U.S. patent application number 13/328644 was filed with the patent office on 2012-06-21 for remote control systems that can distinguish stray light sources.
This patent application is currently assigned to APPLE INC.. Invention is credited to Brett G. Alten.
Application Number | 20120154268 13/328644 |
Document ID | / |
Family ID | 40027010 |
Filed Date | 2012-06-21 |
United States Patent
Application |
20120154268 |
Kind Code |
A1 |
Alten; Brett G. |
June 21, 2012 |
REMOTE CONTROL SYSTEMS THAT CAN DISTINGUISH STRAY LIGHT SOURCES
Abstract
Remote control systems that can distinguish predetermined light
sources from stray light sources, e.g., environmental light sources
and/or reflections are provided. The predetermined light sources
can be disposed in asymmetric substantially linear or
two-dimensional patterns. The predetermined light sources also can
be configured to exhibit signature characteristics. The
predetermined light sources also can output light at different
signature wavelengths. The predetermined light sources also can
emit light polarized in one or more predetermined polarization
axes. Remote control systems of the present invention also can
include methods for adjusting an allocation of predetermined light
sources and/or the technique used to distinguish the predetermined
light sources from the stray light sources.
Inventors: |
Alten; Brett G.; (Cupertino,
CA) |
Assignee: |
APPLE INC.
Cupertino
CA
|
Family ID: |
40027010 |
Appl. No.: |
13/328644 |
Filed: |
December 16, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11803674 |
May 14, 2007 |
8102365 |
|
|
13328644 |
|
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Current U.S.
Class: |
345/156 ;
250/225 |
Current CPC
Class: |
G09G 3/006 20130101;
G06F 3/0304 20130101; G09G 2360/144 20130101; G09G 3/20 20130101;
G09G 2320/02 20130101 |
Class at
Publication: |
345/156 ;
250/225 |
International
Class: |
G06F 3/01 20060101
G06F003/01; G01J 1/04 20060101 G01J001/04 |
Claims
1.-20. (canceled)
21. A system comprising: one or more predetermined light sources
configured to emit light polarized in one or more predetermined
polarization axes; a photodetector for detecting light from light
sources, wherein the photodetector is configured to generate
photodetector data; one or more polarizing filters disposed to
accept light from the light sources before the light is detected by
the photodetector, wherein the one or more polarizing filters are
configured in one or more predetermined polarization axes; and a
controller configured to distinguish the one or more predetermined
light sources from other light sources based on the photodetector
data.
22. The system of claim 21, wherein the one or more predetermined
light sources comprise multiple predetermined light sources
disposed in a pattern that is asymmetric about at least a first
axis.
23. The system of claim 22, wherein the controller is configured to
identify multiple light sources from the photodetector data that
form a derivative pattern indicative of the asymmetric pattern.
24. The system of claim 21, wherein: the one or more predetermined
light sources comprise multiple predetermined light sources; and
the controller is configured to identify multiple light sources
from the photodetector data that exhibit expected relative
intensities.
25. The system of claim 21, wherein the photodetector, one or more
polarizing filters, and controller are disposed in a remote
control.
26. The system of claim 21, wherein the one or more predetermined
light sources are disposed in a remote control.
27. A method for distinguishing multiple predetermined light
sources from stray light sources, the method comprising: emitting
polarized light from the multiple predetermined light sources at
one or more predetermined intensities, wherein the polarized light
is polarized in one or more predetermined polarization axes;
filtering light from light sources using one or more polarizing
filters; detecting light from the light sources using a
photodetector after the light is filtered by the polarizing filter;
generating photodetector data representative of the detected light;
and identifying multiple light sources from the photodetector data
that exhibit expected relative intensities.
28. The method of claim 27, wherein the multiple predetermined
light sources is disposed in a pattern that is asymmetric about at
least a first axis, the method further comprising identifying
multiple light sources from the photodetector data that form a
derivative pattern indicative of the asymmetric pattern.
29. The method of claim 27, wherein the photodetector and
polarizing filter are disposed in a remote control, the method
further comprising generating signals responsive to user actuation
of a user input component of the remote control.
30. The method of claim 27, wherein the one or more predetermined
light sources are disposed in a remote control, the method further
comprising generating signals responsive to user actuation of a
user input component of the remote control.
31. The method of claim 27, wherein emitting polarized light from
the multiple predetermined light sources comprises emitting
polarized light from multiple coherent light sources.
32. The method of claim 27, wherein emitting polarized light from
the multiple predetermined light sources comprises emitting
polarized light through one or more polarizing filters.
33. A method for identifying a technique for distinguishing one or
more predetermined light sources from other light sources, the
method comprising: accepting data indicative of one or more
conditions under which a photodetector is detecting light emitted
from the one or more predetermined light sources; and identifying a
first technique for distinguishing the one or more predetermined
light sources from the other light sources based on the data.
34. The method of claim 33, further comprising initiating the first
technique by generating signals for controlling hardware associated
with the first technique.
35. The method of claim 33, further comprising: identifying a
second technique for distinguishing the one or more predetermined
light sources from the other light sources, wherein the second
technique comprises a default technique; and changing from the
second technique to the first technique to distinguish the one or
more predetermined light sources from the other light sources.
36. The method of claim 33, wherein the data comprises ambient
light data, data indicative of the proximity of the one or more
predetermined light sources to the photodetector, data indicative
of an image being shown by a display associated with the one or
more predetermined light sources, data indicative of a
signal-to-noise ratio, data from a user indicative of a
user-preferred technique, or any combination thereof.
Description
CROSS-REFERENCE TO RELATED CASES
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/803,674, filed on May 14, 2007, which is incorporated
herein by reference in its entirety. This application is related to
U.S. patent application Ser. No. 11/594,313, filed on Nov. 7, 2006,
Attorney Docket No. P4736US1, now U.S. Pat. No. 7,566,858, which is
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention can relate to remote control systems
that can distinguish one or more predetermined light sources from
stray light sources.
BACKGROUND OF THE INVENTION
[0003] Some remote control systems use infrared (IR) emitters to
determine the position and/or movement of a remote control. For
example, if IR emitters are mounted proximate to a television, the
remote control may be able to detect its own motion by measuring
the relative motion of the IR emitters with respect to the remote
control.
[0004] Such systems, however, may not be able to distinguish
desired or predetermined IR light sources from undesirable
environmental IR sources, e.g., the sun or a light bulb. Because
those systems may mistakenly identify unintended environmental IR
sources as intended IR emitters, the systems may incorrectly
determine the position and/or movement of the remote control.
[0005] Such systems also may experience another common problem in
that the systems may not be able to distinguish IR emitters from
reflections of the IR emitters, e.g., from the surface of a table
or a window. For example, when IR emitters are disposed in a
pattern that is symmetrical about a horizontal axis, the remote
control system may mistake reflections of the IR emitters from a
table surface for the actual IR emitters. Or, when IR emitters are
disposed in a pattern that is symmetrical about a vertical axis,
the remote control system may mistake reflections of the IR
emitters from a window for the actual IR emitters. Again, such
mistakes may result in incorrect determinations of the position
and/or movement of the remote control.
SUMMARY OF THE INVENTION
[0006] The present invention relates to remote control systems that
can distinguish predetermined light sources from stray or
unintended light sources, such as environmental light sources
and/or reflections.
[0007] In one embodiment of the present invention, the
predetermined light sources can be disposed in asymmetric
substantially linear or two-dimensional patterns. Here, a
photodetector can detect light output by the predetermined light
sources and stray light sources, and transmit data representative
of the detected light to one or more controllers. The controllers
can identify a derivative pattern of light sources from the
detected light indicative of the asymmetric pattern in which the
predetermined light sources are disposed.
[0008] In another embodiment of the present invention, the
predetermined light sources can output waveforms modulated in
accordance with signature modulation characteristics. By
identifying light sources that exhibit the signature modulation
characteristics, a controller can distinguish the predetermined
modulated light sources from those that do not modulate in that
same way.
[0009] In another embodiment of the present invention, each
predetermined light source can output light at one or more
different signature wavelengths. For example, a photodetector
module of the present invention can detect the signature
wavelengths using multiple photodetectors, each of which can detect
one of the signature wavelengths. Alternatively, the photodetector
module can include an interleaved photodetector having an array of
interleaved pixels. Different portions of the interleaved pixels
can detect one of the signature wavelengths.
[0010] In yet another embodiment of the present invention, a
display can have a matrix of pixels having one or more signature
pixels. The signature pixel(s) can exhibit one or more signature
characteristics that distinguish the signature pixel(s) from the
other pixels in the matrix and from other light sources that do not
exhibit the signature characteristic(s). For example, the signature
pixel(s) can exhibit one or more signature modulation
characteristics, wavelengths, polarization axes, intensities,
shapes, etc. The present invention also can include methods for
adjusting the allocation of signature pixels in the display based
on data indicative of conditions under which a photodetector
detects the signature pixels.
[0011] In another embodiment of the present invention, a light
transmitter can be configured to transmit light that is polarized.
For example, the light can have one or more predetermined
polarization axes. Based on the measured intensity of light
received by one or more complementary photodetectors, a controller
can distinguish the polarized light from unpolarized stray
sources.
[0012] The present invention also can include methods for adjusting
the technique used for distinguishing predetermined light sources
from stray light sources. The adjustment can be based on data
indicative of one or more conditions under which a photodetector is
detecting light emitted from the predetermined light sources.
[0013] Combinations of the embodiments described herein also are
within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other advantages of the present invention will
be apparent upon consideration of the following detailed
description, taken in conjunction with accompanying drawings, in
which like reference characters refer to like parts throughout, and
in which:
[0015] FIG. 1 illustrates one embodiment of a remote control system
of the present invention having an asymmetric pattern of
predetermined light sources;
[0016] FIG. 2 illustrates a process for distinguishing
predetermined light sources from stray light sources based on the
pattern in which the light sources are disposed in accordance with
one embodiment of the present invention;
[0017] FIGS. 3A-3E illustrate additional embodiments of asymmetric
patterns of predetermined light sources in accordance with the
present invention;
[0018] FIG. 4 illustrates a remote control system of one embodiment
of the present invention that can distinguish predetermined light
sources from stray light sources based on signature modulation
characteristics with which output waveforms of the predetermined
light sources are modulated;
[0019] FIG. 5 illustrates a process of one embodiment of the
present invention for distinguishing predetermined light sources
from stray light sources based on signature modulation
characteristics with which output waveforms of the predetermined
light sources are modulated;
[0020] FIGS. 6A-6B illustrate interleaved photodetectors in
accordance with one embodiment of the present invention;
[0021] FIGS. 7A-B show an illustrative display having one or more
integrated signature pixels, the output of which can be used to
measure relative controller motion, such as by modulation,
polarization, etc., in accordance with one embodiment of the
present invention;
[0022] FIG. 7C illustrates a process for adjusting the allocation
of signature pixels in the display of FIGS. 7A-B based on data
indicative of conditions under which a photodetector is detecting
light emitted from the signature pixels in accordance with one
embodiment of the present invention;
[0023] FIG. 8A shows an illustrative remote control system
configured to distinguish one or more predetermined light sources
from stray light sources by generating and detecting light at one
or more predetermined polarization axes in accordance with one
embodiment of the present invention;
[0024] FIG. 8B shows four illustrative predetermined light sources
that emit light in four illustrative predetermined polarization
axes in accordance with one embodiment of the present
invention;
[0025] FIGS. 8C-8F show illustrative relative intensities of light
a photodetector can expect to receive from the illustrative
predetermined light sources of FIG. 8B when a remote control rolls
about the z-axis and the relative locations from which those
predetermined light sources can be expected to emit the light in
accordance with one embodiment of the present invention; and
[0026] FIG. 9 shows an illustrative process for adjusting the
technique used by a remote control system for distinguishing
predetermined light sources from stray light sources in accordance
with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention can include remote control systems
that can distinguish predetermined light sources from stray light
sources, such as environmental light sources and/or
reflections.
[0028] FIG. 1 illustrates one embodiment of a remote control system
of the present invention. Remote control system 10 can include
remote control 12 and multiple predetermined light sources 16.
Predetermined light sources 16 can be disposed in frame 18 to form
light transmitter 14 or integrated with display 20. As used herein,
light sources can either generate light or reflect light shined
thereon. If light source(s) act as reflector(s), another light
source can project light towards the reflector(s). The reflector(s)
can reflect the light back to a photodetector. For example, the
photodetector and the other light source can be disposed on remote
control 12, whereas the reflector(s) can be disposed proximate to,
near, on, or in display 20.
[0029] Remote control system 10 can permit a user to interact with
an image shown on display 20 by manipulating remote control 12.
Display 20 can project an image substantially defined by orthogonal
x- and y-axes. Display 20 can include a television having a screen
with a nominal curvature, a computer monitor having a screen with a
nominal curvature, a flat-screen television, a flat-screen monitor,
a surface upon which a projector can project images, or any other
type of display known in the art or otherwise.
[0030] Remote control system 10 can permit a user to move or
otherwise select object 19 (e.g., a cursor) shown on display 20 in
the x- and y-axes by pointing remote control 12 at desired
locations on or proximate to display 20. Ray R can indicate the
location at which remote control 12 is pointing. Remote control
system 10 can detect the remote control's motion by measuring the
motion of predetermined light sources 16 with respect to its own.
Based on the detected motion, remote control system 10 can
determine the absolute x- and y-positions of the location to which
the remote control is pointing with respect to one or more
reference locations, e.g., one or more of the predetermined light
sources. Remote control system 10 then can be used to move object
19 to the determined location. Thus, when the user moves remote
control 12 in the x- and y-axes, display 20 can show a
corresponding movement in object 19 in the x- and y-axes.
[0031] Predetermined light sources 16 can emit, e.g., infrared (IR)
light 22 to remote control 12. Remote control 12 can detect the
emitted light using photodetector 24. Photodetector 26 can include
CCD arrays, CMOS arrays, two-dimensional position sensitive
photodiode arrays, other types of photodiode arrays, other types of
light detection devices known in the art or otherwise, or a
combination thereof.
[0032] In accordance with the present invention, predetermined
light sources 16 can be spatially constrained in an asymmetric
substantially linear pattern in frame 18. The substantially linear
pattern can be parallel to a longitudinal axis of transmitter 14
and asymmetric about an axis orthogonal to the longitudinal axis of
transmitter 14. For example, as shown in FIG. 1, remote control
system 10 can include three predetermined light sources 16 disposed
in a substantially linear pattern. The distance between left-most
predetermined light source 16a and middle predetermined light
source 16b can be less than that between middle predetermined light
source 16b and right-most predetermined light source 16c. While
FIG. 1 illustrates three predetermined light sources, remote
control system 10 can include four or more predetermined light
sources disposed in an asymmetric substantially linear pattern.
[0033] Predetermined light sources 16 can be disposed proximate any
edge of display 20, e.g., a top, bottom, or vertical edge of
display 20 either in frame 18 or integrated with display 20.
Predetermined light sources 16 also can be disposed substantially
co-planar with the screen of the display. Alternatively,
transmitter 14 and/or predetermined light sources 16 can be
disposed at another location near, on, or beneath display 20.
[0034] Remote control system 10 also can include controller 26,
which can be disposed in remote control 12. Controller 26 can
accept data representative of light detected by photodetector 24.
In a manner described in greater detail below with respect to FIG.
2, controller 26 can distinguish predetermined light sources from
stray light sources using the photodetector data. The controllers
described herein can include processors, memory, ASICs, circuits
and/or other electronic components.
[0035] Remote control 12 also can incorporate user input component
28. A user may actuate user input component 28 when the user wants
remote control system 10 to perform an action. For example, a user
may actuate user input component 28 when the user is moving remote
control 12 and wants object 19 to reflect similar motion on display
20. When the user is not actuating user input component 28, remote
control system 10 can be configured to take no action.
[0036] User input component 28 can be a scrollwheel similar to that
incorporated by a portable media player sold under the trademark
iPod.TM. by Apple Inc. of Cupertino, Calif. The scrollwheel can
include one or more buttons and a touchpad or other input device.
The touchpad can permit a user to scroll through software menus by
running the user's finger around the track of the scrollwheel. User
input component 38 also can include, for example, one or more
buttons, a touchpad, a touchscreen display, or a combination
thereof.
[0037] Remote control system 10 also can include optional console
30. Console 30 can have controller 32 that can perform some or all
of the processing described for controller 26. For example, remote
control 12 can transmit data representing detected IR light 22 to
console 30. Controller 32 in console 30 then can identify
predetermined light sources 16 from the light sources detected by
photodetector 24.
[0038] In one embodiment of the present invention, console 30 can
communicate with remote control 12 using cable 34 and/or one or
more wireless communication protocols known in the art or
otherwise. Console 30 also can communicate with transmitter 14
using cable 35 and/or one or more wireless communication protocols
known in the art or otherwise. Console 30 also can communicate with
display 20 using cable 36 and/or one or more wireless communication
protocols known in the art or otherwise. Alternatively, console 30
can be integrated with display 20 as one unit.
[0039] Console 30 also can have one or more connectors to which
accessories can be coupled. Accessories can include cables, game
cartridges, portable memory devices (e.g., memory cards, external
hard drives, etc.), adapters for interfacing with another
electronic device (e.g., computers, camcorders, cameras, media
players, etc.), or combinations thereof.
[0040] FIG. 2 illustrates one embodiment of a process that
controller 26 or 32 can employ to distinguish predetermined light
sources from stray light sources based on the pattern in which the
predetermined light sources are disposed. In step 40, controller 26
or 32 can accept data representative of light detected by
photodetector 24. In step 42, controller 26 or 32 can identify a
plurality of (e.g., all) points of interest (POIs) or detected
light sources from the photodetector data, regardless of whether
the light source is one of predetermined light sources 16 or a
stray light source. Identification of a POI can include determining
positional characteristics of the detected light source. As used
herein, the "positional characteristics" of a light source or group
of light sources can include characteristics that indicate the
absolute or relative position and/or geometry of the light
source(s), e.g., the absolute x- and y-positions of the light
source(s).
[0041] To determine the absolute x- and y-positions of the light
sources detected by photodetector 24, controller 26 or 32 can use
any available techniques known in the art. For example, U.S. Pat.
No. 6,184,863 to Sibert et al., issued on Feb. 6, 2001, and No.
7,053,932 to Lin et al, issued on May 30, 2006, the entireties of
which are incorporated herein by reference, describe two techniques
that can be employed by controller 26 or 32. U.S. Patent
Application Publication No. 2004/0207597 to Marks, published on
Oct. 21, 2004; No. 2006/0152489 to Sweetser et al., published on
Jul. 13, 2006; No. 2006/0152488 to Salsman et al., published on
Jul. 13, 2006; and No. 2006/0152487 to Grunnet-Jepsen et al.,
published on Jul. 13, 2006, the entireties of which also are
incorporated herein by reference, describe additional techniques
that can be employed by controller 26 or 32. Remote control system
10 also can employ other techniques known in the art or
otherwise.
[0042] In step 44, controller 26 or 32 can identify a plurality of
(e.g., all possible) permutations of the light sources identified
in step 42. Each permutation can contain the same number of light
sources as the number of predetermined light sources. In the
illustrative embodiment of FIG. 1, controller 26 or 32 can identify
a plurality of (e.g., all possible) triads, which can be sets of
three POIs identified in step 42. In step 46, controller 26 or 32
can correlate the pattern formed by each permutation or triad
identified in step 44 to the asymmetric pattern in which
predetermined light sources 16 are disposed. Correlation techniques
can include statistical techniques, e.g., Chi-square test,
least-squares test, or another correlation technique known in the
art or otherwise. Controller 26 or 32 can quantify the correlation
by determining a correlation coefficient for each permutation or
triad. Each correlation coefficient can indicate how well the
pattern formed by each permutation matches the pattern formed by
the predetermined light sources.
[0043] When a user is manipulating remote control 12, the remote
control may not be aligned with predetermined light sources 16 in
such a way that any of the permutations or triads identified in
step 44 will have a pattern that perfectly matches the asymmetric
pattern in which predetermined light sources 16 are disposed.
Accordingly, in correlating the pattern formed by each permutation
or triad identified in step 44 to the asymmetric pattern of
predetermined light sources 16, controller 26 or 32 can account for
perceived translation, roll, and/or scaling of the asymmetric
pattern in the x- and/or y-axes. As used herein, roll of a pattern
of predetermined light sources may refer to the rotation of the
pattern about an axis orthogonal to the x- and y-axes. Scaling of a
pattern of predetermined light sources may refer to the enlargement
or reduction of the pattern in the x- and/or y-axes.
[0044] In step 48, controller 26 or 32 can identify a predetermined
number of N permutations or triads that form patterns that
approximate the asymmetric pattern in which predetermined light
sources 16 are disposed. Assuming that the correlation coefficients
determined in step 46 increase the closer the pattern formed by a
permutation correlates to the pattern in which predetermined light
sources 16 are disposed, controller 26 or 32 can identify
permutations having the best correlation by identifying
permutations having the highest correlation coefficients. However,
if the correlation coefficients determined in step 46 decrease the
closer the pattern formed by a permutation correlates to the
pattern in which predetermined light sources 16 are disposed,
controller 26 or 32 can identify permutations having the best
correlation by identifying permutations having the lowest
correlation coefficients.
[0045] In step 50, controller 26 or 32 can compare the positional
characteristics of each permutation or triad identified in step 48
with "good" values determined in previous solutions. Positional
characteristics compared in step 50 may include, e.g., the
x-position of each POI, y-position of each POI, perceived
translation of the pattern formed by predetermined light sources
16, perceived roll of the pattern formed by predetermined light
sources 16, and/or perceived scaling of the pattern formed by
predetermined light sources 16. Based on the comparison performed
in step 50, controller 26 or 32 can identify the "winning"
permutation or triad that most likely corresponds to predetermined
light sources 16 in step 52.
[0046] In one embodiment of the present invention, controller 26 or
32 can identify in step 48 the permutation having the best
correlation (i.e., N=1). In this case, steps 50 and/or 52 may be
unnecessary.
[0047] As discussed above, remote control 12 may not be aligned
with predetermined light sources 16 in such a way that the pattern
of the "winning" permutation will perfectly match the asymmetric
pattern in which predetermined light sources 16 are disposed.
Instead, the pattern of the "winning" permutation may be a
derivative indicative of the asymmetric pattern in which
predetermined light sources 16 are disposed. For example, the
derivative pattern of the "winning" permutation may be translated,
rotated, and/or scaled with respect to the asymmetric pattern in
which predetermined light sources 16 are disposed.
[0048] In one embodiment of the present invention, controller 26 or
32 can continuously reiterate steps 40-52 for each frame of data
collected by photodetector 24. However, there may not be a need to
distinguish predetermined light sources 16 from stray light sources
with each frame of data collected by photodetector 24. In the
latter case, controller 26 or 32 can be configured to only perform
steps 40-52 for every Jth frame of data collected by photodetector
24, wherein J is a predetermined number. For example, after
controller 26 or 32 performs step 44, the controller can be
configured to determine whether photodetector 24 has collected J
frames of data (step 54). If photodetector 24 has collected J
frames of data, controller 26 or 32 then can perform step 46 as
described above. However, if photodetector 24 has not collected J
frames of data yet, controller 26 or 32 can jump to step 50. That
is, controller 26 or 32 can compare positional characteristics of
each permutation or triad identified in step 44 with "good" values
determined in previous solutions. Based on the comparison performed
in step 50, controller 26 or 32 can identify the "winning"
permutation that most likely corresponds to predetermined light
sources 16 in step 52.
[0049] FIGS. 3A-3C illustrate alternative asymmetric patterns in
which to dispose predetermined light sources in accordance with the
present invention. Similar to the embodiment of FIG. 1,
predetermined light sources 62 of FIGS. 3A-3C also can be disposed
in frame 64 to form transmitter 60 or integrated with display 20.
In the embodiments of FIGS. 3A-3C, however, predetermined light
sources 62 can be spatially constrained in a two-dimensional
pattern that is asymmetric about longitudinal axis L and/or an axis
orthogonal thereto.
[0050] For example, as shown in FIG. 3A, predetermined light
sources 62 can be disposed in a two-dimensional pattern that is
asymmetric about longitudinal axis L. This configuration may be
useful to assist remote control system 10 in distinguishing
predetermined light sources 62 from reflections of the
predetermined light sources from a surface disposed parallel to
longitudinal axis L, e.g., a table surface.
[0051] As shown in FIG. 3B, predetermined light sources 62 can be
disposed in a two-dimensional pattern that is asymmetric about an
axis orthogonal to longitudinal axis L. This configuration may be
useful to assist remote control system 10 in distinguishing
predetermined light sources 62 from reflections of the
predetermined light sources from a surface disposed parallel to an
axis orthogonal to longitudinal axis L, e.g., a window.
[0052] As shown in FIG. 3C, predetermined light sources 62 can be
disposed in a two-dimensional pattern that is asymmetric about both
longitudinal axis L and an axis orthogonal thereto.
[0053] FIGS. 3D-3E illustrate alternative asymmetric patterns in
which predetermined light sources can be spatially constrained in
accordance with the present invention. Predetermined light sources
72 can be disposed on frames 74a-74d, which in turn can be disposed
proximate to the edges of display 20, e.g., top, bottom, and/or
vertical edges. Alternatively, predetermined light sources 72 can
be integrated into display 20 proximate to the edges of display 20.
Advantageously, when predetermined light sources are disposed
proximate to top and bottom edges of display 20, remote control
system 10 can detect a greater range of vertical motion.
[0054] When disposed proximate to display, predetermined light
sources 72 can form a two-dimensional pattern that can be
asymmetric about an axis parallel and/or orthogonal to the
direction of gravity. This is not to say that each group of
predetermined light sources 72 disposed proximate to each edge of
display 20 needs to form a two-dimensional pattern and/or be
asymmetric about an axis parallel and/or orthogonal to the
direction of gravity. For example, in FIG. 3D, predetermined light
sources 72a can form a symmetric two-dimensional pattern and
predetermined light sources 72b can form an asymmetric
one-dimensional pattern. In FIG. 3E, predetermined light sources
72c and predetermined light sources 72d each can form an asymmetric
substantially linear pattern. Indeed, the pattern formed by
predetermined light sources 72d can be the same pattern formed by
predetermined light sources 72c, but rotated 180 degrees.
Advantageously, each of the illustrative patterns formed by the
predetermined light sources in FIGS. 3D and 3E may be useful in
assisting remote control system 10 to distinguish the predetermined
light sources from reflections of the predetermined light sources
from surfaces disposed both parallel and orthogonal to the
direction of gravity.
[0055] Asymmetric arrangements of predetermined light sources,
whether in substantially linear or two-dimensional patterns, also
can permit remote control system 10 to determine whether remote
control 12 is upside-down or not. For example, if a remote control
system employs a symmetrical pattern of IR emitters, the controller
may not be able to distinguish whether a user is holding the remote
control with, e.g., user input component 28 pointing in the
positive y-direction or in the negative y-direction. By disposing
predetermined light sources 16 in an asymmetric pattern, a
controller of the present invention can distinguish between these
configurations by comparing the locations of the detected
predetermined light sources relative to each other.
[0056] In accordance with another aspect of the present invention,
remote control systems can modulate output waveform(s) of one or
more predetermined light sources in accordance with one or more
predetermined or signature modulation characteristics. For example,
genres of signature modulation characteristics can include, e.g.,
frequency, duty cycle, phase shift, another pulse train signature,
or a combination thereof. For example, the remote control system
can continuously turn two predetermined light sources ON and OFF at
first and second predetermined frequencies or otherwise adjust the
signal strengths of the two predetermined light source output
waveforms at the predetermined frequencies. The first and second
frequencies can have the same value or different values. The remote
control system can distinguish predetermined light sources that
output modulated waveforms from stray light sources by identifying
light sources that exhibit the signature modulation
characteristics.
[0057] FIG. 4 illustrates one embodiment of remote control system
80 of the present invention that can distinguish predetermined
light sources from stray light sources by identifying light sources
that exhibit, e.g., the signature frequencies at which
predetermined light source waveforms may be modulated. Transmitter
81 can include first and second predetermined light sources 82a and
82b and one or more frames 84 on which the predetermined light
sources are disposed. Modulator(s) 85 can frequency-modulate output
of predetermined light sources 82a and 82b so that the
predetermined light sources are turned ON and OFF at frequencies f1
and f2 (respectively). Alternatively, modulator(s) 85 can
frequency-modulate the output of the predetermined light sources so
that the signal strengths of the outputs are otherwise adjusted in
a predetermined manner at frequencies f1 and f2. In one embodiment
of the present invention, light output from predetermined light
sources 82a and 82b can be modulated at predetermined frequencies
that may be less likely to be encountered in a user's environment,
e.g., between 100 KHz and 300 KHz, inclusive.
[0058] Remote control 86 can include photodetector 88 and
controller 90. In one embodiment of the present invention,
photodetector 88 can be a two-dimensional position sensitive diode
(PSD). In the embodiment of FIG. 4, frequencies f1 and f2 can have
different values that are greater than the frame rate at which
photodetector 88 captures data.
[0059] Controller 90 can include first and second frequency
demodulators 92a and 92b, each of which can demodulate the
photodetector data in accordance with one of the signature
frequencies at which predetermined light sources 82a and 82b may be
modulated. Demodulator 92a can accept output from photodetector 88
and extract the x- and y-positions of predetermined light source
82a with respect to remote control 86. Likewise, demodulator 92b
can accept output from photodetector 88 and extract the x- and
y-positions of predetermined light source 82b with respect to
remote control 86. In alternative embodiments of the present
invention, controller 90 can be disposed in a console, e.g.,
console 30 of FIG. 1, or within display 20.
[0060] While FIG. 4 illustrates transmitter 81 with two
predetermined light sources, one of the predetermined light sources
can be eliminated or additional predetermined light sources can be
added. In the latter case, the predetermined light sources can be
disposed in an asymmetric or symmetric pattern. Furthermore, the
signature frequency or frequencies at which the predetermined light
sources can be modulated can be slower than the frame rate at which
a photodetector collects data. In one embodiment of the present
invention, one or more predetermined light sources can be modulated
at a signature frequency on the order of 10 Hz.
[0061] In alternative embodiments of the present invention,
modulator(s) 85 can modulate output waveforms of predetermined
light sources 82a and 82b in accordance with another genre or
combinations of genres of signature modulation characteristic(s).
Demodulators 92a and 92b then can be configured to demodulate
output data from photodetector 88 with respect to those genres of
signature modulation characteristic(s). In further alternative
embodiments of the present invention, the demodulators of FIG. 4
may be replaced with correction filters.
[0062] FIG. 5 illustrates one embodiment of a process that a remote
control system of the present invention can employ to distinguish
predetermined light sources from stray light sources by identifying
light sources that exhibit, e.g., the signature frequencies at
which output waveforms of the predetermined light sources are
modulated. In step 100, the controller can accept data
representative of light detected by a photodetector disposed, e.g.,
in a remote control. In step 102, the controller can identify a
plurality of (e.g., all) points of interest (POIs) or detected
light sources from the photodetector data, regardless of whether
the light source is one of the predetermined light sources or a
stray light source. Identification of a POI may include determining
positional characteristics of each detected light source.
[0063] In step 104, the controller can track each POI identified in
step 102 for a predetermined number of M frames. Thereafter, in
step 106, the controller can determine a modulation characteristic,
e.g., the frequency, at which the light detected for each POI is
modulated over those M frames. For stray light sources that may not
modulate or infrequently modulates its light output over the M
frames, e.g., the sun, the determined frequency may be very low,
e.g., approximately zero.
[0064] In step 108, the controller can correlate the modulation
characteristics, e.g., the frequencies, determined in step 106 to
the signature modulation characteristic(s) at which the
predetermined light sources are modulated. The controller can
quantify the correlation by determining a correlation coefficient
for each POI. The correlation coefficient may indicate how well the
modulation characteristic determined for each POI in step 106
matches the signature modulation characteristic(s) at which
waveforms output by the predetermined light sources are
modulated.
[0065] In step 110, the controller can identify a predetermined
number K of POIs having modulation characteristics that approximate
the signature modulation characteristic(s) at which waveforms
output by the predetermined light sources are modulated. Assuming
that the correlation coefficients determined in step 110 increase
the closer a modulation characteristic determined in step 106
correlates to one of the signature modulation characteristics, the
controller can identify POIs having the best correlation by
identifying the POIs having the highest correlation coefficients.
However, if the correlation coefficients determined in step 108
decrease the closer a modulation characteristic determined in step
106 correlates to one of the signature modulation characteristics,
the controller can identify POIs having the best correlation by
identifying the POIs having the lowest correlation
coefficients.
[0066] In step 112, the controller can compare the positional
characteristics of each POI identified in step 110 with "good"
values determined in previous solutions. Based on the comparison
performed in step 112, the controller can identify the "winning"
POIs that most likely correspond to the predetermined light sources
in step 114.
[0067] In one embodiment of the present invention, the controller
can continuously reiterate steps 100-114 for each frame of data
collected by the photodetector. However, there may not be a need to
distinguish the predetermined light sources from stray light
sources with each frame of data collected by the photodetector. In
the latter case, the controller can be configured to only perform
steps 100-114 for every Lth frame of data collected by the
photodetector, wherein L is a predetermined number. For example,
after the controller performs step 102, the controller can be
configured to determine whether the photodetector has collected L
frames of data (step 116). If the photodetector has collected L
frames of data, the controller then can perform step 104 as
described above. However, if the photodetector has not collected L
frames of data yet, the controller can jump to step 112. That is,
the controller can compare the positional characteristics of each
POI identified in step 102 with "good" values determined in
previous solutions. Based on the comparison performed in step 112,
the controller can identify the "winning" POIs that most likely
correspond to predetermined light sources in step 114.
[0068] In addition to or instead of modulating the outputs of
predetermined light sources at signature frequencies, the remote
control system of the present invention also can modulate output
waveform(s) of one or more predetermined light sources at signature
or predetermined duty cycle(s). Output waveforms can be modulated
at different or the same predetermined duty cycle(s). The remote
control system also can incorporate one or more phase shifts
between waveforms output by multiple predetermined light
sources.
[0069] In one embodiment of the present invention, a remote control
system can have two or more predetermined light sources, the output
waveforms of which can be modulated in accordance with different
signature modulation characteristics having different predetermined
values or genres. Advantageously, this may permit the remote
control system to determine whether remote control is upside-down.
For example, if a remote control system employs a symmetrical
pattern of IR emitters, the controller may not be able to
distinguish whether a user is holding the remote control with,
e.g., a user input component pointing in the positive y-direction
or in the negative y-direction. By modulating the predetermined
light source outputs in accordance with different signature
modulation characteristics, a controller of the present invention
can distinguish between these configurations.
[0070] In accordance with another aspect of the present invention,
predetermined light sources can output light at different signature
wavelengths, e.g., in the IR spectrum. For example, a remote
control system of the present invention can include first and
second predetermined light sources. The first predetermined light
source can emit light at first wavelength Al and the second
predetermined light source can emit light at second wavelength A2.
A photodetector module, e.g., disposed in a remote control, can
include first and second photodetectors. The first photodetector
can be configured to detect light having first wavelength Al and
the second photodetector can be configured to detect light having
second wavelength A2. Alternatively, the photodetector module can
be an interleaved photodetector. Advantageously, a remote control
system having predetermined light sources that output light of
different wavelengths can permit the remote control system to
determine whether a remote control is upside-down.
[0071] FIGS. 6A-6B illustrate embodiments of interleaved
photodetectors in accordance with the present invention.
Interleaved photodetector 120 can be a single unit having an array
of interleaved pixels 122. Predetermined pixels 122a of the array
can be configured to detect light having first wavelength Al
whereas other predetermined pixels 122b of the array can be
configured to detect light having second wavelength A2. For
example, alternating rows of pixels (see FIG. 6A) or alternating
columns of pixels can be configured to detect light having
different wavelengths A1 and A2. Alternatively, as shown in FIG.
6B, a checkerboard of pixels can be configured to detect light
having different wavelengths Al and A2. In the embodiments of FIGS.
6A-6B, pixels indicated with hatching may be configured to detect
light having first wavelength A1 and pixels indicated without
hatching may be configured to detect light having second wavelength
A2.
[0072] FIGS. 7A-B illustrates a display having one or more
integrated signature pixels which can be configured to exhibit
signature characteristics. Display 130 can incorporate matrix of
pixels 132 for showing an image. Pixels 132 can be arranged in any
predetermined configuration (e.g., in rows and columns) and driven
by a controller, e.g., control circuitry or a processor (not
shown). The controller can be disposed in the display itself or in
a separate control device (e.g., a computer, set-top box, etc.). To
reduce the amount of IR light emitted from the display to the
viewer, display 130 also can incorporate IR filter 134, which can
cover all or some of pixels 132. IR filter 134 can be applied, for
example, onto an internally-facing surface of screen 136.
[0073] One or more signature pixels 140 can be integrated into
matrix of pixels 132. The signature pixel(s) can exhibit one or
more signature characteristics that, when detected by a
complementary photodetector, distinguish the signature pixel(s)
from light sources that do not exhibit the same signature
characteristics. For example, the light emitted by one or more of
the signature pixels can be modulated in accordance with one or
more signature characteristics, e.g., frequencies, duty cycles,
phase shifts, polarization axes, intensities, etc. The light
emitted by one or more of the signature pixels also can have a
signature wavelength. Each signature pixel or multiple signature
pixels also can form one or more signature shapes. For example, a
signature pixel can physically have a shape that distinguishes that
signature pixel from the other pixels in matrix 132, or multiple
signature pixels can form a shape that distinguishes those
signature pixels from the other pixels in matrix 132. In one
embodiment, the predetermined signature shape can include an
asymmetric arrangement of the signature pixels similar to those
described herein with respect to FIGS. 1-3E. The signature pixel(s)
also can exhibit combinations of these and other signature
characteristics.
[0074] In one embodiment of the present invention, one or more of
signature pixels 140 can occupy a border position of the matrix.
One or more of pixels 140 also can occupy an internal position of
the matrix. Multiple signature pixels 140 also can be distributed
within matrix 132 in an asymmetric pattern similar to those
discussed herein with respect to FIGS. 1-3E.
[0075] In one embodiment of the present invention, IR filter 134
can have one or more selective transmission features to facilitate
communication of IR light emitted by signature pixels 140 through
the filter. For example, IR filter can include holes 138 disposed
to permit IR light generated by signature pixels 140 to be emitted
from display 130 to a photodetector (e.g., in a remote control).
This can, for example, permit transmission of signature modulated
IR light from signature pixels 140 without undue attenuation in the
signal. IR filter 134 also can have one or more high-pass filters,
low-pass filters, and/or band-pass filters configured to permit
transmission of signature wavelength(s) of light from signature
pixels 140. IR filter 134 also can have one or more polarizing
filters configured to polarize light emitted from signature pixels
140 in one or more predetermined polarization axes.
[0076] To distinguish signature pixel(s) from other sources of
light (including the remaining pixels in matrix 132), a remote
control similar, for example, to those described with respect to
FIGS. 1-6B can be used.
[0077] FIG. 7C illustrates a process for adjusting the allocation
of signature pixels in the display of FIGS. 7A-B based on data
indicative of conditions under which a photodetector is detecting
light emitted from the signature pixels in accordance with one
embodiment of the present invention. For example, display 130 can
be configured to allocate a default number and configuration of
pixels from matrix 132 to serve as signature pixels 140. In step
142, a controller in display 130 or another host device can
initiate such default allocation of signature pixels. This can
include, for example, determining which pixels in matrix 132 will
exhibit signature characteristics and, in some cases, generating
signals that instruct those signature pixels to exhibit signature
characteristics. For example, the default allocation of signature
pixels can include a predetermined number of signature pixels
chosen to form a predetermined shape and emit light modulated in
accordance with predetermined modulation characteristics.
[0078] In step 144, the controller can accept data indicative of
the conditions under which a complimentary photodetector (e.g., in
a remote control) is detecting light emitted from the signature
pixels. Such data can include one or more of the following: ambient
light data, data indicative of the proximity of the predetermined
light sources (e.g., signature pixels) to the photodetector, data
indicative of the signal-to-noise ratio, data indicative of the
image being shown by the remaining pixels in matrix 132, data from
a user indicative of the preferred allocation of signature pixels,
etc. One or more sensors can be used to generate some or all of the
data accepted in step 144.
[0079] In step 146, the controller can identify another subset of
signature pixels having a more optimal allocation based on the data
gathered in step 144. For example, the controller can determine
that more or less pixels of matrix 132 should serve as signature
pixels. The controller also can determine that the signature pixels
should occupy different locations in matrix 132. For example, if
the data indicates that the signal-to-noise ratio is low, the
controller may determine that additional pixels from matrix 132
need to serve as signature pixels. Thereafter, in step 148, the
controller can generate signals that instruct those additional
pixels to exhibit one or more signature characteristics.
Alternatively, if the data indicates that the signal-to-noise ratio
is high, the controller may determine that one or more of the
signature pixels is unnecessary. Thereafter, in step 148, the
controller can generate signals for driving those pixels to show an
image on the display along with the remaining pixels in matrix 132,
rather than exhibit any signature characteristics.
[0080] The controller also may determine that a predetermined
signature shape formed by the signature pixels in matrix 132 may be
inappropriate based on the data collected in step 144. For example,
the predetermined shape may be similar to an image shown on display
130 by the remaining pixels in matrix 132 or similar to the shape
formed by another light source in the external environment.
Responsive to such determination, the controller can identify a set
of pixels having a different, more optimal configuration to serve
as the signature pixels and, in step 148, generate signals to
initiate that more optimal configuration.
[0081] The controller can perform steps 144-148 when it is
triggered by predetermined events that can occur during operation
of a remote control system (e.g., each time the system is turned ON
or exits a low-power state). Alternatively, the controller can be
configured to perform steps 144-148 at predetermined intervals or
continuously during the entire time the remote control system is in
operation.
[0082] FIG. 8A shows an illustrative remote control system
configured to distinguish one or more predetermined light sources
from stray light sources by generating and detecting light at one
or more predetermined polarization axes in accordance with one
embodiment of the present invention. Light transmitter 150 can
incorporate, for example, controller 152 and one or more
predetermined light sources 154. Controller 152 can generate
signals for instructing predetermined light sources 154 to emit
light PL at one or more predetermined intensities. To emit
polarized light, light source 154 can be a coherent or non-coherent
light source (e.g., laser, LED, etc.) and a polarizing filter (not
shown) can be used.
[0083] Remote 156 can be configured to distinguish predetermined
light sources 154 from stray light sources by identifying the light
sources that emit light polarized at the predetermined polarization
axis or axes. Remote 156 can be equipped, for example, with one or
more polarizing filters 158 disposed over photodetector 160. The
polarizing filters can have polarization axes that have an
orientation or orientations that complement (e.g., match) the
polarization axes of the light emitted by light transmitter 150.
Polarizing filters 158 can filter out light waves that are not
polarized in accordance with its polarization axis or axes.
Controller 162 of remote 156 can then analyze the intensities of
the detected light to distinguish the predetermined light sources
from the stray light sources.
[0084] Advantageously, when one or more predetermined light sources
are configured to emit light at one or more predetermined
polarization axes and one or more predetermined intensities,
controller 162 can determine the roll of remote control 156 based
on the intensity of the light received from the predetermined light
sources. For example, if the predetermined polarization axis aligns
with the Y axis, photodetector 160 may detect decreasing intensity
from light emitted by predetermined light source 154 as remote 156
(and thus the orientation of polarizing filter 158) is rotated out
of alignment with the Y-axis towards the X-axis. The amount of roll
can be calculated as a function of the intensity.
[0085] In one embodiment of the present invention, light source 154
can include two or more predetermined light sources configured to
emit light at one or more predetermined polarization axes and at
one or more predetermined intensities. Because the relative
polarizations, intensities, and locations of the predetermined
light sources are known, controller 162 can distinguish the
predetermined light sources from stray light sources by identifying
the light sources having the expected relative intensities.
[0086] Although FIG. 8A illustrates light transmitter 150 as being
an independent device, light transmitter 150 can be integrated
within a host electronic device, e.g., a display. If the light
transmitter is integrated within a host device, controller 152 can
be dedicated to controlling light source 154 or combined with
another controller in the host device.
[0087] Furthermore, although FIG. 8A illustrates photodetector 160
and polarizing filter 158 disposed in remote 156, in an alternative
embodiment of the present invention, light transmitter 150 can
instead be integrated within remote 156 and photodetector 160 and
polarizing filter 158 can be integrated into a host device or be
provided as an independent unit.
[0088] FIG. 8B shows four illustrative predetermined light sources
that emit light in four illustrative predetermined polarization
axes in accordance with one embodiment of the present invention. In
the illustrative embodiment shown in FIG. 8B, four predetermined
light sources A-D can emit light having polarization axes
orientated along the x-axis, at 45.degree. angle with respect to
the x- and y-axes, at 135.degree. angle with respect to the x- and
y-axes, and along the y-axis, respectively. The predetermined light
sources can be disposed, for example, in a structurally-independent
light transmitter, in a display, in remote control 156, or in
another host device. Complementary photodetector 160 and polarizing
filter 158 can be disposed, for example, in remote control 156 or
another host device. Polarizing filter 158 can have a polarization
axis illustratively oriented along the x-axis either permanently
(e.g., when the filter is disposed in a immobile host device) or
(if incorporated within remote control 156) when the remote control
is disposed with user input component 164 pointing in the positive
y-direction.
[0089] FIGS. 8C-8F show illustrative relative intensities of light
photodetector 160 can expect to receive from illustrative
predetermined light sources A-D of FIG. 8B when remote control 156
rolls about the z-axis and the relative locations from which those
predetermined light sources can be expected to emit the light in
accordance with one embodiment of the present invention. For
example, when remote control 156 is disposed with user input
component 164 pointing in the positive y-axis (FIG. 8C),
photodetector 160 can expect to detect a datum level of 100% light
intensity from predetermined light source A after the incoming
light is filtered by polarizing filter 158. In comparison to that
datum level and assuming that all predetermined light sources A-D
emit substantially the same intensity of light, photodetector 160
can expect to detect 50% light intensity from predetermined light
sources B and C and 0% light intensity from predetermined light
source D, after the incoming light is filtered by polarizing filter
158. When remote control 156 is disposed with user input component
164 pointing in the negative x-axis (FIG. 8D), photodetector 160
can expect to detect a datum level of 100% light intensity from
predetermined light source D, 50% light intensity from
predetermined light sources B and C, and 0% light intensity from
predetermined light source A.
[0090] When remote control 156 is disposed with user input
component 164 pointing in the negative y-axis (FIG. 8E) or in the
positive x-axis (FIG. 8F), photodetector 160 can expect to detect
the same relative intensities of light from predetermined light
sources A-D as compared to those when the remote control 156 is
disposed with the user input component pointed in the positive
y-axis and negative x-axis, respectively. However, the oppositely
corresponding orientations of remote control 156 can be
distinguished from each other based on the relative locations from
which those predetermined light sources can be expected to emit
light. For example, in FIG. 8C, photodetector 160 can expect to
receive light emitted by predetermined light source A from the top
left corner of the group of predetermined light sources. In
comparison, photodetector 160 can expect to receive light emitted
by predetermined light source A from the bottom right corner of the
group of predetermined light sources in FIG. 8E. Similarly, in
FIGS. 8D and 8F, photodetector 160 can expect to receive light
emitted by predetermined light source D from the bottom left corner
and the top right corner of the group of predetermined light
sources, respectively.
[0091] The oppositely corresponding orientations of remote control
156 also can be distinguished, for example, by (1) comparing data
from the current data frame to data from one or more preceding
frames; (2) disposing the predetermined light sources in an
asymmetric pattern similar to those discussed with respect to FIGS.
1-3E; (3) configuring one or more of the predetermined light
sources to exhibit a different signature characteristic; (4)
accepting data from a single or multi-dimensional accelerometer or
other sensor that can generate data indicative of the orientation
of the remote control; or (5) any combination thereof.
[0092] While FIGS. 8B-8F illustrate four predetermined light
sources, a remote control system of the present invention can
include more than four predetermined light sources that emit light
in one or more predetermined polarization axes. Alternatively, one
or more of the predetermined light sources can be eliminated. For
example, two or three predetermined light sources can be configured
to emit light in one or more predetermined polarization axes.
Because the expected relative intensities of light and the relative
locations from which the predetermined light sources can be
expected to emit the light are known, the remote control system of
the present invention can distinguish the predetermined light
sources from stray light sources.
[0093] In an alternative embodiment of the present invention,
remote 156 can simultaneously transmit and receive light from a
separate light transmitter in accordance with the principles of the
present invention. For example, remote 156 can transmit polarized
light to a first set of photodetector and polarizing filter that
are integrated into a host device or provided in an independent
unit. Remote 156 also can incorporate its own photodetector and
polarizing filter to receive polarized light from a separate light
transmitter disposed, for example, in the same device that houses
the first set of photodetector and polarizing filter.
[0094] In accordance with another aspect of the present invention,
a remote control system of the present invention can combine two or
more of the embodiments described herein. For example, a remote
control system of the present invention can have multiple
predetermined light sources disposed in an asymmetric pattern. The
output waveform of one of the predetermined light sources can be
modulated in accordance with one or more signature modulation
characteristics. The remote control system of the present invention
can be configured to distinguish the predetermined light sources
from stray light sources using a two step process. First, the
remote control system can identify a light source that exhibits the
signature modulation characteristic(s). Second, the remote control
system can identify a derivative pattern of light sources that
include the light source identified in the first step and that is
indicative of the asymmetric pattern in which the predetermined
light sources are disposed.
[0095] FIG. 9 shows an illustrative process for adjusting the
technique used for distinguishing predetermined light sources from
stray light sources in accordance with one embodiment of the
present invention. In one embodiment, a remote control system can
be equipped with the hardware and software to support multiple
techniques for distinguishing predetermined light sources from
stray light sources (e.g., any of the techniques described herein).
Based on data indicative of conditions under which the system is
detecting the predetermined light sources, the system can be
configured to adjust the technique used.
[0096] In step 170, a controller in a light transmitter, remote
control, console, display, and/or other host unit can identify a
default technique for distinguishing predetermined light sources
from stray light sources. The default technique may include any one
or more of the embodiments described herein with respect to FIGS.
1-8F. In step 172, the controller can initiate the default
technique. This can include, for example, identifying pixels in an
asymmetric pattern in a display to serve as signature pixels and/or
identifying other predetermined light sources to be driven to
exhibit one or more signature characteristics. This also can
include generating signals that instruct those pixels and/or
predetermined light sources to emit light in accordance with the
default technique.
[0097] In step 174, the controller can accept data indicative of
one or more conditions under which the remote control is detecting
light emitted from the predetermined light sources. Again, such
data can include one or more of the following: ambient light data,
data indicative of the proximity of the predetermined light sources
to the photodetector, data indicative of the signal-to-noise ratio,
data indicative of the image being shown by a display associated
with the predetermined light sources or remote control system, data
from a user indicative of a user-preferred technique, etc. One or
more sensors can be used to generate some or all of the data
accepted in step 174.
[0098] In step 176, the controller can identify another technique
for distinguishing predetermined light sources from other light
sources based on the data gathered in step 174. For example, if the
default technique results in a low signal-to-noise ratio, the
controller may change the technique employed for distinguishing the
predetermined light sources to attempt to increase the
signal-to-noise ratio.
[0099] In one embodiment of the present invention, each technique
for distinguishing predetermined light sources that is supported by
the remote control system can be associated with one or more
conditions under which the technique is more suited. For example,
one or more techniques may be better suited for use during the
daytime whereas other techniques may be better suited for use
during the evenings. Thus, in step 176, the controller may change
the technique employed for distinguishing the predetermined light
sources based on ambient light data. Alternatively, one or more
techniques may be better suited than other techniques when the
predetermined light sources are located far away from the
photodetector. Thus, in step 176, the controller may change the
technique employed for distinguishing the predetermined light
sources based on data indicative of the proximity of the
predetermined light sources to the photodetector.
[0100] Thereafter, in step 178, the controller can initiate the
other technique selected in step 176 by, for example, generating
drive signals for the appropriate hardware.
[0101] The controller can perform steps 170-178 when it is
triggered by predetermined event that can occur during operation of
a remote control system (e.g., each time the system is turned ON or
exits a low-power state). Alternatively, the controller can be
configured to perform steps 170-178 at predetermined intervals or
continuously during the entire time the remote control system is in
operation.
[0102] Although particular embodiments of the present invention
have been described above in detail, it will be understood that
this description is merely for purposes of illustration.
Alternative embodiments of those described hereinabove also are
within the scope of the present invention. For example,
predetermined light sources can be disposed in a remote control and
a photodetector can be disposed in a display, in a frame disposed
proximate to the display, or at any location proximate to, on, or
near a display.
[0103] A remote control of the present invention can be any
electronic device in a system that may need to distinguish
predetermined light sources from stray light sources. For example,
the remote control can be any portable, mobile, hand-held, or
miniature consumer electronic device. Illustrative electronic
devices can include, but are not limited to, music players, video
players, still image players, game players, other media players,
music recorders, video recorders, cameras, other media recorders,
radios, medical equipment, calculators, cellular phones, other
wireless communication devices, personal digital assistances,
programmable remote controls, pagers, laptop computers, printers,
or combinations thereof. Miniature electronic devices may have a
form factor that is smaller than that of hand-held devices.
Illustrative miniature electronic devices can include, but are not
limited to, watches, rings, necklaces, belts, accessories for
belts, headsets, accessories for shoes, virtual reality devices,
other wearable electronics, accessories for sporting equipment,
accessories for fitness equipment, key chains, or combinations
thereof.
[0104] While the above description may have described certain
components as being physically separate from other components, one
or more of the components can be integrated into one unit. For
example, the photodetector or photodetector module can be
integrated with one or more controllers.
[0105] Also, a controller in the display can perform some or all of
the processing described above for controllers 26 and/or 32. Thus,
multiple controllers may be used to control remote control systems
of the present invention.
[0106] Furthermore, while the illustrative remote control systems
described above may have included predetermined light sources that
output light waves, one or more of the predetermined light sources
can be replaced with component(s) that output or reflect other
types of energy waves either alone or in conjunction with light
waves. For example, the component(s) can output radio waves.
[0107] The above described embodiments of the present invention are
presented for purposes of illustration and not of limitation, and
the present invention is limited only by the claims which
follow.
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