U.S. patent application number 15/878751 was filed with the patent office on 2019-09-05 for lightguide optical combiner for head wearable display.
The applicant listed for this patent is Google LLC. Invention is credited to Bernard C. Kress, Adam E. Norton, Ehsan Saeedi, Edouard Schmidtlin.
Application Number | 20190271844 15/878751 |
Document ID | / |
Family ID | 61525545 |
Filed Date | 2019-09-05 |
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United States Patent
Application |
20190271844 |
Kind Code |
A1 |
Kress; Bernard C. ; et
al. |
September 5, 2019 |
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.
Inventors: |
Kress; Bernard C.; (Redwood
City, CA) ; Saeedi; Ehsan; (San Francisco, CA)
; Norton; Adam E.; (Palo Alto, CA) ; Schmidtlin;
Edouard; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Google LLC |
Mountain View |
CA |
US |
|
|
Family ID: |
61525545 |
Appl. No.: |
15/878751 |
Filed: |
January 24, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14271083 |
May 6, 2014 |
9915823 |
|
|
15878751 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 2027/0178 20130101;
G02B 27/0172 20130101; G02B 5/04 20130101; G02B 2027/0174
20130101 |
International
Class: |
G02B 27/01 20060101
G02B027/01 |
Claims
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.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 14/271,083, filed May 6, 2014, the disclosure
of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] This disclosure relates generally to the field of optics,
and in particular but not exclusively, relates to eyepieces for
head wearable displays.
BACKGROUND INFORMATION
[0003] A head mounted display ("HMD") or head wearable display is a
display device worn on or about the head. HMDs usually incorporate
some sort of near-to-eye optical system to create a magnified
virtual image placed a few meters in front of the user. Single eye
displays are referred to as monocular HMDs while dual eye displays
are referred to as binocular HMDs. Some HMDs display only a
computer generated image ("CGI"), while other types of HMDs are
capable of superimposing CGI over a real-world view. This latter
type of HMD typically includes some form of see-through eyepiece
and can serve as the hardware platform for realizing augmented
reality. With augmented reality the viewer's image of the world is
augmented with an overlaying CGI, also referred to as a heads-up
display ("HUD").
[0004] HMDs have numerous practical and leisure applications.
Aerospace applications permit a pilot to see vital flight control
information without taking their eye off the flight path. Public
safety applications include tactical displays of maps and thermal
imaging. Other application fields include video games,
transportation, and telecommunications. There is certain to be new
found practical and leisure applications as the technology evolves;
however, many of these applications are limited due to the cost,
size, weight, field of view, eye box, and efficiency of
conventional optical systems used to implemented existing HMDs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Non-limiting and non-exhaustive embodiments of the invention
are described with reference to the following figures, wherein like
reference numerals refer to like parts throughout the various views
unless otherwise specified. The drawings are not necessarily to
scale, emphasis instead being placed upon illustrating the
principles being described.
[0006] FIGS. 1A and 1B are cross-sectional views of an eyepiece for
use with a head wearable display, in accordance with an embodiment
of the disclosure.
[0007] FIGS. 2A and 2B are cross-sectional views of an eyepiece for
use with a head wearable display, in accordance with another
embodiment of the disclosure.
[0008] FIG. 3A is a cross-sectional view of an eyepiece including
an alcove notched into a lightguide component to accommodate a
camera module within a temple housing, in accordance with an
embodiment of the disclosure.
[0009] FIG. 3B is a perspective view of an eyepiece including an
alcove notched into a lightguide component to accommodate a camera
module within a temple housing, in accordance with an embodiment of
the disclosure.
[0010] FIGS. 4A and 4B illustrate a demonstrative head wearable
display using an eyepiece including a lightguide optical combiner,
in accordance with an embodiment of the disclosure.
DETAILED DESCRIPTION
[0011] Embodiments of a system and apparatus that integrates a
total internal reflection ("TIR") based lightguide and optical
combiner into an eyepiece for a head wearable display are described
herein. In the following description numerous specific details are
set forth to provide a thorough understanding of the embodiments.
One skilled in the relevant art will recognize, however, that the
techniques described herein can be practiced without one or more of
the specific details, or with other methods, components, materials,
etc. In other instances, well-known structures, materials, or
operations are not shown or described in detail to avoid obscuring
certain aspects.
[0012] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
the appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment. Furthermore, the
particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments.
[0013] FIGS. 1A and 1B are cross-sectional views of an eyepiece 100
for use with a head wearable display, in accordance with an
embodiment of the disclosure. The illustrated embodiment of
eyepiece 100 includes a lightguide component 105 and a see-through
add-on component 110. The illustrated embodiment of lightguide
component 105 includes an input surface 115, a first folding
surface 120, a second folding surface 125, an eye-ward facing
surface 130, a curved reflective surface 135, and an end surface
140. See-through add-on component 110 includes an interface surface
145, an external scene facing surface 147, and an end surface 150.
In the illustrated embodiment a diffusor 155 is coated over end
surfaces 140 and 150.
[0014] Display source 160 is aligned to inject display light 165
into lightguide component 105 through input surface 115. Display
source 160 is located at a peripheral location (proximal end),
which is offset from a viewing region 170 near the distal end of
eyepiece 100. Display light 165 is emitted from lightguide
component 105 in viewing region 170 along an eye-ward direction for
viewing by a user. As such, lightguide component 105 operates as a
lightguide that transports display light 165 from a peripheral
location outside of the user's center of vision to viewing region
170 located nearer to the user's central or foveal vision.
[0015] Eyepiece 100 can be implemented in a see-through or
non-see-through version, and as such see-through add-on component
110 is an optional component. In see-through embodiments, curved
reflective surface 135 is layered with a partially reflective
element (e.g., beam splitter coating, polarizing beam splitter
coating, diffractive reflector, etc.). The partial reflectivity of
curved reflective surface 135 permits ambient scene light 175 to
pass through viewing region 170 and combine with display light 165
emitted out through viewing region 170. When indexed matched to
lightguide component 105, see-through add-on component 110 defeats
the optical power associated with curved reflective surfaced 135
for the ambient scene light 175 passing through. Accordingly,
interface surface 145 of see-through add-on component 110 has a
size and curvature that mates to and complements the curvature of
curved reflective surface 135 of lightguide component 105.
Correspondingly, external scene facing surface 147 is complementary
to eye-ward facing surface 130 in viewing region 170 to ensure
ambient scene light 175 experiences substantially no optical
power.
[0016] In non-see-through embodiments, curved reflective surface
135 may implemented as a mirror surface with or without add-on
component 110 according to industrial design choice.
[0017] In one embodiment, lightguide component 105 and add-on
component 110 are fabricated as two independent pieces that are
bonded together along interface surface 145 and curved reflective
surface 135 using a clear adhesive. Lightguide component 105 and
add-on component 110 may be fabricated of two different materials
having the same index of refraction, or both of the same material.
For example, lightguide component 105 and add-on component 110 may
be fabricated of optical grade plastic (e.g., Zeonex E-48R), glass,
or otherwise. In one embodiment, the components are injection
molded to shape, processed to add various optical coatings/layers
discussed below, and then bonded together along interface surface
145 and curved reflective surface 135. In one embodiment,
lightguide component 105 and add-on component 110 are fabricated of
a material having a higher index of refraction than air to induce
total interface reflection ("TIR") at first folding surface 120,
second folding surface 125, and eye-ward facing surface 130.
[0018] In an embodiment wherein curved reflective surface 135 is
coated with a partially reflective material, the splitting ratio
may be selected according to design needs, but in one embodiment
may be implemented as a 50/50 beam splitter. In embodiments where
curved reflective surface 135 is implemented using a polarizing
beam splitter ("PBS"), display source 160 would output polarized
light with a polarization selected to substantially reflect off of
the PBS material. A PBS design can serve to increase the efficiency
of the optical system. For example, LCD or liquid crystal on
silicon ("LCoS") are example display technologies that output
polarized light. Of course, external polarizing films may be used
in connection with other non-polarized display technologies. When
operating with polarized light, it can be beneficial to use low
stress materials to reduce the influence of birefringence on the
optical design. Accordingly, in some embodiments, lightguide
component 105 may be fabricated of low stress plastics, glass, or
other low stress optical grade materials.
[0019] In see-through embodiments, lightguide component 105 and
add-on component 110 are fabricated of optically transmissive
materials (e.g., clear plastic) that permit at least a portion of
external scene light 175 to pass through viewing region 170 to the
user's eye. As such, eyepiece 100 operates as an optical combiner
combining external scene light 175 with display light 165 emitted
out through eye-ward facing surface 130 in viewing region 170 along
an eye-ward direction into the eye. In this way, eyepiece 100 is
capable of displaying an augmented reality to the user.
[0020] During operation, display source 160 emits display light 165
from a peripheral location offset from viewing region 170 into
lightguide component 105. Display source 120 may be implemented
using a variety of different display technologies including LCD
displays, LCoS displays, organic light emitting diode ("OLED")
displays, or otherwise. Display light 165 may include computer
generated images.
[0021] Display light 165 is incident into lightguide component 105
through input surface 115. Input surface 115 is a curved surface
with optical power. In one embodiment, input surface 115 is a
cylindrical lensing surface that in connection with the other
lensing surfaces can be adjusted to correct aberrations and
distortions in the optical system. In the illustrated embodiment,
input surface 115 is a cylindrical convex surface (as viewed from
display source 160) having its center axis of symmetry in the plane
of the page running parallel to the line drawn as input surface
115.
[0022] After display light 165 enters into lightguide component 105
through input surface 115, it is incident upon first folding
surface 120, which is disposed proximate to input surface 115.
First folding surface 120 operates to reflect display light 165
towards second folding surface 125. In the illustrated embodiment,
first folding surface 120 is also a curved surface with reflective
optical power. For example, first folding surface 120 may be
implemented as a cylindrical surface with optical power to aid in
correction of aberrations and distortions in the optical system. In
the illustrated embodiment, first folding surface 120 is a
cylindrical concave surface (as viewed external to lightguide
component 105) having its center axis of symmetry in the plane of
the page running parallel to the line drawn as first folding
surface 120.
[0023] After folding (e.g., reflecting) and lensing display light
165 at first folding surface 120, display light 165 is directed
towards second folding surface 125 where display light 125 is once
again redirected back across lightguide component 105 to eye-ward
facing surface 130. In the illustrated embodiment, second folding
surface 125 is a planar surface without optical power; however, in
other embodiments, second folding surface 125 may also have
curvature to impart optical power.
[0024] Display light 165 incident upon eye-ward facing surface 130
for the first time is reflected to curved reflective surface 135.
In one embodiment, eye-ward facing surface 130 is a planar surface
without optical power that is opposite, but parallel to second
folding surface 125. Eye-ward facing surface 130 and first folding
surface 120 are non-coplanar surfaces off-set from each other.
[0025] Curved reflective surface 135 is implemented as an off-axis
aspheric lens that provides reflective optical power to collimate
or nearly collimate display light 165 emitted from eyepiece 100.
For example, display light 165 may be virtually displaced to appear
to 2 m to 3 m in front of the user. Of course other amounts of
collimation may be implemented. After reflection off of curved
reflective surface 135, display light 165 is directed back to
eye-ward facing surface 130 in viewing region 170 where display
light 165 is emitted out of eyepiece 100 along an eye-ward
direction. The second encounter with eye-ward facing surface 130
does not result in TIR, since the angle of incidence is steeper
than the required critical angle for TIR.
[0026] Eyepiece 100 provides a relatively large eye box (e.g., 8.5
mm horizontal and 6.2 mm vertical) due to its inherent design. This
large eye box is due in part to the close proximity of curved
reflective surface 135 to the user's eye. Additionally, the
relatively shallow oblique angle of curved reflective surface 135
projects a large horizontal eye box area onto eye-ward facing
surface 130 in viewing region 170, which also contributes to the
eye box size. A large eye box accommodates larger inter-pupillary
deviations, thereby providing a larger cross-section of the
population with an improved user experience.
[0027] In one embodiment, first folding surface 120, second folding
surface 125, and eye-ward facing surface 130 are clear surfaces
that reflect display light 165 via TIR and careful design control
over the incident angles of the light path followed by display
light 165. By using TIR for the reflections off of the folding
surfaces, eyepiece 100 achieves desirable industrial design
characteristics, since eyepiece 100 will appear as a clear eyepiece
to external observers. Furthermore, TIR reflections are highly
efficient. In an example where curved reflective surface 135 is a
50/50 beam splitter, embodiments of eyepiece 100 can approach near
50% efficiency. In other embodiments, first folding surface 120 and
second folding surface 125 may be coated with reflecting films to
reflect display light 165 without need of TIR. FIG. 1B illustrates
example optical paths through eyepiece 100 by a number of ray trace
bundles of display light 165 output from display source 160.
[0028] In the illustrated embodiment, diffusor 155 is coated over
the distal ends 140 and 150 of lightguide component 105 and add-on
component 110, respectively. Diffusor 155 operates to absorb
incident light to reduce deleterious back reflections. Diffusor 155
may be implemented as a dark diffusive paint (e.g., matte black
paint), and in some embodiments, further includes an
anti-reflective coating under the dark diffusive paint. In one
embodiment, diffusor 155 includes an opening to permit a portion of
display light 165 to bleed out the distal end of eyepiece 200 as a
sort of indicator light. The indicator light provides third persons
a visual cue that display source 160 is turned on. In one
embodiment, the opening may be an image or logo stenciled into the
dark diffusive paint and may include a transparent diffusive
element under the stenciled image/logo to diffuse the display light
emitted as a visual cue.
[0029] FIGS. 2A and 2B are cross-sectional views of an eyepiece 200
for use with a head wearable display, in accordance with another
embodiment of the disclosure. The illustrated embodiment of
eyepiece 200 includes a lightguide component 205 and a see-through
add-on component 210. The illustrated embodiment of lightguide
component 205 includes an input surface 215, notch surfaces 217 and
218, a first folding surface 220, a second folding surface 225, an
eye-ward facing surface 230, curved reflective surface 235, and an
end surface 240. See-through add-on component 210 includes an
interface surface 245, an external scene facing surface 247, and an
end surface 250. In the illustrated embodiment a diffusor 255 is
coated over end surfaces 240 and 250.
[0030] Eyepiece 200 is similar to eyepiece 100 except that notch
surfaces 217 and 218 proximal to input surface 215 form an alcove
219 suitably sized to house a camera module or other
optical/electrical systems. Furthermore, first folding surface 220
is tilted towards display source 160 and lengthened to extend
between (and directly interface with) input surface 215 and
eye-ward facing surface 230.
[0031] FIGS. 3A and 3B illustrate an example housing configuration
for eyepiece 200, in accordance with an embodiment of the
disclosure. FIG. 3A is a cross-sectional view while FIG. 3B is a
perspective view of the same. As illustrated, the proximal end of
eyepiece 200 inserts into a housing 305. Housing 305 is shaped for
mounting to a temple region of an eyewear-like frame for wearing on
a head of user (e.g., see FIGS. 4A and 4B). Frame 305 positions
display source 160 peripherally to the user's central vision.
Further as illustrated, alcove 219 provides a convenient location
for additional circuitry or optical components, such as for
example, a forward facing camera module 310.
[0032] In one embodiment, eyepiece 200 delivers display light 265
with a 15 degree field of view having a 16:9 aspect ratio (e.g., 13
degree horizontal and 7.35 degrees vertical) and a resolution of
approximately 4 arc mins based upon display source 160 having a
640.times.360 pixel display and 7.5 um pixel size. Additional
design specification of such an embodiment include an eye relief
(D1) of 18 mm and approximate lightguide component dimensions
including: D2=7.2 mm, D3=25 mm, D4=15 mm, and rectangular cross
sectional dimensions along line A-A' of 7.2 mm.times.10 mm.
Eyepiece 200 is also capable of providing a relatively large eye
box (e.g., 8.5 mm horizontal by 6.2 mm vertical) for similar
reasons as discussed above in connection with eyepiece 100. Of
course, these dimensions are merely demonstrative and alternative
dimensions may be implemented. In one embodiment, curved reflective
surface 235 is an off-axis asphere with a sag equation:
Z ( r ) = r 2 R 1 1 + 1 - ( 1 + k ) ( r / R ) 2 + .beta. 3 r 3 +
.beta. 4 r 4 , ##EQU00001##
where R=-81.62, k=-3.63, .beta..sub.3=-5.00 E-05, and
.beta..sub.4=-3.81 E-08. In one embodiment, input surface 215 is a
regular cylinder with a radius of R=-6.502 having an orientation
that is similar to that described above in connection with input
surface 115. In the illustrated embodiment, the local coordinate
system of curved reflective surface 235 for the sag equation
provided above is offset compared to the center of viewing region
270 by -43.52 mm in X, 2.4 mm in Y, and 11.32 mm in Z. In this
embodiment, the local coordinate system of curved reflective
surface 235 is further rotated in the Y-Z plane by -3.7 degrees,
and in the X-Z plane -8.95 degrees. In one embodiment, first
folding surface 220 is an off axis toroid with a sag equation:
Z ( y ) = y 2 R 1 1 + 1 - ( 1 + k ) ( y / R ) 2 + .alpha. y
##EQU00002##
where R=-7.113, a=0.061, k=0.00, and a radius of rotation of 1468.
In this embodiment, the center of the radius of rotation is offset
-453.77 mm in X, 0 mm in Y and 1401.06 mm in Z relative to the
center of the viewing region 270. In other embodiments, first
folding surface 220 is a cylinder having an orientation that is
similar to that described above in connection with first folding
surface 120. In one embodiment, input surface 215 is a cylinder
with a convex radius of -7.175 mm and an angle of 70 degrees to
eye-ward facing surface 230. Of course, these curvatures,
positions, and angles are merely demonstrative and alternative
curvatures, positions, and angles may be implemented.
[0033] FIGS. 4A and 4B illustrate a monocular head wearable display
400 using a eyepiece 401, in accordance with an embodiment of the
disclosure. FIG. 4A is a perspective view of head wearable display
400, while FIG. 4B is a top view of the same. Eyepiece 401 may be
implemented with embodiments of eyepieces 100 or 200 as discussed
above. Eyepiece 401 is mounted to a frame assembly, which includes
a nose bridge 405, left ear arm 410, and right ear arm 415.
Housings 420 and 425 may contain various electronics including a
microprocessor, interfaces, one or more wireless transceivers, a
battery, a camera, a speaker, etc. Although FIGS. 4A and 4B
illustrate a monocular embodiment, head wearable display 400 may
also be implemented as a binocular display with two eyepieces 401
each aligned with a respective eye of the user when display 400 is
worn.
[0034] Eyepiece 401 is secured into an eye glass arrangement or
head wearable display that can be worn on the head of a user. The
left and right ear arms 410 and 415 rest over the user's ears while
nose bridge 405 rests over the user's nose. The frame assembly is
shaped and sized to position the viewing region in front of an eye
of the user. Other frame assemblies having other shapes may be used
(e.g., traditional eyeglasses frame, a single contiguous headset
member, a headband, goggles type eyewear, etc.).
[0035] The illustrated embodiment of head wearable display 400 is
capable of displaying an augmented reality to the user. A
see-through embodiment permits the user to see a real world image
via ambient scene light 175. Left and right (binocular embodiment)
display light 480 may be generated by display sources 160 mounted
in peripheral corners outside the user's central vision. Display
light 480 is seen by the user as a virtual image superimposed over
ambient scene light 175 as an augmented reality. In some
embodiments, ambient scene light 175 may be fully, partially, or
selectively blocked to provide sun shading characteristics and
increase the contrast of display light 480.
[0036] The above description of illustrated embodiments of the
invention, including what is described in the Abstract, is not
intended to be exhaustive or to limit the invention to the precise
forms disclosed. While specific embodiments of, and examples for,
the invention are described herein for illustrative purposes,
various modifications are possible within the scope of the
invention, as those skilled in the relevant art will recognize.
[0037] These modifications can be made to the invention in light of
the above detailed description. The terms used in the following
claims should not be construed to limit the invention to the
specific embodiments disclosed in the specification. Rather, the
scope of the invention is to be determined entirely by the
following claims, which are to be construed in accordance with
established doctrines of claim interpretation.
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