polarizer 1304
absorbs 50% of light in that band.
[0065] In some embodiments, multiple (e.g., three) narrowband
linear polarizers are used with one quarter-wave plate. Thus a
circular polarizer 1304 could comprise three linear polarizers
(e.g., one red, one green, and one blue) and only one quarter-wave
plate. Some embodiments use just one quarter-wave plate because a
wideband achromatic quarter-wave plate is common.
[0066] FIG. 14 illustrates an embodiment of a flowchart of a
process 1400 for using a lens system. Process 1400 begins with step
1404 with emitting light from a source (e.g., source 410). Light
from the source is coupled into a waveguide (e.g., waveguide 604)
using a coupling element (e.g., coupling element 350), step 1408.
Light is guided through the waveguide to a decoupling element
(e.g., decoupling element 365). The decoupling element is used to
couple light out of the waveguide and toward an eye (e.g., eye 220)
of a user, step 1412. In step 1416, light is transmitted through a
first lens (e.g., waveplate 704) to generate circularly-polarized
light. The first lens is made of an optically anisotropic material;
the first lens does not comprise a polarizer; and the first lens is
between the decoupling element and the eye of the user. In step
1418, light is transmitted through the second lens, wherein the
second lens is configured to specifically receive
circularly-polarized light (e.g., it is a PBP lens). The second
lens is optically between the first lens and the eye of the user;
and light is transmitted from the decoupling element and to the
second lens without passing through a polarizer.
[0067] FIG. 15 illustrates an embodiment of a flowchart of a
process 1500 for creating a lens (e.g., waveplate 704) having an
anisotropic material with a birefringence that varies spatially.
Process 1500 begins with step 1504 with emitting light from a
source (e.g., source 410). Light from the source is coupled into a
waveguide (e.g., waveguide 604) using a coupling element (e.g.,
coupling element 350), step 1508. Light is guided through the
waveguide to a decoupling element (e.g., decoupling element 365).
The decoupling element is used to couple light out of the
waveguide, step 1512. In step 1516, polarization of light coupled
out of the waveguide is analyzed. In step 1518, a lens (e.g.,
waveplate 704) is designed to have position-variable birefringence
based on analyzing the polarization of light coupled out of the
waveguide. In some embodiments, analyzing the polarization of light
coupled out of the waveguide is performed by dividing the light
into a plurality of zones (e.g., quadrants) and determining
polarization of light in each zone (e.g., as discussed in relation
with FIG. 11).
[0068] Light from an optical source (e.g., from source assembly 310
and/or source 410) can be coupled into one or more waveguides 604
by one or more coupling elements (e.g., coupling element 350). The
light from the optical source can be polarized (e.g., emitted as
polarized light or polarized before the coupling element 350). The
light can be linearly polarized or elliptically polarized. In some
embodiments, light from the optical source is not polarized before
being coupled into the waveguide 604. In some embodiments, three
waveguides 604 are used; one for red light, one for green light,
and one for blue light. Light from a waveguide 604 is coupled out
of the waveguide 604 by a decoupling element 365. The decoupling
element can comprise a grating.
[0069] In some embodiments, the grating is configured to couple
light out of the waveguide 604 so that the light is uniformly
polarized, spatially (e.g., linearly polarized or elliptically
polarized as discussed in conjunction with FIG. 9). A waveplate is
designed to change the uniformly polarized light from the waveguide
into circularly-polarized light (e.g., as discussed in conjunction
with FIG. 10). Circularly-polarized light passes through a PBP lens
and is focused by the PBP lens before reaching an eye 220 of a user
of the near-eye display 100.
[0070] In some embodiments, light is coupled out of the waveguide
604 with a deterministic and spatially varying polarization (e.g.,
as discussed in conjunction with FIG. 11). The polarization of
light in non-uniform. A waveplate is designed to match the
non-uniform polarization of light exiting the one or more
waveguides 604 to change the light into circularly-polarized light
(e.g., as described in conjunction with FIG. 12).
Circularly-polarized light passes through a PBP lens and is focused
by the PBP lens before reaching an eye 220 of a user of the
near-eye display 100.
[0071] In some embodiments, one or more circular polarizers are
used to circularly polarize light in narrow bands (e.g., 30 nm
bands; as discussed in conjunction with FIG. 13). The narrow bands
correspond to emission bands of sources (e.g., LEDs) of an optical
source. Circularly-polarized light passes through a PBP lens and is
focused by the PBP lens before reaching an eye 220 of a user of the
near-eye display 100.
[0072] Embodiments of the invention may include or be implemented
in conjunction with an artificial reality system. Artificial
reality is a form of reality that has been adjusted in some manner
before presentation to a user, which may include, e.g., a virtual
reality (VR), an augmented reality (AR), a mixed reality (MR), a
hybrid reality, or some combination and/or derivatives thereof.
Artificial reality content may include completely generated content
or generated content combined with captured (e.g., real-world)
content. The artificial reality content may include video, audio,
haptic feedback, or some combination thereof, and any of which may
be presented in a single channel or in multiple channels (such as
stereo video that produces a three-dimensional effect to the
viewer). Additionally, in some embodiments, artificial reality may
also be associated with applications, products, accessories,
services, or some combination thereof, that are used to, e.g.,
create content in an artificial reality and/or are otherwise used
in (e.g., perform activities in) an artificial reality. The
artificial reality system that provides the artificial reality
content may be implemented on various platforms, including a
head-mounted display (HMD) connected to a host computer system, a
standalone HMD, a mobile device or computing system, or any other
hardware platform capable of providing artificial reality content
to one or more viewers.
[0073] The foregoing description of the embodiments of the
disclosure has been presented for the purpose of illustration; it
is not intended to be exhaustive or to limit the disclosure to the
precise forms disclosed. Persons skilled in the relevant art can
appreciate that many modifications and variations are possible in
light of the above disclosure.
[0074] Some portions of this description describe the embodiments
of the disclosure in terms of algorithms and symbolic
representations of operations on information. These algorithmic
descriptions and representations are commonly used by those skilled
in the data processing arts to convey the substance of their work
effectively to others skilled in the art. These operations, while
described functionally, computationally, or logically, are
understood to be implemented by computer programs or equivalent
electrical circuits, microcode, or the like. Furthermore, it has
also proven convenient at times, to refer to these arrangements of
operations as modules, without loss of generality. The described
operations and their associated modules may be embodied in
software, firmware, and/or hardware.
[0075] Steps, operations, or processes described may be performed
or implemented with one or more hardware or software modules, alone
or in combination with other devices. In some embodiments, a
software module is implemented with a computer program product
comprising a computer-readable medium containing computer program
code, which can be executed by a computer processor for performing
any or all of the steps, operations, or processes described.
[0076] Embodiments of the disclosure may also relate to an
apparatus for performing the operations described. The apparatus
may be specially constructed for the required purposes, and/or it
may comprise a general-purpose computing device selectively
activated or reconfigured by a computer program stored in the
computer. Such a computer program may be stored in a
non-transitory, tangible computer readable storage medium, or any
type of media suitable for storing electronic instructions, which
may be coupled to a computer system bus. Furthermore, any computing
systems referred to in the specification may include a single
processor or may be architectures employing multiple processor
designs for increased computing capability.
[0077] Embodiments of the disclosure may also relate to a product
that is produced by a computing process described herein. Such a
product may comprise information resulting from a computing
process, where the information is stored on a non-transitory,
tangible computer readable storage medium and may include any
embodiment of a computer program product or other data combination
described herein.
[0078] The language used in the specification has been principally
selected for readability and instructional purposes, and it may not
have been selected to delineate or circumscribe the inventive
subject matter. It is therefore intended that the scope of the
disclosure be limited not by this detailed description, but rather
by any claims that issue on an application based hereon.
Accordingly, the disclosure of the embodiments is intended to be
illustrative, but not limiting, of the scope of the disclosure,
which is set forth in the following claims.
* * * * *