U.S. patent application number 14/172901 was filed with the patent office on 2015-10-01 for optical configurations for head worn computing.
The applicant listed for this patent is Osterhout Group, Inc.. Invention is credited to John N. Border, John D. Haddick, Edward H. Nortrup, Ralph F. Osterhout.
Application Number | 20150277120 14/172901 |
Document ID | / |
Family ID | 53544638 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150277120 |
Kind Code |
A1 |
Border; John N. ; et
al. |
October 1, 2015 |
OPTICAL CONFIGURATIONS FOR HEAD WORN COMPUTING
Abstract
Aspects of the present invention relate to optical systems in
head worn computing.
Inventors: |
Border; John N.; (Walworth,
NY) ; Osterhout; Ralph F.; (San Francsico, CA)
; Haddick; John D.; (San Rafael, CA) ; Nortrup;
Edward H.; (Stoneham, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Osterhout Group, Inc. |
San Francisco |
CA |
US |
|
|
Family ID: |
53544638 |
Appl. No.: |
14/172901 |
Filed: |
February 4, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14160377 |
Jan 21, 2014 |
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14172901 |
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14163646 |
Jan 24, 2014 |
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14160377 |
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Current U.S.
Class: |
345/8 |
Current CPC
Class: |
G02B 2027/0174 20130101;
G02B 2027/0118 20130101; G02B 27/0093 20130101; G02B 2027/014
20130101; G02B 27/0172 20130101; G02B 2027/0178 20130101; G02B
27/0101 20130101; G02B 26/0833 20130101; G02B 5/30 20130101; G02B
2027/0138 20130101 |
International
Class: |
G02B 27/01 20060101
G02B027/01 |
Claims
1. A head worn computer, comprising a. A housing adapted to be worn
on the head of a user, wherein the housing is adapted to hold an
optical system; b. The optical system adapted to present digital
content to a visual field of the user, when the user is wearing the
head worn computer, the optical system also adapted to be
transmissive such that the user can view a surrounding environment
through the optical system; c. The optical system further comprised
of a DLP positioned to provide image light from a position in the
housing into an optical system that directs the image light to the
user's eye; and d. The housing further comprising a light absorber
positioned in proximity to a DLP "off" state light path to collect
and absorb the "off" pixel light.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to and is a
continuation-in-part of the following U.S. patent applications,
each of which is hereby incorporated by reference in its
entirety:
[0002] U.S. non-provisional application Ser. No. 14/160,377,
entitled Optical Configurations for Head Worn Computing, filed Jan.
21, 2014; and
[0003] U.S. non-provisional application Ser. No. 14/163,646,
entitled Peripheral Lighting for Head Worn Computing, filed Jan.
24, 2014.
BACKGROUND
[0004] 1. Field of the Invention
[0005] This invention relates to head worn computing. More
particularly, this invention relates to optical systems used in
head worn computing.
[0006] 2. Description of Related Art
[0007] Wearable computing systems have been developed and are
beginning to be commercialized. Many problems persist in the
wearable computing field that need to be resolved to make them meet
the demands of the market.
SUMMARY
[0008] Aspects of the present invention relate to optical systems
in head worn computing. Aspects relate to the management of "off"
pixel light. Aspects relate to absorbing "off" pixel light. Aspects
relate to improved see-through transparency of the HWC optical path
to the surrounding environment. Aspects relate to improved image
contrast, brightness, sharpness and other image quality through the
management of stray light. Aspects relate to eye imaging through
"off" pixels. Aspects relate to security compliance and security
compliance tracking through eye imaging. Aspects relate to guest
access of a HWC through eye imaging. Aspects relate to providing
system and software access based on eye imaging.
[0009] These and other systems, methods, objects, features, and
advantages of the present invention will be apparent to those
skilled in the art from the following detailed description of the
preferred embodiment and the drawings. All documents mentioned
herein are hereby incorporated in their entirety by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments are described with reference to the following
Figures. The same numbers may be used throughout to reference like
features and components that are shown in the Figures:
[0011] FIG. 1 illustrates a head worn computing system in
accordance with the principles of the present invention.
[0012] FIG. 2 illustrates a head worn computing system with optical
system in accordance with the principles of the present
invention.
[0013] FIG. 3a illustrates a large prior art optical
arrangement.
[0014] FIG. 3b illustrates an upper optical module in accordance
with the principles of the present invention.
[0015] FIG. 4 illustrates an upper optical module in accordance
with the principles of the present invention.
[0016] FIG. 4a illustrates an upper optical module in accordance
with the principles of the present invention.
[0017] FIG. 4b illustrates an upper optical module in accordance
with the principles of the present invention.
[0018] FIG. 5 illustrates an upper optical module in accordance
with the principles of the present invention.
[0019] FIG. 5a illustrates an upper optical module in accordance
with the principles of the present invention.
[0020] FIG. 5b illustrates an upper optical module and dark light
trap according to the principles of the present invention.
[0021] FIG. 5c illustrates an upper optical module and dark light
trap according to the principles of the present invention.
[0022] FIG. 5d illustrates an upper optical module and dark light
trap according to the principles of the present invention.
[0023] FIG. 5e illustrates an upper optical module and dark light
trap according to the principles of the present invention.
[0024] FIG. 6 illustrates upper and lower optical modules in
accordance with the principles of the present invention.
[0025] FIG. 7 illustrates angles of combiner elements in accordance
with the principles of the present invention.
[0026] FIG. 8 illustrates upper and lower optical modules in
accordance with the principles of the present invention.
[0027] FIG. 8a illustrates upper and lower optical modules in
accordance with the principles of the present invention.
[0028] FIG. 8b illustrates upper and lower optical modules in
accordance with the principles of the present invention.
[0029] FIG. 8c illustrates upper and lower optical modules in
accordance with the principles of the present invention.
[0030] FIG. 9 illustrates an eye imaging system in accordance with
the principles of the present invention.
[0031] FIG. 10 illustrates a light source in accordance with the
principles of the present invention.
[0032] FIG. 10a illustrates a back lighting system in accordance
with the principles of the present invention.
[0033] FIG. 10b illustrates a back lighting system in accordance
with the principles of the present invention.
[0034] FIG. 11a to 11d illustrate a light source and filter in
accordance with the principles of the present invention.
[0035] FIGS. 12a to 12c illustrate a light source and quantum dot
system in accordance with the principles of the present
invention.
[0036] FIG. 13a illustrates optical components of a lower optical
module together with an outer lens.
[0037] FIG. 13b illustrates a cross section of the embodiment
described in FIG. 13a.
[0038] FIG. 13c illustrates an embodiment where the combiner
element is angled away from the eye at the top and towards the eye
at the bottom.
[0039] FIG. 14a illustrates a removable and replaceable flexible
eye cover with an opening that can be attached and removed quickly
from the through the use of magnets.
[0040] FIG. 14b illustrates a removable and replaceable flexible
eye cover that is adapted as a single eye cover.
[0041] FIG. 14c illustrates an embodiment of a light suppression
system.
[0042] While the invention has been described in connection with
certain preferred embodiments, other embodiments would be
understood by one of ordinary skill in the art and are encompassed
herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0043] Aspects of the present invention relate to head-worn
computing ("HWC") systems. HWC involves, in some instances, a
system that mimics the appearance of head-worn glasses or
sunglasses. The glasses may be a fully developed computing
platform, such as including computer displays presented in each of
the lenses of the glasses to the eyes of the user. In embodiments,
the lenses and displays may be configured to allow a person wearing
the glasses to see the environment through the lenses while also
seeing, simultaneously, digital imagery, which forms an overlaid
image that is perceived by the person as a digitally augmented
image of the environment, or augmented reality ("AR").
[0044] HWC involves more than just placing a computing system on a
person's head. The system may need to be designed as a lightweight,
compact and fully functional computer display, such as wherein the
computer display includes a high resolution digital display that
provides a high level of emersion comprised of the displayed
digital content and the see-through view of the environmental
surroundings. User interfaces and control systems suited to the HWC
device may be required that are unlike those used for a more
conventional computer such as a laptop. For the HWC and associated
systems to be most effective, the glasses may be equipped with
sensors to determine environmental conditions, geographic location,
relative positioning to other points of interest, objects
identified by imaging and movement by the user or other users in a
connected group, and the like. The HWC may then change the mode of
operation to match the conditions, location, positioning,
movements, and the like, in a method generally referred to as a
contextually aware HWC. The glasses also may need to be connected,
wirelessly or otherwise, to other systems either locally or through
a network. Controlling the glasses may be achieved through the use
of an external device, automatically through contextually gathered
information, through user gestures captured by the glasses sensors,
and the like. Each technique may be further refined depending on
the software application being used in the glasses. The glasses may
further be used to control or coordinate with external devices that
are associated with the glasses.
[0045] Referring to FIG. 1, an overview of the HWC system 100 is
presented. As shown, the HWC system 100 comprises a HWC 102, which
in this instance is configured as glasses to be worn on the head
with sensors such that the HWC 102 is aware of the objects and
conditions in the environment 114. In this instance, the HWC 102
also receives and interprets control inputs such as gestures and
movements 116. The HWC 102 may communicate with external user
interfaces 104. The external user interfaces 104 may provide a
physical user interface to take control instructions from a user of
the HWC 102 and the external user interfaces 104 and the HWC 102
may communicate bi-directionally to affect the user's command and
provide feedback to the external device 108. The HWC 102 may also
communicate bi-directionally with externally controlled or
coordinated local devices 108. For example, an external user
interface 104 may be used in connection with the HWC 102 to control
an externally controlled or coordinated local device 108. The
externally controlled or coordinated local device 108 may provide
feedback to the HWC 102 and a customized GUI may be presented in
the HWC 102 based on the type of device or specifically identified
device 108. The HWC 102 may also interact with remote devices and
information sources 112 through a network connection 110. Again,
the external user interface 104 may be used in connection with the
HWC 102 to control or otherwise interact with any of the remote
devices 108 and information sources 112 in a similar way as when
the external user interfaces 104 are used to control or otherwise
interact with the externally controlled or coordinated local
devices 108. Similarly, HWC 102 may interpret gestures 116 (e.g
captured from forward, downward, upward, rearward facing sensors
such as camera(s), range finders, IR sensors, etc.) or
environmental conditions sensed in the environment 114 to control
either local or remote devices 108 or 112.
[0046] We will now describe each of the main elements depicted on
FIG. 1 in more detail; however, these descriptions are intended to
provide general guidance and should not be construed as limiting.
Additional description of each element may also be further
described herein.
[0047] The HWC 102 is a computing platform intended to be worn on a
person's head. The HWC 102 may take many different forms to fit
many different functional requirements. In some situations, the HWC
102 will be designed in the form of conventional glasses. The
glasses may or may not have active computer graphics displays. In
situations where the HWC 102 has integrated computer displays the
displays may be configured as see-through displays such that the
digital imagery can be overlaid with respect to the user's view of
the environment 114. There are a number of see-through optical
designs that may be used, including ones that have a reflective
display (e.g. LCoS, DLP), emissive displays (e.g. OLED, LED),
hologram, TIR waveguides, and the like. In embodiments, lighting
systems used in connection with the display optics may be solid
state lighting systems, such as LED, OLED, quantum dot, quantum dot
LED, etc. In addition, the optical configuration may be monocular
or binocular. It may also include vision corrective optical
components. In embodiments, the optics may be packaged as contact
lenses. In other embodiments, the HWC 102 may be in the form of a
helmet with a see-through shield, sunglasses, safety glasses,
goggles, a mask, fire helmet with see-through shield, police helmet
with see through shield, military helmet with see-through shield,
utility form customized to a certain work task (e.g. inventory
control, logistics, repair, maintenance, etc.), and the like.
[0048] The HWC 102 may also have a number of integrated computing
facilities, such as an integrated processor, integrated power
management, communication structures (e.g. cell net, WiFi,
Bluetooth, local area connections, mesh connections, remote
connections (e.g. client server, etc.)), and the like. The HWC 102
may also have a number of positional awareness sensors, such as
GPS, electronic compass, altimeter, tilt sensor, IMU, and the like.
It may also have other sensors such as a camera, rangefinder,
hyper-spectral camera, Geiger counter, microphone, spectral
illumination detector, temperature sensor, chemical sensor,
biologic sensor, moisture sensor, ultrasonic sensor, and the
like.
[0049] The HWC 102 may also have integrated control technologies.
The integrated control technologies may be contextual based
control, passive control, active control, user control, and the
like. For example, the HWC 102 may have an integrated sensor (e.g.
camera) that captures user hand or body gestures 116 such that the
integrated processing system can interpret the gestures and
generate control commands for the HWC 102. In another example, the
HWC 102 may have sensors that detect movement (e.g. a nod, head
shake, and the like) including accelerometers, gyros and other
inertial measurements, where the integrated processor may interpret
the movement and generate a control command in response. The HWC
102 may also automatically control itself based on measured or
perceived environmental conditions. For example, if it is bright in
the environment the HWC 102 may increase the brightness or contrast
of the displayed image. In embodiments, the integrated control
technologies may be mounted on the HWC 102 such that a user can
interact with it directly. For example, the HWC 102 may have a
button(s), touch capacitive interface, and the like.
[0050] As described herein, the HWC 102 may be in communication
with external user interfaces 104. The external user interfaces may
come in many different forms. For example, a cell phone screen may
be adapted to take user input for control of an aspect of the HWC
102. The external user interface may be a dedicated UI, such as a
keyboard, touch surface, button(s), joy stick, and the like. In
embodiments, the external controller may be integrated into another
device such as a ring, watch, bike, car, and the like. In each
case, the external user interface 104 may include sensors (e.g.
IMU, accelerometers, compass, altimeter, and the like) to provide
additional input for controlling the HWD 104.
[0051] As described herein, the HWC 102 may control or coordinate
with other local devices 108. The external devices 108 may be an
audio device, visual device, vehicle, cell phone, computer, and the
like. For instance, the local external device 108 may be another
HWC 102, where information may then be exchanged between the
separate HWCs 108.
[0052] Similar to the way the HWC 102 may control or coordinate
with local devices 106, the HWC 102 may control or coordinate with
remote devices 112, such as the HWC 102 communicating with the
remote devices 112 through a network 110. Again, the form of the
remote device 112 may have many forms. Included in these forms is
another HWC 102. For example, each HWC 102 may communicate its GPS
position such that all the HWCs 102 know where all of HWC 102 are
located.
[0053] FIG. 2 illustrates a HWC 102 with an optical system that
includes an upper optical module 202 and a lower optical module
204. While the upper and lower optical modules 202 and 204 will
generally be described as separate modules, it should be understood
that this is illustrative only and the present invention includes
other physical configurations, such as that when the two modules
are combined into a single module or where the elements making up
the two modules are configured into more than two modules. In
embodiments, the upper module 202 includes a computer controlled
display (e.g. LCoS, DLP, OLED, etc.) and image light delivery
optics. In embodiments, the lower module includes eye delivery
optics that are configured to receive the upper module's image
light and deliver the image light to the eye of a wearer of the
HWC. In FIG. 2, it should be noted that while the upper and lower
optical modules 202 and 204 are illustrated in one side of the HWC
such that image light can be delivered to one eye of the wearer,
that it is envisioned by the present invention that embodiments
will contain two image light delivery systems, one for each
eye.
[0054] FIG. 3b illustrates an upper optical module 202 in
accordance with the principles of the present invention. In this
embodiment, the upper optical module 202 includes a DLP (also known
as DMD or digital micromirror device) computer operated display 304
which includes pixels comprised of rotatable mirrors (such as, for
example, the DLP3000 available from Texas Instruments), polarized
light source 302, 1/4 wave retarder film 308, reflective polarizer
310 and a field lens 312. The polarized light source 302 provides
substantially uniform polarized light that is generally directed
towards the reflective polarizer 310. The reflective polarizer
reflects light of one polarization state (e.g. S polarized light)
and transmits light of the other polarization state (e.g. P
polarized light). The polarized light source 302 and the reflective
polarizer 310 are oriented so that the polarized light from the
polarized light source 302 is reflected generally towards the DLP
304. The light then passes through the 1/4 wave film 308 once
before illuminating the pixels of the DLP 304 and then again after
being reflected by the pixels of the DLP 304. In passing through
the 1/4 wave film 308 twice, the light is converted from one
polarization state to the other polarization state (e.g. the light
is converted from S to P polarized light). The light then passes
through the reflective polarizer 310. In the event that the DLP
pixel(s) are in the "on" state (i.e. the mirrors are positioned to
reflect light towards the field lens 312, the "on" pixels reflect
the light generally along the optical axis and into the field lens
312. This light that is reflected by "on" pixels and which is
directed generally along the optical axis of the field lens 312
will be referred to as image light 316. The image light 316 then
passes through the field lens to be used by a lower optical module
204.
[0055] The light that is provided by the polarized light source
302, which is subsequently reflected by the reflective polarizer
310 before it reflects from the DLP 304, will generally be referred
to as illumination light. The light that is reflected by the "off"
pixels of the DLP 304 is reflected at a different angle than the
light reflected by the `on" pixels, so that the light from the
"off" pixels is generally directed away from the optical axis of
the field lens 312 and toward the side of the upper optical module
202 as shown in FIG. 3. The light that is reflected by the "off"
pixels of the DLP 304 will be referred to as dark state light
314.
[0056] The DLP 304 operates as a computer controlled display and is
generally thought of as a MEMs device. The DLP pixels are comprised
of small mirrors that can be directed. The mirrors generally flip
from one angle to another angle. The two angles are generally
referred to as states. When light is used to illuminate the DLP the
mirrors will reflect the light in a direction depending on the
state. In embodiments herein, we generally refer to the two states
as "on" and "off," which is intended to depict the condition of a
display pixel. "On" pixels will be seen by a viewer of the display
as emitting light because the light is directed along the optical
axis and into the field lens and the associated remainder of the
display system. "Off" pixels will be seen by a viewer of the
display as not emitting light because the light from these pixels
is directed to the side of the optical housing and into a light
trap or light dump where the light is absorbed. The pattern of "on"
and "off" pixels produces image light that is perceived by a viewer
of the display as a computer generated image. Full color images can
be presented to a user by sequentially providing illumination light
with complimentary colors such as red, green and blue. Where the
sequence is presented in a recurring cycle that is faster than the
user can perceive as separate images and as a result the user
perceives a full color image comprised of the sum of the sequential
images. Bright pixels in the image are provided by pixels that
remain in the "on" state for the entire time of the cycle, while
dimmer pixels in the image are provided by pixels that switch
between the "on" state and "off" state within the time of the
cycle, or frame time when in a video sequence of images.
[0057] FIG. 3a shows an illustration of a system for a DLP 304 in
which the unpolarized light source 350 is pointed directly at the
DLP 304. In this case, the angle required for the illumination
light is such that the field lens 352 must be positioned
substantially distant from the DLP 304 to avoid the illumination
light from being clipped by the field lens 352. The large distance
between the field lens 352 and the DLP 304 along with the straight
path of the dark state light 354, means that the light trap for the
dark state light 354 is also located at a substantial distance from
the DLP. For these reasons, this configuration is larger in size
compared to the upper optics module 202 of the preferred
embodiments.
[0058] The configuration illustrated in FIG. 3b can be lightweight
and compact such that it fits into a small portion of a HWC. For
example, the upper modules 202 illustrated herein can be physically
adapted to mount in an upper frame of a HWC such that the image
light can be directed into a lower optical module 204 for
presentation of digital content to a wearer's eye. The package of
components that combine to generate the image light (i.e. the
polarized light source 302, DLP 304, reflective polarizer 310 and
1/4 wave film 308) is very light and is compact. The height of the
system, excluding the field lens, may be less than 8 mm. The width
(i.e. from front to back) may be less than 8 mm. The weight may be
less than 2 grams. The compactness of this upper optical module 202
allows for a compact mechanical design of the HWC and the light
weight nature of these embodiments help make the HWC lightweight to
provide for a HWC that is comfortable for a wearer of the HWC.
[0059] The configuration illustrated in FIG. 3b can produce sharp
contrast, high brightness and deep blacks, especially when compared
to LCD or LCoS displays used in HWC. The "on" and "off" states of
the DLP provide for a strong differentiator in the light reflection
path representing an "on" pixel and an "off" pixel. As will be
discussed in more detail below, the dark state light from the "off"
pixel reflections can be managed to reduce stray light in the
display system to produce images with high contrast.
[0060] FIG. 4 illustrates another embodiment of an upper optical
module 202 in accordance with the principles of the present
invention. This embodiment includes a light source 404, but in this
case, the light source can provide unpolarized illumination light.
The illumination light from the light source 404 is directed into a
TIR wedge 418 such that the illumination light is incident on an
internal surface of the TIR wedge 418 (shown as the angled lower
surface of the TRI wedge 418 in FIG. 4) at an angle that is beyond
the critical angle as defined by Eqn 1.
Critical angle=arc-sin(1/n) Eqn 1
[0061] Where the critical angle is the angle beyond which the
illumination light is reflected from the internal surface when the
internal surface comprises an interface from a solid with a higher
refractive index (n) to air with a refractive index of 1 (e.g. for
an interface of acrylic, with a refractive index of n=1.5, to air,
the critical angle is 41.8 degrees; for an interface of
polycarbonate, with a refractive index of n=1.59, to air the
critical angle is 38.9 degrees). Consequently, the TIR wedge 418 is
associated with a thin air gap 408 along the internal surface to
create an interface between a solid with a higher refractive index
and air. By choosing the angle of the light source 404 relative to
the DLP 402 in correspondence to the angle of the internal surface
of the TIR wedge 418, illumination light is turned toward the DLP
402 at an angle suitable for providing image light 414 as reflected
from "on" pixels. Wherein, the illumination light is provided to
the DLP 402 at approximately twice the angle of the pixel mirrors
in the DLP 402 that are in the "on" state, such that after
reflecting from the pixel mirrors, the image light 414 is directed
generally along the optical axis of the field lens. Depending on
the state of the DLP pixels, the illumination light from "on"
pixels may be reflected as image light 414 which is directed
towards a field lens and a lower optical module 204, while
illumination light reflected from "off" pixels (generally referred
to herein as "dark" state light, "off" pixel light or "off" state
light) 410 is directed in a separate direction, which may be
trapped and not used for the image that is ultimately presented to
the wearer's eye.
[0062] The light trap for the dark state light 410 may be located
along the optical axis defined by the direction of the dark state
light 410 and in the side of the housing, with the function of
absorbing the dark state light. To this end, the light trap may be
comprised of an area outside of the cone of image light 414 from
the "on" pixels. The light trap is typically made up of materials
that absorb light including coatings of black paints or other light
absorbing materials to prevent light scattering from the dark state
light degrading the image perceived by the user. In addition, the
light trap may be recessed into the wall of the housing or include
masks or guards to block scattered light and prevent the light trap
from being viewed adjacent to the displayed image.
[0063] The embodiment of FIG. 4 also includes a corrective wedge
420 to correct the effect of refraction of the image light 414 as
it exits the TIR wedge 418. By including the corrective wedge 420
and providing a thin air gap 408 (e.g. 25 micron), the image light
from the "on" pixels can be maintained generally in a direction
along the optical axis of the field lens (i.e. the same direction
as that defined by the image light 414) so it passes into the field
lens and the lower optical module 204. As shown in FIG. 4, the
image light 414 from the "on" pixels exits the corrective wedge 420
generally perpendicular to the surface of the corrective wedge 420
while the dark state light exits at an oblique angle. As a result,
the direction of the image light 414 from the "on" pixels is
largely unaffected by refraction as it exits from the surface of
the corrective wedge 420. In contrast, the dark state light 410 is
substantially changed in direction by refraction when the dark
state light 410 exits the corrective wedge 420.
[0064] The embodiment illustrated in FIG. 4 has the similar
advantages of those discussed in connection with the embodiment of
FIG. 3b. The dimensions and weight of the upper module 202 depicted
in FIG. 4 may be approximately 8.times.8 mm with a weight of less
than 3 grams. A difference in overall performance between the
configuration illustrated in FIG. 3b and the configuration
illustrated in FIG. 4 is that the embodiment of FIG. 4 doesn't
require the use of polarized light as supplied by the light source
404. This can be an advantage in some situations as will be
discussed in more detail below (e.g. increased see-through
transparency of the HWC optics from the user's perspective).
Polarized light may be used in connection with the embodiment
depicted in FIG. 4, in embodiments. An additional advantage of the
embodiment of FIG. 4 compared to the embodiment shown in FIG. 3b is
that the dark state light (shown as DLP off light 410) is directed
at a steeper angle away from the optical axis of the image light
414 due to the added refraction encountered when the dark state
light 410 exits the corrective wedge 420. This steeper angle of the
dark state light 410 allows for the light trap to be positioned
closer to the DLP 402 so that the overall size of the upper module
202 can be reduced. The light trap can also be made larger since
the light trap doesn't interfere with the field lens, thereby the
efficiency of the light trap can be increased and as a result,
stray light can be reduced and the contrast of the image perceived
by the user can be increased. FIG. 4a illustrates the embodiment
described in connection with FIG. 4 with an example set of
corresponding angles at the various surfaces with the reflected
angles of a ray of light passing through the upper optical module
202. In this example, the DLP mirrors are provided at 17 degrees to
the surface of the DLP device. The angles of the TIR wedge are
selected in correspondence to one another to provide TIR reflected
illumination light at the correct angle for the DLP mirrors while
allowing the image light and dark state light to pass through the
thin air gap, various combinations of angles are possible to
achieve this.
[0065] FIG. 5 illustrates yet another embodiment of an upper
optical module 202 in accordance with the principles of the present
invention. As with the embodiment shown in FIG. 4, the embodiment
shown in FIG. 5 does not require the use of polarized light.
Polarized light may be used in connection with this embodiment, but
it is not required. The optical module 202 depicted in FIG. 5 is
similar to that presented in connection with FIG. 4; however, the
embodiment of FIG. 5 includes an off light redirection wedge 502.
As can be seen from the illustration, the off light redirection
wedge 502 allows the image light 414 to continue generally along
the optical axis toward the field lens and into the lower optical
module 204 (as illustrated). However, the off light 504 is
redirected substantially toward the side of the corrective wedge
420 where it passes into the light trap. This configuration may
allow further height compactness in the HWC because the light trap
(not illustrated) that is intended to absorb the off light 504 can
be positioned laterally adjacent the upper optical module 202 as
opposed to below it. In the embodiment depicted in FIG. 5 there is
a thin air gap between the TIR wedge 418 and the corrective wedge
420 (similar to the embodiment of FIG. 4). There is also a thin air
gap between the corrective wedge 420 and the off light redirection
wedge 502. There may be HWC mechanical configurations that warrant
the positioning of a light trap for the dark state light elsewhere
and the illustration depicted in FIG. 5 should be considered
illustrative of the concept that the off light can be redirected to
create compactness of the overall HWC. FIG. 5a illustrates an
example of the embodiment described in connection with FIG. 5 with
the addition of more details on the relative angles at the various
surfaces and a light ray trace for image light and a light ray
trace for dark light are shown as it passes through the upper
optical module 202. Again, various combinations of angles are
possible.
[0066] FIG. 4b shows an illustration of a further embodiment in
which a solid transparent matched set of wedges 456 is provided
with a reflective polarizer 450 at the interface between the
wedges. Wherein the interface between the wedges in the wedge set
456 is provided at an angle so that illumination light 452 from the
polarized light source 458 is reflected at the proper angle (e.g.
34 degrees for a 17 degree DLP mirror) for the DLP mirror "on"
state so that the reflected image light 414 is provided along the
optical axis of the field lens. The general geometry of the wedges
in the wedge set 456 is similar to that shown in FIGS. 4 and 4a. A
quarter wave film 454 is provided on the DLP 402 surface so that
the illumination light 452 is one polarization state (e.g. S
polarization state) while in passing through the quarter wave film
454, reflecting from the DLP mirror and passing back through the
quarter wave film 454, the image light 414 is converted to the
other polarization state (e.g. P polarization state). The
reflective polarizer is oriented such that the illumination light
452 with it's polarization state is reflected and the image light
414 with it's other polarization state is transmitted. Since the
dark state light from the "off pixels 410 also passes through the
quarter wave film 454 twice, it is also the other polarization
state (e.g. P polarization state) so that it is transmitted by the
reflective polarizer 450.
[0067] The angles of the faces of the wedge set 450 correspond to
the needed angles to provide illumination light 452 at the angle
needed by the DLP mirrors when in the "on" state so that the
reflected image light 414 is reflected from the DLP along the
optical axis of the field lens. The wedge set 456 provides an
interior interface where a reflective polarizer film can be located
to redirect the illumination light 452 toward the mirrors of the
DLP 402. The wedge set also provides a matched wedge on the
opposite side of the reflective polarizer 450 so that the image
light 414 from the "on" pixels exits the wedge set 450
substantially perpendicular to the exit surface, while the dark
state light from the `off` pixels 410 exits at an oblique angle to
the exit surface. As a result, the image light 414 is substantially
unrefracted upon exiting the wedge set 456, while the dark state
light from the "off" pixels 410 is substantially refracted upon
exiting the wedge set 456 as shown in FIG. 4b.
[0068] By providing a solid transparent matched wedge set, the
flatness of the interface is reduced, because variations in the
flatness have a negligible effect as long as they are within the
cone angle of the illuminating light 452. Which can be f#2.2 with a
26 degree cone angle. In a preferred embodiment, the reflective
polarizer is bonded between the matched internal surfaces of the
wedge set 456 using an optical adhesive so that Fresnel reflections
at the interfaces on either side of the reflective polarizer 450
are reduced. The optical adhesive can be matched in refractive
index to the material of the wedge set 456 and the pieces of the
wedge set 456 can be all made from the same material such as BK7
glass or cast acrylic. Wherein the wedge material can be selected
to have low birefringence as well to reduce non-uniformities in
brightness. The wedge set 456 and the quarter wave film 454 can
also be bonded to the DLP 402 to further reduce Fresnel reflections
at the DLP interface losses. In addition, since the image light 414
is substantially normal to the exit surface of the wedge set 456,
the flatness of the surface is not critical to maintain the
wavefront of the image light 414 so that high image quality can be
obtained in the displayed image without requiring very tightly
toleranced flatness on the exit surface.
[0069] A yet further embodiment of the invention that is not
illustrated, combines the embodiments illustrated in FIG. 4b and
FIG. 5. In this embodiment, the wedge set 456 is comprised of three
wedges with the general geometry of the wedges in the wedge set
corresponding to that shown in FIGS. 5 and 5a. A reflective
polarizer is bonded between the first and second wedges similar to
that shown in FIG. 4b, however, a third wedge is provided similar
to the embodiment of FIG. 5. Wherein there is an angled thin air
gap between the second and third wedges so that the dark state
light is reflected by TIR toward the side of the second wedge where
it is absorbed in a light trap. This embodiment, like the
embodiment shown in FIG. 4b, uses a polarized light source as has
been previously described. The difference in this embodiment is
that the image light is transmitted through the reflective
polarizer and is transmitted through the angled thin air gap so
that it exits normal to the exit surface of the third wedge.
[0070] FIG. 5b illustrates an upper optical module 202 with a dark
light trap 514a. As described in connection with FIGS. 4 and 4a,
image light can be generated from a DLP when using a TIR and
corrective lens configuration. The upper module may be mounted in a
HWC housing 510 and the housing 510 may include a dark light trap
514a. The dark light trap 514a is generally
positioned/constructed/formed in a position that is optically
aligned with the dark light optical axis 512. As illustrated, the
dark light trap may have depth such that the trap internally
reflects dark light in an attempt to further absorb the light and
prevent the dark light from combining with the image light that
passes through the field lens. The dark light trap may be of a
shape and depth such that it absorbs the dark light. In addition,
the dark light trap 514b, in embodiments, may be made of light
absorbing materials or coated with light absorbing materials. In
embodiments, the recessed light trap 514a may include baffles to
block a view of the dark state light. This may be combined with
black surfaces and textured or fiberous surfaces to help absorb the
light. The baffles can be part of the light trap, associated with
the housing, or field lens, etc.
[0071] FIG. 5c illustrates another embodiment with a light trap
514b. As can be seen in the illustration, the shape of the trap is
configured to enhance internal reflections within the light trap
514b to increase the absorption of the dark light 512. FIG. 5d
illustrates another embodiment with a light trap 514c. As can be
seen in the illustration, the shape of the trap 514c is configured
to enhance internal reflections to increase the absorption of the
dark light 512.
[0072] FIG. 5e illustrates another embodiment of an upper optical
module 202 with a dark light trap 514d. This embodiment of upper
module 202 includes an off light reflection wedge 502, as
illustrated and described in connection with the embodiment of
FIGS. 5 and 5a. As can be seen in FIG. 5e, the light trap 514d is
positioned along the optical path of the dark light 512. The dark
light trap 514d may be configured as described in other embodiments
herein. The embodiment of the light trap 514d illustrated in FIG.
5e includes a black area on the side wall of the wedge, wherein the
side wall is located substantially away from the optical axis of
the image light 414. In addition, baffles 5252 may be added to one
or more edges of the field lens 312 to block the view of the light
trap 514d adjacent to the displayed image seen by the user.
[0073] FIG. 6 illustrates a combination of an upper optical module
202 with a lower optical module 204. In this embodiment, the image
light projected from the upper optical module 202 may or may not be
polarized. The image light is reflected off a flat combiner element
602 such that it is directed towards the user's eye. Wherein, the
combiner element 602 is a partial mirror that reflects image light
while transmitting a substantial portion of light from the
environment so the user can look through the combiner element and
see the environment surrounding the HWC.
[0074] The combiner 602 may include a holographic pattern, to form
a holographic mirror. If a monochrome image is desired, there may
be a single wavelength reflection design for the holographic
pattern on the surface of the combiner 602. If the intention is to
have multiple colors reflected from the surface of the combiner
602, a multiple wavelength holographic mirror maybe included on the
combiner surface. For example, in a three-color embodiment, where
red, green and blue pixels are generated in the image light, the
holographic mirror may be reflective to wavelengths substantially
matching the wavelengths of the red, green and blue light provided
by the light source. This configuration can be used as a wavelength
specific mirror where pre-determined wavelengths of light from the
image light are reflected to the user's eye. This configuration may
also be made such that substantially all other wavelengths in the
visible pass through the combiner element 602 so the user has a
substantially clear view of the surroundings when looking through
the combiner element 602. The transparency between the user's eye
and the surrounding may be approximately 80% when using a combiner
that is a holographic mirror. Wherein holographic mirrors can be
made using lasers to produce interference patterns in the
holographic material of the combiner where the wavelengths of the
lasers correspond to the wavelengths of light that are subsequently
reflected by the holographic mirror.
[0075] In another embodiment, the combiner element 602 may include
a notch mirror comprised of a multilayer coated substrate wherein
the coating is designed to substantially reflect the wavelengths of
light provided by the light source and substantially transmit the
remaining wavelengths in the visible spectrum. For example, in the
case where red, green and blue light is provided by the light
source to enable full color images to be provided to the user, the
notch mirror is a tristimulus notch mirror wherein the multilayer
coating is designed to reflect narrow bands of red, green and blue
light that are matched to the what is provided by the light source
and the remaining visible wavelengths are transmitted through the
coating to enable a view of the environment through the combiner.
In another example where monochrome images are provided to the
user, the notch mirror is designed to reflect a single narrow band
of light that is matched to the wavelength range of the light
provided by the light source while transmitting the remaining
visible wavelengths to enable a see-thru view of the environment.
The combiner 602 with the notch mirror would operate, from the
user's perspective, in a manner similar to the combiner that
includes a holographic pattern on the combiner element 602. The
combiner, with the tristimulus notch mirror, would reflect the "on"
pixels to the eye because of the match between the reflective
wavelengths of the notch mirror and the color of the image light,
and the wearer would be able to see with high clarity the
surroundings. The transparency between the user's eye and the
surrounding may be approximately 80% when using the tristimulus
notch mirror. In addition, the image provided by the upper optical
module 202 with the notch mirror combiner can provide higher
contrast images than the holographic mirror combiner due to less
scattering of the imaging light by the combiner.
[0076] Light can escape through the combiner 602 and may produce
face glow as the light is generally directed downward onto the
cheek of the user. When using a holographic mirror combiner or a
tristimulus notch mirror combiner, the escaping light can be
trapped to avoid face glow. In embodiments, if the image light is
polarized before the combiner, a linear polarizer can be laminated,
or otherwise associated, to the combiner, with the transmission
axis of the polarizer oriented relative to the polarized image
light so that any escaping image light is absorbed by the
polarizer. In embodiments, the image light would be polarized to
provide S polarized light to the combiner for better reflection. As
a result, the linear polarizer on the combiner would be oriented to
absorb S polarized light and pass P polarized light. This provides
the preferred orientation of polarized sunglasses as well.
[0077] If the image light is unpolarized, a microlouvered film such
as a privacy filter can be used to absorb the escaping image light
while providing the user with a see-thru view of the environment.
In this case, the absorbance or transmittance of the microlouvered
film is dependent on the angle of the light. Where steep angle
light is absorbed and light at less of an angle is transmitted. For
this reason, in an embodiment, the combiner with the microlouver
film is angled at greater than 45 degrees to the optical axis of
the image light (e.g. the combiner can be oriented at 50 degrees so
the image light from the file lens is incident on the combiner at
an oblique angle.
[0078] FIG. 7 illustrates an embodiment of a combiner element 602
at various angles when the combiner element 602 includes a
holographic mirror. Normally, a mirrored surface reflects light at
an angle equal to the angle that the light is incident to the
mirrored surface. Typically, this necessitates that the combiner
element be at 45 degrees, 602a, if the light is presented
vertically to the combiner so the light can be reflected
horizontally towards the wearer's eye. In embodiments, the incident
light can be presented at angles other than vertical to enable the
mirror surface to be oriented at other than 45 degrees, but in all
cases wherein a mirrored surface is employed (including the
tristimulus notch mirror described previously), the incident angle
equals the reflected angle. As a result, increasing the angle of
the combiner 602a requires that the incident image light be
presented to the combiner 602a at a different angle which positions
the upper optical module 202 to the left of the combiner as shown
in FIG. 7. In contrast, a holographic mirror combiner, included in
embodiments, can be made such that light is reflected at a
different angle from the angle that the light is incident onto the
holographic mirrored surface. This allows freedom to select the
angle of the combiner element 602b independent of the angle of the
incident image light and the angle of the light reflected into the
wearer's eye. In embodiments, the angle of the combiner element
602b is greater than 45 degrees (shown in FIG. 7) as this allows a
more laterally compact HWC design. The increased angle of the
combiner element 602b decreases the front to back width of the
lower optical module 204 and may allow for a thinner HWC display
(i.e. the furthest element from the wearer's eye can be closer to
the wearer's face).
[0079] FIG. 8 illustrates another embodiment of a lower optical
module 204. In this embodiment, polarized image light provided by
the upper optical module 202, is directed into the lower optical
module 204. The image light reflects off a polarized mirror 804 and
is directed to a focusing partially reflective mirror 802, which is
adapted to reflect the polarized light. An optical element such as
a 1/4 wave film located between the polarized mirror 804 and the
partially reflective mirror 802, is used to change the polarization
state of the image light such that the light reflected by the
partially reflective mirror 802 is transmitted by the polarized
mirror 804 to present image light to the eye of the wearer. The
user can also see through the polarized mirror 804 and the
partially reflective mirror 802 to see the surrounding environment.
As a result, the user perceives a combined image comprised of the
displayed image light overlaid onto the see-thru view of the
environment.
[0080] While many of the embodiments of the present invention have
been referred to as upper and lower modules containing certain
optical components, it should be understood that the image light
and dark light production and management functions described in
connection with the upper module may be arranged to direct light in
other directions (e.g. upward, sideward, etc.). In embodiments, it
may be preferred to mount the upper module 202 above the wearer's
eye, in which case the image light would be directed downward. In
other embodiments it may be preferred to produce light from the
side of the wearer's eye, or from below the wearer's eye. In
addition, the lower optical module is generally configured to
deliver the image light to the wearer's eye and allow the wearer to
see through the lower optical module, which may be accomplished
through a variety of optical components.
[0081] FIG. 8a illustrates an embodiment of the present invention
where the upper optical module 202 is arranged to direct image
light into a TIR waveguide 810. In this embodiment, the upper
optical module 202 is positioned above the wearer's eye 812 and the
light is directed horizontally into the TIR waveguide 810. The TIR
waveguide is designed to internally reflect the image light in a
series of downward TIR reflections until it reaches the portion in
front of the wearer's eye, where the light passes out of the TIR
waveguide 812 into the wearer's eye. In this embodiment, an outer
shield 814 is positioned in front of the TIR waveguide 810.
[0082] FIG. 8b illustrates an embodiment of the present invention
where the upper optical module 202 is arranged to direct image
light into a TIR waveguide 818. In this embodiment, the upper
optical module 202 is arranged on the side of the TIR waveguide
818. For example, the upper optical module may be positioned in the
arm or near the arm of the HWC when configured as a pair of head
worn glasses. The TIR waveguide 818 is designed to internally
reflect the image light in a series of TIR reflections until it
reaches the portion in front of the wearer's eye, where the light
passes out of the TIR waveguide 812 into the wearer's eye.
[0083] FIG. 8c illustrates yet further embodiments of the present
invention where an upper optical module 202 is directing polarized
image light into an optical guide 828 where the image light passes
through a polarized reflector 824, changes polarization state upon
reflection of the optical element 822 which includes a 1/4 wave
film for example and then is reflected by the polarized reflector
824 towards the wearer's eye, due to the change in polarization of
the image light. The upper optical module 202 may be positioned to
direct light to a mirror 820, to position the upper optical module
202 laterally, in other embodiments, the upper optical module 202
may direct the image light directly towards the polarized reflector
824. It should be understood that the present invention comprises
other optical arrangements intended to direct image light into the
wearer's eye.
[0084] Another aspect of the present invention relates to eye
imaging. In embodiments, a camera is used in connection with an
upper optical module 202 such that the wearer's eye can be imaged
using pixels in the "off" state on the DLP. FIG. 9 illustrates a
system where the eye imaging camera 802 is mounted and angled such
that the field of view of the eye imaging camera 802 is redirected
toward the wearer's eye by the mirror pixels of the DLP 402 that
are in the "off" state. In this way, the eye imaging camera 802 can
be used to image the wearer's eye along the same optical axis as
the displayed image that is presented to the wearer. Wherein, image
light that is presented to the wearer's eye illuminates the
wearer's eye so that the eye can be imaged by the eye imaging
camera 802. In the process, the light reflected by the eye passes
back though the optical train of the lower optical module 204 and a
portion of the upper optical module to where the light is reflected
by the "off" pixels of the DLP 402 toward the eye imaging camera
802.
[0085] In embodiments, the eye imaging camera may image the
wearer's eye at a moment in time where there are enough "off"
pixels to achieve the required eye image resolution. In another
embodiment, the eye imaging camera collects eye image information
from "off" pixels over time and forms a time lapsed image. In
another embodiment, a modified image is presented to the user
wherein enough "off" state pixels are included that the camera can
obtain the desired resolution and brightness for imaging the
wearer's eye and the eye image capture is synchronized with the
presentation of the modified image.
[0086] The eye imaging system may be used for security systems. The
HWC may not allow access to the HWC or other system if the eye is
not recognized (e.g. through eye characteristics including retina
or iris characteristics, etc.). The HWC may be used to provide
constant security access in some embodiments. For example, the eye
security confirmation may be a continuous, near-continuous,
real-time, quasi real-time, periodic, etc. process so the wearer is
effectively constantly being verified as known. In embodiments, the
HWC may be worn and eye security tracked for access to other
computer systems.
[0087] The eye imaging system may be used for control of the HWC.
For example, a blink, wink, or particular eye movement may be used
as a control mechanism for a software application operating on the
HWC or associated device.
[0088] The eye imaging system may be used in a process that
determines how or when the HWC 102 delivers digitally displayed
content to the wearer. For example, the eye imaging system may
determine that the user is looking in a direction and then HWC may
change the resolution in an area of the display or provide some
content that is associated with something in the environment that
the user may be looking at. Alternatively, the eye imaging system
may identify different user's and change the displayed content or
enabled features provided to the user. User's may be identified
from a database of users eye characteristics either located on the
HWC 102 or remotely located on the network 110 or on a server 112.
In addition, the HWC may identify a primary user or a group of
primary users from eye characteristics wherein the primary user(s)
are provided with an enhanced set of features and all other user's
are provided with a different set of features. Thus in this use
case, the HWC 102 uses identified eye characteristics to either
enable features or not and eye characteristics need only be
analyzed in comparison to a relatively small database of individual
eye characteristics.
[0089] FIG. 10 illustrates a light source that may be used in
association with the upper optics module 202 (e.g. polarized light
source if the light from the solid state light source is polarized
such as polarized light source 302 and 458), and light source 404.
In embodiments, to provide a uniform surface of light 1008 to be
directed into the upper optical module 202 and towards the DLP of
the upper optical module, either directly or indirectly, the solid
state light source 1002 may be projected into a backlighting
optical system 1004. The solid state light source 1002 may be one
or more LEDs, laser diodes, OLEDs. In embodiments, the backlighting
optical system 1004 includes an extended section with a
length/distance ratio of greater than 3, wherein the light
undergoes multiple reflections from the sidewalls to mix of
homogenize the light as supplied by the solid state light source
1002. The backlighting optical system 1004 can also include
structures on the surface opposite (on the left side as shown in
FIG. 10) to where the uniform light 1008 exits the backlight 1004
to change the direction of the light toward the DLP 302 and the
reflective polarizer 310 or the DLP 402 and the TIR wedge 418. The
backlighting optical system 1004 may also include structures to
collimate the uniform light 1008 to provide light to the DLP with a
smaller angular distribution or narrower cone angle. Diffusers or
polarizers can be used on the entrance or exit surface of the
backlighting optical system. Diffusers can be used to spread or
uniformize the exiting light from the backlight to improve the
uniformity or increase the angular spread of the uniform light
1008. Elliptical diffusers that diffuse the light more in some
directions and less in others can be used to improve the uniformity
or spread of the uniform light 1008 in directions orthogonal to the
optical axis of the uniform light 1008. Linear polarizers can be
used to convert unpolarized light as supplied by the solid state
light source 1002 to polarized light so the uniform light 1008 is
polarized with a desired polarization state. A reflective polarizer
can be used on the exit surface of the backlight 1004 to polarize
the uniform light 1008 to the desired polarization state, while
reflecting the other polarization state back into the backlight
where it is recycled by multiple reflections within the backlight
1004 and at the solid state light source 1002. Therefore by
including a reflective polarizer at the exit surface of the
backlight 1004, the efficiency of the polarized light source is
improved.
[0090] FIGS. 10a and 10b show illustrations of structures in
backlight optical systems 1004 that can be used to change the
direction of the light provided to the entrance face 1045 by the
light source and then collimates the light in a direction lateral
to the optical axis of the exiting uniform light 1008. Structure
1060 includes an angled sawtooth pattern in a transparent waveguide
wherein the left edge of each sawtooth clips the steep angle rays
of light thereby limiting the angle of the light being redirected.
The steep surface at the right (as shown) of each sawtooth then
redirects the light so that it reflects off the left angled surface
of each sawtooth and is directed toward the exit surface 1040. The
sawtooth surfaces shown on the lower surface in FIGS. 10a and 10b,
can be smooth and coated (e.g. with an aluminum coating or a
dielectric mirror coating) to provide a high level of reflectivity
without scattering. Structure 1050 includes a curved face on the
left side (as shown) to focus the rays after they pass through the
exit surface 1040, thereby providing a mechanism for collimating
the uniform light 1008. In a further embodiment, a diffuser can be
provided between the solid state light source 1002 and the entrance
face 1045 to homogenize the light provided by the solid state light
source 1002. In yet a further embodiment, a polarizer can be used
between the diffuser and the entrance face 1045 of the backlight
1004 to provide a polarized light source. Because the sawtooth
pattern provides smooth reflective surfaces, the polarization state
of the light can be preserved from the entrance face 1045 to the
exit face 1040. In this embodiment, the light entering the
backlight from the solid state light source 1002 passes through the
polarizer so that it is polarized with the desired polarization
state. If the polarizer is an absorptive linear polarizer, the
light of the desired polarization state is transmitted while the
light of the other polarization state is absorbed. If the polarizer
is a reflective polarizer, the light of the desired polarization
state is transmitted into the backlight 1004 while the light of the
other polarization state is reflected back into the solid state
light source 1002 where it can be recycled as previously described,
to increase the efficiency of the polarized light source.
[0091] FIG. 11a illustrates a light source 1100 that may be used in
association with the upper optics module 202. In embodiments, the
light source 1100 may provide light to a backlighting optical
system 1004 as described above in connection with FIG. 10. In
embodiments, the light source 1100 includes a tristimulus notch
filter 1102. The tristimulus notch filter 1102 has narrow band pass
filters for three wavelengths, as indicated in FIG. 11c in a
transmission graph 1108. The graph shown in FIG. 11b, as 1104
illustrates an output of three different colored LEDs. One can see
that the bandwidths of emission are narrow, but they have long
tails. The tristimulus notch filter 1102 can be used in connection
with such LEDs to provide a light source 1100 that emits narrow
filtered wavelengths of light as shown in FIG. 11d as the
transmission graph 1110. Wherein the clipping effects of the
tristimulus notch filter 1102 can be seen to have cut the tails
from the LED emission graph 1104 to provide narrower wavelength
bands of light to the upper optical module 202. The light source
1100 can be used in connection with a combiner 602 with a
holographic mirror or tristimulus notch mirror to provide narrow
bands of light that are reflected toward the wearer's eye with less
waste light that does not get reflected by the combiner, thereby
improving efficiency and reducing escaping light that can cause
faceglow.
[0092] FIG. 12a illustrates another light source 1200 that may be
used in association with the upper optics module 202. In
embodiments, the light source 1200 may provide light to a
backlighting optical system 1004 as described above in connection
with FIG. 10. In embodiments, the light source 1200 includes a
quantum dot cover glass 1202. Where the quantum dots absorb light
of a shorter wavelength and emit light of a longer wavelength (FIG.
12b shows an example wherein a UV spectrum 1202 applied to a
quantum dot results in the quantum dot emitting a narrow band shown
as a PL spectrum 1204) that is dependent on the material makeup and
size of the quantum dot. As a result, quantum dots in the quantum
dot cover glass 1202 can be tailored to provide one or more bands
of narrow bandwidth light (e.g. red, green and blue emissions
dependent on the different quantum dots included as illustrated in
the graph shown in FIG. 12c where three different quantum dots are
used. In embodiments, the LED driver light emits UV light, deep
blue or blue light. For sequential illumination of different
colors, multiple light sources 1200 would be used where each light
source 1200 would include a quantum dot cover glass 1202 with a
quantum dot selected to emit at one of the desired colors. The
light source 1100 can be used in connection with a combiner 602
with a holographic mirror or tristimulus notch mirror to provide
narrow transmission bands of light that are reflected toward the
wearer's eye with less waste light that does not get reflected.
[0093] Another aspect of the present invention relates to the
generation of peripheral image lighting effects for a person
wearing a HWC. In embodiments, a solid state lighting system (e.g.
LED, OLED, etc), or other lighting system, may be included inside
the optical elements of an lower optical module 204. The solid
state lighting system may be arranged such that lighting effects
outside of a field of view (FOV) of the presented digital content
is presented to create an emersive effect for the person wearing
the HWC. To this end, the lighting effects may be presented to any
portion of the HWC that is visible to the wearer. The solid state
lighting system may be digitally controlled by an integrated
processor on the HWC. In embodiments, the integrated processor will
control the lighting effects in coordination with digital content
that is presented within the FOV of the HWC. For example, a movie,
picture, game, or other content, may be displayed or playing within
the FOV of the HWC. The content may show a bomb blast on the right
side of the FOV and at the same moment, the solid state lighting
system inside of the upper module optics may flash quickly in
concert with the FOV image effect. The effect may not be fast, it
may be more persistent to indicate, for example, a general glow or
color on one side of the user. The solid state lighting system may
be color controlled, with red, green and blue LEDs, for example,
such that color control can be coordinated with the digitally
presented content within the field of view.
[0094] FIG. 13a illustrates optical components of a lower optical
module 204 together with an outer lens 1302. FIG. 13a also shows an
embodiment including effects LED's 1308a and 1308b. FIG. 13a
illustrates image light 1312, as described herein elsewhere,
directed into the upper optical module where it will reflect off of
the combiner element 1304, as described herein elsewhere. The
combiner element 1304 in this embodiment is angled towards the
wearer's eye at the top of the module and away from the wearer's
eye at the bottom of the module, as also illustrated and described
in connection with FIG. 8 (e.g. at a 45 degree angle). The image
light 1312 provided by an upper optical module 202 (not shown in
FIG. 13a) reflects off of the combiner element 1304 towards the
collimating mirror 1310, away from the wearer's eye, as described
herein elsewhere. The image light 1312 then reflects and focuses
off of the collimating mirror 1304, passes back through the
combiner element 1304, and is directed into the wearer's eye. The
wearer can also view the surrounding environment through the
transparency of the combiner element 1304, collimating mirror 1310,
and outer lens 1302 (if it is included). As described herein
elsewhere, various surfaces are polarized to create the optical
path for the image light and to provide transparency of the
elements such that the wearer can view the surrounding environment.
The wearer will generally perceive that the image light forms an
image in the FOV 1305. In embodiments, the outer lens 1302 may be
included. The outer lens 1302 is an outer lens that may or may not
be corrective and it may be designed to conceal the lower optical
module components in an effort to make the HWC appear to be in a
form similar to standard glasses or sunglasses.
[0095] In the embodiment illustrated in FIG. 13a, the effects LEDs
1308a and 1308b are positioned at the sides of the combiner element
1304 and the outer lens 1302 and/or the collimating mirror 1310. In
embodiments, the effects LEDs 1308a are positioned within the
confines defined by the combiner element 1304 and the outer lens
1302 and/or the collimating mirror. The effects LEDs 1308a and
1308b are also positioned outside of the FOV 1305. In this
arrangement, the effects LEDs 1308a and 1308b can provide lighting
effects within the lower optical module outside of the FOV 1305. In
embodiments the light emitted from the effects LEDs 1308a and 1308b
may be polarized such that the light passes through the combiner
element 1304 toward the wearer's eye and does not pass through the
outer lens 1302 and/or the collimating mirror 1310. This
arrangement provides peripheral lighting effects to the wearer in a
more private setting by not transmitting the lighting effects
through the front of the HWC into the surrounding environment.
However, in other embodiments, the effects LEDs 1308a and 1308b may
be unpolarized so the lighting effects provided are made to be
purposefully viewable by others in the environment for
entertainment such as giving the effect of the wearer's eye glowing
in correspondence to the image content being viewed by the
wearer.
[0096] FIG. 13b illustrates a cross section of the embodiment
described in connection with FIG. 13a. As illustrated, the effects
LED 1308a is located in the upper-front area inside of the optical
components of the lower optical module. It should be understood
that the effects LED 1308a position in the described embodiments is
only illustrative and alternate placements are encompassed by the
present invention. Additionally, in embodiments, there may be one
or more effects LEDs 1308a in each of the two sides of HWC to
provide peripheral lighting effects near one or both eyes of the
wearer.
[0097] FIG. 13c illustrates an embodiment where the combiner
element 1304 is angled away from the eye at the top and towards the
eye at the bottom (e.g. in accordance with the holographic or notch
filter embodiments described herein). In this embodiment, the
effects LED 1308a is located on the outer lens 1302 side of the
combiner element 1304 to provide a concealed appearance of the
lighting effects. As with other embodiments, the effects LED 1308a
of FIG. 13c may include a polarizer such that the emitted light can
pass through a polarized element associated with the combiner
element 1304 and be blocked by a polarized element associated with
the outer lens 1302.
[0098] Another aspect of the present invention relates to the
mitigation of light escaping from the space between the wearer's
face and the HWC itself. Another aspect of the present invention
relates to maintaining a controlled lighting environment in
proximity to the wearer's eyes. In embodiments, both the
maintenance of the lighting environment and the mitigation of light
escape are accomplished by including a removable and replaceable
flexible shield for the HWC. Wherein the removable and replaceable
shield can be provided for one eye or both eyes in correspondence
to the use of the displays for each eye. For example, in a night
vision application, the display to only one eye could be used for
night vision while the display to the other eye is turned off to
provide good see-thru when moving between areas where visible light
is available and dark areas where night vision enhancement is
needed.
[0099] FIG. 14a illustrates a removable and replaceable flexible
eye cover 1402 with an opening 1408 that can be attached and
removed quickly from the HWC 102 through the use of magnets. Other
attachment methods may be used, but for illustration of the present
invention we will focus on a magnet implementation. In embodiments,
magnets may be included in the eye cover 1402 and magnets of an
opposite polarity may be included (e.g. embedded) in the frame of
the HWC 102. The magnets of the two elements would attract quite
strongly with the opposite polarity configuration. In another
embodiment, one of the elements may have a magnet and the other
side may have metal for the attraction. In embodiments, the eye
cover 1402 is a flexible elastomeric shield. In embodiments, the
eye cover 1402 may be an elastomeric bellows design to accommodate
flexibility and more closely align with the wearer's face. FIG. 14b
illustrates a removable and replaceable flexible eye cover 1404
that is adapted as a single eye cover. In embodiments, a single eye
cover may be used for each side of the HWC to cover both eyes of
the wearer. In embodiments, the single eye cover may be used in
connection with a HWC that includes only one computer display for
one eye. These configurations prevent light that is generated and
directed generally towards the wearer's face by covering the space
between the wearer's face and the HWC. The opening 1408 allows the
wearer to look through the opening 1408 to view the displayed
content and the surrounding environment through the front of the
HWC. The image light in the lower optical module 204 can be
prevented from emitting from the front of the HWC through internal
optics polarization schemes, as described herein, for example.
[0100] FIG. 14c illustrates another embodiment of a light
suppression system. In this embodiment, the eye cover 1410 may be
similar to the eye cover 1402, but eye cover 1410 includes a front
light shield 1412. The front light shield 1412 may be opaque to
prevent light from escaping the front lens of the HWC. In other
embodiments, the front light shield 1412 is polarized to prevent
light from escaping the front lens. In a polarized arrangement, in
embodiments, the internal optical elements of the HWC (e.g. of the
lower optical module 204) may polarize light transmitted towards
the front of the HWC and the front light shield 1412 may be
polarized to prevent the light from transmitting through the front
light shield 1412.
[0101] In embodiments, an opaque front light shield 1412 may be
included and the digital content may include images of the
surrounding environment such that the wearer can visualize the
surrounding environment. One eye may be presented with night vision
environmental imagery and this eye's surrounding environment
optical path may be covered using an opaque front light shield
1412. In other embodiments, this arrangement may be associated with
both eyes.
[0102] Another aspect of the present invention relates to
automatically configuring the lighting system(s) used in the HWC
102. In embodiments, the display lighting and/or effects lighting,
as described herein, may be controlled in a manner suitable for
when an eye cover 1408 is attached or removed from the HWC 102. For
example, at night, when the light in the environment is low, the
lighting system(s) in the HWC may go into a low light mode to
further control any amounts of stray light escaping from the HWC
and the areas around the HWC. Covert operations at night, while
using night vision or standard vision, may require a solution which
prevents as much escaping light as possible so a user may clip on
the eye cover(s) 1408 and then the HWC may go into a low light
mode. The low light mode may, in some embodiments, only go into a
low light mode when the eye cover 1408 is attached if the HWC
identifies that the environment is in low light conditions (e.g.
through environment light level sensor detection). In embodiments,
the low light level may be determined to be at an intermediate
point between full and low light dependent on environmental
conditions.
[0103] Another aspect of the present invention relates to
automatically controlling the type of content displayed in the HWC
when eye covers 1408 are attached or removed from the HWC. In
embodiments, when the eye cover(s) 1408 is attached to the HWC, the
displayed content may be restricted in amount or in color amounts.
For example, the display(s) may go into a simple content delivery
mode to restrict the amount of information displayed. This may be
done to reduce the amount of light produced by the display(s). In
an embodiment, the display(s) may change from color displays to
monochrome displays to reduce the amount of light produced. In an
embodiment, the monochrome lighting may be red to limit the impact
on the wearer's eyes to maintain an ability to see better in the
dark.
[0104] Although embodiments of HWC have been described in language
specific to features, systems, computer processes and/or methods,
the appended claims are not necessarily limited to the specific
features, systems, computer processes and/or methods described.
Rather, the specific features, systems, computer processes and/or
and methods are disclosed as non-limited example implementations of
HWC. All documents referenced herein are hereby incorporated by
reference.
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