U.S. patent application number 14/704979 was filed with the patent office on 2015-08-20 for rendering based on predicted head movement in augmented or virtual reality systems.
This patent application is currently assigned to Magic Leap, Inc.. The applicant listed for this patent is Magic Leap, Inc.. Invention is credited to Samuel A. Miller, Brian T. Schowengerdt.
Application Number | 20150235453 14/704979 |
Document ID | / |
Family ID | 51525486 |
Filed Date | 2015-08-20 |
United States Patent
Application |
20150235453 |
Kind Code |
A1 |
Schowengerdt; Brian T. ; et
al. |
August 20, 2015 |
RENDERING BASED ON PREDICTED HEAD MOVEMENT IN AUGMENTED OR VIRTUAL
REALITY SYSTEMS
Abstract
One embodiment is directed to a user display device comprising a
housing frame mountable on the head of the user, a lens mountable
on the housing frame and a projection sub system coupled to the
housing frame to determine a location of appearance of a display
object in a field of view of the user based at least in part on at
least one of a detection of a head movement of the user and a
prediction of a head movement of the user, and to project the
display object to the user based on the determined location of
appearance of the display object.
Inventors: |
Schowengerdt; Brian T.;
(Seattle, WA) ; Miller; Samuel A.; (Hollywood,
FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Magic Leap, Inc. |
Dania Beach |
FL |
US |
|
|
Assignee: |
Magic Leap, Inc.
Dania Beach
FL
|
Family ID: |
51525486 |
Appl. No.: |
14/704979 |
Filed: |
May 6, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14212961 |
Mar 14, 2014 |
|
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14704979 |
|
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61801219 |
Mar 15, 2013 |
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Current U.S.
Class: |
345/633 |
Current CPC
Class: |
G06T 1/60 20130101; G02B
27/01 20130101; G06T 19/006 20130101; G02B 27/0093 20130101; G06T
19/00 20130101; G06F 3/011 20130101; G06T 7/70 20170101; G02B
2027/014 20130101; G06F 3/013 20130101; G02B 27/017 20130101; G02B
27/0172 20130101; G06F 3/012 20130101; G02B 2027/0178 20130101;
G09G 2320/0266 20130101; G02B 2027/0187 20130101; G09G 3/007
20130101; G06T 2219/024 20130101 |
International
Class: |
G06T 19/00 20060101
G06T019/00; G02B 27/01 20060101 G02B027/01; G06F 3/01 20060101
G06F003/01 |
Claims
1. A projector apparatus to project at least virtual images in an
augmented reality system, the projector apparatus comprising: a
projector element; a support that supports the projector element
with the projector element moveable in at least one axis of
freedom; at least one actuator coupled to selectively move the
projector element; and a control subsystem communicatively coupled
to control the actuator such that the projector element is moved in
response to at least one of a detection of a head movement of an
end user that exceeds a nominal head movement value and a
prediction of a head movement of the end user that is predicted to
exceed the nominal head movement value.
2. The projector apparatus of claim 1, wherein the projector
element further comprises at least a first optical fiber, the first
optical fiber having a back end and a front end, the back end
coupled to receive images, the front end positioned to transmit
images therefrom.
3. The projector apparatus of claim 2, wherein the support element
comprises a piezoelectric collar that receives at least the first
optical fiber proximate but spaced rear-wardly from the front end
of the first optical fiber such that a portion of the first optical
fiber proximate the front end thereof extends from the
piezoelectric collar and is free to oscillate with a defined
resonance frequency.
4. The projector apparatus of claim 3, wherein the support element
comprises a gimbal and the projector element is translatable along
at least one axis.
5. The projector apparatus of claim 3, wherein the support element
comprises a gimbal and the projector element is translatable
rotatable about at least one axis.
6. The projector apparatus of claim 3, wherein the support element
comprises a gimbal and the projector element is moveable in at
least three axes of freedom.
7. The projector apparatus of claim 1, wherein the control
subsystem is communicatively coupled to receive head tracking data
supplied via at least one transducer, the head tracking data
indicative of at least an orientation of a head of the end
user.
8. The projector apparatus of claim 1, wherein the at least one
control subsystem: for each of at least some of a plurality of
images presented to the end user, determines a location of
appearance of a virtual object in a field of view of the end user
relative to an end user frame of reference; assesses whether the
determined location requires the end user to turn a head of the end
user; and predicts the occurrence of the head movement based on the
assessment.
9. The projector apparatus of claim 1, further comprising a
processor to modify at least a portion of the virtual image based
at least in part on at least one of the detected head movement and
the predicted head movement.
10. The projector apparatus of claim 1, further comprising at least
a pair of cameras to track a movement of the user's eyes, wherein
the at least one of the detected head movement and predicted head
movement is determined based at least in part on the tracked
movement of the user's eyes.
Description
RELATED APPLICATION
[0001] The present application is a continuation of U.S.
application Ser. No. 14/212,961, filed on Mar. 14, 2014, which
claims the benefit under 35 U.S.C .sctn.119 to U.S. provisional
patent application Ser. No. 61/801,219, filed on Mar. 15, 2013. The
foregoing applications are hereby incorporated by reference into
the present application in their entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to systems and
methods configured to facilitate interactive virtual or augmented
reality environments for one or more users.
BACKGROUND
[0003] A number of display systems can benefit from information
regarding the head pose of a viewer or user (i.e., the orientation
and/or location of user's head).
[0004] For instance, head-worn displays (or helmet-mounted
displays, or smart glasses) are at least loosely coupled to a
user's head, and thus move when the user's head moves. If the
user's head motions are detected by the display system, the data
being displayed can be updated to take the change in head pose into
account.
[0005] As an example, if a user wearing a head-worn display views a
virtual representation of a 3D object on the display and walks
around the area where the 3D object appears, that 3D object can be
re-rendered for each viewpoint, giving the user the perception that
he or she is walking around an object that occupies real space. If
the head-worn display is used to present multiple objects with a
virtual space (for instance, a rich virtual world), measurements of
head pose can be used to re-render the scene to match the user's
dynamically changing head location and orientation and provide an
increased sense of immersion in the virtual space.
[0006] Especially for display systems that fill a substantial
portion of the user's visual field with virtual elements, it is
critical that the accuracy of head-tracking is high and that the
overall system latency is very low from the first detection of head
motion to the updating of the light that is delivered by the
display to the user's visual system. If the latency is high, the
system can create a mismatch between the user's vestibular and
visual sensory systems, and generate motion sickness or simulator
sickness.
[0007] Some head-worn displays enable the concurrent viewing of
real and virtual elements--an approach often described as augmented
reality or mixed reality. In one such configuration, often referred
to as a "video see-through" display, a camera captures elements of
a real scene, a computing system superimposes virtual elements onto
the captured real scene, and a non-transparent display presents the
composite image to the eyes. Another configuration is often
referred to as an "optical see-through" display, in which the user
can see through transparent (or semi-transparent) elements in the
display system to view directly the light from real objects in the
environment. The transparent element, often referred to as a
"combiner", superimposes light from the display over the user's
view of the real world.
[0008] In both video and optical see-through displays, detection of
head pose can enable the display system to render virtual objects
such that they appear to occupy a space in the real world. As the
user's head moves around in the real world, the virtual objects are
re-rendered as a function of head pose, such that the virtual
objects appear to remain stable relative to the real world. In the
case of an optical see-through display, the user's view of the real
world has essentially a zero latency while his or her view of the
virtual objects has a latency that depends on the head-tracking
rate, processing time, rendering time, and display frame rate. If
the system latency is high, the apparent location of virtual
objects will appear unstable during rapid head motions.
[0009] In addition to head-worn display systems, other display
systems can benefit from accurate and low latency head pose
detection. These include head-tracked display systems in which the
display is not worn on the user's body, but is, e.g., mounted on a
wall or other surface. The head-tracked display acts like a window
onto a scene, and as a user moves his head relative the "window"
the scene is re-rendered to match the user's changing viewpoint.
Other systems include a head-worn projection system, in which a
head-worn display projects light onto the real world.
SUMMARY
[0010] Embodiments of the present invention are directed to
devices, systems and methods for facilitating virtual reality
and/or augmented reality interaction for one or more users.
[0011] One embodiment is directed to a method of operation in a
virtual image system or an augmented reality system, the method
comprising, for each of at least some of a plurality of frames
being presented to an end user, determining a location of
appearance of a virtual object in a field of view of the end user
relative to an end user frame of reference, and adjusting a
presentation of at least one subsequent frame based at least in
part on the determined location of appearance of the virtual object
in the field of view of the end user. The virtual object may be
newly introduced in the field of view of the end user temporally
relative to previous frames presented to the end user. The newly
introduced virtual object may be determined to likely attract an
attention of the end user. The virtual object may be in a new
position in the frame relative to a position in at least one
previous frame. Or, the virtual object may be in a new position as
presented to the end user relative to a previous position of the
virtual object as previously presented to the end user.
[0012] The method may further comprise selecting the virtual object
based on input indicative of an attention of the end user to the
virtual object. The input indicative of the attention of the end
user to the virtual object may be based at least in part on an
appearance of the virtual object in a new position as presented to
the end user relative to a position of the virtual object as
previously presented to the end user. Or, the input indicative of
the attention of the end user to the virtual object may be based at
least in part on how quickly a position of the virtual object as
presented to the end user changes relative to the position of the
virtual object as previously presented to the end user.
[0013] The adjusting of the presentation of the at least one
subsequent frame may include presenting the at least one subsequent
frame with a center of the at least one subsequent frame shifted
toward the determined location of appearance of the virtual object
in the field of view of the end user. Or, the adjusting of the
presentation of the at least one subsequent frame may include
presenting the at least one subsequent frame with a center of the
at least one subsequent frame shifted to the determined location of
appearance of the virtual object in the field of view of the end
user.
[0014] The method may further comprise predicting an occurrence of
a head movement of the end user based at least in part on the
determined location of appearance of the virtual object in the
field of view of the end user. The method may further comprise
estimating at least one value indicative of an estimated speed of
the predicted head movement of the end user, determining at least
one value that at least partially compensates for the estimated
speed of the predicted head movement of the end user, and rendering
the at least one subsequent frame based at least in part on the
determined value.
[0015] The method may further comprise estimating at least one
change in the speed in the predicted head movement of the end user,
wherein the at least one change in the speed occurs between a start
of the predicted head movement and an end of the predicted head
movement, and wherein estimating the at least one value indicative
of the estimated speed of the predicted head movement includes
estimating the at least one value indicative of the estimated speed
that at least partially accommodates for the estimated changes in
the speed in the predicted head movement of the end user.
[0016] The estimating of the at least one change in the speed in
the predicted head movement of the end user may include estimating
the at least one change between a first defined time after the
start of the predicted head movement and a second defined time
before the end of the predicted head movement.
[0017] The method may further comprise estimating at least one
value indicative of an estimated acceleration of the predicted head
movement of the end user, determining at least one value that at
least partially compensates for the estimated acceleration of the
predicted head movement of the end user, and rendering the at least
one subsequent frame based at least in part on the determined
value.
[0018] The method may further comprise receiving information
indicative of an identity of the end user, and retrieving at least
one user specific historical attribute for the end user based on
the received information indicative of the identity of the end
user, wherein the user specific historical attribute is indicative
of at least one of a previous head movement speed for the end user,
a previous head movement acceleration for the end user, and a
previous eye movement to head movement relationship for the end
user.
[0019] The virtual object may be at least one of a virtual text
object, a virtual numeric object, a virtual alphanumeric object, a
virtual tag object, a virtual field object, a virtual chart object,
a virtual map object, a virtual instrumentation object or a virtual
visual representation of a physical object.
[0020] Another embodiment is directed to a method of operation in
an augmented reality system, the method comprising receiving
information indicative of an identity of the end user, retrieving
at least one user specific historical attribute for the end user
based at least in part on the received information indicative of
the identity of the end user, and providing frames to the end user
based at least in part on the retrieved at least one user specific
historical attribute for the end user. The received information may
be image information indicative of an image of at least a portion
of an eye of the end user.
[0021] The retrieved at least one user specific historical
attribute for the end user may be at least one attribute that
provides an indication of at least one head movement attribute for
the end user, wherein the head movement attribute is indicative of
at least one previous head movement of the end user. Or the
retrieved at least one user specific historical attribute for the
end user may be at least one attribute that provides an indication
of at least one previous head movement speed for at least one
previous head movement for the end user. Or, the retrieved at least
one user specific historical attribute for the end user may be at
least one attribute that provides an indication of variation in a
head movement speed across at least part of a range of at least one
previous head movement by the end user. Or, the retrieved at least
one user specific historical attribute for the end user may be at
least one attribute that provides an indication of at least one
previous head movement acceleration for at least one previous head
movement by the end user. Or, the retrieved at least one user
specific historical attribute for the end user may be at least one
attribute that provides an indication of a relationship between at
least one previous head movement and at least one previous eye
movement by the end user. Or, the retrieved at least one user
specific historical attribute for the end user may be at least one
attribute that provides an indication of a ratio between at least
one previous head movement and at least one previous eye movement
by the end user.
[0022] The method may further comprise predicting at least an end
point of a head movement of the end user, and providing frames to
the end user based at least in part on the retrieved at least one
user specific historical attribute for the end user includes
rendering at least one subsequent frame to at least one image
buffer, the at least one subsequent frame shifted toward the
predicted end point of the head movement.
[0023] The method may, further comprise rendering a plurality of
subsequent frames that shift toward the predicted end point of the
head movement in at least partial accommodation of at least one
head movement attribute for the end user, the head movement
attribute indicative of at least one previous head movement of the
end user.
[0024] The head movement attribute indicative of at least one
previous head movement of the end user may be a historical head
movement speed, a historical head movement acceleration for the end
user or a historical ratio between head movement and eye movement
for the end user.
[0025] The method may further comprise predicting an occurrence of
a head movement of the end user based at least in part on a
location of appearance of the virtual object in the field of view
of the end user. The location of appearance of the virtual object
may be determined in the same manner described above.
[0026] Another embodiment is directed to detecting an indication
that a spacing as presented to an end user between some pixels in a
frame will differ from a spacing between other pixels in the frame,
adjusting a first set of pixels based on the detected indication,
and providing at least a portion of at least one subsequent frame
with the adjusted first set of pixels to at least partially
compensate for the difference in spacing as presented to the end
user. The pixel characteristics (e.g., size, intensity, etc.) may
be perceptible to the end user.
[0027] The method may further comprise selecting a first set of
pixels of the frame based on a direction of the detected head
movement, wherein the direction of the first set of pixels is the
same as the direction of the detected head movement, and increasing
a size of the first set of pixels of the at least one subsequent
frame. The method may further comprise selecting a first set of
pixels of the frame based on a direction of the detected head
movement wherein the direction of the first set of pixels is the
same as the direction of the detected head movement, and increasing
an intensity of the first set of pixels of the at least one
subsequent frame in response to the detected head movement.
[0028] The method may further comprise selecting a first set of
pixels of the frame based on a direction of the detected head
movement wherein the direction of the first set of pixels is the
opposite as the direction of the detected head movement, and
decreasing a size of the first set of pixels of the at least one
subsequent frame in response to the detected head movement.
[0029] The method may further comprise selecting a first set of
pixels of the frame based on a direction of the detected head
movement wherein the direction of the first set of pixels is the
opposite as the direction of the detected head movement, and
decreasing an intensity of the first set of pixels of the at least
one subsequent frame in response to the detected head movement.
[0030] Another embodiment id directed to a method of operation in a
virtual image presentation system, the method comprising rendering
a first complete frame to an image buffer, wherein the first
complete frame includes pixel information for sequential
presentation of pixels to form an image of a virtual object,
starting a presentation of the first complete frame, and
dynamically interrupting the presenting of the first complete frame
before completion of the presentation of the first complete frame
by a presentation of an update to the first complete frame in which
a portion of the pixel information has changed from the first
complete frame.
[0031] Another embodiment is directed to a method of operation in a
virtual image presentation system, the method comprising rendering
a first complete frame having a first field and a second field to
an image buffer, wherein the first field includes at least a first
spiral scan line and the second field includes at least a second
spiral scan line, the second spiral scan line interlaced with at
least the first spiral scan line, reading out of the frame buffer
which stores the first complete frame, and dynamically interrupting
the reading out of the first complete frame before completion of
the reading of the first complete frame by a reading out of an
update to the first complete frame in which a portion of the pixel
information has changed from the first complete frame. The dynamic
interruption of the reading out may be based on a detected head
movement of an end user, wherein the detected head movement exceeds
a nominal head movement value.
[0032] Another embodiment is directed to a method of operation in a
virtual image presentation system, the method comprising rendering
a first complete frame having a first field and a second field to
an image buffer, wherein the first field includes at least a first
Lissajous scan line and the second field includes at least a second
Lissajous scan line, the second Lissajous scan line interlaced with
at least the first Lissajous scan line, reading out of the frame
buffer which stores the first complete frame, and dynamically
interrupting, based on a detected head movement of an end user
exceeding a nominal head movement value, the reading out of the
first complete frame before completion of the reading of the first
complete frame by a reading out of an update to the first complete
frame in which a portion of the pixel information has changed from
the first complete frame. The method may further comprise phase
shifting the Lissajous scan lines to interlace the Lissajous scan
lines.
[0033] Another embodiment is directed to a method of operation in a
virtual image presentation system, the method comprising for each
of a plurality of frames, determining a respective resolution for
each of at least two portions of the respective frame in response
to a detected head movement of an end user, and presenting the
virtual objects based on the determined respective resolutions of
the at least two portions of the respective frame. The portion of
the respective frame may be at least one of a field of the frame, a
line of the frame, a pixel of the frame. The method may further
comprise adjusting a characteristic of a drive signal between
presenting a first portion of a the frame and a second portion of
the frame to create a variable resolution in the image of the
virtual object. The characteristic of the drive signal may be at
least one of an amplitude of the drive signal and a slope of the
drive signal.
[0034] The method may further comprise assessing a point of
attention in at least a first image for the end user, based on at
least one of a processed eye tracking data, a determined location
of appearance of a virtual object in a field of view of the end
user relative to an end user frame of reference, a determined
location of appearance of the virtual object when newly introduced
in the field of view of the end user, and a determined location of
appearance of the virtual object in a new position in an image
relative to a position of the virtual object in at least one
previous image.
[0035] The method may further comprise increasing the resolution in
at least one subsequent image in a portion of the at least one
subsequent image that is at least proximate to the assessed point
of attention relative to other portions of the at least one
subsequent image. The method may further comprise decreasing the
resolution in at least one subsequent image in a portion of the at
least one subsequent image that is distal to the assessed point of
attention relative to other portions of the at least one subsequent
image.
[0036] Another embodiment is directed to a method of operation in a
virtual image presentation system, the method comprising displaying
at least one virtual object to an end user, and temporarily
blanking a portion of the display of the at least one virtual
object when at least one of a detected head movement exceeds a
nominal head movement value and a predicted head movement is
predicted to exceed a head movement value. The method may further
comprise processing head tracking data supplied via at least one
transducer to determine the at least one of the detected head
movement and the predicted head movement, wherein the head tracking
data indicative of at least an orientation of a head of the end
user.
[0037] Another embodiment is directed to a projector apparatus to
project at least virtual images in an augmented reality system, the
projector apparatus comprising a projector element, a support that
supports the projector element with the projector element moveable
in at least one axis of freedom, at least one actuator coupled to
selectively move the projector element, and a control subsystem
communicatively coupled to control the actuator such that the
projector element is moved in response to at least one of a
detection of a head movement of an end user that exceeds a nominal
head movement value and a prediction of a head movement of the end
user that is predicted to exceed the nominal head movement value.
The projector element may further comprise at least a first optical
fiber, the first optical fiber having a back end and a front end,
the back end coupled to receive images, the front end positioned to
transmit images therefrom.
[0038] The support element may comprise a piezoelectric collar that
receives at least the first optical fiber proximate but spaced
rear-wardly from the front end of the first optical fiber such that
a portion of the first optical fiber proximate the front end
thereof extends from the piezoelectric collar and is free to
oscillate with a defined resonance frequency.
[0039] The projector apparatus of claim 1, wherein the at least on
control subsystem is communicatively coupled to receive head
tracking data supplied via at least one transducer, the head
tracking data indicative of at least an orientation of a head of
the end user. The control subsystem, for each of at least some of a
plurality of images presented to the end user, determines a
location of appearance of a virtual object in a field of view of
the end user relative to an end user frame of reference, assesses
whether the determined location requires the end user to turn a
head of the end user, and predicts the occurrence of the head
movement based on the assessment.
[0040] Another embodiment is directed to a method of operation in a
virtual image presentation system, the method comprising
over-rendering a frame for a defined field of view such that a
pixel information for a set of pixels of the frame exceeds the
maximum area of display at the maximum resolution, determining a
portion of the frame to present to the end user based on at least
one of a detected head movement and a predicted head movement, and
selectively reading out only the determined portion of the
frame.
[0041] Another embodiment is directed to a user display device,
comprising a housing frame mountable on a head of a user, a lens
mountable on the housing frame, and a projection subsystem coupled
to the housing frame to determine a location of appearance of a
display object in a field of view of the user based at least in
part on at least one of a detection of a head movement of the user
and a prediction of a head movement of the user, and to project the
display object to the user based on the determined location of
appearance of the display object. The location of appearance of the
display object may be moved in response to the at least one of the
detection of the head movement of the user or prediction of the
head movement of the user that exceeds or it predicted to exceed a
nominal head movement value. The prediction of the head movement of
the user may be based on a prediction of a user's shift in focus or
on a set historical attributes of the user.
[0042] The user display device may further comprise a first pair of
cameras mountable on the housing frame to track a movement of the
user's eyes and estimate a depth of focus of the user's eyes based
on the tracked eye movements. The projection subsystem may project
the display object based on the estimated depth of focus.
[0043] The user display device may further comprise a second pair
of cameras mountable on the housing frame to capture a field of
view image as seen by the user's eyes, wherein the field of view
image contains at least one physical object. The projection sub
system may project the display object in a manner such that the
display object and the physical object captured through the second
pair of cameras are intermixed and appear together in the same
frame. The location of appearance may be based at least in part on
the physical object. The display object and the physical object may
have a predetermined relationship. The captured field of view image
may be used to gather information regarding movements of the head
of the user, wherein the information regarding movements of the
head of the user comprises a center of attention of the user, an
orientation of the head of the user, a direction of the head of the
user, a speed of movement of the head of the user, an acceleration
of the head of the user and a distance of the head of the user in
relation to a local environment of the user.
[0044] The lens may comprise at least one transparent surface to
selectively allow a transmission light such that the user is able
to view a local environment. The projection subsystem may project
the display object in a manner such that the user views both the
display object and the local environment as viewed through the
transparent surface of the lens.
[0045] The user display device may further comprise at least one
intertial transducer to capture a set of intertial measurements
indicative of movement of the head of the user, wherein the set of
intertial measurements comprises a speed of movement of the head of
the user, an acceleration of movement of the head of the user, a
direction of movement of the head of the user, a position of the
head of the user and an orientation of the head of the user.
[0046] The user display device may further comprise at least one
light source to illuminate at least one of the head of the user and
a local environment of the user.
[0047] The projection sub system may adjust at least one of a
perceived size, an intensity and a resolution of a set of pixels
associated with the display object to compensate for the at least
one of the detected head movement and the predicted head movement.
The display object may be one of a virtual object and an augmented
virtual object.
[0048] Additional and other objects, features, and advantages of
the invention are described in the detail description, figures and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 illustrates an example of using predictive head
tracking for rendering frames to an end user.
[0050] FIG. 2 illustrates an example of a technique that predicts
head movement based on characteristics of virtual objects presented
to the end user.
[0051] FIG. 3 illustrates an example where a center of the frame is
shifted.
[0052] FIG. 4 illustrates an example of a technique that predicts
head movement based on a set of historical attributes of the end
user.
[0053] FIG. 5 illustrates another example of the technique that
predicts head movement based on historical attributes.
[0054] FIG. 6 illustrates an example of retrieving various
historical attributes of the user
[0055] FIG. 7 illustrates an example of rendering a subsequent
frame based on a predicted end point.
[0056] FIG. 8 illustrates another example of rendering the
subsequent frame.
[0057] FIG. 9 illustrates an example of predicting an occurrence of
head movement.
[0058] FIG. 10 illustrates an example of adjusting pixels based on
head movement.
[0059] FIG. 11 illustrates an example of rendering frames with
adjusted pixels.
[0060] FIG. 12 illustrates an example of increasing a size and/or
intensity of pixels.
[0061] FIG. 13 illustrates an example of dynamically interrupting a
presentation of a frame.
[0062] FIG. 14 illustrates an example of presenting a portion of an
updated frame.
[0063] FIG. 15 illustrates an example of reading an update
frame.
[0064] FIG. 16 illustrates an example of phase shifting.
[0065] FIG. 17 illustrates an example of causing variable
resolution within an image.
[0066] FIG. 18 illustrates an example of adjusting an amplitude of
a drive signal.
[0067] FIG. 19 illustrates an example of adjusting a resolution in
a subsequent image based on the end user's point of attention.
[0068] FIG. 20 illustrates another example of adjusting the
resolution.
[0069] FIG. 21 illustrates an example of determining a location of
appearance of a virtual object.
[0070] FIG. 22 illustrates an example of blanking a portion of
displaying a virtual object.
[0071] FIG. 23 illustrates an example of predicting head movement
based on attractiveness of virtual object.
[0072] FIG. 24 illustrates an example of strobing.
[0073] FIG. 25 illustrates an example of selectively activating an
actuator to move a projector element.
[0074] FIG. 26 illustrates an example of selectively reading out
portions of a frame.
[0075] FIG. 27 illustrates an example of selectively reading out
portions based on a determined location of a virtual object.
[0076] FIG. 28 illustrates another example of selectively reading
out portions.
[0077] FIG. 29 illustrates an example of determining a portion of
an image to present to the end user.
[0078] FIG. 30 illustrates an example of dynamically addressing a
portion of an over-rendered frame.
[0079] FIG. 31 illustrates an example of a frame having pixel
information.
[0080] FIG. 32 illustrates an example of a raster scan pattern.
[0081] FIG. 33 illustrates an example of a spiral scan pattern.
[0082] FIG. 34 illustrates an example of a Lissajous scan
pattern.
[0083] FIG. 35 illustrates an example of a multi-field spiral scan
pattern.
[0084] FIG. 36A illustrates an example of a distortion of a raster
scan pattern during rapid lateral movement of the end user's
head.
[0085] FIG. 36B illustrates an example of a distortion of a raster
scan pattern during vertical upward movement of the end user's
head.
[0086] FIG. 37A illustrates an example of a distortion of a spiral
scan line during rapid lateral movement of the end user's head to
the left.
[0087] FIG. 37B illustrates an example of a distortion of a spiral
scan line during very rapid lateral movement of the user's head to
the left.
[0088] FIG. 38 illustrates an overview of the virtual image
generation system.
DETAILED DESCRIPTION
[0089] The description that follows relates to display systems and
methods to be used in virtual reality and/or augmented reality
systems. However, it is to be understood that the while the
invention lends itself well to applications in virtual reality, the
invention, in its broadest aspects, may not be so limited.
[0090] Referring first to FIG. 38, FIG. 38 shows a virtual image
generation system 3800 which may operate to provide virtual images
to an end user 3802, according to one illustrated embodiment.
[0091] The virtual image generation system 3800 may be operated as
an augmented reality system, providing images of virtual objects
intermixed with physical objects in a field of view of the end
user. There are two fundamental approaches when operating the
virtual image generation system 3800 as an augmented reality
system. A first approach employs one or more imagers (e.g.,
cameras) to capture images of the ambient environment. The virtual
image generation system 3800 may inter-mix the virtual images into
the data representing the images of the ambient environment. A
second approach employs one or more at least partially transparent
surfaces through which the ambient environment can be seen and on
to which the virtual image generation system 3800 produces images
of virtual objects. As will be apparent to those of skill in the
art, at least some of the aspects described herein are particularly
suited to augmented reality systems.
[0092] The virtual image generation system 3800 may be operated as
a virtual reality system, providing images of virtual objects in a
virtual environment.
[0093] The virtual image generation system 3800, and the various
techniques taught herein, may be employed in applications other
than augmented reality and virtual reality systems. For example,
various techniques may be applied to any projection or display
system. For example, the various techniques described herein may be
applied to pico projectors where movement may be movement of an end
user's hand rather than head movement. Thus, while often described
herein in terms of an augmented reality system, the teachings
should not be limited to such systems or such uses.
[0094] At least for augmented reality applications, it may be
desirable to spatially position various virtual objects relative to
respective physical objects in a field of view of an end user 3802.
Virtual objects, also referred to herein as virtual tags or tag or
call outs, may take any of a large variety of forms, basically any
variety of data, information, concept or logical construct capable
of being represented as an image. Non-limiting examples of virtual
objects may include: a virtual text object, a virtual numeric
object, a virtual alphanumeric object, a virtual tag object, a
virtual field object, a virtual chart object, a virtual map object,
a virtual instrumentation object or a virtual visual representation
of a physical object.
[0095] Head tracking accuracy and latency have been problems for
virtual reality and augmented reality systems. Tracking
inaccuracies and latency produce inconsistency between the end
user's visual system and vestibular system. Such may lead to
queasiness and discomfort. Such is particularly problematic in
display systems that fill a large portion of the end user's field
of view. Approaches to addressing such may include increasing frame
rate or effective frame rate, for instance via strobing or flashing
or via other techniques. As described herein, predictive head
tracking may be employed to address such, for instance by reducing
latency. Predictive head tracking may rely on any of a large
variety of factors or approaches, including historical data or
attributes for a specific end user. Also as described herein,
blanking of display or presentation may be effectively employed,
for instance blanking during rapid head movements.
[0096] At least for augmented reality applications, placement of
virtual objects in spatial relation to physical objects (e.g.,
presented to appear spatially proximate a physical object in two-
or three-dimensions) may be a nontrivial problem. For example, head
movement may significantly complicated placement of virtual objects
in a view of an ambient environment. Such is true whether the view
is captured as an image of the ambient environment and then
projected or displayed to the end user 3802, or whether the end
user 3802 perceives the view of the ambient environment directly.
For instance, head movement will like cause a field of view of the
end user 3802 to change, which will likely require an update to
where various virtual objects are displayed in the field of view of
the end user 3802. Additionally, head movements may occur within a
large variety of ranges and speeds. Head movement speed may vary
not only between different head movements, but within or across the
range of a single head movement. For instance, head movement speed
may initially increase (e.g., linearly or not) from a starting
point, and may decrease as a ending point is reached, obtaining a
maximum speed somewhere between the starting and ending points of
the head movement. Rapid head movements may even exceed the ability
of the particular display or projection technology to render images
that appear uniform and/or as smooth motion to the end user
3802.
[0097] In the embodiment illustrated in FIG. 38, the virtual image
generation system 3800 includes a projection subsystem 3804
operable to project images on a partially transparent display
surface 3806 which is positioned in the end user's 3802 field of
view between the eyes 3808 of the end user 3802 and an ambient
environment. The virtual image generation system 3800 may be worn
or mounted on a head 3810 of the end user 3802, for example
incorporated into a pair of glasses or a visor.
[0098] In the illustrated embodiment, the projection subsystem 3804
includes one or more optical fibers 3812 (e.g., single mode optical
fiber) which have a back or distal end 3812a into which light is
received and a front or proximate end 3812b from which light is
provided to the partially transparent display surface 38063806 or
projected directly into the eyes 3808 of the end user 3802. The
projection subsystem 3804 may also include one or more light
sources 3815 that produces the light (e.g., emits light of
different colors in defined patterns), and communicatively couples
the light to the back or distal end 3812a of the one or more
optical fibers 3812. The light source(s) 3815 may take any of a
large variety of forms, for instance a set of RGB lasers (e.g.,
laser diodes capable of outputting red, green and blue light)
operable to respectively produce red, green and blue coherent
collimated light according to a defined pixel patterns specified in
respective frames of pixel information or data. Laser light
provides high color saturation and are highly energy efficient.
[0099] While FIG. 38 shows a single optical fiber 3812, some
implementations may employ two or more optical fibers 3812,
breaking the light up into multiple channels. In such
implementations, the optical fibers 3812 may have staggered tips or
beveled and polished tips to bend the light, reducing optical
spacing between the channels. The optical fibers 3812 may be
conveniently packaged as a ribbon cable. Suitable optics may
produce a conjugate of the respective images produced by each of
the channels.
[0100] The one or more optical fibers 3812 may be supported by a
yoke 3814 with a portion of the front or proximate end 3812b
extending therefrom. The yoke 3814 may be operable to set the front
or proximate end 3812b in oscillatory motion. For example, the yoke
3814 may comprise a tube of a piezoelectric transducer 3814a (only
one shown in FIG. 38). A number of electrodes 3813 (e.g., four
illustrated, only one called out) are radially arranged about the
piezoelectric transducer 3814a. Applying control signals, e.g., via
frame buffer 3828, to respective electrodes 3813 associated with
the piezoelectric transducer 3814a can cause the front or proximate
end 3812b of the optical fiber(s) 3812 to oscillate vibrate in a
first resonance mode. A size of vibrations or amount of travel off
center is controllable via the applied drive signals to obtain any
of a variety of at least bi-axial patterns. Patterns may, for
instance, include a raster scan pattern, spiral or volute scan
pattern, or a Lissajous or FIG. 8 scan pattern.
[0101] FIG. 31 shows a frame 3100 of pixel information or data that
specifies pixel information or data to present an image, for
example, an image of one or more virtual objects, according to one
illustrated embodiment. The frame 3100 is schematically illustrated
with a cell 3100a,-3100n (only two called out, collectively 3102)
each pixel. Sequences of cells arranged in rows or lines 3104a,
31004b-3100n (three called out, collectively 3104), illustrated as
extending horizontally across the drawing sheet in FIG. 31. The
frame 3100 includes a plurality of lines 3104. FIG. 31 employs
ellipses to represent missing information, such as cells or lines
that have been omitted for clarity of illustration.
[0102] Each cell 3102 of the frame 3100 may specify values
(collectively 3106) for each of a plurality of colors for the
respective pixel to which the cell corresponds and/or intensities.
For instance, the frame 3100 may specify one or more values for red
3106a, one or more values for green 3106b and one or more values
for blue 3106c for each pixel. The values 3106 may be specified as
binary representations for each of the colors, for instance a
respective 4 bit number for each color. Each cell 3102 of the frame
3100 may additionally include an amplitude or radial value #P06d
that specifies an amplitude or radial dimension for each pixel, for
example where the frame 3100 may be used with a spiral scan line
pattern based system or with a Lissajous scan line pattern based
system.
[0103] The frame 3100 may include one or more fields, collectively
3110. The frame 3100 may consist of a single field. Alternatively,
the frame 3100 may comprise two, or even more fields 3110a-3110b.
The frame 3100 illustrated in FIG. 31 shows two fields 3110a-3110b.
The pixel information for a complete first field 3110a of the frame
3100 may be specified before the pixel information for the complete
second field 3110b, for example occurring before the pixel
information for the second field 3110b in an array, an ordered list
or other data structure (e.g., record, linked list). A third or
even a fourth field may follow the second field 3110b, assuming a
presentation system is configured to handle more than two fields
3110a-3110b.
[0104] FIG. 32 schematically represents a raster scan pattern 3200.
In the raster scan pattern 3200, pixels 3202 (only one called out)
are sequentially presented. The raster scan pattern 3200 typically
presents pixels from left to right (indicated by arrows 3204a,
3204b, then from top to bottom (indicated by arrow 3206). Thus, the
presentation may start at the upper right corner and traverse left
across a first line 3208a until the end of the line is reached. The
raster scan pattern 3200 typically then starts from the left in a
next line down. The presentation may be temporarily blacked out or
blanked which returning from the end of one line to the start of
the next line. This process repeats line-by-line until the bottom
line 3208n is completed, for example at the bottom right most
pixel. With the frame 3100 being complete, a new frame is started,
again returning the right of the top most line of the next frame.
Again, the presentation may be blanked while returning from the
bottom left to the top right to present the next frame.
[0105] Many implementations of raster scanning employ what is term
as an interlaced scan pattern. In interlaced raster scan patterns,
lines from the first and the second fields 3210a, 3210b are
interlaced. For example, when presenting lines of the first field
3210a, the pixel information for the first field 3210a may be used
for the odd numbered lines only, while the pixel information for
the second field 3210b may be used for the even numbered lines
only. Thus, all of the lines of the first field 3210a of the frame
3100 (FIG. 31) are typically presented before the lines of the
second field 3210b. The first field 3210a may be presented using
the pixel information of the first field 3210a to sequentially
present line 1, line 3, line 5, etc. Then the second field 3210b of
the frame 3100 (FIG. 31) may be presented following the first field
3210a, by using the pixel information of the second field 3210b to
sequentially present line 2, line 4, line 6, etc.
[0106] FIG. 33 schematically represents a spiral scan pattern 3300,
according to one illustrated embodiment. The spiral scan pattern
3300 may consist of a single spiral scan line 3302, which may
include one or more complete angular cycles (e.g., 360 degrees)
which may be denominated as coils or loops. The pixel information
is used to specify the color and/or intensity of each sequential
pixel, as the angle increments. An amplitude or radial value 3208
(FIG. 31) specifies a radial dimension #R06 from a starting point
3308 of the spiral scan line 3302.
[0107] FIG. 34 schematically represents a Lissajous scan pattern
3400, according to one illustrated embodiment. The Lissajous scan
pattern 3400 may consist of a single Lissajous scan line 3402,
which may include one or more complete angular cycles (e.g., 360
degrees) which may be denominated as coils or loops. Alternatively,
the Lissajous scan pattern 3400 may include two or more Lissajous
scan lines 3402, each phase shifted with respect to one another to
nest the Lissajous scan lines 3402. The pixel information is used
to specify the color and/or intensity of each sequential pixel, as
the angle increments. An amplitude or radial value 3208 (FIG. 31)
specifies a radial dimension from a starting point of the Lissajous
scan line 3402.
[0108] FIG. 35 schematically represents a multi-field spiral scan
pattern 3500, according to one illustrated embodiment. The
multi-field spiral scan pattern 3500 includes two or more distinct
spiral scan lines, collectively 3502, FIG. 35 illustrating four
spiral scan lines 3502a-3502d. The pixel information for each
spiral scan 3502 line may be specified by a respective field (e.g.,
3210a, 3210b) of a frame 3100 (FIG. 31). Advantageously, multiple
spiral scan lines 3502 may be nested simply by shifting a phase
between each successive ones of the spiral scan lines 3502. The
phase difference between spiral scan lines 3502 should be a
function of the total number of spiral scan lines 3502 which will
be employed. For example, four spiral scan lines 3502a-3502d may be
separate by a 90 degree phase shift. An exemplary embodiment may
operate at a 100 Hz refresh rate with 10 distinct spiral scan lines
(i.e., subspirals). Similar to the embodiment of FIG. 33, one or
more amplitude or radial values 3208 (FIG. 31) specify a radial
dimension 3506 from a starting point 3508 of the spiral scan lines
3502.
[0109] As is evident from FIGS. 34 and 35, relative spacing between
adjacent pixels may vary throughout an image. It may be
advantageous to at least partially accommodate or compensate for
this non-uniformity. For example, it may be advantageous to adjust
pixel size, for instance increasing perceived pixel size for pixels
that are spaced farther apart than other pixels. Such may, for
instance, be implemented via selective blurring (e.g., variable
focus lens, variable diffuser, jitter) to increase Gaussian spot
size. Additionally or alternatively, it may be advantageous to
adjust intensity for pixels that are spaced farther apart than
other pixels.
[0110] Returning to FIG. 38, driving the piezoelectric transducer
3814a with sine wave drive signals at a resonant frequency about a
first axis and at a resonance frequency about a second axis,
perpendicular to the first axis, produces a spiral scan pattern.
The spiral scan pattern may be characterized by a radial dimension
that varies as an angular dimension varies. For example, a radial
dimension may vary linearly, or nonlinearly, while the radial
dimension varies from 0 degrees to, or through, 360 degrees. In
appearance, the spiral scan line may appear as a continuous spiral,
starting at a start point and sweeping radially outward while
rotating in a plane. Each complete angular cycle may be described
as constituting a coil or loop. Spiral scan lines may be defined
has having any desired number of coils or loops before starting
over at the start point. A refresh period in which display or
presentation is blanked may occur between an end of a temporally
first spiral scan pattern and a start of a next temporally
successive spiral scan pattern. An outer most radial dimension of
the spiral scan pattern may be set by amplitude modulating of the
sine wave drive signal. Amplitude modulation of a spiral scan line
pattern adjusts the radial dimension without affecting the angular
dimension. Thus, amplitude modulation will not affect the frequency
of cycles (e.g., number of coils or loops) or number of cycles in a
given time for a given scan line. The position of the front or
proximate end 3812b in the pattern is synchronized with the output
of the light source(s) 3815 to form two- or three-dimensional
images.
[0111] While not illustrated, the projection subsystem 3804 may
include one or more optical components (e.g., lenses, filters,
gratings, prisms, reflectors, dichroic reflectors, defractors) that
direct the output from the front or proximate end 3812b of the one
or more optical fibers 3812 directly or indirectly toward the eyes
3808 of the end user 3802, for example via partially transparent
display surface 3806. While not illustrated, the projection
subsystem 3804 may include one or more optical components that
modulate a depth of Z-axis position of pixel data. Such may, for
example, take the form of a flexible reflective (e.g., nitride
sputter coated with aluminum) membrane and one or more electrodes
operated to cause deflection of the flexible reflective membrane.
The flexible reflective membrane is positioned to reflect and focus
light emitted from the front or proximate end 3812b of the one or
more optical fibers 3812. The flexible reflective membrane is
selectively operable based on depth map for the pixel data or
information to focus light in the Z-dimension or axis. The flexible
reflective membrane may employ Gaussian spots to produce an
appearance of depth, certain virtual objects in an image appearing
in focus while others appearing out of focus. Additionally or
alternatively, the system may employ one or more Kerr effect
lens.
[0112] While not necessary to a head worn embodiment, the optical
fibers 3812, and optionally the yoke 3814, may be supported for
movement in one or more directions. For example, the optical fibers
3812, and optionally the yoke 3814, may be supported via gimbals
3816 for 2, 3 or more degrees of freedom of movement. The gimbals
3816 may include a turntable 3816a, a first actuator 3818a (e.g.,
electric motor, solenoid, piezoelectric transducer) operable to
pivot or rotate about a first axis 3820a. The gimbals 3816 may
include a bracket 3816b supported by a frame 3816c on the turntable
3816a, a second actuator 3818b (e.g., electric motor, solenoid,
piezoelectric transducer) operable to pivot or rotate about a
second axis 3820b. The gimbals 3816 may include a shaft 3816d
pivotally supported by the bracket 3816b, a third actuator 3818c
(e.g., electric motor, solenoid, piezoelectric transducer) operable
to pivot or rotate about a third axis 3820c. The first, second and
third axes (collectively 3820) may be orthogonal axes.
[0113] In the embodiment illustrated in FIG. 38, the virtual image
generation system 3800 includes a control subsystem 3822. The
control subsystem 3822 may take any of a large variety of forms,
one of which is illustrated in FIG. 38.
[0114] The control subsystem 3822 includes a number of controllers,
for instance one or more microcontrollers, microprocessors or
central processing units (CPUs) 3824, digital signal processors
(DSPs), graphics processing units (GPUs) 3826, other integrated
circuit controllers such as application specific integrated
circuits (ASICs), programmable gate arrays (PGAs) for instance
field PGAs (FPGAs), and/or programmable logic controllers (PLUs).
In the embodiment illustrated in FIG. 38, the microprocessor 3824
controls overall operation, while the GPU 3826 renders frames
(e.g., sets of pixel data) to one or more frame buffers 3828a-3828n
(collectively 3828). While not illustrated, one or more additional
integrated circuits may control the reading into and/or reading out
of frames from the frame buffer(s) 3828 and operation of the
piezoelectric transducers or electrodes 3814a, synchronizing both
to produce two- or three dimensional images. Reading into and/or
out of the frame buffer(s) 3828 may employ dynamic addressing, for
instance where frames are over rendered.
[0115] The control subsystem 3822 includes one or more
nontransitory computer- or processor-readable media to store
instructions and data. The nontransitory computer- or
processor-readable media may for example include the frame
buffer(s) 3828. The nontransitory computer- or processor-readable
media may, for example, include one or more nonvolatile memories,
for instance read only memory (RAM) 3830 or flash memory. The
nontransitory computer- or processor-readable media may, for
example, include one or more volatile memories, for instance random
access memory (RAM) 3832. The control subsystem 3822 may include
other volatile and nonvolatile memory, include spinning media
storage as well as solid state storage devices.
[0116] In implementations where the actuators (collectively 3818)
are employed, the control subsystem 3822 may optionally include one
or more dedicated motor controllers 3834 communicatively coupled to
drive the actuators 3818 via motor control signals.
[0117] The control subsystem 3822 may optionally include one or
more communications ports 3836a, 3836b (collectively 3836) that
provide communications with various other systems, components or
devices. For example, the control subsystem 3822 may include one or
more wired interfaces or ports 3836a which provide wired or optical
communications. Also for example, the control subsystem 3822 may
include one or more wireless interfaces or ports such as one or
more radios (i.e., wireless transmitter, receiver, transceiver)
3836b which provide wireless communications.
[0118] As illustrated, the wired interfaces or ports 3836a provide
wired or optical communications with an environmental imaging
system 3838 include one or more cameras 3838a positioned and
oriented to capture images of an environment in which the end user
3802 is located. Such may be used to sense, measure or collect
information about the end user 3802 and/or the environment. For
instance, such may be used to detect or measure movements and/or
positions of the end user 3802 or parts of the end user's 3802
body, such as the head 3810. As illustrated, the wired interfaces
or ports 3836a may optionally provide wired or optical
communications with a structure lighting system 3840 which includes
one or more light sources 3840a positioned and oriented to
illuminate the end user 3802, a portion of the end user 3802 such
as the head 3810 and/or the environment in which the end user 3802
is located.
[0119] As illustrated, the wireless interfaces or ports 3836b
provide wireless (e.g., RF, microwave, IR) communications with one
or more head worn transducer system 3842 that includes one or more
inertial transducers 3842a to capture inertial measures indicative
of movement of the head 3810 of the end user 3802. Such may be used
to sense, measure or collect information about head movements of
the end user 3802. For instance, such may be used to detect or
measure movements, speeds, acceleration, and/or positions of the
head 3810 of the end user 3802. As illustrated, the wired
interfaces or ports 3836a may optionally provide wired or optical
communications with an imaging system 3842 including, for example,
one or more forward facing imagers or cameras 3842a. Such may be
used to capture information about the environment in which the end
user 3802 is located. Such may be used to capture information
indicative of distance and orientation of the end user 3802 with
respect to that environment and specific objects in that
environment. When head worn, the forward facing imagers or cameras
3842a are particularly suited to capture information indicative of
distance and orientation of the end user's head 3810 with respect
to the environment in which the end user 3802 is located and
specific objects in that environment. Such may, for example be
employed to detect head movement, speed and/or acceleration of head
movements. Such may, for example, be employed to detect or infer a
center of attention of the end user 3802, for example based at
least in part on an orientation of the end user's head 3810.
Orientation may be detected in any direction (e.g., up/down,
left/right with respect to reference frame of end user).
[0120] In some implementations all communications may be wired,
while in other implementations all communications may be wireless.
In still further implementations the choice of wired and wireless
communications may be different from that illustrated in FIG. 38.
Thus, the particular choice of wired or wireless communications
should not be considered limiting.
[0121] Various components of the control subsystem 3822, for
example the microprocessor 3824, GPU 3826, frame buffer(s) 3828,
ROM 3830, RAM 3832, and/or optionally dedicated motor controller(s)
3834 may be communicatively coupled via one or more communications
channels, for instances one or more buses 3846 (only one
illustrated). The buses 3846 may take a variety of forms including
instruction buses, data buses, address buses, other communications
bus, and/or power buses.
[0122] The ability to predict head movements allows a virtual image
generation system 3800 (FIG. 38), such as an augmented reality
system, to quickly update the presentation of images and/or to
accommodate or compensate for head movement. For example,
subsequent frames may be rendered or read out earlier than would be
possible if only sensed head movements were employed. As will be
apparent from the discussions herein, accommodation or compensation
may take a variety of forms. For example, subsequent frames may be
rendered or read out with a shifted field of view or a center that
is shifted toward or to an area of attention or focus of the end
user. Also for example, subsequent frames may be rendered or read
out to accommodate or compensate for variation resulting from the
head movement. For instance, in certain display or projection
technologies (e.g., "flying pixel" technologies where pixels are
displayed sequentially, such as raster scan, spiral scan, Lissajous
scan), rapid head movement may cause a change in spacing between
pixels as a frame is presented to the end user. The accommodation
or compensation may include accommodating or compensating for this
variation in pixel spacing. For instance, a size or perceived size
of some pixels may be adjusted relative to other pixels. Also for
instance, an intensity or perceived brightness of some pixels may
be adjusted relative to other pixels. As a further example,
subsequent frames may be rendered or read out with a variable
resolution between different portions of a resulting image. Other
accommodation or compensation techniques will be apparent from the
this discussion. In other aspects, many of these same techniques
may be employed for purposes other than accommodation or
compensation, and may be employed independently of predictive head
tracking, sensed head tracking, and/or with display or projection
technologies that are not "flying pixel" based.
[0123] End user movement, for example head movements may have a
substantial effect on images. As the augmented reality system
attempts to render frames subsequently frames consistent with the
head movement, the resulting images of virtual objects may become
compressed, expanded or otherwise distorted. This is at least
partially the result of the fact that for many display or
presentation technologies (i.e., "flying pixel" technologies),
complete images for any given frame are not presented or displayed
simultaneously, but rather are presented or displayed pixel by
pixel. Thus, there is not a true instantaneous field of view for
these display or presentation technologies. Such may occur, in
different forms, across many different types of image generation
technologies, for instance raster scan, spiral scan or Lissajous
scan approaches. One or more "white" or blank frames or images may
alleviate some of the effects of rapid head movement.
[0124] For example, FIG. 36A shows an exemplary distortion in a
raster scan 3600a produced during rapid lateral movement of an end
user's head. The distortion is likely to be nonlinear since head
motion may speed up after initiation and slow down prior to
termination. The distortion is a function of the direction, speed
and acceleration of head movement and the direction of raster scan
pixel generation (e.g., right to left, top to bottom).
[0125] Also for example, FIG. 36B shows an exemplary distortion in
a raster scan 3600 produced during vertically upward movement of an
end user's head. The distortion is likely to be nonlinear since
head motion may speed up after initiation and slow down prior to
termination. The distortion is a function of the direction, speed
and acceleration of head movement and the direction of raster scan
pixel generation (e.g., right to left, top to bottom).
[0126] As yet another example, FIG. 37A shows an exemplary
distortion in a spiral scan line 3700a produced during rapid
lateral movement of an end user's head to the left. The distortion
is likely to be nonlinear since head motion may speed up after
initiation and slow down prior to termination. The distortion is a
function of the direction, speed and acceleration of head movement
and the direction of spiral scan pixel generation (e.g., clockwise,
increasing radius). As illustrated spacing between successive loops
or coils of the spiral scan line 3700a increases in the direction
of the head movement (e.g., to the left in the drawing sheet), and
decreases in the diametrically opposed direction (e.g., to the
right in the drawing sheet).
[0127] As yet a further example, FIG. 37B shows an exemplary
distortion in a spiral scan line 3700b produced during very rapid
lateral movement of an end user's head to the left. The distortion
is likely to be nonlinear since head motion may speed up after
initiation and slow down prior to termination. In fact, the
distortion may be highly elliptical and de-centered as illustrated
in FIG. 37B. The distortion is a function of the direction, speed
and acceleration of head movement and the direction of spiral scan
pixel generation (e.g., clockwise, increasing radius). As
illustrated spacing between successive loops or coils of the spiral
scan line 3700b increases in the direction of the head movement
(e.g., to the left in the drawing sheet). Where the head movement
is too rapid for the system, the left most portion of each loop or
coil may be located in the same direction as the head movement
relative to a starting point of the spiral scan line 3700b, as
illustrated in FIG. 37B.
[0128] One advantage of employing spiral scan patterns is that the
transformation to address into the image buffer is independent of
the direction of movement (e.g., movement of head, movement of hand
for handheld pico projector).
[0129] The system above is used in all the embodiments described
below. In one embodiment, the system may be used for predictive
head tracking based on predicting a user's shift in focus. FIG. 1
shows a method 100 of operation in an augmented reality system
employing predictive head tracking, according to one illustrated
embodiment.
[0130] At 102, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) presents a plurality of frames
as images to an end user of the augmented reality system. The
frames will typically include pixel information specifying
information for producing one or more virtual objects in a field of
view. As previously noted, the virtual objects may take any of a
wide variety of virtual object forms or formats, which may visual
represent physical objects or may represented information, data or
logical constructions. Non-limiting examples of virtual objects may
include: a virtual text object, a virtual numeric object, a virtual
alphanumeric object, a virtual tag object, a virtual field object,
a virtual chart object, a virtual map object, a virtual
instrumentation object or a virtual visual representation of a
physical object.
[0131] At 104, the augmented reality system selects one or more
virtual objects based at least on input indicative of attention of
the end user.
[0132] The input may be an actual selection by the end user. The
selection may be made in real time or may have been previously
designated by the end user. Thus, an end user may select a certain
set of virtual instruments as being a type of virtual object the
end user typically focuses or pays attention to over other
objects.
[0133] The input may be inferred from a variety of sources. The
input may be related to the virtual objects themselves. The input
may be additionally or alternatively be related to physical objects
in a field of view of the end user or in the field of view of a
display or projector. The input may be additionally or
alternatively be related to the end user themselves, for example a
position and/or orientation of the end user and/or a portion of end
user (e.g., head, eyes), or historical attributes. The historical
attributes may be end user specific, or more generalized or
generic. The historical attributes may be indicative of a set of
defined end user characteristics. End user characteristics may, for
example, include head movement speed, head movement acceleration,
and/or relationship between head movement and eye movement (e.g.,
ratio of one to the other. The end user characteristics tracked by
historical attributes may even include indications of a tendency of
a given end user to pay attention to certain virtual objects. Such
may be specified by virtual object type (e.g., text, charts), by
recentness of virtual object (e.g., newly appearing objects),
movement of a virtual object (e.g., large shifts from image to
image, fast or rapidly movement, direction of movement), and/or
characteristics of the virtual object (e.g., color, brightness,
size).
[0134] At 106, for each of at least some of a plurality of frames
being presented to an end user, the augmented reality system (e.g.,
a controller subsystem and/or processor thereof) determines a
location of appearance of a virtual object in a field of view of
the end user relative to an end user frame of reference. For
example, the augmented reality system may determine a location of a
newly introduced virtual object, a virtual object of a defined
type, a virtual object moving rapidly or over a large distance, or
a virtual object that has historically been a point of attention
for the end user.
[0135] At 108, the augmented reality system adjusts a presentation
of at least one subsequent frame based at least in part on the
determined location of appearance of the virtual object in the
field of view of the end user. Numerous ways of adjusting
appearance of the virtual object in the field of view are discussed
herein, including non-exhaustively accommodation or compensation,
adjusting pixel size, adjusting pixel intensity, adjusting
resolution, windowing, and/or blanking or strobing.
[0136] FIG. 2 shows another method 200 of operation in an augmented
reality system, according to one illustrated embodiment. The method
200 may be employed in executing acts 104 and/or 106 of the method
100 of FIG. 1.
[0137] The method 200 employs techniques that predict head movement
based on characteristics of virtual objects that are or will be
presented to the end user. For example, anticipating that a newly
introduced virtual object or a virtual object who's movement (e.g.,
due to suddenness, speed, and/or distance) will likely attract the
end user's attention, resulting in a head movement to bring the
particular virtual object into or proximate a center of the end
user's field of view. Additionally, or alternatively the augmented
reality system may rely on other characteristics of the virtual
objects in assessing which are most likely to attract attention.
For example, highly attractive (e.g., flashing, shimmering), large,
fast moving, or bright virtual objects may be more likely to
attract attention than other virtual objects.
[0138] Focusing on the case of a newly introduced virtual object,
the augmented reality system (e.g., a controller subsystem and/or
processor thereof) selects and/or determines the location of
appearance of a virtual object when newly introduced in the field
of view of the end user at #AB02. A virtual object is considered
newly introduced when not appearing in previous (temporally)
related frames presented to the end user. In particular, the
augmented reality system relies on the fact that newly introduced
virtual objects are like to attract the attention of the end user
relative to virtual objects that appear in immediately preceding
frames. Additionally, or alternatively the augmented reality system
may rely on other characteristics of the virtual objects in
assessing which are most likely to attract attention, for example
to select or prioritize among multiple newly introduced virtual
objects. For example, highly attractive (e.g., flashing,
shimmering), large, fast moving, or bright virtual objects may be
more likely to attract attention than other virtual objects.
[0139] Focusing on the case of a moving virtual object, the
augmented reality system (e.g., a controller subsystem and/or
processor thereof) selects and/or determines a location of an
appearance of a virtual object in a new position in a frame
relative to a position of the same virtual object in at least one
previous frame at 204. Thus, a sudden shifting, a quick shifting,
and/or a spatially large shifting of a position of a virtual object
from one frame to one or more subsequent frames may be likely to
attract the attention or focus of the end user. Additionally, or
alternatively the augmented reality system may rely on other
characteristics of the virtual objects in assessing which are most
likely to attract attention, for example to select or prioritize
among multiple newly introduced virtual objects. For example,
highly attractive (e.g., flashing, shimmering), large, or bright
virtual objects may be more likely to attract attention than other
virtual objects.
[0140] FIG. 3 shows a method 300 of operation in an augmented
reality system, according to one illustrated embodiment. The method
300 may be employed in executing act 108 of the method 100 of FIG.
1.
[0141] At 302, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) presents the at least one
subsequent frame with a center of the at least one subsequent frame
shifted at least towards, if not centered on, the determined
location of appearance of the virtual object in the field of view
of the end user. The center of the subsequent frame(s) or image(s)
may be shifted to be co-located with the location of the selected
virtual object that is predicted to attract the end user's
attention. Alternatively, the center of the subsequent frame(s) may
be shifted to be proximate the location of the selected virtual
object that is predicted to attract the end user's attention. Such
may be performed in two-dimensions or in three-dimensions. For
example, the two dimensional or three dimensional position of the
virtual object may be used to adjust a field of view of subsequent
images(s) in two- or three-dimensions, respectively. The shifted
subsequent frame(s) or image(s) are preferably timed with the
predicted head movement of the end user. Thus, the shifted
subsequent frame(s) or image(s) should be presented to the end user
as close in timing with the actual head movement as possible. As
discussed herein, such may account for speed, acceleration, and
variations in speed and acceleration.
[0142] FIG. 4 shows a method 400 of operation in an augmented
reality system, according to one illustrated embodiment. The method
400 may be employed in performing the method 100 of FIG. 1.
[0143] Optionally at 402, the augmented reality system receives
information indicative of an identity of the end user. The
information may take any of a large variety of forms. For example,
the information may be a user name or other user identifier entered
by the end user (e.g., keyed) or read from a transponder, magnetic
stripe, or machine-readable symbol associated with the end user.
For example, the information may include biometric information
indicative of one or more physical characteristics of the end user.
In one particularly advantageous implementation, the augmented
reality system may receive image data that represents a portion
(e.g., retina) of one or both eyes of the end user. For instance,
the augmented reality system may project light, for example via one
or more optical fibers, into one or both eyes of an end user. The
light may be modulated, for example to increase a signal to noise
ratio and/or limit heating of the eye. An image sensor may capture
an image of the portion of the eye, for example via the one or more
optical fibers that project the light, the optical fiber(s)
providing a bi-directional path. Alternatively, a dedicated optical
fiber may be employed. As a further alternative an image sensor may
be positioned proximate the eye, eliminating the use of the optical
fiber(s) as a return path to the image sensor. Certain portions of
the human eye (e.g., vasculature of retina) may be considered
sufficiently distinctive to serve as a unique end user
identifier.
[0144] Optionally at 404, the augmented reality system retrieves at
least one user specific historical attribute for the end user based
in the received information indicative of the identity of the end
user. The user specific historical attribute(s) may be indicative
of at least one of: a previous head movement speed for the end
user, previous head movement acceleration for the end user,
previous eye movement to head movement relationship for the end
user, tendencies of end user to pay attention to virtual objects of
certain types or with certain characteristics.
[0145] At 406, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) predicts an occurrence of a
head movement of the end user based at least in part on the
determined location of appearance of the virtual object in the
field of view of the end user. Again, the augmented reality system
may rely on an attractiveness of a virtual object in predicting
head movements, for example on an end user by end user basis.
[0146] The augmented reality system may employ estimated speed
and/or estimated changes in speed or estimated acceleration to at
least partially synchronize image presentation with the predicted
head movement of the end user. The estimated change in the speed in
the predicted head movement may be based on a range extending
between a first defined time after the start of the predicted head
movement and a second defined time before the end of the predicted
head movement.
[0147] At 408, the augmented reality system estimates at least one
value indicative of an estimated speed of the predicted head
movement of the end user. The augmented reality system may estimate
speed based on one or more values, parameters or characteristics.
For example, the augmented reality system may rely on a range of
movement required to move to the end user's head to a new position
to observe the selected or identified virtual object. The augmented
reality system may rely on average speed for a sampling of humans,
or may rely on historical head movement speeds for the particular
end user. The augmented reality system may rely on historical
attributes for the particular end user. Speeds may be represented
in angular velocities.
[0148] At 410, the augmented reality system estimates at least one
change in the speed in the predicted head movement of the end user
which occurs over a range of head movement, between a start of the
predicted head movement and an end of the predicted head movement.
The changes in speed may occur at different increments throughout
some portion of the predicted range of movement.
[0149] At 412, the augmented reality system estimates at least one
value indicative of an estimated acceleration of the predicted head
movement of the end user. The estimated acceleration may be over an
entire range of the head movement or over only a portion thereof.
The estimated acceleration may be over discrete intervals of the
range of head movement. Estimates of acceleration may be determined
for one or more intervals at some defined duration after the start
of head movement. Estimates for acceleration may be determined for
one or more intervals at some defined duration before the end of
head movement. Estimating spaced from the start and/or end points
may avoid large variation in acceleration measurements.
[0150] Optionally at 414, the augmented reality system determines
at least one value that at least partially accommodates or
compensates for the estimated speed of the predicted head movement
of the end user. For example, the augmented reality system may
determine values with respect a total number of frames to present
in a given time and/or values that specify where and/or how quickly
one or more virtual objects should move across a scene in a series
of images to be rendered and/or presented. Such may be used to
render subsequent frames.
[0151] Optionally at 416, the augmented reality system renders the
at least one subsequent frame based at least in part on the at
least one value that at least partially compensates for the
estimated speed of the predicted head movement of the end user. For
example, the augmented reality system may determine values with
respect a total number of frames to present in a given time and/or
values that specify where and/or how quickly one or more virtual
objects should move across a scene in a series of images to be
rendered and/or presented. Such may be used to render subsequent
frames.
[0152] In another embodiment, the system may be used for predictive
head tracking based on a user's historical attributes. FIG. 5 shows
a method 500 of operation in an augmented reality system employing
predictive head tracking, according to one illustrated
embodiment.
[0153] The augmented reality system may employ historical
attributes in performing predictive head tracking. The historical
attributes may be end user specific, or more generalized or
generic. The historical attributes may be indicative of a set of
defined end user characteristics. End user characteristics may, for
example, include head movement speed, head movement acceleration,
and/or relationship between head movement and eye movement (e.g.,
ratio of one to the other. The end user characteristics tracked by
historical attributes may even include indications of a tendency of
a given end user to pay attention to certain virtual objects.
[0154] At 502, the augmented reality system receives information
indicative of an identity of the end user. The information may take
any of a large variety of forms, for example information actively
provided be the end user, read from nontransitory storage media,
read from the user (e.g., biometric data or characteristics), or
inferred from end user actions.
[0155] At 504, the augmented reality system retrieves at least one
user specific historical attribute for the end user based at least
in part on the received information indicative of the identity of
the end user. The identity information may be received, produced or
determined in any of a large variety of ways.
[0156] At 506, the augmented reality system provides frames to the
end user based at least in part on the retrieved at least one user
specific historical attribute for the end user. For example, the
augmented reality system may provide frames from a frame buffer to
a projector or display device (e.g., light source paired with one
or more optical fibers), or may render frames to a frame buffer.
The augmented reality system may provide light via at least one
optical fiber which is moveable at least bi-axially. The augmented
reality system may receive image information indicative of an image
of at least a portion of an eye of the end user via the at least an
optical fiber which also provides the frames to the end user.
[0157] FIG. 6 shows a method 600 of operation in an augmented
reality system employing predictive head tracking, according to one
illustrated embodiment. The method 600 may be employed in executing
act 504 of the method 500 of FIG. 5.
[0158] At 602, the augmented reality system retrieves at least one
historical attribute that provides an indication of at least one
head movement attribute for the end user. The head movement
attribute(s) is or are indicative of at least one previous head
movement of the end user. The historical attributes may be stored
in nontransitory media, for example in a database or other logical
construct.
[0159] At 604, the augmented reality system retrieves at least one
historical attribute that provides an indication of head movement
speed for at least one previous head movement for the end user.
[0160] At 606, the augmented reality system retrieves at least one
historical attribute that provides an indication of variation in a
head movement speed across at least part of a range of at least one
previous head movement by the end user.
[0161] At 608, the augmented reality system retrieves at least one
historical attribute that provides an indication of head movement
acceleration for at least one previous head movement by the end
user.
[0162] At 610, the augmented reality system retrieves at least one
historical attribute that provides an indication of a relationship
between head movement and eye movement for at least one previous
head and eye movement combination by the end user. The relationship
may, for example, be represented as a ratio of a head movement
value representative of at least one previous head movement and a
value representative of at least one previous eye movement by the
end user. The values may be representative of an amount of movement
the head and eyes, respectively, for example represented as an
angular change. The ratio may be a ratio of historical averages of
head movements and historical averages of eye movements by the end
user. Additionally or alternatively, other relationships between
head and eye movement may be employed, for example speed or
acceleration.
[0163] FIG. 7 shows a method 700 of operation in an augmented
reality system employing predictive head tracking, according to one
illustrated embodiment. The method 700 may be employed in executing
act 506 of the method 500 of FIG. 5.
[0164] At 702, the augmented reality system predicts at least an
end point of a head movement of the end user. For example, where
the appearance of a virtual object is used to predict the head
movement, the relative location of the particular virtual object
may be used as the end point.
[0165] At 704, the augmented reality system renders at least one
subsequent frame to at least one image buffer. The at least one
subsequent frame is shifted at least towards, or even all the way
to, the predicted end point of the head movement.
[0166] FIG. 8 shows a method 800 of operation in an augmented
reality system employing predictive head tracking, according to one
illustrated embodiment. The method 800 may be employed in executing
act 704 of the method 700 of FIG. 7.
[0167] At 802, the augmented reality system renders a plurality of
subsequent frames that are shift at least toward the predicted end
point of the head movement in at least partial accommodation of at
least one head movement attribute for the end user. The head
movement attributes may be indicative of various physical traits of
head movement, particularly historical physical traits of head
movement of the end user. The head movement attribute(s) may, for
example, include one or more of: a historical head movement speed
for the end user, a historical head movement acceleration for the
end user, and/or a historical relationship (e.g., ratio) between
head movement and eye movement for the end user. Shifting may be
implemented by rendering subsequent frames with the corresponding
image shifted or a center of the corresponding image shifted
relative to images corresponding to a previous frame.
[0168] FIG. 9 shows a method 900 of operation in an augmented
reality system employing predictive head tracking, according to one
illustrated embodiment. The method 900 may be employed in executing
act 703 of the method 700 of FIG. 7.
[0169] At 902, the augmented reality system predicts an occurrence
of a head movement of the end user based at least in part on an
appearance of a virtual object in the field of view of the end
user.
[0170] The appearance may be an appearance of a new virtual object
when newly introduced in the field of view as presented to the end
user, temporally, relative to previous frames presented as images
to the end user. Alternatively or additionally, the appearance may
be an appearance of a virtual object in a new position in the field
of view as presented to the end user, relative to a position of the
virtual object as previously presented to the end user. The
prediction may, for example take into account of factors. For
example, the prediction may be based in part on a size or
prominence of the virtual object, an amount or percentage of change
in position, speed, suddenness acceleration or other change in the
position of the virtual object.
[0171] The system may also be used for dynamic control of pixel
characteristics FIG. 10 shows a method 1000 of operation in an
augmented reality system, according to one illustrated
embodiment.
[0172] At 1002, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) detects an indication that
spacing as presented to an end user between some pixels in a frame
will differ from the spacing between other pixels in the same
frame. For example, the augmented reality system may detect an
indication that the spacing as presented to the end user between
pixels of a first set of pixels in the frame will differ from the
spacing as presented to the end user between pixels of at least a
second set of pixels in the frame. For instance, where pixels of a
frame are sequentially presented (e.g., read out of the frame
buffer) over a period of time (e.g., "flying pixel" patterns such
as raster scan pattern, spiral scan pattern, Lissajous scan
pattern), rapid head movement may cause a variation in pixel
spacing between different portions of an image or frame.
[0173] In response to a detection that the spacing between some
pixels in the frame will differ as presented to the end user from
the spacing of other pixels in the frame, the augmented reality
system provides at least a portion of at least one subsequent frame
with at least a first set of pixels adjusted to at least partially
compensate at least one pixel characteristic, perceptible by an end
user, of the pixels of the first set at 1004. Such may at least
partially compensate for a difference in spacing between pixels in
different portions of an image as presented to the end user.
[0174] FIG. 11 shows a method 1100 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1100 may be employed in executing the method 1000 of FIG. 10.
[0175] Optionally at 1102, the augmented reality system (e.g., a
controller subsystem and/or processor thereof) receives signals
indicative of an output of at least one head worn inertial sensor
worn by the end user. The inertial sensors may take a variety of
forms, for example gyroscopic sensors or acceleration sensors.
Inertial sensors may be single axis or multi-axis devices. The
inertial sensors may take the form of MEMS devices.
[0176] Optionally at 1104, the augmented reality system receives
signals indicative of an output of at least one head worn imager
worn by the end user. The imager may, for example, take the form of
a digital camera or other image capture device. Such may be a
forward facing camera, to capture a field of view that at least
approximates a field of view of the end user.
[0177] Optionally at 1106, the augmented reality system detects a
head movement exceeding a nominal head movement value. For example,
the augmented reality system may detect a head movement exceeding a
nominal speed and/or a nominal acceleration. The augmented reality
system may employ signals from the inertial sensors to detect
movement, and in particular acceleration. The augmented reality
system may employ signals from the head mounted camera to detect
changes in position of physical objects in the ambient environment,
particularly fixed physical objects such as wall, floors, ceilings.
The augmented reality system may employ any number of image
processing techniques. The detected change in position allows the
augmented reality system to determine a change in position of the
head, speed of movement and acceleration. The augmented reality
system may employ other information in addition or in place of the
inertial sensor and head worn imager information. For example, the
augmented reality system may employ signals from a system that
monitors the ambient environment and is not worn by the user, but
rather tracks the user. Such a system may employ one or more
imager, for instance digital cameras, to monitor the ambient
environment. The imager(s) detect movement of the end user and
parts of the end user such as the head. Again, various image
processing techniques may be employed. Such a system may be
advantageously paired with a structured light system.
Alternatively, the method #CB00 may be executed independently of
detected or even predicted head movement.
[0178] At 1108, the augmented reality system selects a first set of
pixels of the frame, for example based on a direction of the
detected head movement. The augmented reality system may
additionally select the first set of pixels of the frame based on
other criteria, for example a speed of the detected head
movement.
[0179] At 1110, the augmented reality system adjusts at least one
of a size and/or an intensity of at least some of the pixels of the
first set of pixels of at least one subsequent frame. The
adjustment may be designed to at least accommodate or at least
partially compensate for undesired variation in the frame or image
that result from the head movement.
[0180] Optionally at 1112, the augmented reality system renders the
at least one subsequent frame. The rendered subsequent frame
includes adjusted pixel information to at least partially
accommodate or at least partially accommodate or compensate for
undesired variation in the frame or image that result from the head
movement.
[0181] Optionally at 1114, the augmented reality system reads out
the at least one subsequent frame from at least one frame buffer
that stores one or more subsequent frames. For example, the
augmented reality system may selectively read out the at least one
subsequent frame from at least one frame buffer. Such may take
advantage of over rendering where frames are over rendered relative
to the size of the image area or field of view. The system,
particularly when head mounted, will in most instances be dedicated
to a fixed display surface having a known area and known
resolution. This is in contrast to computers and other devices
which are intended to supply signals to displays of a wide variety
of sizes and resolutions. Thus, the augmented reality system
selectively reads into or out of the frame buffer(s) rather than
reading in or reading out the entire frame from the frame buffer.
Over rendering may prevent running the GPU as excessively as might
otherwise be required if a new frame where rendered to create
subsequent images to show those portions that are outside of a
previous image. For instance, without over rendering, the augmented
reality system would need to render a new frame each time the end
user's head was moved. With over rendering, a dedicated set of
electronics may be employed for selecting or reading out the
desired portions of the over rendered frames, essentially moving a
window within a previously rendered frame.
[0182] FIG. 12 shows a method 1200 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1200 may be employed in executing acts 1108 and 1110 of the method
1100 of FIG. 11.
[0183] At 1202, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) selects at least a first set of
pixels of the frame such that the first set of pixels are in a
given direction (e.g., same direction, opposite direction) with
respect to a direction of a detected head movement.
[0184] At 1202, the augmented reality system adjusts a size of
pixels of the selected set(s) as presented to the user of the
pixels of the first set of pixels of the at least one subsequent
frame.
[0185] For example, the augmented reality system may select a first
set of pixels of the frame such that the first set of pixels are
positioned in a same direction as a direction of the detected head
movement, relative to other pixels. For instance, the first set of
pixels may be oriented relatively toward a left in an image
relative to a second set of pixels oriented generally to a right in
the image. For instance, the first set of pixels may be oriented
relatively toward a top in an image relative to a second set of
pixels oriented generally to a bottom in the image. The augmented
reality system may provide one or more subsequent frames or images
where the pixels of the first set have an increased size, relative
to some other pixels in the subsequent frame(s). Such can at least
partially accommodate or at least partially compensate for a
spreading between pixels that may result from rapid head movement
which the augmented reality system cannot keep up with.
[0186] For example, the augmented reality system may select a first
set of pixels of the frame such that the first set of pixels are
positioned in an opposite direction from a direction of the
detected head movement, relative to other pixels. The augmented
reality system may provide one or more subsequent frames or images
where the pixels of the first set have a decreased size, relative
to some other pixels in the subsequent frame(s). Such can at least
partially accommodate or at least partially compensate for a
spreading between pixels that may result from rapid head movement
which the augmented reality system cannot keep up with.
[0187] Adjusting (e.g., increasing, decreasing) a size of the
pixels of selected set(s) may include adjusting a variable focus
element. Adjusting (e.g., increasing, decreasing) a size of the
pixels of selected set(s) may include adjusting a variable size
source. Adjusting (e.g., increasing, decreasing) a size of the
pixels of selected set(s) may include adjusting a jitter.
[0188] As a further example, the augmented reality system may
select a first set of pixels of the frame such that the first set
of pixels are positioned in a same direction as a direction of the
detected head movement relative to other pixels. The augmented
reality system may provide one or more subsequent frames or images
where the pixels of the first set have an increased intensity,
relative to some other pixels in the subsequent frame(s). Such can
at least partially accommodate or at least partially compensate for
a spreading between pixels that may result from rapid head movement
which the augmented reality system cannot keep up with.
[0189] As yet an even further example, the augmented reality system
may select a first set of pixels of the frame such that the first
set of pixels are positioned in an opposite direction as a
direction of the detected head movement. The augmented reality
system may provide one or more subsequent frames or images where
the pixels of the first set have a decreased intensity, relative to
some other pixels in the subsequent frame(s). Such can at least
partially accommodate or at least partially compensate for a
spreading between pixels that may result from rapid head movement
which the augmented reality system cannot keep up with.
[0190] As noted above, the augmented reality system may adjust only
the size of the selected pixels, only the intensity of the selected
pixels, or both the size and intensity of selected pixels. Further,
the augmented reality system may adjust intensity of some pixels,
the size of other pixels, the intensity and size of yet even other
pixels, and/or not adjust either the intensity or size of yet
further pixels.
[0191] The system may also be used for dynamically updating on less
than whole frame by whole frame basis, as illustrated below. FIG.
13 shows a method 00 of operation in an augmented reality system,
according to one illustrated embodiment.
[0192] At 1302, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) renders a first complete frame
to an image buffer. The first complete frame comprises pixel
information for sequential presentation of pixels to form an image
of a number of virtual objects. The first complete frame may take a
variety of forms suitable for various display technologies. For
example, a complete frame may include pixel information suitable
for forming a complete raster scan frame, which may be an
interlaced raster scan frame with two fields. Each field of the
interlaced raster scan may include a plurality of lines, a first
field comprising the odd lines and a second field comprising the
even lines. The odd and even lines may be interlaced at least as
displayed to the end user. A particularly advantageous technology
employs spiral scan lines. The spiral scan approach may employ a
single field per frame, for instance consisting of a single spiral
trace. Alternatively, the spiral scan approach may employ two or
more fields per frame, for instance consisting of two or more
spiral traces, presented sequentially. The spiral traces may
advantageously be interlaced or nested simply by introducing a
phase shift between each field of the frame. Another technology
employs a Lissajous scan approach. The Lissajous scan approach may
employ a single field per frame, for instance consisting of a
single Lissajous trace. Alternatively, the Lissajous scan approach
may employ two or more fields per frame, for instance consisting of
two or more Lissajous traces, presented sequentially. The Lissajous
traces may advantageously be interlaced or nested simply by
introducing a phase shift between each field of the frame.
[0193] At 1304, the augmented reality system starts a presentation
of the first complete frame. Such may include reading out of the
frame buffer(s), for example to drive a light source(s) and end of
one or more optical fibers. The reading out may include dynamically
determining which portions of the frame buffer to read out.
[0194] Optionally at 1306, the augmented reality system detects a
head movement of an end user exceeding a nominal head movement
value. Such may employ any of the various approaches previously
discussed.
[0195] At 1308, the augmented reality system dynamically interrupts
the presentation of the first complete frame before completion of
the presentation of the entire first complete frame. In particular,
the augmented reality system starts presentation of an update to
the first complete frame. At least a portion of the pixel
information in the update to the complete frame has changed from
the first complete frame. For example, in an interlaced raster scan
based system, the augmented reality system may present all or part
of a first field, replacing the second field with an update second
field. Also for example, in an interlaced spiral scan based system,
the augmented reality system may present all or part of a first
field (e.g., a first spiral scan line or trace), replacing the
second field with an update second field (e.g., an updated second
spiral scan line or trace, different from the original second
spiral scan or trace). Similarly, in an interlaced Lissajous scan
based system, the augmented reality system may present all or part
of a first field (e.g., a first Lissajous scan line or trace, i.e.,
a complete FIG. 8 cycle), replacing the second field with an update
second field (e.g., an updated second Lissajous scan line or trace,
different from the original second spiral scan or trace). While
examples are given in terms of fields, such is not limited to
entire fields. The presentation may be interpreted during a
presentation of a field, for example during presentation of the
first or second, or even a tertiary field. Presentation may be
interpreted during presentation of any given line (e.g., row of a
raster scan, complete cycle of a spiral or a Lissajous scan).
[0196] FIG. 14 shows a method 1400 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1400 may be employed in executing the method 1300 of FIG. 13.
[0197] At 1402, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) renders an updated first
complete frame. The updated first complete frame includes pixel
information that is different in at least one respect from the
pixel information of the first complete frame.
[0198] Rendering an updated first complete frame may include
rendering the update complete frame with a first field and at least
a second field. The second field may be interlaced with the first
field, typically be presenting sequentially following presentation
of the first field. For instance, the first field may consist of
even numbered lines in a raster scan while the second field
consists of odd number lines. Also for example, a first field may
consist of a first spiral scan line or a first Lissajous scan line,
while the second field consists of a second spiral scan line or a
second Lissajous scan line. Thus, rendering an updated first
complete frame may include rendering the updated complete frame
with a first field and at least a second field, the second field
interlaced with at least the first field.
[0199] At 1404, the augmented reality system presents a portion of
the updated first complete frame in lieu of a counterpart portion
of the first complete frame. Thus, a portion of the updated frame
is substitute for all or a portion of the first complete frame
following the interruption of the original not updated first
complete frame.
[0200] For example, the augmented reality system may present a
second field of the updated first complete frame in lieu of a
second field of the original (i.e., not updated) first complete
frame. Also for example, the augmented reality system may present a
second portion of a first field along with a second field of the
updated first complete frame in lieu of a corresponding portion of
a first field and the entire second field of the first original
(i.e., not updated) first complete frame.
[0201] Also for example, the augmented reality system may present a
portion (e.g., line, part of line, set of pixels, pixel) of a field
of the updated first complete frame in lieu of a counterpart
portion of a counterpart field of the first complete frame. For
instance, the augmented reality system may present a portion of a
field of the updated first complete frame of a raster scan frame in
lieu of a counterpart portion of a counterpart field of the
original (i.e., not updated) first complete frame of the raster
scan frame.
[0202] As another example, the augmented reality system may present
a line of the updated first complete frame in lieu of a counterpart
line of the original (i.e., not updated) first complete frame. As
yet another example, the augmented reality system may present a
spiral line of the updated first complete frame in lieu of a
counter spiral line of the original (i.e., not updated) first
complete frame. As a further example, the augmented reality system
may present a portion of a line of the updated first complete frame
in lieu of a counterpart portion of a counterpart line of the
original (i.e., not updated) first complete frame. As yet a further
example, the augmented reality system may present at least one
pixel of the updated first complete frame in lieu of a counterpart
at least one pixel of the original (i.e., not updated) first
complete frame. As still an additional example, the augmented
reality system may present one full cycle of a Lissajous pattern
scan of the updated first complete frame in lieu of a counter part
one full cycle of a Lissajous pattern scan of the original (i.e.,
not updated) first complete frame.
[0203] FIG. 15 shows a method 1500 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1500 may be employed in executing the method 1300 of FIG. 13.
[0204] At 1502, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) renders a first complete frame
to a frame buffer. The first complete frame may, for example,
include a first field and at least a second field. The first field
may, for example, include pixel information for at least a first
spiral scan line and the second field may include pixel information
for at least a second spiral scan line. The scan line(s) of the
second field may be interlaced with the scan line(s) of the first
field. The first field may, for example, include pixel information
for at least a first Lissajous scan line and the second field may
include pixel information for at least a second Lissajous scan
line. The scan line(s) of the second field may be interlaced with
the scan line(s) of the first field. Interlacing of scan lines for
both spiral and Lissajous scan patterns may be efficiently achieved
with phase shifts. The number of fields or scan lines can be
greater than two, for example three, four, eight, sixteen or
more.
[0205] At 1504, the augmented reality system starts to read out of
the frame buffer, which stores the first complete frame. The
augmented reality system may drive the light sources and a yoke or
other device or structure to generate an image based on the pixel
data specified in the frame from the image buffer.
[0206] At 1506, the augmented reality system renders an updated
first complete frame to the frame buffer. The updated first
complete frame includes pixel information that specifies a frame, a
portion of which has changed from the information specified by the
original (i.e., not updated) first complete frame
[0207] At 1508, the augmented reality system starts to read out the
updated first complete frame before completion of the reading out
of the first complete frame from the frame buffer, thereby
interrupting presentation of the original (i.e., not updated) first
complete frame. Some implementations may take advantage of having
two or more frame buffers, allowing rendering to one frame buffer
while a frame is being read out of the other frame buffer. Such
should not be considered limiting in the various implementations of
augmented reality systems may employ one, two, three or even more
frame buffers.
[0208] FIG. 16 shows a method 1600 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1600 may be employed in executing the method 1300 of FIG. 13.
[0209] At 1602, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) generates pixel information for
a first scan line (e.g., spiral, Lissajous).
[0210] Optionally at 1604, the augmented reality system generates
pixel information for a second scan line (e.g., spiral, Lissajous)
phase shifted relative to the first scan line (e.g., spiral,
Lissajous). Phase shifting advantageously interfaces or nests the
second scan line with the first scan line for spiral and Lissajous
scan lines.
[0211] Optionally at 1606, the augmented reality system generates
pixel information for a third scan line (e.g., spiral, Lissajous)
phase shifted relative to the second scan line (e.g., spiral,
Lissajous). Phase shifting advantageously interfaces or nests the
third scan line with the first and the second scan lines for spiral
and Lissajous scan lines.
[0212] Optionally at 1608, the augmented reality system generates
pixel information for a fourth scan line (e.g., spiral, Lissajous)
phase shifted relative to the third scan line (e.g., spiral,
Lissajous). Phase shifting advantageously interfaces or nests the
fourth scan line with the first, the second, and the third scan
lines for spiral and Lissajous scan lines.
[0213] FIG. 17 shows a method 1700 of operation in an augmented
reality system, according to one illustrated embodiment.
[0214] At 1702, for each of a plurality of frames the augmented
reality system (e.g., a controller subsystem and/or processor
thereof) determine a respective resolution for each of at least two
portions of the respective frame. Portions may be fields, lines,
other subdivision, or even individual pixels.
[0215] At 1704, the augmented reality system causes a presentation
of images of virtual objects based on the plurality of frames, at
least some of the images having a variable resolution within the
image as presented to an end user. For example, spacing between
adjacent pixels may differ from one portion to another.
[0216] FIG. 18 shows a method 1800 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1800 may be employed in executing the method 1700 of FIG. 17.
[0217] At 1802, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) render frames as respective
pixel data for a spiral scan pattern.
[0218] At 1804, the augmented reality system adjusts the amplitude
of a drive signal between the time of presenting a first portion of
a first one of the frames and presenting a second portion of the
first one of the frames. This change in amplitude results in the
variable resolution in the image that corresponds to the first one
of the frames. The augmented reality system may for example vary a
slope or ramp of the drive signal. Such is particularly useful
where used with a spiral scan pattern. For instance, a first field
of a frame may have one slope or ramp which the second field has a
different slope or ramp, thereby changing the effective resolution
with a single frame. The higher resolution or pixel density may be
employed at or proximate locations of end user interest or
attraction, while lower resolution or pixel density may be used
away from such locations. Where a center or image is shifted toward
a center of an end user's attraction or focus, the high resolution
may appear around the center of an image, while surround portions
appear at lower resolutions. Such essentially implements what can
be denominated a foviated display, with steerable pixels.
[0219] FIG. 19 shows a method 1900 of operation in an augmented
reality system, according to one illustrated embodiment. The method
1800 may be employed in conjunction or as part of executing the
method 1700 of FIG. 17.
[0220] At 1902, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) assesses a point of attention
in a least a first image for the end user. The augmented reality
system may use any of the previously described techniques for
assessing such. For example, determining whether and where a new
virtual object will appear, or where a virtual object will move to
within a field of view of the end user. Also for example, the
augmented reality system may assess a relative attractiveness of
the virtual objects (e.g., speed, color, size, brightness,
shimmer). Such may also employ eye tracking information, indicative
of a location in a field of view which the eyes of the end user are
tracking or focused on.
[0221] Eye tracking information may, for example, be supplied via
one or more head worn transducers, for instance head worn cameras.
Such eye tracking information may, for example, be discerned by
projecting light at the end user's eyes, and detecting the return
or reflection of at least some of that projected light. For
instance, a projection subsystem that creates or projects the
images may project a pixel, dot or other element of light from the
at least one optical fiber to create a glint off the end user's
cornea. Eye tracking may employ, one, two, three or even more spots
or dots of light. The more spots or dots of light, the more
information may be discerned. The light sources (e.g., laser
diodes) may be pulsed or modulated, for example in synchronization
with a frame rate of a camera or image sensor. In which case, spots
or dots may appear as lines as eyes move. A direction of the lines
as the lines trace across a sensor may indicate a direction of the
eye movement. Orientation of the lines (e.g., vertical, horizontal,
diagonal) indicates orientation of the eye movement. A length of a
line is indicative of speed of eye movement.
[0222] For eye tacking, the light may be modulated (e.g.,
temporally, intensity) to increase the signal to noise ratio.
Additionally or alternatively, the light may be of a specific
wavelength (e.g., near-IR), allowing such to be distinguished from
background light or even the light that forms the image that the
end user is watching. The light may be modulated to reduce a total
amount of energy (e.g., heat) that the augmented reality system is
providing to the eye(s). The glint may be returned via the same, or
another, optical fiber to a sensor. The sensor may, for example
take the form of a two-dimensional image sensor, for instance a CCD
sensor or a CMOS sensor.
[0223] Thus, the augmented reality system may detect and track
relative movements of the eyes, providing an indication of a point
or location of the end user's attention or focus. The augmented
reality system may logically associate a virtual object or virtual
event (e.g., appearance or movement of a virtual object) with the
identified point or location of the end user's attention or focus.
For example, the augmented reality system may designate a virtual
object that appears at or at least proximate the point or location
of the end user's attention or focus as an attractive virtual
object to the end user.
[0224] At 1904, the augmented reality system adjusts (e.g.,
increases, decreases) resolution in at least one portion of at
least one subsequent image. The augmented reality system may employ
any of the various techniques described herein, as well as other
techniques to adjust resolution of a portion of a subsequent page
relative to other portions of the same subsequent page.
[0225] FIG. 20 shows a method 2000 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2000 may be employed in executing act 1904 of the method 1900 of
FIG. 19.
[0226] At 2002, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) increases a resolution in a
portion of the at least one subsequent image that is at least
proximate the assessed point of attention relative to other
portions of the at least one subsequent image. As previously
explained, resolution may be adjusted for spiral scan patterns by
controlling a magnitude or amplitude (e.g., current, voltage) of
the drive signal. The resolution may be adjusted by adjusting a
slope of the drive signal. Resolution may thus be increased by
increasing the amplitude of the drive signal, while the phase is
left unchanged.
[0227] At 2004, the augmented reality system decreases a resolution
in a portion of the at least one subsequent image that is distal to
the assessed point of attention relative to other portions of the
at least one subsequent image. Resolution may be decreased by
decreasing the amplitude of the drive signal, while the phase is
left unchanged.
[0228] In some implementations the resolution is only increased,
increasing in some portions while neither increasing nor decreasing
in other portions. In other implementations the resolution is only
decreased, decreasing in some portions while neither increasing nor
decreasing in other portions. In yet still other implementations
resolution is both increased in some portions while decreased in
other portions.
[0229] FIG. 21 shows a method 2100 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2100 may be employed in conjunction with the method 1700 of FIG.
17.
[0230] At 2102, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) processes eye tracking data.
The eye tracking data is indicative of at least an orientation of
at least one eye of the end user. The eye tracking data is supplied
via at least one transducer. For example, the eye tracking data may
be supplied via a head worn transducer. In some implementations,
eye tracking data is collected via an optical fiber, with a
transducer positioned at or proximate a distal end thereof. For
instance, the optical fiber may collect light reflected from a
portion of the end user's eye(s), which may be a glint. The optical
fiber may be the same optical fiber as used to create the image for
display or projection to the end user.
[0231] At 2104, the augmented reality system processes head
tracking data. The head tracking data is indicative of at least an
orientation of a head of the end user. The head tracking data may
be supplied via at least one transducer.
[0232] For example, one or more head worn or mounted transducers
such as inertial sensors (e.g., gyroscopic sensors,
accelerometers). Head movement tracking may be implemented using
one or more head worn or head mounted light sources and at least
one sensor. Head tracking may employ, one, two, three or even more
spots or dots of light. The more spots or dots of light, the more
information may be discerned. The light sources (e.g., laser
diodes) may be pulsed or modulated, for example in synchronization
with a frame rate of a camera or image sensor (e.g., front facing
camera). The laser source(s) may be modulated at a frequency that
is lower than the frame rate of the camera or image sensor. In
which case, spots or dots may appear as lines as the head move. A
direction of the lines as the lines trace across a sensor may
indicate a direction of the head movement. Orientation of the lines
(e.g., vertical, horizontal, diagonal) indicates orientation of the
head movement. A length of a line is indicative of speed of head
movement. Reflected light may also provide information regarding
objects in the ambient environment, such as distance and/or
geometry (e.g., planar, curved) and/or orientation (e.g., angled or
perpendicular). For instance, one laser bean may produce
information regarding direction and velocity (e.g., length of dash
or line). A second laser beam may add information regarding depth
or distance (e.g., Z-axis). A third laser beam may add information
about the geometry and/or orientation of a surface in the ambient
environment. Lasers or other light sources may be pulsed during
head movement or during part of the head movement.
[0233] Additionally or alternatively, the head tracking data may be
supplied via transducers that are not head worn. For example, a
camera or imager system may image the end user, including the head
of the end user, tracking movement thereof. Such may, for example,
track movement relative to some external reference frame, for
instance a reference frame defined by the tracking system or a room
in which the tracking system is located.
[0234] At 2106, the augmented reality system determines a location
of appearance of a virtual object in a field of view of the end
user relative to an end user frame of reference. The appearance may
be an appearance of a new virtual object, when newly introduced in
a field of view of the end user. The appearance may be an
appearance of a virtual object in a new position in an image
relative to a position of the virtual object in at least one
previous image. The augmented reality system may employ any of the
numerous techniques described elsewhere herein to determine the
location of appearance of the virtual object.
[0235] The system may also use blanking to improve end user
perception.
[0236] FIG. 22 shows a method 2200 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2200 effectively employs blanking to improve end user perception
experience.
[0237] At 2202, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) displays at least one virtual
object to an end user. The augmented reality system may render
frames to a frame buffer, read out the frames to drive one or more
light sources and/or yoke or other system to produce an at least
bi-axial movement or trace of the light.
[0238] At 2204, the augmented reality system detects and/or
predicts an occurrence of a head movement of the end user. The
augmented reality system may employ any of the numerous techniques
described elsewhere herein to detect and/or predict an occurrence
of a head movement. Without limitation, those techniques include
directly sensing head movement, for example via inertial
transducers or sensor, or via images from a head worn imager or an
environmental imager that images an area in which the end user is
present and visible. Those techniques also include indirectly
predicting head movement, for instance by determining where a new
virtual object will appear, where an existing virtual object will
move, or where particularly attractive virtual objects are
positioned in the image.
[0239] At 2206, the augmented reality system assesses whether the
detected and/or the predicted head movement exceeds or is predicted
to exceed a nominal head movement value. The augmented reality
system may employ any of the numerous techniques described
elsewhere herein to assesses whether the detected and/or the
predicted head movement exceeds or is predicted to exceed a nominal
head movement value. Such may include simple comparison of detected
or predicted speed to a nominal speed. Such may include simple
comparison of detected or predicted acceleration to a nominal
acceleration. Such may include simple comparison of detected or
predicted range to a nominal range. Such may include more
complicated comparisons, including averages or integrations of
speed, acceleration or range over multiple times during a movement.
Such may even employ historical attributes or other
information.
[0240] At 2208, the augmented reality system temporarily blanks at
least a portion of the display of the at least one virtual object
to the end user. For example, the augmented reality system may stop
reading from the frame buffer. Additionally or alternatively, the
augmented reality system may turn off an illumination or light
source. Such may include temporarily turning off a back light of an
LCD display.
[0241] FIG. 23 shows a method 2300 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2300 may be employed in performing the method 2200 of FIG. 22.
[0242] At 2302, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) processes head tracking data.
The head tracking data is indicative of at least an orientation of
a head of the end user. The head tracking data may be supplied via
at least one transducer, which may or may not be head worn by the
end user. The augmented reality system may employ any of the
numerous techniques described elsewhere herein to process the head
tracking data.
[0243] At 2304, for each of at least some of the images presented
to the end user, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) determines a location of
appearance of a virtual object in a field of view of the end user
relative to an end user frame of reference. The determining a
location of appearance of a virtual object when newly introduced in
a field of view of the end user. The determining a location of
appearance of a virtual object in a new position in an image
relative to a position of the virtual object in at least one
previous image. The augmented reality system may employ any of the
numerous techniques described elsewhere herein to determine a
location of appearance of a virtual object.
[0244] At 2306, the augmented reality system assesses whether
determined appearance of virtual object is sufficiently attractive.
For example, the augmented reality system may assess a relative
visual attractiveness of the virtual objects (e.g., speed, color,
size, brightness, shimmer, transparency, special optical effects).
Also for example, the augmented reality system may assess the
relative interest attractiveness (e.g., newness, recentness,
previous attention, previous identification by the end user,
previous interaction with by the end user).
[0245] At 2308, the augmented reality system assesses whether the
determined location requires the end user to turn the end user's
head relative to a current position of the end user's head. The
augmented reality system may employ a current position and/or
orientation of the end user's head and a relative position and/or
orientation of the virtual object. The augmented reality system may
determine a distance, for example angular distance between a
current focus of the end user and the position and/or orientation
of the virtual object. The augmented reality system may determine
whether the determined distance is within a range of eye movement,
or whether the end user must also turn their head. If the end user
must turn their head, the system may assess how far the end user
must turn their head. For example, the augmented reality system may
employ information that specifies a relationship between eye
movement and head movement for the end user. Such may indicate to
what extent the end user will shift their gaze via eye movements
alone, before turning their heads. Notably, the relationship
between eye movement and head movement may be specified for various
different directions, for instance a) up to down, b) down to up, c)
left to right, d) right to left, e) diagonally from lower left to
upper right, f) diagonally from lower right to upper left, g)
diagonally from upper left to lower right, or h) diagonally from
upper right to lower left.
[0246] At 2310, the augmented reality system predicting the
occurrence of the head movement based on the assessment. The
augmented reality system may use one or more factors form the
assessment in predicting whether head movement will occur, a
direction and/or orientation of the head movement, and/or speed or
acceleration of the head movement. The augmented reality system may
employ historical data either end user specific or more generic to
a group of end users. The augmented reality system may implement
one or more machine learning algorithms to increase the accuracy of
head movement prediction.
[0247] FIG. 24 shows a method 2400 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2400 may be employed in performing act 2208 of the method 2200 of
FIG. 22.
[0248] At 2402, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) strobes or flashes a display or
a backlight of a display. The strobing or flashing occur over all
or a portion of the detected head movement or predicted head
movement. Such may advantageously effectively reduce the perception
of inconsistencies in a frame or presentation of virtual objects.
Such may also effectively increase perceived frame rate.
[0249] FIG. 25 shows a method 2500 of operation in an augmented
reality system, according to one illustrated embodiment.
[0250] At 2502, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) detects and/or predicts an
occurrence of a head movement of an end user. For example, the
augmented reality system may process head tracking data indicative
of at least an orientation of a head of the end user. Additionally
or alternatively, the augmented reality system may determining a
location of appearance of a virtual object in a field of view of
the end user relative to an end user frame of reference, assess
whether the determined location requires the end user to turn a
head of the end user, and predict an occurrence of the head
movement based on the assessment. The augmented reality system may
employ any of the numerous techniques described elsewhere herein to
detect and/or predict an occurrence of a head movement.
[0251] At 2504, the augmented reality system determines whether the
detected or the predicted head movement exceeds a nominal head
movement value. The augmented reality system may employ any of the
numerous techniques described elsewhere herein to determine whether
the detected or the predicted head movement exceeds a nominal head
movement value.
[0252] At 2506, in response to determining that the detected or the
predicting head movement exceeding the nominal head movement value,
the augmented reality system selectively activates an actuator to
move the projector in at least one degree of freedom. Moving the
projector may include translating the first optical fiber along at
least one axis. Moving the projector may include pivoting the first
optical fiber about at least one axis.
[0253] FIG. 26 shows a method 2600 of operation in an augmented
reality system, according to one illustrated embodiment.
[0254] The augmented reality system may over render frames,
producing frames that are much larger than need for a maximum area
and maximum resolution of a given display technology. For example,
in a head worn or mounted augmented reality system the area
available for display or projection may be set by the various
parameters of the equipment. Likewise, while the augmented reality
system may be capable of operating at multiple distinct
resolutions, the equipment will set an upper end or maximum
resolution. An over rendered frame includes pixel information for a
set of pixels that exceeds the maximum area of display at the
maximum resolution. Such may advantageously allow the augmented
reality system to read out only portions of frames (e.g., a portion
of each field of the frame, if not interrupted). Such may allow the
augmented reality system to shift an image presented to the
user.
[0255] At 2602, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) over renders each of a
plurality of frames for a defined field of view. Such requires
generating more pixel information that would otherwise be required
for the maximum area at maximum resolution. For example, the area
of the frame may be increase by a percentage of the maximum area,
for example increasing the pixel information in either a
horizontal, vertical or diagonal direction defined by the frame.
The larger the frame size the more freedom the augmented reality
system will have to shift the boundaries of the images presented to
the user.
[0256] At 2604, the augmented reality system successively buffers
the over rendered frames in at least one frame buffer. The
augmented reality system may employ a frame buffer that is larger
than the frame size required for the maximum display size at
maximum resolution. Some implementations employ multiple frame
buffers. Such may facilitate interruption of presentation for
frames, as described elsewhere herein.
[0257] At 2606, the augmented reality system determines a portion
of a respective image to present. The augmented reality system may
determine the portion based on any of a variety of factors. For
example, the factors may be indicative of a location in an image or
scene at which the end user is paying attention to, focusing on or
has otherwise attracted the attention of the end user. Again
various techniques may be employed, including but not limited to
eye tracking. Also for example, the factors may be indicative of a
location in an image or scene at which the end user is predicted to
pay attention to, focus on or will otherwise attract the attention
of the end user. Again various techniques may be employed including
but not limited to identifying newly appearing virtual objects,
fast or rapidly moving virtual objects, virtual objects that are
visually attractive, virtual objects that have been previously
designated (e.g., designated by the end user or by previously
tracking the end user's interaction) and/or virtual objects that
are attractive of attention based on the inherent nature of the
vertical object. Virtual objects that are attractive of attention
based on the inherent nature of the vertical object may, for
example, include a virtual object that visually represents an
object or item of concern or suspense to either generalized end
users or a specific end user (e.g., imminent threats).
[0258] At 2608, the augmented reality system selectively reads out
of the portion of the over rendered frame from the frame buffer.
The portion is based at least in part on the determined portion of
the respective image to present. For example, the portion that is
read out may have a center that is shifted to be proximate, or even
match or co-align, with the identified location. The identified
location may, for example, be a location in a previous image or
frame that has attracted an end user's attention. The identified
location may, for example, be a location in a subsequent frame
which the augmented reality system has predicted will attract the
end user's attention.
[0259] FIG. 27 shows a method 2700 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2700 may be employed in performing the method 2600 of FIG. 26. For
instance, the method 2700 may be used to predict a location in a
subsequent frame or image which will attract the end user's
attention.
[0260] At 2702, for each of at least some of the frames the
augmented reality system (e.g., a controller subsystem and/or
processor thereof) determines a location of appearance of a virtual
object in a field of view of the end user relative to an end user
frame of reference.
[0261] At 2704, the augmented reality system selectively reads out
of the frame buffer based at least in part on the determining a
location of appearance of a virtual object in a field of view. For
example, the portion that is read out may have a center that is
shifted to be proximate, or even match or co-align, with the
identified location. Alternative, the boundaries of the portion
that is read out may be shifted to encompass the determined
location an immediately surrounding areas, in two- or even
three-dimensions. For example, the augmented reality system may
select a portion (e.g., 80%) of the entire over rendered frame to
be read out of the frame buffer for presentation to the end user.
The augmented reality system may select that portion such that the
boundaries are shifted relative to a current location of the end
user's attention, for instance in images currently being presented
to the end user. The augmented reality system may select the
boundaries based on a combination of the current location and the
predicted location, while setting the boundary such that both
locations will be presented to the end user in the subsequently
presented image(s).
[0262] FIG. 28 shows a method 2800 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2800 may be employed in performing the method 2600 of FIG. 26. For
example, the method 2800 may be employed to determine a location in
an image that has attracted or is predicted to attract the
attention of the end user.
[0263] At 2802, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) determines the location of
appearance of a new virtual object, when the new virtual is newly
introduced in the field of view of the end user. The augmented
reality system may employ any of the various techniques described
herein to identify the introduction of a virtual object, which is
new relative to immediately previous frames or images presented to
the end user. Thus, even if a virtual object has previously been
presented to the end user at some other portion of a presentation,
the virtual object may be identified as newly introduced if a
sufficient number of intervening images have been presented to make
the reintroduction of the virtual object attract the attention of
the end user.
[0264] At 2804, the augmented reality system determines the
location of appearance of the virtual object in a new position in
the frame relative to a position in at least one previous frame.
The augmented reality system may employ any of the various
techniques described herein to identify the moving of a virtual
object to a new or different position in a number of images, which
is move relative to immediately previous frames or images presented
to the end user. Thus, even if a virtual object has previously been
presented to the end user at that some location in some other
portion of a presentation, the virtual object may be identified as
moved or moving if a sufficient number of intervening images have
been presented to make the reappearance of the virtual object at
the previous location attract the attention of the end user.
[0265] At 2806, the augmented reality system determines a location
of a virtual object having at least a defined minimum speed in a
field of view of the end user. The augmented reality system may
employ any of the various techniques described herein to determine
speed of movement of a virtual object from image to image and to
compare that speed to a defined or nominal speed. The determined
speed may be relative to a fixed reference frame in the image or
relative to other virtual objects and/or physical objects that
appear in the image.
[0266] At 2808, the augmented reality system determines a portion
of a respective image to present based at least in part on a
location of the virtual object in an image. The augmented reality
system may employ any of the various techniques described herein to
determine the portion of a respective image to present. The
determination may be based on any of a variety of factors. The
factors may, for example, include factors or data that is
indicative of a location in an image or scene at which the end user
is paying attention to, focusing on or has otherwise attracted the
attention of the end user. The factors may, for example, include
factors or data that is indicative of a location in an image or
scene at which the end user is predicted to pay attention to, focus
on or will otherwise attract the attention of the end user. The
augmented reality system may employ any of the various techniques
described elsewhere herein for identifying locations that have
attracted the end user's attention, whether via actual detection or
via prediction.
[0267] At 2810, the augmented reality system reads out a portion of
the frame buffer for at least one subsequent frame. The portion
that is read out shifts a center of the image at least toward the
determined portion of the respective image that will be presented.
The augmented reality system may employ any of the various
techniques described herein to read out of the frame buffer a
portion of a frame that shifts the center or boundaries of the
image based on the location of an end user's actual or predicted
center of attention.
[0268] FIG. 29 shows a method 2900 of operation in an augmented
reality system, according to one illustrated embodiment. The method
2900 may be employed in performing the method 2600 of FIG. 26. In
particular, the method 2900 may be employed to determine a which
portion of a frame to read out based on a predicted head movement
of the end user.
[0269] At 2902, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) predicts an occurrence of a
head movement of the end user. The augmented reality system may
employ any of the various techniques described herein to predict
head movement. Such techniques include, but are not limited to,
detecting the appearance in images of a new virtual object, a
moving virtual object, a virtual objecting moving rapidly, a
previously selected virtual object and/or a visually attractive
virtual object.
[0270] At 2904, the augmented reality system determines a portion
of a respective frame or image to present based at least in part on
the predicted head movement. The augmented reality system may
employ any of the various techniques described herein to determine
the portion of the frame to be used. For example, the augmented
reality system may select the portion such that the boundaries
encompass the location of a predicted end point of the predicted
head movement. Where the head movement prediction is predicated on
the appearance of a virtual object (e.g., newly introduced, moving,
attractive appearance, previously selected by end user), the end
point may be coincident with the location of that virtual object in
a subsequent frame or image.
[0271] FIG. 30 shows a method 3000 of operation in an augmented
reality system, according to one illustrated embodiment.
[0272] The augmented reality system may over render frames,
producing frames that are much larger than need for a maximum area
and maximum resolution of a given display technology. For example,
in a head worn or mounted augmented reality system the area
available for display or projection may be set by the various
parameters of the equipment. Likewise, while the augmented reality
system may be capable of operating at multiple distinct
resolutions, the equipment will set an upper end or maximum
resolution. An over rendered frame includes pixel information for a
set of pixels that exceeds the maximum area of display at the
maximum resolution. Such may advantageously allow the augmented
reality system to read out only portions of frames (e.g., a portion
of each field of the frame, if not interrupted). Such may allow the
augmented reality system to shift an image presented to the
user.
[0273] At 3002, the augmented reality system (e.g., a controller
subsystem and/or processor thereof) over renders each of a
plurality of frames for a defined field of view. Such requires
generating more pixel information that would otherwise be required
for the maximum area at maximum resolution. For example, the area
of the frame may be increase by a percentage of the maximum area,
for example increasing the pixel information in either a
horizontal, vertical or diagonal direction defined by the frame.
The larger the frame size the more freedom the augmented reality
system will have to shift the boundaries of the images presented to
the user.
[0274] At 3004, the augmented reality system determines a portion
of a respective image to present. The augmented reality system may
determine the portion based on any of a variety of factors. For
example, the factors may be indicative of a location in an image or
scene at which the end user is paying attention to, focusing on or
has otherwise attracted the attention of the end user. Again
various techniques may be employed, including but not limited to
eye tracking. Also for example, the factors may be indicative of a
location in an image or scene at which the end user is predicted to
pay attention to, focus on or will otherwise attract the attention
of the end user. Again various techniques may be employed including
but not limited to identifying newly appearing virtual objects,
fast or rapidly moving virtual objects, virtual objects that are
visually attractive, virtual objects that have been previously
designated (e.g., designated by the end user or by previously
tracking the end user's interaction) and/or virtual objects that
are attractive of attention based on the inherent nature of the
vertical object. Virtual objects that are attractive of attention
based on the inherent nature of the vertical object may, for
example, include a virtual object that visually represents an
object or item of concern or suspense to either generalized end
users or a specific end user (e.g., imminent threats).
[0275] At 3006, the augmented reality system dynamically addresses
one or more determined portions of the over rendered frame into the
buffer(s). The determined portion(s) may, for example, have a
center that is shifted to be proximate, or even match or co-align,
with an identified location of an end user's attraction, interest
or focus. The identified location may, for example, be a location
in a previous image or frame that has attracted an end user's
attention. The identified location may, for example, be a location
in a subsequent frame which the augmented reality system has
predicted will attract the end user's attention. Some
implementations employ multiple frame buffers. Such may facilitate
interruption of presentation for frames, as described elsewhere
herein.
At 3008, the augmented reality system reads out of the determined
portion(s) of the over rendered frame from the frame buffer.
[0276] Various exemplary embodiments of the invention are described
herein. Reference is made to these examples in a non-limiting
sense. They are provided to illustrate more broadly applicable
aspects of the invention. Various changes may be made to the
invention described and equivalents may be substituted without
departing from the true spirit and scope of the invention. In
addition, many modifications may be made to adapt a particular
situation, material, composition of matter, process, process act(s)
or step(s) to the objective(s), spirit or scope of the present
invention. Further, as will be appreciated by those with skill in
the art that each of the individual variations described and
illustrated herein has discrete components and features which may
be readily separated from or combined with the features of any of
the other several embodiments without departing from the scope or
spirit of the present inventions. All such modifications are
intended to be within the scope of claims associated with this
disclosure.
[0277] The invention includes methods that may be performed using
the subject devices. The methods may comprise the act of providing
such a suitable device. Such provision may be performed by the end
user. In other words, the "providing" act merely requires the end
user obtain, access, approach, position, set-up, activate, power-up
or otherwise act to provide the requisite device in the subject
method. Methods recited herein may be carried out in any order of
the recited events which is logically possible, as well as in the
recited order of events.
[0278] Exemplary aspects of the invention, together with details
regarding material selection and manufacture have been set forth
above. As for other details of the present invention, these may be
appreciated in connection with the above-referenced patents and
publications as well as generally known or appreciated by those
with skill in the art. The same may hold true with respect to
method-based aspects of the invention in terms of additional acts
as commonly or logically employed.
[0279] In addition, though the invention has been described in
reference to several examples optionally incorporating various
features, the invention is not to be limited to that which is
described or indicated as contemplated with respect to each
variation of the invention. Various changes may be made to the
invention described and equivalents (whether recited herein or not
included for the sake of some brevity) may be substituted without
departing from the true spirit and scope of the invention. In
addition, where a range of values is provided, it is understood
that every intervening value, between the upper and lower limit of
that range and any other stated or intervening value in that stated
range, is encompassed within the invention.
[0280] Also, it is contemplated that any optional feature of the
inventive variations described may be set forth and claimed
independently, or in combination with any one or more of the
features described herein. Reference to a singular item, includes
the possibility that there are plural of the same items present.
More specifically, as used herein and in claims associated hereto,
the singular forms "a," "an," "said," and "the" include plural
referents unless the specifically stated otherwise. In other words,
use of the articles allow for "at least one" of the subject item in
the description above as well as claims associated with this
disclosure. It is further noted that such claims may be drafted to
exclude any optional element. As such, this statement is intended
to serve as antecedent basis for use of such exclusive terminology
as "solely," "only" and the like in connection with the recitation
of claim elements, or use of a "negative" limitation.
[0281] Without the use of such exclusive terminology, the term
"comprising" in claims associated with this disclosure shall allow
for the inclusion of any additional element--irrespective of
whether a given number of elements are enumerated in such claims,
or the addition of a feature could be regarded as transforming the
nature of an element set forth in such claims. Except as
specifically defined herein, all technical and scientific terms
used herein are to be given as broad a commonly understood meaning
as possible while maintaining claim validity.
[0282] The breadth of the present invention is not to be limited to
the examples provided and/or the subject specification, but rather
only by the scope of claim language associated with this
disclosure.
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