U.S. patent application number 17/449468 was filed with the patent office on 2022-02-17 for spectrally selective light control film.
The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Owen M. Anderson, Steven R. Anderson, Gilles J. Benoit, Rolf W. Biernath, Guanglei Du, Gary E. Gaides, Brian W. Lueck, Neeraj Sharma, John A. Wheatley, David T. Yust.
Application Number | 20220050237 17/449468 |
Document ID | / |
Family ID | 1000005931057 |
Filed Date | 2022-02-17 |
United States Patent
Application |
20220050237 |
Kind Code |
A1 |
Wheatley; John A. ; et
al. |
February 17, 2022 |
SPECTRALLY SELECTIVE LIGHT CONTROL FILM
Abstract
A light control film is disclosed that includes a plurality of
spaced apart first regions. Each first region has a substantially
low transmission in one or two of a first wavelength range from
about 300 nm to about 400 nm, a second wavelength range from about
400 nm to about 700 nm, and a third wavelength range from about 700
nm to about 1200 nm, and a substantially high transmission in the
remaining wavelength ranges. The light control film has a viewing
angle of less than about 70 degrees along a predetermined first
direction.
Inventors: |
Wheatley; John A.;
(Stillwater, MN) ; Benoit; Gilles J.;
(Minneapolis, MN) ; Du; Guanglei; (Painted Post,
NY) ; Anderson; Steven R.; (Woodbury, MN) ;
Anderson; Owen M.; (Woodbury, MN) ; Yust; David
T.; (Woodbury, MN) ; Biernath; Rolf W.;
(Wyoming, MN) ; Gaides; Gary E.; (Woodbury,
MN) ; Lueck; Brian W.; (Houlton, WI) ; Sharma;
Neeraj; (Woodbury, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Family ID: |
1000005931057 |
Appl. No.: |
17/449468 |
Filed: |
September 30, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16349664 |
May 14, 2019 |
11163099 |
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PCT/US2016/064303 |
Dec 1, 2016 |
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17449468 |
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62425337 |
Nov 22, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 5/201 20130101;
G02B 5/208 20130101; G02B 5/22 20130101; G02B 2207/123 20130101;
G02B 5/003 20130101 |
International
Class: |
G02B 5/22 20060101
G02B005/22; G02B 5/00 20060101 G02B005/00; G02B 5/20 20060101
G02B005/20 |
Claims
1. A light control film comprising a plurality of spaced apart
first regions and a second region, each first region having a width
W and a height H, H/W.gtoreq.1, each first region having a
substantially high transmission in a predetermined first wavelength
range and a substantially low transmission in a predetermined
non-overlapping second wavelength range, the second region having
substantially high transmission in each of the predetermined first
and second wavelength ranges.
2. The light control film of claim 1 comprising a major
microstructured first surface having a plurality of alternating
ribs and channels, each channel at least partially filled with a
first material to form one of the first regions in the plurality of
spaced apart first regions.
3. The light control film of claim 2, wherein the second region
comprises a plurality of second region segments, each rib
comprising one of the second region segments.
4. The light control film of claim 1, wherein the second region is
disposed on a major surface of the light control film.
5. The light control film of claim 1, wherein the second region
extends across and covers at least some of the first regions.
6. The light control film of claim 1, wherein the first wavelength
range is about 400 nm to about 700 nm.
7. The light control film of claim 1, wherein the first wavelength
range is about 400 nm to about 460 nm.
8. The light control film of claim 1, wherein the first wavelength
range is about 600 nm to about 650 nm.
9. The light control film of claim 1, wherein the first wavelength
range is about 470 nm to about 550 nm.
10. The light control film of claim 1, wherein a wavelength
separation distance between the non-overlapping first and second
wavelength ranges is at least 5 nm.
11. The light control film of claim 1, wherein a wavelength
separation distance between the non-overlapping first and second
wavelength ranges is at least 10 nm.
12. The light control film of claim 1, wherein a wavelength
separation distance between the non-overlapping first and second
wavelength ranges is at least 20 nm.
Description
FIELD OF INVENTION
[0001] The present invention relates generally to light control
films, and more specifically to spectrally selective and angular
selective light control films for use in various optical
applications such as optical communication systems having a light
source, an optical construction, and/or detector system.
BACKGROUND
[0002] The louver structure is known in the art of privacy films in
display devices or window applications applied to, for example,
building, houses, etc. In the case of privacy films, when a user
does not want others to see the contents of a screen of an
electronic display device, the user can physically apply a privacy
film to the screen such that images can be viewed selectively.
Typically, images being displayed on the screen can be viewed
through the privacy film only when the viewer is positioned within
a range of angles referred to as "viewing angle". Normally, the
viewing angle is some range of angles centered on an axis normal to
the surface of the privacy film. As the position of the viewer
changes such that the viewer is positioned outside the viewing
angle, images being displayed are less or no longer viewable.
[0003] In the case of window applications, the louver structure is
typically a window blind or shutter with horizontal slats that are
angled to admit background light but keep out direct sunshine. The
amount of light that can go through the louver structure depends on
the angle of the slats (or the louver orientation).
SUMMARY
[0004] Generally, the present invention relates to light control
films. The present invention also relates to light control films
that have different viewing angle for different wavelength
ranges.
[0005] In one embodiment of the invention a light control film
includes a plurality of spaced apart first regions, where each
first region has a substantially low transmission in one or two of
a first wavelength range from about 300 nm to about 400 nm, a
second wavelength range from about 400 nm to about 700 nm, and a
third wavelength range from about 700 nm to about 1200 nm, and a
substantially high transmission in the remaining wavelength ranges.
The light control film has a first viewing angle of less than about
70 degrees along a predetermined first direction. In some cases,
the light control film has a second viewing angle of less than
about 70 degrees along an orthogonal predetermined second direction
different from the first viewing angle. In some cases, the light
control film of claim 1 includes a major microstructured first
surface having a plurality of alternating ribs and channels, where
each channel is at least partially filled with a first material to
form one of the first regions in the plurality of spaced apart
first regions. In some case, the light control film also includes a
plurality of second regions that alternate with the plurality of
first regions. In such cases, each second region may have a
substantially high transmission in each wavelength range the first
regions have a substantially low transmission in.
[0006] In another embodiment, a light control film includes a major
microstructured first surface having a plurality of alternating
ribs and channels. Each channel is at least partially filled with a
first material. Each channel has a width W and a height H, where
H/W 1. Each rib includes a second material, where the absorption of
at least one of the first and second materials varies as a function
of wavelength in a range from about 300 nm to about 1200. In some
cases, the absorption of each of the first and second materials
varies as a function of wavelength in a range from about 400 nm to
about 1200.
[0007] In another embodiment, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a substantially low transmission in a first
wavelength range from about 700 nm to about 1200 nm, and the second
region has a substantially low transmission in a second wavelength
range from about 300 nm to about 400 nm.
[0008] In another embodiment, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a substantially low transmission in at least one
of a first wavelength range from about 300 nm to about 400 nm, a
second wavelength range from about 400 nm to about 700 nm, and a
third wavelength range from about 700 to about 1200 nm. The second
region has a substantially low transmission in at least one of the
at least one of the three wavelength ranges each first region has
substantially low transmission in. In some cases, each first region
and the second region have substantially low transmission in the
same two of the three wavelength ranges.
[0009] In another embodiment, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a substantially high transmission in a first
wavelength range from about 300 nm to about 400 nm and a
substantially low transmission in a second wavelength range from
about 400 nm to about 700 nm. The second region has a substantially
high transmission in each of the first and second wavelength
regions.
[0010] In some embodiments, a detector system includes a detector
that is sensitive to wavelengths in a detection wavelength range.
The detector system further includes a light control film that is
disposed on the detector and includes a plurality of alternating
first and second regions, where each first region has a width W and
a height H, H/W.gtoreq.1. Each first region has a substantially low
transmission in a first portion of the detection wavelength range
and a substantially high transmission in the remaining portions of
the detection wavelength range. Each second region has a
substantially high transmission in the detection wavelength range.
In some cases, the detection wavelength range is from about 800 to
about 1600 and the first portion of the detection wavelength range
is from about 900 nm to about 1100 nm.
[0011] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region, where
each first region has a width W and a height H, H/W.gtoreq.1. Each
first region has substantially low transmissions in each of
non-overlapping predetermined first and second wavelength ranges.
The second region has a substantially low transmission in the
predetermined second wavelength range. In some cases, the
predetermined first wavelength range includes shorter wavelengths
and the predetermined second wavelength range includes longer
wavelengths.
[0012] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a width W and a height H, H/W.gtoreq.1, and a
substantially low transmissions in each of non-overlapping
predetermined first and second wavelength ranges. The second region
has substantially high transmission in the predetermined second
wavelength range.
[0013] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a width W and a height H, H/W.gtoreq.1, and a
substantially high transmission in a predetermined first wavelength
range and a substantially low transmission in a predetermined
non-overlapping second wavelength range. The second region has
substantially high transmission in each of the predetermined first
and second wavelength ranges.
[0014] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region, where
each first region has a width W and a height H, H/W.gtoreq.1, and a
substantially low transmission in a predetermined first wavelength
range and a substantially high transmission in a predetermined
non-overlapping second wavelength range. Each second region has
substantially low transmission in each of the predetermined first
and second wavelength ranges.
[0015] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region. Each
first region has a width W and a height H, H/W.gtoreq.1, and a
substantially high transmission in a predetermined first wavelength
range and a substantially low transmission in a predetermined
non-overlapping second wavelength range. The second region has
substantially low transmission in each of the predetermined first
and second wavelength ranges.
[0016] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region, where
each first region has a width W and a height H, H/W.gtoreq.1, and a
substantially low transmission in a predetermined first wavelength
range and a substantially high transmission in a predetermined
non-overlapping second wavelength range. The second region has
substantially high transmission in each of the predetermined first
and second wavelength ranges.
[0017] In some embodiments, a light control film is configured to
block light in a predetermined wavelength range and includes a
plurality of spaced apart first regions. Each first region has a
width W and a height H, H/W.gtoreq.1, and a substantially high
transmission in a predetermined first wavelength range, a
substantially low transmission in a predetermined second wavelength
range, and a substantially high transmission in a predetermined
third wavelength range. The second wavelength range is disposed
between the first and third wavelength ranges
[0018] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region, such
that for light incident normally to a plane of the light control
film an average optical transmittance of the light control film is
less than about 10% in a predetermined first wavelength range
having shorter wavelengths, and an average optical transmittance of
the light control film is greater than about 50% in a predetermined
second wavelength range having longer wavelengths. Furthermore, for
light incident at or greater than about 30 degrees from the plane
of the light control film an average optical transmittance of the
light control film is less than about 20% in each of the
predetermined first and second wavelength ranges.
[0019] In some embodiments, a light control film includes a
plurality of spaced apart first regions and a second region, such
that when an angle of incidence of light incident on the light
control film changes from about 90 degrees to about 60 degrees
relative to a plane of the light control film, an average optical
transmittance of the light control film changes by less than about
10% in a predetermined first wavelength range having shorter
wavelengths, and greater than about 40% in a predetermined second
wavelength range having longer wavelengths.
[0020] In some embodiments, a light control film includes a major
microstructured first surface that includes a plurality of
alternating ribs and channels. Each channel is at least partially
filled with a first material to form a first region. The light
control further includes a second region positioned adjacent at
least a portion of at least one first region. The second region
includes a second material. Each of the first and second materials
absorbs light in one or two of a first wavelength range from about
300 nm to about 400 nm, a second wavelength range from about 400 nm
to about 700 nm, and a third wavelength range from about 700 nm to
about 1200 nm. Each channel includes a width W and a height H,
where H/W 1.
[0021] In some embodiments, a light source system includes a light
source that is configured to emit light having a first spectral
profile along a first direction and a second spectral profile along
a different second direction. The light source system further
includes a light control film that is disposed on the light source
for receiving and transmitting light emitted by the light source.
The light control film includes a plurality of spaced apart first
regions. Each first region has a width W and a height H, where
H/W.gtoreq.1. The first regions are oriented relative to the first
and second directions and have a spectral absorbance profile so
that when light emitted by the light source is transmitted by the
light control film, the transmitted light has a third spectral
profile along the first direction and a fourth spectral profile
along the second direction, where the difference between the third
and fourth spectral profiles is less than the difference between
the first and second spectral profiles.
[0022] In some embodiments, a retroreflective system includes a
retroreflective sheet for retroreflecting light, and a light
control film that is disposed on the retroreflective sheet. For a
first wavelength, light incident on the light control film at each
of a first and second angles of incidence is retroreflected, and
for a second wavelength, light incident on the light control film
at the first, but not the second, angle of incidence is
retroreflected. In some cases, the light control film has a greater
first viewing angle for the first wavelength and a smaller viewing
angle for the second wavelength.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention may be more completely understood in
consideration of the following detailed description in connection
with the following figures. The figures are not necessarily drawn
to scale. Like numbers used in the figures refer to like
components. However, it will be understood that the use of a number
to refer to a component in a given figure is not intended to limit
the component in another figure labeled with the same number.
[0024] FIGS. 1, 1A, 1B, 1C, 1D, 1E, IF and 1G are schematic
cross-sectional views of exemplary light control films;
[0025] FIG. 2 is a schematic cross-sectional view of an exemplary
optical communication system;
[0026] FIGS. 2A and 2B are schematic perspective views of exemplary
light control films;
[0027] FIG. 3 is a schematic cross-sectional view of an exemplary
light control film;
[0028] FIG. 4 is a schematic cross-sectional view of another
exemplary light control film;
[0029] FIG. 5 is a schematic plot of detector sensitivity vs.
wavelength;
[0030] FIG. 6 is a schematic cross-sectional view of an exemplary
light control film applied to a window of an enclosure, such as a
building, a house or a vehicle;
[0031] FIG. 7 is a schematic plot of transmission of a light
control film vs. wavelength;
[0032] FIG. 8 is a schematic view of an exemplary application where
a light control film is applied to a plane or an aircraft;
[0033] FIG. 9 is a plot of transmission vs. wavelength of an
exemplary light control film;
[0034] FIG. 10 is a schematic of an exemplary optical communication
system including a light control film and a light source;
[0035] FIG. 10A is a schematic plot of spectral profile of light
emitted by the light source of FIG. 10 along different
directions;
[0036] FIG. 10B is a schematic plot of spectral profile of light
transmitted by the light control of FIG. 10 along different
directions;
[0037] FIG. 10C is a schematic plot of absorbance of portions of
the light control film of FIG. 10;
[0038] FIG. 11 is a schematic cross-sectional view of an exemplary
optical communication system including a light control film
combined with a retroreflector; and
[0039] FIG. 12 is a schematic cross-sectional view of an exemplary
wearable optical communication system including a light control
film and a wrist watch with a pulse sensor.
DETAILED DESCRIPTION
[0040] In the following description, reference is made to the
accompanying figures that form a part thereof and in which various
embodiments are shown by way of illustration. It is to be
understood that other embodiments are contemplated and may be made
without departing from the scope or spirit of the present
disclosure. The following detailed description, therefore, is not
to be taken in a limiting sense.
[0041] The louver structure is known as having angle selectivity
such that in privacy applications, such as when the louver
structure is placed in front of a display, a viewer can see the
displayed images only when the viewer is within the viewing angle
of the louver structure, and in window applications, such as when
the louver structure is placed on, for example, a building window,
the sun light can go through the window only for light rays that
are within the viewing angle of the louver structure. The "viewing
angle" is defined herein with respect to the normal to the plane of
the structure as the range of angles over which the louver
structure is substantially transmissive. For example, the viewing
angle of a light control film may be defined as the range of angles
over which the transmission of the light control film is within
60%, or within 50%, or within 40% of the peak transmission. One
type of the louver structure in the privacy film which typically
includes a substantially transparent louver film disposed on a
polymeric substrate where the louvers include light absorbing
material resulting in alternating transparent and light absorbing
regions. The light absorbing regions are relatively positioned to
provide a restricted viewing angle. Exemplary louver structures are
described in U.S. Pat. No. 6,398,370 B1 (Chiu et al.), U.S. Pat.
No. 8,213,082 B2 (Gaides et al.) and U.S. Pat. No. 9,229,253 B2
(Schwartz et al.).
[0042] The louver structures disclosed herein may be applied to
various optical applications such as optical communication systems
having a light source, an optical construction, and/or a detector
system where the optical construction includes a light control film
to make the optical communication systems angle selective and/or
spectral selective. In some cases, in addition to one or more
louver structures, an optical communication system may also have
other films or structures to provide additional or enhanced angle
selectivity. The louver structures, and other films or structures
may have 2 dimensional or 3 dimensional structures. Exemplary
additional structures that may be included in an optical
communication system include optical diffusers, brightness
enhancement films and reflective polarizers. In some embodiments,
the disclosed light control films include light absorbing or
reflecting regions including light absorbing or reflecting
materials that make the regions wavelength selective (spectral
selective). In some embodiments, the light control film has at
least two different types of materials and each material may absorb
or reflect light differently in at least a part of at least one of
ultraviolet, visible and infrared wavelength ranges. With the
variety of combinations among the louver structures and the light
absorbing or reflecting materials, the light control film can have
a variety of angle selectivity and wavelength selectivity (spectral
selectivity) so that the light control film can be applied in many
applications for variety of purposes.
[0043] FIG. 1 and FIGS. 1A-1G show schematic cross-sectional views
of exemplary optical films that may be useful in forming a light
control film (LCF). A LCF 100 includes an optical film 150 and the
optical film 150 has a major first surface 110 and a major second
surface 120 opposed to the first surface 110. The optical film 150
includes at least one microstructured surface. For example, either
the first surface 110 or the second surface 120 or both surfaces
may be microstructured. For instance, FIGS. 1A, 1D, IF and 1G, show
that the first surface 110 is microstructured and FIG. 1B shows
that the second surface 120 is microstructured and FIG. 1C shows
that both major surfaces 110 and 120 are microstructured. While the
major surfaces 110 and 120 are referred to as the respective first
surface and the second surface for reference purposes, it will be
recognized that in use, the first surface may be facing a viewer or
a light source, the second surface may be facing a viewer or a
light source, or either the first surface or the second surface may
be facing both a viewer and a light source. Microstructures are
generally projections, protrusions and/or indentations in the
surface of an article that deviate in profile from an average
center line drawn through the microstructure. For example, as shown
in FIG. 1, the first surface 110 has a plurality of alternating
ribs 180 and channels 130 extending across the first surface 110 of
the optical film 150. Each channel 130 is at least partially filled
with a first material 132 to form a first region. In some cases,
such as in the case of the LCF 100 shown schematically in, for
example, FIGS. 1A and 1B, channels 130 do not extend across the
entire thickness of the optical film 150 resulting in a continuous
land 131 between the base of the channels 130 and the second
surface 120 of the optical film 150. In some cases, such as in the
case of the LCF 100 shown schematically in FIG. 1D, at least some
of the channels 130 extend all the way through the thickness of the
optical film 150 resulting in no or a discontinuous land 131. In
some cases, the channels 130 may become first regions by at least
partially filling each channel with a first material 132. As shown
in FIG. 1C, the channels or the first regions 130 may be formed on
both the first surface 110 and the second surface 120 of the
optical film 150. In some cases, the optical film 150 also includes
a second region 140 that is adjacent at least a portion of at least
one first region and includes a second material 142. In the
exemplary embodiments shown in FIGS. 1A, 1B, 1C, IF and 1G, the
second region 140 is formed on at least one of the first surface
110 and second surface 120. The second region 140 in these
embodiments may be coated, printed or laminated with the second
material 142 on at least one of the first surface 110 and second
surface 120. As another example, in FIG. 1D, the second region 140
is formed inside the optical film 150 between and/or below the
first regions 130. In general, in the case of alternating first and
second regions, the second regions may have a connecting portion,
for example, in the form of a land portion, connecting the second
regions near at least one of the first and second major surfaces,
where the connecting or land portion may or may not be continuous.
For example, the second regions 140 are connected by a
discontinuous land 131. As another example, in FIG. 1E, the second
regions 140 are connected to one another near each of the major
surfaces by continuous land portions 131. Furthermore, in some
cases, such as the exemplary light control film 100 shown in FIG.
1E, the second region 140 include a plurality of second region
segments alternating with the plurality of first regions 130. In
some cases, the second region 140 is formed on at least portion or
portions of the first surface 110 and/or second surface 120. For
example, the second region 140 is formed on a portion or spaced
part portions of the first surface 110, as shown in FIGS. 1F and
1G, where in the exemplary embodiment shown in FIG. 1G, the second
region 140 is disposed on at least portions of the ribs 180. As
shown in FIG. 1F, the second region 140 is formed on spaced apart
portions of the first surface 110 resulting in a discontinuous
second region having a plurality of second region segments 140
alternating with the first regions 130. In each of the exemplary
embodiments shown in FIGS. 1D and 1G, the first and second regions
alternate, and each second region has a width W and a height W. In
FIG. 1D, H/W is typically greater than 1 or greater than 2 or
greater than 5, and in FIG. 1G, W/H is typically greater than 1 or
greater than 2 or greater than 5. Furthermore, as shown in FIG. 1G,
the second region 140 is disposed on at least portions of the ribs
180. In general, the first regions 130 and the second region 140
may be formed in the same layer or different layers of the LCF 100.
For example, in FIGS. 1A, 1B, IF and 1G, the first and second
regions 130 and 140 are formed in two neighboring layers of the LCF
100. As another example, in FIGS. 1D and 1E, the first and second
regions 130 and 140 are both formed in the same optical film 150.
Moreover, each of the first and second materials 132 and 142
absorbs and/or reflects light in one or two of a first ultraviolet
wavelength range from about 300 nm to about 400 nm, a second
visible wavelength range from about 400 nm to about 700 nm, and a
third near infrared wavelength range from about 700 nm to about
1200 nm. In some cases, such as in the exemplary embodiment shown
in FIG. 1, each channel 130 and each rib 180 has a height H.
Furthermore, each channel 130 has a width W and each rib 180 has a
width Y, and pitch P indicates spacing of the channels 130 and the
ribs 180. Width Y of the rib is P-W. The land 131 has a height L
such that the thickness of the film 150 is H+L. The channel aspect
ratio for the film 150 is defined as H/W, and rib aspect ratio as
H/Y. In some cases, H/W.gtoreq.1, or H/W .lamda.2 2, or
H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. In some
embodiments, the rib aspect ratio H/Y is greater than about 0.1, or
0.5, or 1 or 1.5, or greater than about 2.0, or greater than about
3.0. In some cases, the height of the land 131 (L) is typically
minimized to optimize light absorption once the channels 130 are
filled with the first material 132 such as light absorbers or
reflectors while sufficiently thick to support a large number of
ribs 180. The exemplary ribs 180 in FIG. 1 have sides or walls 105
that are substantially parallel to each other, although, in
general, the walls 105 may be angled and have any shape that may be
desirable in an application such as shown, for example, in FIG. 4
of U.S. Pat. No. 9,229,261 (Schwartz et al.). Parameters "H", "W",
"P", "Y", "L" and indices of refraction of the LCF materials may
have any suitable values as long as the LCF 100 functions as
desired.
[0044] FIG. 2 shows partial schematic cross-sectional view of
another exemplary optical film that may be useful in forming a
light control film (LCF). LCF 200 includes an optical film 250 and
the optical film 250 has a major microstructured first surface 210
and a major second surface 220 opposed to the first surface 210.
The microstructured first surface 210 has a plurality of
alternating ribs 280 and channels 230 extending across the first
surface 210 of the optical film 250. Each channel 230 is at least
partially filled with a first material 232 to form at least one of
first regions 230 in the plurality of spaced apart first regions
230. At least one of the ribs 280 a second material 242 to form a
second region 240. A continuous land 231 may be present between the
base of the channels 230 and the second surface 220. Each channels
230 and ribs 280 has a height H. Each channels 230 has a width W
and each ribs 280 has a width Y, and pitch P indicates spacing of
the channels 230 and the ribs 280. Width Y of the rib is P-W. The
land 231 has a height L such that the thickness of the film 250 is
H+L. The spacing and shape of the channels 230 and/or the ribs 280
determine viewing angle 20v, where 20v is the angle between
limiting light rays 202 and 204 transmitted by channels 230 without
reflection from walls 205. In general, parameters/dimensions of the
channels/ribs are selected such that a desired viewing angle 20v is
provided by the LCF 200. In one aspect, the viewing angle 20v
ranges from 10 degree to 80 degree or, or about 10 degrees to about
70 degrees. In some cases, the viewing angle is less than about 80
degrees, or less than about 75 degrees, or less than about 70
degrees, or less than about 65 degrees, or less than about 60
degrees, or less than about 55 degrees, or less than about 50
degrees, or less than about 45 degrees, or less than about 40
degrees, or less than about 35 degrees, or less than about 30
degrees, or less than about 25 degrees, or less than about 20
degrees, or less than about 15 degrees, or less than about 10
degrees, or less than about 5 degrees. In general, it is desirable
for the LCF parameters to be selected such that an adequate amount
of light can pass through the optical film 250. In some cases,
narrower channels width W and larger pitch P may lead to increased
viewing angle 2.theta.v and the amount of light passing through the
LCF 200 may be increased. In some cases, increasing the channel
aspect ratio (H/W) and reducing the pitch "P" may decrease the
viewing angle 2.theta.v. In some cases, a LCF 200 includes a
plurality of spaced apart first regions 230. Each first region 230
has a substantially low transmission in one or two of a first
wavelength range from about 300 nm to about 400 nm, a second
wavelength range from about 400 nm to about 700 nm, and a third
wavelength range from about 700 nm to about 1200 nm, and a
substantially high transmission in remaining wavelength ranges. In
some embodiments, the LCF 200 includes a first viewing angle
2.theta.v of less than about 70 degrees along a predetermined first
direction A.
[0045] In some embodiments, LCF 200 includes a plurality of spaced
apart parallel first regions 230. LCF 200 also includes an optical
film 250 having a major first surface 210 and an opposing major
second surface 220. The plurality of first regions 230 are formed
in the major first surface 210 and extend into the optical film 250
and may or may not reach the major surface second 220. In the
exemplary LCF 200 shown in FIG. 2A, the first regions 230 may be
generally referred to as two-dimensional regions or structures
meaning that the width W and the height H of each region 230 are
much smaller than the length L of the first region 230. As such,
each first region 230 may be thought of as having finite extents
along two dimensions (width W and height H) while extending
infinitely along the third dimension (length L). As shown in FIG.
2A, the first regions 230 are extended along a first direction "A"
and the LCF 200 has a first viewing angle 20v along the first
direction "A". In some cases, the first viewing angle 20v along the
predetermined first direction A may be less than about 70 degrees,
or less than about 60 degrees, or less than about 50 degrees, or
less than about 40 degrees, or less than about 30 degrees. In some
embodiments, LCF 200 may have three-dimensional first regions 230
having finite extents along three mutually orthogonal directions.
For example, FIG. 2B shows another LCF 200 that includes a
plurality of three-dimensional first regions 230 extending into the
optical film 250 from the first surface 210 toward the second
surface 220. As shown in FIG. 2B, the first regions 230 are
extended along a first direction "A" and also extended along a
second direction "B". The LCF 200 has a first viewing angle 20v
along the first direction "A" and a second viewing angle along an
orthogonal predetermined second direction "B", where the second
viewing angle may be equal to or different from the first viewing
angle 20v. In some cases, the first viewing angle 20v along the
predetermined first direction "A" may be less than about 70
degrees, or less than about 60 degrees, or less than about 50
degrees, or less than about 40 degrees, or less than about 30
degrees. In some embodiments, the second viewing angle along the
predetermined second direction "B" may be less than about 70
degrees, or less than about 60 degrees, or less than about 50
degrees, or less than about 40 degrees, or less than about 30
degrees. The cross-sectional views of the first regions 230
perpendicular to the thickness direction may be square, rectangle,
triangle, circle, ellipse, or any combination thereof, or any shape
that may be desirable in an application. In general, an LCF may
include one or more of the optical films disclosed herein combined
with other films such as those described in, for example, U.S. Pat.
No. 6,398,370 incorporated herein in its entirety. In some cases,
the first regions 230 in FIG. 2B may be posts, pyramids, cones,
truncated cones, truncated pyramids, hemispheres, or any shape that
may be desirable in an application. Furthermore, the first regions
230 may be asymmetric structures, symmetric structures, tilted
structures, spatially variant structures, and any other structure
that may be desirable in an application such as any structure that
includes angular-dependent light transmitting or light blocking
capabilities. In some embodiments, each rib 280 has a substantially
high transmission in each wavelength range that the first regions
230 have a substantially low transmission in. In other embodiments,
each rib 280 has a substantially low transmission in at least one
wavelength range that the first regions 230 have a substantially
high transmission in. In some cases, the LCF 200 includes a
plurality of second regions 240 alternating with the plurality of
first regions 230, each second region 240 having a substantially
high transmission in each wavelength range the first regions 230
have a substantially low transmission in. In some embodiments, the
LCF 200 includes a plurality of second regions 240 alternating with
the plurality of first regions 230, each second region 240 having a
substantially low transmission in at least one wavelength range the
first regions 230 have a substantially high transmission in. In
some examples, the LCF 200 may includes a second region 240
extending across and covering at least some of the first regions
230 as shown in FIGS. 1A, 1B, IF and 1G. The second region 240 has
a substantially low transmission in at most one, but not all,
wavelength regions the first regions 230 have a substantially high
transmission in. In some embodiments, the first wavelength range is
from about 350 nm to about 400 nm, or from about 350 nm to about
380 nm. In some embodiments, the second wavelength range is from
about 400 nm to about 460 nm, or from about 470 nm to about 550 nm.
In some embodiments, the third wavelength range is from about 800
nm to about 1000 nm, or from about 820 nm to about 1200 nm, or from
about 885 nm to about 1200 nm, or from about 920 nm to about 1200
nm.
[0046] In some cases, an LCF 200, for example as shown in FIG. 2,
may includes a major microstructured first surface 210 having a
plurality of alternating ribs 280 and channels 230. Each channel
230 is at least partially filled with a first material 232. The
channel aspect ratio for the optical film 250 is defined as H/W. In
some cases, the aspect ratio H/W is at least 1 (H/W.gtoreq.1), or
H/W.gtoreq.2, or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20.
Each rib 280 includes a second material 242. In some cases, an
absorption of at least one of the first and second materials 232
and 242 varies as a function of wavelength in a range from about
400 nm to about 1200. In other cases, the absorption of each of the
first and second materials 232 and 242 varies as a function of
wavelength in a range from about 400 nm to about 1200.
[0047] FIG. 3 shows a schematic cross-sectional view of an
exemplary optical film that may be useful in forming a light
control film (LCF). As shown in FIG. 3, an optical film 350
includes a major first surface 310 and a plurality of spaced apart
substantially parallel first regions 330 formed in, and extending
from, the major first surface toward an opposing major second
surface 320, and a second region 340 provided on the major first
surface 310 and extending across and covering the plurality of
first regions 330. The first regions 330 may be filled at least
partially with a first material 332 and the second region 340 may
include a second material 342. In some cases, the first material
332 and the second material 342 absorb, reflect or block light to
have a substantially low transmission in one or two of a first
wavelength range from about 300 nm to about 400 nm, a second
wavelength range from about 400 nm to about 700 nm, and a third
wavelength range from about 700 nm to about 1200 nm, and a
substantially high transmission in the remaining wavelength ranges.
In some cases, the second region 340 may be coated, printed or
laminated with the second material 342 on at least one of the first
surface 310 and second surface 320. In some embodiments, the first
material 332 or the second material 342 may include a pigment, a
dye, a black colorant such as a carbon black, or combinations
thereof so that the first and second materials 332 and 342 may
absorb or reflect light. A variety of light absorbers or light
reflectors may be used in the disclosed LCFs. For example, several
compositions of visibly transparent infrared absorbing transparent
conducting oxides (TCOs) both as thin films and nanoparticle
powders and dispersions may be included useful in the disclosed
LCFs. Exemplary TCOs include indium tin oxide (ITO), antimony tin
oxide (ATO), gallium tin oxide (GTO), antimony zinc oxide (AZO),
aluminum/indium doped zinc oxide, doped tungsten oxides like cesium
tungsten oxides, and tungsten blue oxides. Other visibly
transparent infrared absorbers include metal borides like lanthanum
hexaborides, and conducting polymer nanoparticles like PEDOT-PSS.
Metal chalcogenides like metal sulfides and selenides also absorb
infrared light including, for example, copper sulfide and copper
selenide nanoparticles, tungsten disulfides and molybdenum
disulfides. Another class of visibly transparent tunable infrared
absorbers are metallic plasmonic nanoparticles such as those made
of gold, silver copper etc. Moreover, near infrared dyes and
pigments may be applied to the disclosed LCFs. These dyes have low
visible absorption but strong narrow band infrared absorption. Many
of these dyes and pigments are organic/organometallic or metal
organic in nature. Some of major classes of dyes/pigments include
phthalocyanines, cyanine, transitional metal dithioline,
squarilium, croconium, quniones, anthraquinones, iminium, pyriliu,
thiapyrilium, azulenium, azo, perylene and indoanilines. Many of
these dyes and pigments can exhibit both visible and/or infrared
lights absorption as well. Further, many different types of visible
dyes and colorants may be used with the disclosed LCFs and they
fall in one or more classes like acid dyes, azoic coloring matters,
coupling components, diazo components. Basic dyes include
developers, direct dyes, disperse dyes, fluorescent brightners,
food dyes, ingrain dyes, leather dyes, mordant dyes, natural dyes
and pigments, oxidation bases, pigments, reactive dyes, reducing
agents, solvent dyes, sulfur dyes, condense sulfur dyes, vat dyes.
Some of the organic pigments may belong to one of more monoazo, azo
condensation insoluble metal salts of acid dyes and disazo,
naphthols, arylides, diarylides, pyrazolone, acetoarylides,
naphthanilides, phthalocyanines, anthraquinone, perylene,
flavanthrone, triphendioxazine, metal complexes, quinacridone,
polypryrrolopyrrole etc. Moreover, metal oxide pigments may be used
in the disclosed LCFs. For example, metal chromates, molybdates,
titanates, tungstates, aluminates, ferrites are some of the common
pigments. Many contain transition metals like iron, managanese,
nickel, titanium, vanadium, antimony, cobalt, lead, cadmium,
chromium etc. Bismuth vanadates are non-cadmium yellows. These
pigments may be milled to create nanoparticles which may be useful
where transparency and low scattering is desired. In some examples,
the first or second materials 332 or 342 may be a particulate
materials having an average particle size less than 10 microns, or
1 micron, or less. The first or second materials 332 or 342 may, in
some embodiments, have a mean particle size of less than 1 micron.
In some embodiments, the first or second materials 332 or 342 may
be dispersed in a suitable binder. In some embodiments, rather than
in the form of particles, the first or second materials 332 or 342
may be a light absorbing resin, such as a light absorbing polymer,
at least partially forming light absorbing regions 330 and 340. In
some cases, the first regions 330 may include particles or
scattering elements that may function to block light from being
transmitted through the first regions 330. In some cases, at least
one of the first material 332 and the second material 342 may be
selected among the materials that are spectrally selective in at
least a part of at least one of ultraviolet, visible and infrared
light ranges. In some cases, both the first material 332 and the
second material 342 may be selected among the materials that are
spectrally selective in at least a part of at least one of
ultraviolet, visible and infrared light ranges so that a
transmission of a light passing through the LCF 300 is spectrally
selective in at least two of the ultraviolet, visible and infrared
light ranges. Stated differently, the first and second materials
332 and 342 are spectrally selective in at least a part of
ultraviolet, visible and infrared light ranges in order to make the
transmission vary as a function of wavelength of light. As shown in
FIG. 3, a "light B" propagates along an axis that is normal to the
plane of the LCF 300. As described herein, by "normal" to the LCF
is meant perpendicular to the plane of the LCF, discounting any
local variation in the smoothness of the LCF where the variation
may, for example, be general surface roughness or a regular
microstructure formed in a major surface of the LCF. For the
purpose of this disclosure, the angle between an incident light ray
"b" and the normal to the LCF is referred to as the "incidence
angle, Oi". For example, the incidence angle of light B is zero. In
general, the incidence angle may range from 0 degree (i.e. normal
to the film) to 90 degree (i.e. parallel to the film). Therefore,
"normal incidence angle" may mean incident perpendicularly to the
film, discounting any local variation in the LCF. In some
embodiments, at the normal incidence angle where a viewer is
looking at an image through the LCF 300 in a direction that is
perpendicular to the film surface, the image is viewable and
brightest and the transmission of a light passing through the LCF
300 may be greatest. In some embodiments, such as when the channels
or first regions 330 are symmetric and oriented perpendicularly to
the LCF 300, as the incidence angle increases, the amount of light
transmitted through the LCF 300 decreases until the incidence angle
reaches the viewing angle 20v from which point on substantially all
the light is blocked by the first material 332 as shown in FIG. 3
as a "light A" and the image is no longer viewable. In some
embodiments, the transmission of a light passing through the second
region 340 and at least partially absorbed by the second material
342 is substantially uniform for at least one incidence angle. For
example, the transmission of a "light C" as shown in the FIG. 3,
passing through the second region 340 and being partially absorbed
by the second material 342 and exiting the LCF 300 (without going
through the first regions 330 or being absorbed by the first
material 332) is substantially uniform. In some embodiments, second
region 340 absorbs some light in a pre-determined wavelength range,
and in some cases, absorbs substantially all incident light having
wavelengths in the pre-determined wavelength range. In some cases,
the optical transmission of a light C having a wavelength in the
pre-determined wavelength range and passing through the second
region 340 may be less than about 10%, where in some cases, the
transmission may be substantially independent from the incidence
angle of the light C. In some cases, in order to achieve the
transmission of a light having a wavelength in the pre-determined
wavelength range and passing through the second region 340 be less
than about 10%, thickness or size of the second materials 342 may
be increased, or the second region 340 might include multiple
layers of the second materials 342, or the multiple layers of the
second materials 342 may be provided on at least one of the first
surface 310 and second surface 320, or either first or second
surfaces 310 and 320 may include multiple layers of the second
materials 342, or the concentration of the second materials 342 may
be increased. In some cases, the transmission of a light having a
wavelength in the pre-determined wavelength range may be less than
10% by providing scattering particles in and/or on the optical film
350.
[0048] In some embodiments, the optical film 350 described in the
present invention may also include a base substrate layer (not
shown), which may be integrally formed with, or separately added to
the optical film 350 (whether by extrusion, cast-and-cure, or any
other known that may be suitable in a desired application). The
chemical composition and thickness of the base material may depend
on the requirements of the product that is being constructed. That
is, balancing the needs for strength, clarity, optical retardance,
temperature resistance, surface energy, adherence to the other
layers, among others, as specifically described in, for example,
U.S. Pat. No. 8,213,082 (Gaides et al.) incorporated herein in its
entirety. In some embodiments, the optical film 350 may be combined
with a cover layer that may provide, for instance, an anti-glare
coating, an anti-reflective coating, an anti-soiling coating, or
some combination thereof. Materials for the base substrate layer or
the cover layer may include, for instance, polycarbonate. The
particular polycarbonate material may be selected so as to provide
a matte finish or a glossy finish. The cover layer and base
substrate layer may be each or both be matte or/and glossy. The
cover layer may be bonded to the second region 340 or the major
first surface 310 of the optical film 350 with an adhesive. The
adhesive may be any optically clear adhesive, such as a UV-curable
acrylate adhesive, a transfer adhesive, and the like. Moreover, the
LCF 300 may include any number of other films or layers including,
for example, polarizing film, wavelength selective interference
filter layer, prismatic film to form multilayer structures.
[0049] In some embodiments, the disclosed light control or optical
films, such as optical film 350, may be prepared by molding and
ultraviolet curing a polymerizable resin on a polycarbonate
substrate. Such processing are currently used to make known optical
films available from 3M Company, St. Paul, Minn., under the trade
designation. An exemplary manufacturing method and suitable
composition for known optical films are described in U.S. Pat. No.
8,213,082 (Gaides et al.).
[0050] Referring to FIG. 4, a light control film (LCF) 400 includes
a plurality of spaced apart first regions 430. Each first region
430 includes a first material 432. As shown in FIG. 4, the first
regions 430 may have a wide variety of shapes and may extend from
either/both the first surface 410 or/and the second surface 420 or
be formed in the middle of the optical film 450. The first material
432 substantially absorbs or/and reflects light in a first
wavelength range and substantially transmits light in a different
second wavelength range. For example, in some cases, the first
material 432 absorbs or/and reflects at least 70%, or at least 80%,
or at least 90%, or at least 95% of light in the first wavelength
range, and transmits at least 70%, or at least 80%, or at least
90%, or at least 95% of light in the second wavelength range. In
some cases, the first wavelength range is an infrared light range,
and the second wavelength range is a visible light range. For
example, in some cases, the first wavelength range may be from
about 700 nm to about 1200 nm, and the second wavelength range may
be from about 400 nm to about 700 nm. LCF 400 further includes a
second region 440 disposed adjacent at least a portion of at least
one first region 430. In some cases, such as in the exemplary
embodiment of the LCF 400 shown in FIG. 4, second region 440
extends across a majority, but not all, of the first regions 430.
In some cases, second region 440 may extend across all first
regions 430. The second region 440 includes a second material 442
that substantially absorbs or/and reflects light in a third
wavelength range and substantially transmits light in a fourth
wavelength range different from the third wavelength range. For
example, in some cases, the second material 442 absorbs or/and
reflects at least 70%, or at least 80%, or at least 90%, or at
least 95% of light in the third wavelength range, and transmits at
least 70%, or at least 80%, or at least 90%, or at least 95% of
light in the fourth wavelength range. In some cases, the third
wavelength range is a ultraviolet light range, and the fourth
wavelength range is a visible light range. For example, in some
cases, the third wavelength range may be from about 350 nm to about
400 nm, and the fourth wavelength range may be from about 400 nm to
about 700 nm. The transmission of a light 490 passing through the
LCF 400 varies as a function of an incidence angle (0i) (the angle
between an incident light 490 and the normal 495 to the LCF) and a
wavelength of the light. For example, the transmission is: (1) no
more than about 10% of incident light in a ultraviolet light range
substantially independent of the incidence angle; (2) greater than
about 40% for light in a visible light range substantially
independent of the incidence angle; (3) greater than about 40% for
light in an infrared light range for the incidence angles within a
viewing angle(2.theta.v refer to the FIG. 2); and (4) less than
about 10% for light in the infrared light range for the incidence
angles outside the viewing angle.
[0051] In some embodiments, as shown in FIG. 1, an LCF 100 includes
a plurality of spaced apart first regions 130 and a second region
140. Each first region 130 may have a substantially low
transmission in a first near infrared wavelength range from about
700 nm to about 1200 nm and the second region 140 may have a
substantially low transmission in a second ultraviolet wavelength
range from about 300 nm to about 400 nm. The second region 140 is
adjacent at least a portion of at least one first region 130. In
the exemplary embodiments shown in FIGS. 1A, 1B 1F and 1G, the
second region 140 is formed on at least one of the respective first
surface 110 and second surface 120. As another example, in FIG. 1D,
the second region 140 is formed in the optical film 150 between
and/or below the first regions 130. In some embodiments, when at
least some of the first regions 130 may extend all the way through
the thickness of the optical film 150, the second region 140 is
formed between channels 130 resulting in a plurality of spaced
apart second regions 141 interconnected via a land 131 which in
some cases, may be continuous and in some other cases, may be
discontinuous. Further, in some cases, as shown in FIG. 1E, the
second region 140 includes a plurality of segments alternating with
the plurality of first regions 130. In some cases, the second
region 140 is disposed in at least portions of the ribs 180. In
some embodiments, the second region 140 is formed on at least one
of the first surface 110. As shown in FIGS. 1F and 1G, the second
region 140 is partially formed on the first surface 110 and/or
second surface 120. As shown in FIG. 1F, the second region 140 may
be partially formed on the first surface 110 alternating with the
first regions 130. Furthermore, as shown in FIG. 1G, the second
region 140 is disposed on at least portions of the ribs 180.
[0052] In some embodiments, as shown in FIG. 1, an LCF 100 includes
a plurality of spaced apart first regions 130 and a second region
140. Each first region 130 may have a substantially low
transmission in at least one of a first wavelength range from about
300 nm to about 400 nm and a second wavelength range from about 400
nm to about 700 nm, and a third wavelength range from about 700 to
about 1200 nm. The second region 140 may have a substantially low
transmission in at least one of the at least one of the three
wavelength ranges each first region has substantially low
transmission in. In some cases, each first region 130 and the
second region 140 may have substantially low transmission in the
same two of the three wavelength ranges. LCF 100 includes a major
microstructured first surface 110 that includes a plurality of
alternating ribs 180 and channels 130, where each channel is at
least partially filled with a first material 132 to form one of the
first regions 130 in the plurality of spaced apart first regions.
In some cases, the second region 140 includes a plurality of second
region segments, and each rib includes one of the second region
segments. In some cases, the second region 140 is disposed on the
major surface 110 of the light control film, where, in some cases,
the second region extends across and covers at least some of the
first regions 130.
[0053] In some embodiments, as shown in FIG. 1, a LCF 100 includes
a plurality of spaced apart first regions 130 and a second region
140. Each first region 130 may have a substantially high
transmission in a first wavelength range from about 300 nm to about
400 nm and a substantially low transmission in a second wavelength
range from about 400 nm to about 700 nm. The second regions 140 may
have a substantially high transmission in each of the first and
second wavelength regions. In some cases, each first region 130 and
the second region 140 may have substantially high transmissions in
a third wavelength range from about 700 nm to about 1200 nm. In
some examples, each first region 130 may have a substantially low
transmission region in a third wavelength range from about 700 nm
to about 1200 nm, and the second region has a substantially high
transmission region in the third wavelength range.
In some examples, the light control films (LCFs) disclosed herein
may be part of an optical communication system. The "optical
communication system" as referred to herein is a system that is for
communication of light over a distance from a light source through
a disclosed LCF to a target, where the target may include a
detector or human eye and the light source my include ambient
light. In general the light source the light source may be any
light source desirable in an application. Exemplary light source
include a light emitting diode (LED), a laser light source, a
halogen light source, a metal halide light source, a tungsten light
source, a mercury vapor light source, a short arc xenon light
source, or the sun. In some cases, the LCFs disclosed herein may be
part of an optical communication system with a detector system. In
some cases, the detector system may provide various types of
outputs, such as electronic signals, when receiving light passing
through the LCF of the optical communication system. In an
exemplary examples as shown in FIG. 2, a detector system includes a
detector 290 that is sensitive to wavelengths in a detection
wavelength range and an LCF 200 disposed on the detector 290. The
LCF 200 includes a plurality of alternating first and second
regions 230 and 240. Each first region 230 has a width W and a
height H and an aspect ratio H/W. In some cases, the aspect ratio
H/W is at least 1 (H/W.gtoreq.1), or H/W.gtoreq.2, or H/W.gtoreq.5,
or H/W.gtoreq.10, or H/W.gtoreq.20. FIG. 5 schematically shows the
relation between the detector sensitivity and wavelength
illustrating that the detector is sensitive to wavelengths in the
detection wavelength range 572. Each first region 230 has a
substantially low transmission in a first portion 574 of the
detection wavelength range 572 and a substantially high
transmission in the remaining portion 576 of the detection
wavelength range. Each second region has a substantially high
transmission in the detection wavelength range 572. In some cases,
the detection wavelength range 572 is from about 800 nm to about
1600 nm and the first portion 574 of the detection wavelength range
572 is from about 900 nm to about 1100 nm. In some examples, a
viewing angle 20v of the LCF in the first portion 574 of the
detection wavelength range 572 is less than about 70 degrees along
a first direction "A" (referring to FIG. 2, 2A or 2B). In some
cases, the detector is or includes a photovoltaic device. In some
cases, the detector is configured to detect solar radiation, for
example, to charge a battery. In such cases, the detector is or may
include a solar battery, a solar cell, or a solar detector. In some
cases, the detector may be the detector in a camera for detecting
and/or recording an image. In some cases, the detector may be a in
a camera or camera system. In some cases, a camera may include the
detector system of FIG. 2.
[0054] In some cases, as shown in FIG. 2, an LCF 200 includes a
plurality of spaced apart first regions 230 and a second region
240. Each first region 230 has a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region 230 has substantially low transmissions in each of
non-overlapping predetermined first and second wavelength ranges
and the second region 240 has a substantially low transmission in
the predetermined second wavelength range. Specifically, the
predetermined first wavelength range may include shorter
wavelengths and the predetermined second wavelength range may
include longer wavelengths. In some cases, the predetermined first
wavelength range may be from about 400 nm to about 700 nm and the
predetermined second wavelength range may be from about 700 nm to
about 1200 nm. In some cases, the average optical transmittance of
each first region 230 in the predetermined first wavelength range
may be less than about 25, or 15%, or 10%, or 5%, or 1%, or 0.1%,
or 0.01%, or 0.001, or 0.0001%. In some cases, the average optical
transmittance of each first region 230 in the predetermined second
wavelength range is less than about 25, or 15%, or 10%%, or 5%, or
1%, or 0.1%, or 0.01%, or 0.001, or 0.0001. In some cases, the
average optical transmittance of the second region 240 in the
predetermined second wavelength range may be less than about 25, or
15%, or 10%%, or 5%, or 1%, or 0.1%, or 0.01%, or 0.001, or 0.0001.
Each first region 230 may have a substantially high absorption in
the predetermined first wavelength range. For example, the average
optical absorption of each first region 230 in the predetermined
second wavelength range may be greater than about 70%, or 80%, or
90%, or 95%, or 99%. Each first region may have a substantially
high reflectance in the predetermined first wavelength range. For
example, the average optical reflectance of each first region 230
in the predetermined second wavelength range may be greater than
about 70%, or 80%, or 90%, or 95%, or 99%. In general, each first
region 230 may have a first index of refraction, and the second
region may have a second index of refraction. In some embodiments,
it may be desirable to substantially match indices of refraction
between the first regions and the regions between them and/or
between the first regions and the second region. In some cases, a
difference between the first and second indices of refraction may
be less than about 0.01. In some cases, the second region 240 may
have a substantially low transmission in the predetermined first
wavelength range. In such cases, the average optical transmittance
of the second region 240 in the predetermined second wavelength
range may be less than about 10%. In some embodiments, the second
region 240 may have a substantially high transmission in the
predetermined first wavelength range. In such cases, the average
optical transmittance of the second region 240 in the predetermined
first wavelength range may be greater than about 70%. The second
region 140 may include a plurality of segments alternating with the
plurality of first regions 130 as shown in, for example, FIG. 1E.
In some cases, the second region 140 may extend across and cover at
least some of the first regions 130 as shown in, for example, FIGS.
1, 1A, 1B, IF and 1G. Furthermore, in some cases, the second region
140 may be discontinuous as shown in, for example, FIGS. 1E and
1F.
[0055] In some embodiments, as shown in FIG. 2, an LCF 200 includes
a plurality of spaced apart first regions 230 and a second region
240. Each first region 230 may have a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region may have substantially low transmissions in each of
non-overlapping predetermined first and second wavelength ranges
and the second region 240 may have substantially high transmission
in the predetermined second wavelength range. In exemplary
embodiments, the predetermined first wavelength range may include
shorter wavelengths and the predetermined second wavelength range
may include longer wavelengths. In some cases, the predetermined
first wavelength range may be from about 400 nm to about 700 nm and
the predetermined second wavelength range may be from about 700 nm
to about 1200 nm. In some cases, the average optical transmittance
of each first region 230 in the predetermined first wavelength
range may be less than about 10%. In some cases, the average
optical transmittance of each first region in the predetermined
second wavelength range may be less than about 10%. In some cases,
the average optical transmittance of the second region in the
predetermined second wavelength range may be greater than about
70%. In some embodiments, the second region may have a
substantially low transmission in the predetermined first
wavelength range. For example, the average optical transmittance of
the second region 240 in the predetermined first wavelength range
may be less than about 10%. In some cases, the second region 240
may have a substantially high transmission in the predetermined
first wavelength range. For example, the average optical
transmittance of the second region in the predetermined first
wavelength range may be greater than about 70%.
[0056] In some cases, as shown in FIG. 2, an LCF 200 includes a
plurality of spaced apart first regions 230 and a second region
240. Each first region 230 may have a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region 230 may have a substantially high transmission in a
predetermined first wavelength range and a substantially low
transmission in a predetermined non-overlapping second wavelength
range. The second region 240 may have substantially high
transmission in each of the predetermined first and second
wavelength ranges.
[0057] In some cases, the light control films (LCFs) disclosed
herein may be part of an optical communication system including an
optical construction combined with, for example, a window as shown
in FIG. 6. In this example, the LCF 600 is a part of an optical
construction 601 with a natural light source such as sun light 690.
In particular, FIG. 6 shows an exemplary application of a disclosed
LCF applied to a window to an enclosure, such as a building, a
house or a vehicle. LCF 600 may be disposed on a window substrate
675 of a building, a house, a car or any enclosure 670. The LCF 600
includes an optical film 650 that includes a plurality of spaced
apart first regions 630 and a second region 640 adjacent at least a
portion of at least one first region 630. The first regions 630 may
be filled at least partially with a first material 632 and the
second region 640 may include a second material 642. The first
material 632 and the first region 630 may be any suitable material
and shape such that each first region 630 has an average optical
transmittance of greater than about 50%, or 60%, or 70%, or 80%, or
90% in a first wavelength range from about 400 nm to about 700 nm
and an average optical transmittance of less than about 10% in a
non-overlapping second wavelength range from about 700 nm to about
1200 nm. The second material 642 and the second region 640 may be
any suitable material and shape such that the second region 540 has
an average optical transmittance of greater than about 30%, or 40%,
or 50%, or 60%, or 70%, or 80%, or 90% in each of the predetermined
first and second wavelength ranges. In addition, the second region
640 may have an average optical transmittance of less than about
10% in a wavelength range from about 350 nm to 400 nm. In some
cases, the wavelength separation distance between the
non-overlapping first and second wavelength ranges may be at least
5 nm, or at least 10 nm, or at least 15 nm, or at least 20 nm. In
some cases, the LCF 600 has a viewing angle 2.theta.v of less than
about 40 degrees for at least one wavelength in the second
wavelength range. In this example, when sun light 690 is incident
on the front surface of the LCF 600, the second material 642 of the
second region 640 absorbs or/and reflects at least a part of light
incident having wavelengths in a range from about 350 nm to 400 nm
(the ultraviolet light range) substantially independent of the
incidence angle of the light 690. The second region 640 is
sufficiently absorbing or/and reflecting light such that the
transmission of the ultraviolet light passing through the second
region 640 and exiting the LCF 600 is uniform and desirably, less
than about 10% and substantially independent of the incidence angle
of the light. In some cases, in order to achieve the transmission
of the ultraviolet light passing through the second region 640 and
exiting the LCF 600 than about 10%, thickness or size of the second
materials 642 may be increased, or the second region 640 may
include multiple layers of the second materials 642, or the
multiple layers of the second materials 642 may be provided on at
least one of the first surface 610 and second surface 620, or
either the first or second surfaces 610, 620 may include multiple
layers of the second materials 642, or the concentration of the
second materials 642 may be increased. In some cases, the
transmission in the ultraviolet light range may be less than 10% by
providing scattering particles in and/or on the optical film 650.
At the same time, the second region 640 has an average optical
transmittance of greater than about 30%, or 40%, or 50%, or 60%, or
70%, or 80%, or 90% in each of the range from about 400 nm to about
700 nm and from about 700 nm to about 1200 nm. The transmission of
the infrared light (from about 700 nm to about 1200 nm) by the
first regions 630 vary as a function of the incidence angle of the
light. In particular, when the sun light 690 is incident
perpendicularly to the LCF 600, the infrared light and the visible
light may both be transmitted through the optical film 650.
However, as the incidence angle of the light from the sun 690
increases, the amount of the infrared light transmitted through the
LCF 600 decreases until the incidence angle reaches the viewing
angle 20v from which point on substantially all the infrared light
is blocked by the first material 632. At the same time, first
regions 630 transmit substantially all light in the visible light
range. Therefore, in the exemplary optical communication system of
FIG. 6, substantially all visible light may be transmitted by the
LCF 600, but the ultraviolet light range may not be transmitted by
the LCF 600 or only a restricted amount of the ultraviolet light
range, desirably less than about 10% of the ultraviolet wavelength
range, may be transmitted by the LCF 600. And regarding the
infrared light range of the sun light 690, the transmission of the
infrared light passing through the LCF 600 is a function of the
incidence angle. That is, during the morning hours when the
infrared portion of the sun light 690 is relatively small and the
sun light 690 is incident on the window at normal incidence angle,
most of the infrared light may be transmitted by the LCF 600. On
the other hand, close to noon, when the infrared portion of the sun
light 690 is relatively large and the incident angle of the sun
light 690 is increased close to or beyond the viewing angle
2.theta.v of the LCF 600, very little of the incident infrared
light is transmitted by the LCF 600 and finally blocked so that the
viewer or resident 677 inside of the building or house 670 may not
be exposed to the hot infrared light. And also, the LCF 600 may
prevent household items from being damaged due to exposure to the
ultraviolet light of the sun light 690 regardless of the incidence
angle and, at the same time, the viewer or resident 677 may not
become hot from exposure to the infrared light, while the visible
light may be transmitted through the LCF 600 such that the sun
light 690 may effectively be used to provide lighting to the
enclosure 670.
[0058] In some embodiments, as shown in FIG. 2, an LCF 200 includes
a plurality of spaced apart first regions 230 and a second region
240. Each first region 230 may have a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region 230 may have a substantially low transmission in a
predetermined first wavelength range and a substantially high
transmission in a predetermined non-overlapping second wavelength
range. Each second region 240 may have substantially low
transmission in each of the predetermined first and second
wavelength ranges.
[0059] In other cases, as shown in FIG. 2, an LCF 200 includes a
plurality of spaced apart first regions 230 and a second region
240. Each first region 230 may have a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region 230 may have a substantially high transmission in a
predetermined first wavelength range and a substantially low
transmission in a predetermined non-overlapping second wavelength
range. The second region 240 may have substantially low
transmission in each of the predetermined first and second
wavelength ranges.
[0060] In some cases, as shown in FIG. 2, an LCF 200 includes a
plurality of spaced apart first regions 230 and a second region
240. Each first region 230 may have a width W and a height H and an
aspect ratio H/W that is at least 1 (H/W.gtoreq.1) or H/W.gtoreq.2,
or H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. Each first
region 230 may have a substantially low transmission in a
predetermined first wavelength range and a substantially high
transmission in a predetermined non-overlapping second wavelength
range. The second region 240 may have substantially high
transmission in each of the predetermined first and second
wavelength ranges.
[0061] In further examples as shown in FIG. 7, each first region of
a disclosed LCF may have a substantially high transmission in a
predetermined first wavelength range "A", a substantially low
transmission in a predetermined second wavelength range "B", and a
substantially high transmission in a predetermined third wavelength
range "C", where the second wavelength range B is disposed between
the first and third wavelength ranges A and, respectively. In some
cases, the second wavelength range B is about 20 nm wide from a
first wavelength 712 to a second wavelength 714 and centered on a
laser visible emission wavelength, the first wavelength range A is
from about 400 nm to about the first wavelength 712, and the third
wavelength range C is from about the second wavelength 714 to about
1400 nm. The laser visible emission wavelength may be at least one
of 442 nm, 458 nm, 488 nm, 514 nm, 632.8 nm, 980 nm, 1047 nm, 1064
nm, and 1152 nm. In other examples, the laser visible emission
wavelength is in a range from about 416 nm to about 1360. In
further examples, the LCF further may include a plurality of spaced
apart second regions alternating with the plurality of first
regions and each second region may have a substantially high
transmission in each of the predetermined first, second and third
wavelength ranges. In other example, each second region may have a
substantially low transmission in either/both the predetermined
first or/and third wavelength ranges. In some cases, the LCF has a
viewing angle 2.theta.v of less than about 60 degrees, or 50
degrees, or 40 degrees, or 30 degrees, or 20 degrees in the
predetermined second wavelength range.
[0062] In another exemplary application, the LCFs disclosed herein
may be a part of an optical communication system with a separate
light source such as laser light source as shown in FIG. 8. In
particular, FIG. 8 shows an exemplary application where a LCF is
applied to a plane or an aircraft laser strike defense system to
block an incoming or incident light in a predetermined wavelength
range. An LCF 800 may be attached to, for example, a plane, an
airplane or aircraft 870, etc. and desirably, attached to a surface
(such as a window) of the plane, airplane or aircraft 870. The LCF
800 includes an optical film 850 that includes a plurality of
spaced apart first regions 830 and a second region 840 adjacent at
least a portion of at least one of the first regions 830. The first
regions 830 may be filled at least partially with a first material
832 and the second region 840 includes a second material 842. The
first material 832 or the second material 842 may be any suitable
material such that the first material 832 absorbs or/and reflects
in at least a part of visible light range that includes the laser
light 891 and the second material 842 absorbs or/and reflects in at
least a part of at least one of ultraviolet light and infrared
light ranges that include the laser light 891. More desirably, the
second material 842 may absorb or/and reflect in both ultraviolet
and infrared wavelength ranges in this example. When laser light
891 is incident on the LCF 800, the second material 842 of the
second region 840 absorbs or/and reflects at least a part of
ultraviolet light and infrared wavelength ranges regardless of the
incidence angle of the light 891. Furthermore, the second region
840 transmits in a range of the visible wavelengths that include
the laser light 891 wavelength, but the transmission of the visible
light through the first regions 830 vary as a function of an
incidence angle of the light. When the light is incident
perpendicularly to the surface of the LCF 800, the visible light
can be transmitted through the optical film 850. However, outside
viewing angle, 2.theta.v (refer to FIG. 2), the visible light is
blocked by the first material 832 in the first regions 830.
Therefore, when using the LCF 800 on the plane or aircraft 870, the
visible light from the laser light 891 within the viewing angle
2.theta.v can be transmitted by the LCF 800 but the ultraviolet
light and the infrared light from the laser light 891 may not be
transmitted by the LCF 800 or only a restricted amount of the
ultraviolet light and infrared light, desirably less than about 10%
the ultraviolet light and infrared light respectively may be
transmitted by the LCF 800. And for the visible light, it can be
transmitted by the LCF 800 as a function of an incidence angle and
a wavelength of the light. Laser striker 878 may attack the plane
or aircraft 870, for example, using a green laser 890 in order to
obstruct a view of a pilot 877. Normally, the wavelength of the
green color is about from 495 nm to 570 nm. Therefore, the LCF 800
with the first material 832 that absorbs or/and reflects the range
of the wavelength from 495 nm to 570 nm of the light, so that the
pilot 877 on the plane or aircraft 870 is not affected by the green
laser attack from the laser striker 878 on the ground.
[0063] FIG. 9 is a plot of transmission vs. wavelength for the
exemplary disclosed optical films that may be useful in forming
light control films. In some embodiments, an LCF includes a
plurality of first and second regions, such that for light incident
normally to a plane of the LCF, an average optical transmittance of
the LCF may be less than about 10% in a predetermined first
wavelength range having shorter wavelengths, and an average optical
transmittance of the LCF may be greater than about 50% in a
predetermined second wavelength range having longer wavelengths.
And for light incident at or greater than about 30 degrees from the
plane of the LCF, an average optical transmittance of the LCF may
be less than about 20% in each of the predetermined first and
second wavelength ranges. In exemplary cases, the predetermined
first wavelength range may be from about 400 nm to about 650 nm,
and the predetermined second wavelength range may be from about 750
nm to about 1500 nm. In some cases, the second region includes a
plurality of spaced apart second region segments alternating with
the plurality of first regions. In some cases, the light control
film includes a major microstructured first surface having a
plurality of alternating ribs and channels, where each channel is
at least partially filled with a first material to form one of the
first regions in the plurality of spaced apart first regions. In
some cases, the second region includes a plurality of second region
segments, and each rib incudes one of the second region segments.
In some cases, the second region is disposed on a major surface of
the light control film and extend across and cover at least some of
the first regions. In some cases, the average optical transmittance
of the first regions in the predetermined second wavelength range
is less than about 20%, or less than about 15%, or less than about
10%, or less than about 5%, or less than about 1%. In some cases,
the average optical transmittance of the second region in the
predetermined first wavelength range is less than about 20%, or
less than about 15%, or less than about 10%, or less than about 5%,
or less than about 1%. In some cases, the average optical
transmittance of the second region in the predetermined second
wavelength range is greater than about 40%, or greater than about
50%, or greater than about 60%, or greater than about 70%, or
greater than about 80%, or greater than about 90%. In some cases,
for light incident normally to the plane of the light control film,
the average optical transmittance of the light control film is less
than about 5%, or less than about 1%, in the predetermined first
wavelength range. In some cases, for light incident normally to the
plane of the light control film, the average optical transmittance
of the light control film is greater than about 55%, or 60%, in the
predetermined second wavelength range.
[0064] Furthermore, as shown in FIG. 9, an LCF includes a plurality
of first and second regions, such that plot 910 is the optical
transmission of the LCF for normally incident light, plot 920 is
the optical transmission of the LCF for 30 degree incident light,
and plot 930 is the optical transmission of the LCF for 60 degree
incident light, where all three plots are shown as a function of
the wavelength of the incident light. Hence, the average optical
transmission of the LCF is less than about 10%, or less than about
7%, or less than about 5% for all angles of incidence for
wavelengths from about 400 nm to about 620 nm, or 610 nm, or 600
nm. Furthermore, for the wavelength range from about 700 nm, or
about 710 nm, or about 720 nm to about 1500 nm, the average optical
transmission of the LCF changes from about 60% to about 5% when the
angle of incidence changes from zero degree to about 30 degrees,
and the average optical transmission of the LCF changes from about
60% to about 2%, or about 1% when the angle of incidence changes
from zero degree to about 60 degrees. Hence, when an angle of
incidence of light incident on the LCF changes from about 90
degrees to about 60 degrees relative to the plane of the LCF (or,
about zero degree to about 30 degrees from a line normal to the
plane of the LCF), an average optical transmittance of the LCF may
change by less than about 10% in a predetermined first wavelength
range having shorter wavelengths and greater than about 40% in a
predetermined second wavelength range having longer wavelengths. In
some cases, the average optical transmittance of the first regions
in the predetermined second wavelength range is less than about
20%, or less than about 15%, or less than about 10%, or less than
about 5%, or less than about 1%. In some cases, the average optical
transmittance of the second region in the predetermined first
wavelength range is less than about 20%, or less than about 15%, or
less than about 10%, or less than about 5%, or less than about 1%.
In some cases, the average optical transmittance of the second
region in the predetermined second wavelength range is greater than
about 40%, or greater than about 50%, or greater than about 60%, or
greater than about 70%, or greater than about 80%, or greater than
about 90%. In some cases, when the angle of incidence of light
incident on the light control film changes from about 90 degrees to
about 60 degrees relative to the plane of the light control film,
the average optical transmittance of the light control film changes
by less than about 5%, in the predetermined first wavelength range.
In some cases, when the angle of incidence of light incident on the
light control film changes from about 90 degrees to about 60
degrees relative to the plane of the light control film, the
average optical transmittance of the light control film changes by
less than about 1% in the predetermined first wavelength range. In
some cases, when the angle of incidence of light incident on the
light control film changes from about 90 degrees to about 60
degrees relative to the plane of the light control film, the
average optical transmittance of the light control film changes by
greater than about 55%, or 60%, in the predetermined second
wavelength range. The disclosed light control films (LCFs) may
advantageously be utilized in various applications. For example, in
some cases, the disclosed LCFs may improve angular uniformity of
the spectral profile of a light source. For example, FIG. 10
illustrates a light source system 1001 for improving the emission
spectral profile of a light source along different emission
directions. In particular, FIG. 10 shows a light source 1200 that
is configured to emit light having different spectral profiles
along different directions. For example, referring FIGS. 10A, 10B
and 10C, light source 1200 emits light having a first spectral
profile 1210 along a first direction 1220 and a second spectral
profile 1230 along a different second direction 1240. In the
exemplary light source system 1001, first direction 1220 is normal
to the plane of the light source. In general, the first and second
directions may be any two directions along which the emitted light
may have different spectral profiles. The light source system 1001
further includes a LCF (LCF) 1000 disposed on light source 1200 for
improving the angular spectral profile uniformity of the light
source. LCF 1000 receives light emitted by light source 1200 and
transmits the received light. LCF 1000 may be any LCF disclosed
herein. For example, LCF 1000 includes a plurality of spaced apart
first regions 1030. Each first region has a width W and a height H,
where, in some cases, H/W.gtoreq.1, or H/W.gtoreq.2, or
H/W.gtoreq.5, or H/W.gtoreq.10, or H/W.gtoreq.20. In general, the
orientation and absorbing properties of the first regions 1030 are
at least some of the factors that improve the angular spectral
profile uniformity of light transmitted by the LCF 1000. Other
factors may include, for example, the viewing angle 2.theta.v of
the LCF which may depend on, for example, the pitch of the first
regions 1030 and the ratio H/W. In some cases, first regions 1030
are oriented relative to first direction 1220 and second direction
1240 and the spectral absorbance profile 1320 (refer to FIG. 10C)
of the first regions 1030 is so that when light that is emitted by
the light source 1200 is transmitted by the LCF 1000, the
transmitted light has a third spectral profile 1260 along the first
direction 1220 and a fourth spectral profile 1270 along the second
direction 1240, where the difference between the third and fourth
spectral profiles 1260 and 1270 is less than the difference between
the first and second spectral profiles 1210 and 1230. For example,
in some cases, the difference between the third and fourth spectral
profiles 1260 and 1270 is at least 5%, or at least 10%, or at least
15%, or at least 20%, or at least 30%, or at least 40%, or at least
50% less than the difference between the first and second spectral
profiles 1210 and 1230. In some cases, such as when first direction
1220 is perpendicular to the plane of light source 1200, the
spectral profile of light incident on the LCF 1000 along the first
direction 1220 may remain unchanged upon transmission by the LCF.
In such cases, first spectral profile 1210 may be substantially
equal to third spectral profile 1260. Furthermore, the first
regions 1030 may selectively absorb light propagating along second
direction 1240 so that spectral profile 1230 changes upon
transmission to spectral profile 1270 more closely matching third
spectral profile 1260. In some cases, LCF 1000 improves the angular
spectral profile uniformity of light source 1200 by each first
region 1030 selectively absorbing light within each of the first
and second spectral profiles 1210 and 1230. For example, in cases,
where neither first nor second direction 1220, 1240 is
perpendicular to the plane of light source 1200 or LCF 1000, each
first regions 1030 may selectively absorb light within each of the
first and second spectral profiles 1210 and 1230. In some cases,
second direction 1240 makes an angle .alpha. with a line 1222 that
is normal to the plane of light source 1200. In some cases, angle
.alpha. is greater than .theta.v where 20v is the viewing angle of
LCF 1000. In such cases, at least a majority of light rays emitted
by light source 1200 along first direction 1220 pass through first
regions 1030 and, as a result, may be selectively absorbed. Such
selective absorption may improve the angular color uniformity of
the light source 1200. In some cases, light emitted from the light
source 1200 and propagating along first direction 1220 has a first
set of color coordinates, and light propagating along second
direction 1240 has a second set of color coordinates, wherein light
transmitted by LCF 1000 and propagating along the first direction
1220 has a third set of color coordinates and propagating along the
second direction 1240 has a fourth set of color coordinates, where
the difference between the third and fourth sets of color
coordinates is less than the difference between the first and
second sets of color coordinates. For example, in some cases, the
first set of color coordinates are u1' and v1', the second set of
color coordinates are u2' and v2', the third set of color
coordinates are u3' and v3', and the fourth set of color
coordinates are u4' and v4'. In such cases, the absolute value of
each of (u4'-u3') and (v4'-v3') may be less than 5%, or less than
10%, or less than 15%, or less than 20%, or less than 30%, or less
than 40%, or less than 50% of each of the corresponding (u1'-u2')
and (v1'-v2').
[0065] In some cases, the disclosed light control films (LCFs) may
be utilized in combination with retroreflectors. For example, FIG.
11 shows a retroreflective system 1101 that includes a
retroreflective sheet 1190 for retroreflecting light, and a LCF
1100 disposed on the retroreflective sheet 1190. In general,
retroreflector sheet 1190 is configured to retroreflect light for a
range of incident wavelengths and angles. For example,
retroreflector sheet 1190 may be configured to retroreflect light
for different incident wavelengths .lamda..sub.1 and .lamda..sub.2
and different incident angles .alpha. and .alpha.'. The addition of
LCF 1100 results in system 1101 having modified retroreflective
properties. For example, for a larger angle .alpha. and a smaller
angle .alpha.', the viewing angle 2.theta.v of LCF 1100 may be such
that for the smaller incident angle .alpha.', LCF 1100
substantially transmits light at both wavelengths .lamda..sub.1 and
.lamda.2, but for the larger incident angle .alpha., LCF may
substantially transmit light having wavelength .lamda..sub.1 and
substantially absorb light having wavelength .lamda..sub.2. For
example, in some cases, the viewing angle 2.theta.v of LCF 1100 may
be greater than .alpha.' and less than .alpha.. As another example,
retroreflective system 1101 is so configured that for a first
wavelength .lamda..sub.1, lights 810 and 810' incident on LCF 1100
at corresponding first and second angles of incidence .alpha.' and
a, are both retroreflected as respective retroreflected lights 812
and 812'. Furthermore, for a second wavelength .lamda..sub.2, light
820 incident on the LCF at the first incidence angle .alpha.' is
retroreflected at retroreflected light 822, but light 820' incident
on the LCF at the second incidence angle .alpha. is not
retroreflected. In such cases, light 820' is absorbed by LCF 1100
when it is first incident on the LCF and, in some cases, after it
is partially transmitted by the LCF and retroreflected by the
retroreflective sheet. In some cases, LCF 1100 includes a larger
first viewing angle for the first wavelength and a smaller viewing
angle for the second wavelength. In some cases, the first angle of
incidence .alpha.' is substantially equal to zero relative to a
line 801 normal to a plane of the LCF 1100. In some cases,
retroreflective sheet 1190 includes microsphere beads 610 for
retroreflecting light. In some cases, retroreflective sheet 1190
includes corner cubes 620 for retroreflecting light. In some cases,
LCF 1100 includes a plurality of spaced apart first regions 1130,
where each first region 1130 has a substantially low transmission
at the second wavelength .lamda..sub.2, but not at the first
wavelength .lamda..sub.1.
[0066] In some cases, the light control film (LCF) may be used as
part of an optical communication system having a sensor, more
specifically, an IR sensor in order to improve signal to noise
performance and enable improved directional sensing. In this
example, the first material is spectrally selective in at least a
part of infrared light range and in some cases, the second material
may be spectrally selective in at least a part of at least one of
ultraviolet light and visible light ranges. More desirably, the
second material is spectrally selective in both r ultraviolet light
and visible light ranges. When using the LCF, noises like
ultraviolet light and visible light from the IR sensor are absorbed
through the second material regardless of the incidence angle of
light. The transmission of the ultraviolet light and visible light
from a light source passing through the second region is uniform
and desirably, less than about 10% regardless of the incidence
angle of the light. However, the second region may transmit a range
of the infrared light from light source but the transmission of the
infrared light through the first regions vary as a function of an
incidence angle of the light. When light is incident
perpendicularly to the surface of the LCF, the infrared light may
be transmitted through the optical film. However, outside the
viewing angle, 2.theta.v, the infrared light is blocked by the
first material in the first regions. Therefore, the disclosed
system provides an IR sensor with substantially reduced noise and
substantially improved directional sensing.
In another case, the LCF can be used in a part of an optical
communication system with a sensor, more specifically a pulse
sensor applied to a wrist watch as shown in FIG. 12. In particular,
FIG. 12 shows an exemplary application of an LCF applied to a wrist
watch with a pulse sensor. An LCF 1200 may be attached to a
wearable wrist watch 1280 or any wearable device and desirably,
attached to a surface of the wearable watch 1280. The LCF 1200
includes an optical film 1250 that includes a plurality of first
regions 1230 and a second region 1240 adjacent at least a portion
of a least one first regions 1230. The first regions 1230 may be
filled at least partially with a first material 1232 and the second
region 1240 may include a second material 1242. The first material
1232 or the second material 1242 may be any suitable material such
that the first material 1232 is spectrally selective in at least a
part of visible light range from the light source, for example, LED
1290 and the second material 1242 is spectrally selective in at
least a part of at least one of ultraviolet light and infrared
light ranges from the LED 1209. More desirably, the second material
1242 is spectrally selective in both ranges in the ultraviolet
light and infrared light ranges. When using the LCF 1200, noises
like ultraviolet light and infrared light from the perspective of a
pulse sensor 1285 are absorbed through the second material 1242
regardless of the incidence angle of the light from light source
such as sun light 1295 or LED 1290. The transmission of the
ultraviolet light and infrared light from the light source passing
through the second region 1240 is uniform and desirably, less than
about 10%, regardless of the incidence angle of the light. However,
the second region 1240 transmits a range of the visible light from
LED 1290 but the transmission of the visible light through the
first regions 1230 varies as a function of the incidence angle of
the light. When the light from LED 1290 is incident perpendicularly
on the surface of the LCF 1200, the visible light may be
transmitted through the optical film 1250. However, the first
material 1232 may block or decrease the sun light 1295 or ambient
visible light from other light sources that are incident with
relatively high incidence angle to the wrist 777 of the person
wearing the device so that the LCF 1200 may improve signal (mainly
visible light from LED that is incident within a viewing angle) to
noise (for example, ultraviolet light or infrared light or ambient
visible light from, for example, sunlight, other ambient light
source that is incident outside viewing angle) ratio. In some
cases, the sensor may be a sensor in a camera or camera system. In
some cases, a camera includes the sensor.
[0067] The following is a list of exemplary embodiments of the
present description.
[0068] Embodiment 1 is a light control film that includes a
plurality of spaced apart first regions, each first region having a
substantially low transmission in one or two of a first wavelength
range from about 300 nm to about 400 nm, a second wavelength range
from about 400 nm to about 700 nm, and a third wavelength range
from about 700 nm to about 1200 nm, and a substantially high
transmission in remaining wavelength ranges, wherein the light
control film includes a first viewing angle of less than about 70
degrees along a predetermined first direction.
[0069] Embodiment 2 is the light control film of Embodiment 1
having a second viewing angle of less than about 70 degrees along
an orthogonal predetermined second direction different from the
first viewing angle.
[0070] Embodiment 3 is the light control film of Embodiment 1
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0071] Embodiment 4 is the light control film of Embodiment 3,
wherein each rib has a substantially high transmission in each
wavelength range the first regions have a substantially low
transmission in.
[0072] Embodiment 5 is the light control film of Embodiment 3,
wherein each rib has a substantially low transmission in at least
one wavelength range the first regions have a substantially high
transmission in.
[0073] Embodiment 6 is the light control film of Embodiment 1
further including a plurality of second regions alternating with
the plurality of first regions, each second region having a
substantially high transmission in each wavelength range the first
regions have a substantially low transmission in.
[0074] Embodiment 7 is the light control film of Embodiment 1
further including a plurality of second regions alternating with
the plurality of first regions, each second region having a
substantially low transmission in at least one wavelength range the
first regions have a substantially high transmission in.
[0075] Embodiment 8 is the light control film of Embodiment 6 or 7,
wherein each second region is disposed on a major surface of the
light control film.
[0076] Embodiment 9 is the light control film of Embodiment 1
further including a second region extending across and covering at
least some of the first regions, the second region having a
substantially low transmission in at most one, but not all,
wavelength regions the first regions have a substantially high
transmission in.
[0077] Embodiment 10 is the light control film of Embodiment 1,
wherein the first wavelength range is from about 350 nm to about
400 nm.
[0078] Embodiment 11 is the light control film of Embodiment 1,
wherein the first wavelength range is from about 350 nm to about
380 nm.
[0079] Embodiment 12 is the light control film of Embodiment 1,
wherein the second wavelength range is from about 400 nm to about
460 nm.
[0080] Embodiment 13 is the light control film of Embodiment 1,
wherein the second wavelength range is from about 470 nm to about
550 nm.
[0081] Embodiment 14 is the light control film of Embodiment 1,
wherein the third wavelength range is from about 800 nm to about
1000 nm.
[0082] Embodiment 15 is the light control film of Embodiment 1,
wherein the third wavelength range is from about 820 nm to about
1200 nm.
[0083] Embodiment 16 is the light control film of Embodiment 1,
wherein the third wavelength range is from about 885 nm to about
1200 nm.
[0084] Embodiment 17 is the light control film of Embodiment 1,
wherein the third wavelength range is from about 920 nm to about
1200 nm.
[0085] Embodiment 18 is a light control film that includes a major
microstructured first surface having a plurality of alternating
ribs and channels, each channel at least partially filled with a
first material, each channel including a width W and a height H,
H/W 1, each rib having a second material, wherein an absorption of
at least one of the first and second materials varies as a function
of wavelength in a range from about 300 nm to about 1200.
[0086] Embodiment 19 is the light control film of Embodiment 18,
wherein the absorption of each of the first and second materials
varies as a function of wavelength in a range from about 400 nm to
about 1200.
[0087] Embodiment 20 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a substantially low transmission in a first
wavelength range from about 700 nm to about 1200 nm, the second
region having a substantially low transmission in a second
wavelength range from about 300 nm to about 400 nm.
[0088] Embodiment 21 is the light control film of Embodiment 20
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0089] Embodiment 22 is the light control film of Embodiment 21,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0090] Embodiment 23 is the light control film of Embodiment 20,
wherein the second region is disposed on a major surface of the
light control film.
[0091] Embodiment 24 is the light control film of Embodiment 20,
wherein the second region extends across and covers at least some
of the first regions.
[0092] Embodiment 25 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a substantially low transmission in at least one of a
first wavelength range from about 300 nm to about 400 nm, a second
wavelength range from about 400 nm to about 700 nm, and a third
wavelength range from about 700 to about 1200 nm, the second region
having a substantially low transmission in at least one of the at
least one of the three wavelength ranges each first region has
substantially low transmission in.
[0093] Embodiment 26 is the light control film of Embodiment 25,
wherein each first region and the second region have substantially
low transmission in a same two of the three wavelength ranges.
[0094] Embodiment 27 is the light control film of Embodiment 25
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0095] Embodiment 28 is the light control film of Embodiment 27,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0096] Embodiment 29 is the light control film of Embodiment 25,
wherein the second region is disposed on a major surface of the
light control film.
[0097] Embodiment 30 is the light control film of Embodiment 25,
wherein the second region extends across and covers at least some
of the first regions.
[0098] Embodiment 31 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a substantially high transmission in a first
wavelength range from about 300 nm to about 400 nm and a
substantially low transmission in a second wavelength range from
about 400 nm to about 700 nm, the second region having a
substantially high transmission in each of the first and second
wavelength regions.
[0099] Embodiment 32 is the light control film of Embodiment 31
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0100] Embodiment 33 is the light control film of Embodiment 32,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0101] Embodiment 34 is the light control film of Embodiment 31,
wherein the second region is disposed on a major surface of the
light control film.
[0102] Embodiment 35 is the light control film of Embodiment 31,
wherein the second region extends across and covers at least some
of the first regions.
[0103] Embodiment 36 is the light control film of Embodiment 31,
wherein each first region and the second region have substantially
high transmissions in a third wavelength range from about 700 nm to
about 1200 nm.
[0104] Embodiment 37 is the light control film of Embodiment 31,
wherein each first region has a substantially low transmission
region in a third wavelength range from about 700 nm to about 1200
nm, and the second region has a substantially high transmission
region in the third wavelength range.
[0105] Embodiment 38 is a detector system, including: [0106] a
detector sensitive to wavelengths in a detection wavelength range;
and a light control film disposed on the detector and including a
plurality of alternating first and second regions, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having a substantially low transmission in a first portion
of the detection wavelength range and a substantially high
transmission in a remaining portion of the detection wavelength
range, each second region having a substantially high transmission
in the detection wavelength range.
[0107] Embodiment 39 is the detector system of Embodiment 38,
wherein the detection wavelength range is from about 800 to about
1600 and the first portion of the detection wavelength range is
from about 900 nm to about 1100 nm.
[0108] Embodiment 40 is the detector system of Embodiment 38,
wherein a viewing angle of the light control film in the first
portion of the detection wavelength range is less than about 70
degrees along a first direction.
[0109] Embodiment 41 is the detector system of Embodiment 38,
wherein the light control film includes a major microstructured
first surface having a plurality of alternating ribs and channels,
each channel at least partially filled with a first material to
form one of the first regions, each rib including a second material
and forming one of the second regions.
[0110] Embodiment 42 is the detector system of Embodiment 38,
wherein H/W.gtoreq.5.
[0111] Embodiment 43 is the detector system of Embodiment 38,
wherein H/W.gtoreq.10.
[0112] Embodiment 44 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having substantially low transmissions in each of
non-overlapping predetermined first and second wavelength ranges,
the second region having a substantially low transmission in the
predetermined second wavelength range.
[0113] Embodiment 45 is the light control film of Embodiment 44,
wherein the predetermined first wavelength range includes shorter
wavelengths and the predetermined second wavelength range includes
longer wavelengths.
[0114] Embodiment 46 is the light control film of Embodiment 44,
wherein the predetermined first wavelength range is from about 400
nm to about 700 nm.
[0115] Embodiment 47 is the light control film of Embodiment 44,
wherein the predetermined second wavelength range is from about 700
nm to about 1200 nm.
[0116] Embodiment 48 is the light control film of Embodiment 44,
wherein an average optical transmittance of each first region in
the predetermined first wavelength range is less than about 25, or
15%, or 10%, or 5%, or 1%, or 0.1%, or 0.01%, or 0.001, or
0.0001%.
[0117] Embodiment 49 is the light control film of Embodiment 44,
wherein an average optical transmittance of each first region in
the predetermined second wavelength range is less than about 25, or
15%, or 10%%, or 5%, or 1%, or 0.1%, or 0.01%, or 0.001, or
0.0001.
[0118] Embodiment 50 is the light control film of Embodiment 44,
wherein an average optical transmittance of the second region in
the predetermined second wavelength range is less than about 25, or
15%, or 10%%, or 5%, or 1%, or 0.1%, or 0.01%, or 0.001, or
0.0001.
[0119] Embodiment 51 is the light control film of Embodiment 44,
wherein each first region has a substantially high absorption in
the predetermined first wavelength range.
[0120] Embodiment 52 is the light control film of Embodiment 44,
wherein an average optical absorption of each first region in the
predetermined second wavelength range is greater than about 70%, or
80%, or 90%, or 95%, or 99%.
[0121] Embodiment 53 is the light control film of Embodiment 44,
wherein each first region has a substantially high reflectance in
the predetermined first wavelength range.
[0122] Embodiment 54 is the light control film of Embodiment 44,
wherein an average optical reflectance of each first region in the
predetermined second wavelength range is greater than about 70%, or
80%, or 90%, or 95%, or 99%.
[0123] Embodiment 55 is the light control film of Embodiment 44,
wherein each first region has a first index of refraction, and the
second region has a second index of refraction, a difference
between the first and second indices of refraction being less than
about 0.01
[0124] Embodiment 56 is the light control film of Embodiment 44,
wherein the second region has a substantially low transmission in
the predetermined first wavelength range.
[0125] Embodiment 57 is the light control film of Embodiment 44,
wherein an average optical transmittance of the second region in
the predetermined second wavelength range is less than about
10%.
[0126] Embodiment 58 is the light control film of Embodiment 44,
wherein the second region has a substantially high transmission in
the predetermined first wavelength range.
[0127] Embodiment 59 is the light control film of Embodiment 44,
wherein an average optical transmittance of the second region in
the predetermined first wavelength range is greater than about
70%.
[0128] Embodiment 60 is the light control film of Embodiment 44,
wherein the second region includes a plurality of segments
alternating with the plurality of first regions.
[0129] Embodiment 61 is the light control film of Embodiment 44,
wherein the second region extends across and covers at least some
of the first regions.
[0130] Embodiment 62 is the light control film of Embodiment 44,
wherein the second region is discontinuous.
[0131] Embodiment 63 is the light control film of Embodiment 44
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0132] Embodiment 64 is the light control film of Embodiment 63,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0133] Embodiment 65 is the light control film of Embodiment 44,
wherein the second region is disposed on a major surface of the
light control film.
[0134] Embodiment 66 is the light control film of Embodiment 44,
wherein the second region extends across and covers at least some
of the first regions.
[0135] Embodiment 67 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having substantially low transmissions in each of
non-overlapping predetermined first and second wavelength ranges,
the second region having substantially high transmission in the
predetermined second wavelength range.
[0136] Embodiment 68 is the light control film of Embodiment 67,
wherein the predetermined first wavelength range includes shorter
wavelengths and the predetermined second wavelength range includes
longer wavelengths.
[0137] Embodiment 69 is the light control film of Embodiment 67,
wherein the predetermined first wavelength range is from about 400
nm to about 700 nm.
[0138] Embodiment 70 is the light control film of Embodiment 67,
wherein the predetermined second wavelength range is from about 700
nm to about 1200 nm.
[0139] Embodiment 71 is the light control film of Embodiment 67,
wherein an average optical transmittance of each first region in
the predetermined first wavelength range is less than about
10%.
[0140] Embodiment 72 is the light control film of Embodiment 67,
wherein an average optical transmittance of each first region in
the predetermined second wavelength range is less than about
10%.
[0141] Embodiment 73 is the light control film of Embodiment 67,
wherein an average optical transmittance of the second region in
the predetermined second wavelength range is greater than about
70%.
[0142] Embodiment 74 is the light control film of Embodiment 67,
wherein the second region has a substantially low transmission in
the predetermined first wavelength range.
[0143] Embodiment 75 is the light control film of Embodiment 67,
wherein an average optical transmittance of the second region in
the predetermined first wavelength range is less than about
10%.
[0144] Embodiment 76 is the light control film of Embodiment 67,
wherein the second region has a substantially high transmission in
the predetermined first wavelength range.
[0145] Embodiment 77 is the light control film of Embodiment 67,
wherein an average optical transmittance of the second region in
the predetermined first wavelength range is greater than about
70%.
[0146] Embodiment 78 is the light control film of Embodiment 67
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0147] Embodiment 79 is the light control film of Embodiment 78,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0148] Embodiment 80 is the light control film of Embodiment 67,
wherein the second region is disposed on a major surface of the
light control film.
[0149] Embodiment 81 is the light control film of Embodiment 67,
wherein the second region extends across and covers at least some
of the first regions.
[0150] Embodiment 82 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having a substantially high transmission in a predetermined
first wavelength range and a substantially low transmission in a
predetermined non-overlapping second wavelength range, the second
region having substantially high transmission in each of the
predetermined first and second wavelength ranges.
[0151] Embodiment 83 is the light control film of Embodiment 82
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0152] Embodiment 84 is the light control film of Embodiment 83,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0153] Embodiment 85 is the light control film of Embodiment 82,
wherein the second region is disposed on a major surface of the
light control film.
[0154] Embodiment 86 is the light control film of Embodiment 82,
wherein the second region extends across and covers at least some
of the first regions.
[0155] Embodiment 87 is the light control film of Embodiment 82,
wherein the first wavelength range is about 400 nm to about 700
nm.
[0156] Embodiment 88 is the light control film of Embodiment 82,
wherein the first wavelength range is about 400 nm to about 460
nm.
[0157] Embodiment 89 is the light control film of Embodiment 82,
wherein the first wavelength range is about 600 nm to about 650
nm.
[0158] Embodiment 90 is the light control film of Embodiment 82,
wherein the first wavelength range is about 470 nm to about 550
nm.
[0159] Embodiment 91 is the light control film of Embodiment 82,
wherein a wavelength separation distance between the
non-overlapping first and second wavelength ranges is at least 5
nm, or at least 10 nm, or at least 15 nm, or at least 20 nm.
[0160] Embodiment 92 is an optical construction including the light
control film of Embodiment 82 disposed on a window substrate, each
first region having an average optical transmittance of greater
than about 50%, or 60%, or 70%, or 80%, or 90% in a first
wavelength range from about 400 nm to about 700 nm and an average
optical transmittance of less than about 10% in a non-overlapping
second wavelength range from about 700 nm to about 1200 nm, the
second region having an average optical transmittance of greater
than about 30%, or 40%, or 50%, or 60%, or 70%, or 80%, or 90% in
each of the predetermined first and second wavelength ranges,
wherein the light control film has a viewing angle of less than
about 40 degrees for at least one wavelength in the second
wavelength range.
[0161] Embodiment 93 is the optical construction of Embodiment 92,
wherein the window substrate has an average optical transmittance
of greater than about 50%, or 60%, or 70%, or 80%, or 90% in the
predetermined first and second wavelength ranges.
[0162] Embodiment 94 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having a substantially low transmission in a predetermined
first wavelength range and a substantially high transmission in a
predetermined non-overlapping second wavelength range, each second
region having substantially low transmission in each of the
predetermined first and second wavelength ranges.
[0163] Embodiment 95 is the light control film of Embodiment 94
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0164] Embodiment 96 is the light control film of Embodiment 95,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0165] Embodiment 97 is the light control film of Embodiment 94,
wherein the second region is disposed on a major surface of the
light control film.
[0166] Embodiment 98 is the light control film of Embodiment 94,
wherein the second region extends across and covers at least some
of the first regions.
[0167] Embodiment 99 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having a substantially high transmission in a predetermined
first wavelength range and a substantially low transmission in a
predetermined non-overlapping second wavelength range, the second
region having substantially low transmission in each of the
predetermined first and second wavelength ranges.
[0168] Embodiment 100 is the light control film of Embodiment 99
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0169] Embodiment 101 is the light control film of Embodiment 100,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0170] Embodiment 102 is the light control film of Embodiment 99,
wherein the second region is disposed on a major surface of the
light control film.
[0171] Embodiment 103 is the light control film of Embodiment 99,
wherein the second region extends across and covers at least some
of the first regions.
[0172] Embodiment 104 is a light control film including a plurality
of spaced apart first regions and a second region, each first
region having a width W and a height H, H/W.gtoreq.1, each first
region having a substantially low transmission in a predetermined
first wavelength range and a substantially high transmission in a
predetermined non-overlapping second wavelength range, the second
region having substantially high transmission in each of the
predetermined first and second wavelength ranges.
[0173] Embodiment 105 is the light control film of Embodiment 104
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0174] Embodiment 106 is the light control film of Embodiment 105,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0175] Embodiment 107 is the light control film of Embodiment 104,
wherein the second region is disposed on a major surface of the
light control film.
[0176] Embodiment 108 is the light control film of Embodiment 104,
wherein the second region extends across and covers at least some
of the first regions.
[0177] Embodiment 109 is a light control film configured to block
light in a predetermined wavelength range, including a plurality of
spaced apart first regions, each first region having a width W and
a height H, H/W.gtoreq.1, each first region having a substantially
high transmission in a predetermined first wavelength range, a
substantially low transmission in a predetermined second wavelength
range, and a substantially high transmission in a predetermined
third wavelength range, the second wavelength range disposed
between the first and third wavelength ranges
[0178] Embodiment 110 is the light control film of Embodiment 109,
wherein the second wavelength range is about 20 nm wide from a
first wavelength to a second wavelength and centered on a laser
visible emission wavelength, the first wavelength range is from
about 400 nm to about the first wavelength, and the third
wavelength range is from about the second wavelength to about 1400
nm.
[0179] Embodiment 111 is the light control film of Embodiment 110,
wherein the laser visible emission wavelength is at least one of
442 nm, 458 nm, 488 nm, 514 nm, 632.8 nm, 980 nm, 1047 nm, 1064 nm,
and 1152 nm.
[0180] Embodiment 112 is the light control film of Embodiment 110,
wherein the laser visible emission wavelength is in a range from
about 416 nm to about 1360.
[0181] Embodiment 113 is the light control film of Embodiment 109
further including a plurality of spaced apart second regions
alternating with the plurality of first regions, each second region
having a substantially high transmission in each of the
predetermined first, second and third wavelength ranges.
[0182] Embodiment 114 is the light control film of Embodiment 109
having a viewing angle of less than about 60 degrees, or 50
degrees, or 40 degrees, or 30 degrees, or 20 degrees in the
predetermined second wavelength range.
[0183] Embodiment 115 is a light control film including a plurality
of spaced apart first regions and a second region, such that for
light incident normally to a plane of the light control film:
[0184] an average optical transmittance of the light control film
is less than about 10% in a predetermined first wavelength range
having shorter wavelengths; and
[0185] an average optical transmittance of the light control film
is greater than about 50% in a predetermined second wavelength
range having longer wavelengths; and for light incident at or
greater than about 30 degrees from the plane of the light control
film:
[0186] an average optical transmittance of the light control film
is less than about 20% in each of the predetermined first and
second wavelength ranges.
[0187] Embodiment 116 is the light control film of Embodiment 115,
wherein the predetermined first wavelength range is from about 400
nm to about 650 nm, and the predetermined second wavelength range
is from about 750 nm to about 1500 nm.
[0188] Embodiment 117 is the light control film of Embodiment 115,
wherein the second region includes a plurality of spaced apart
second region segments alternating with the plurality of first
regions.
[0189] Embodiment 118 is the light control film of Embodiment 115
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0190] Embodiment 119 is the light control film of Embodiment 118,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0191] Embodiment 120 is the light control film of Embodiment 115,
wherein the second region is disposed on a major surface of the
light control film.
[0192] Embodiment 121 is the light control film of Embodiment 115,
wherein the second region extends across and covers at least some
of the first regions.
[0193] Embodiment 122 is the light control film of Embodiment 115,
wherein an average optical transmittance of the first regions in
the predetermined second wavelength range is less than about 20%,
or less than about 15%, or less than about 10%, or less than about
5%, or less than about 1%.
[0194] Embodiment 123 is the light control film of Embodiment 115,
wherein an average optical transmittance of the second region in
the predetermined first wavelength range is less than about 20%, or
less than about 15%, or less than about 10%, or less than about 5%,
or less than about 1%.
[0195] Embodiment 124 is the light control film of Embodiment 115,
wherein an average optical transmittance of the second region in
the predetermined second wavelength range is greater than about
40%, or greater than about 50%, or greater than about 60%, or
greater than about 70%, or greater than about 80%, or greater than
about 90%.
[0196] Embodiment 125 is the light control film of Embodiment 115,
wherein for light incident normally to the plane of the light
control film, the average optical transmittance of the light
control film is less than about 5% in the predetermined first
wavelength range.
[0197] Embodiment 126 is the light control film of Embodiment 115,
wherein for light incident normally to the plane of the light
control film, the average optical transmittance of the light
control film is less than about 1% in the predetermined first
wavelength range.
[0198] Embodiment 127 is the light control film of Embodiment 115,
wherein for light incident normally to the plane of the light
control film, the average optical transmittance of the light
control film is greater than about 55% in the predetermined second
wavelength range.
[0199] Embodiment 128 is the light control film of Embodiment 115,
wherein for light incident normally to the plane of the light
control film, the average optical transmittance of the light
control film is greater than about 60% in the predetermined second
wavelength range.
[0200] Embodiment 129 is a light control film including a plurality
of spaced apart first regions and a second region, such that when
an angle of incidence of light incident on the light control film
changes from about 90 degrees to about 60 degrees relative to a
plane of the light control film, an average optical transmittance
of the light control film changes by:
[0201] less than about 10% in a predetermined first wavelength
range having shorter wavelengths; and
[0202] greater than about 40% in a predetermined second wavelength
range having longer wavelengths.
[0203] Embodiment 130 is the light control film of Embodiment 129,
wherein the predetermined first wavelength range is from about 400
nm to about 650 nm, and the predetermined second wavelength range
is from about 750 nm to about 1500 nm.
[0204] Embodiment 131 is the light control film of Embodiment 129,
wherein the second region includes a plurality of spaced apart
second region segments alternating with the plurality of first
regions.
[0205] Embodiment 132 is the light control film of Embodiment 129
including a major microstructured first surface having a plurality
of alternating ribs and channels, each channel at least partially
filled with a first material to form one of the first regions in
the plurality of spaced apart first regions.
[0206] Embodiment 133 is the light control film of Embodiment 132,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0207] Embodiment 134 is the light control film of Embodiment 129,
wherein the second region is disposed on a major surface of the
light control film.
[0208] Embodiment 135 is the light control film of Embodiment 129,
wherein the second region extends across and covers at least some
of the first regions.
[0209] Embodiment 136 is the light control film of Embodiment 129,
wherein an average optical transmittance of the first regions in
the predetermined second wavelength range is less than about 20%,
or less than about 15%, or less than about 10%, or less than about
5%, or less than about 1%.
[0210] Embodiment 137 is the light control film of Embodiment 129,
wherein an average optical transmittance of the second region in
the predetermined first wavelength range is less than about 20%, or
less than about 15%, or less than about 10%, or less than about 5%,
or less than about 1%.
[0211] Embodiment 138 is the light control film of Embodiment 129,
wherein an average optical transmittance of the second region in
the predetermined second wavelength range is greater than about
40%, or greater than about 50%, or greater than about 60%, or
greater than about 70%, or greater than about 80%, or greater than
about 90%.
[0212] Embodiment 139 is the light control film of Embodiment 129,
wherein when the angle of incidence of light incident on the light
control film changes from about 90 degrees to about 60 degrees
relative to the plane of the light control film, the average
optical transmittance of the light control film changes by less
than about 5% in the predetermined first wavelength range.
[0213] Embodiment 140 is the light control film of Embodiment 129,
wherein when the angle of incidence of light incident on the light
control film changes from about 90 degrees to about 60 degrees
relative to the plane of the light control film, the average
optical transmittance of the light control film changes by less
than about 1% in the predetermined first wavelength range.
[0214] Embodiment 141 is the light control film of Embodiment 129,
wherein when the angle of incidence of light incident on the light
control film changes from about 90 degrees to about 60 degrees
relative to the plane of the light control film, the average
optical transmittance of the light control film changes by greater
than about 55% in the predetermined second wavelength range.
[0215] Embodiment 142 is the light control film of Embodiment 129,
wherein when the angle of incidence of light incident on the light
control film changes from about 90 degrees to about 60 degrees
relative to the plane of the light control film, the average
optical transmittance of the light control film changes by greater
than about 60% in the predetermined second wavelength range.
[0216] Embodiment 143 is a light control film including:
a major microstructured first surface having a plurality of
alternating ribs and channels, each channel at least partially
filled with a first material to form a first region; and a second
region adjacent at least a portion of at least one first region and
including a second material; wherein each of the first and second
materials absorbs light in one or two of a first wavelength range
from about 300 nm to about 400 nm, a second wavelength range from
about 400 nm to about 700 nm, and a third wavelength range from
about 700 nm to about 1200 nm, and wherein each channel includes a
width W and a height H, H/W.gtoreq.1.
[0217] Embodiment 144 is the light control film of Embodiment 143,
wherein the second region is disposed in or on at least portions of
the ribs.
[0218] Embodiment 145 is the light control film of Embodiment 143,
wherein the second region includes a plurality of second region
segments, each rib including one of the second region segments.
[0219] Embodiment 146 is the light control film of Embodiment 143,
wherein the second region is disposed on a major surface of the
light control film.
[0220] Embodiment 147 is the light control film of Embodiment 143,
wherein the second region extends across and covers at least some
of the first regions.
[0221] Embodiment 148 is a light source system, including:
a light source configured to emit light having a first spectral
profile along a first direction and a second spectral profile along
a different second direction; and a light control film disposed on
the light source for receiving and transmitting light emitted by
the light source, the light control film including a plurality of
spaced apart first regions, each first region having a width W and
a height H, H/W.gtoreq.1, the first regions oriented relative to
the first and second directions and having a spectral absorbance
profile so that when light emitted by the light source is
transmitted by the light control film, the transmitted light has a
third spectral profile along the first direction and a fourth
spectral profile along the second direction, a difference between
the third and fourth spectral profiles being less than .alpha.
difference between the first and second spectral profiles.
[0222] Embodiment 149 is the light source system of Embodiment 148,
wherein the first direction is substantially perpendicular to a
plane of the light control film.
[0223] Embodiment 150 is the light source system of Embodiment 148,
wherein each first region selectively absorbs light within each of
the first and second spectral profiles.
[0224] Embodiment 151 is the light source system of Embodiment 148,
wherein light emitted from the light source propagating along the
first direction has a first set of color coordinates and
propagating along the second direction has a second set of color
coordinates, wherein light transmitted by the light control film
propagating along the first direction has a third set of color
coordinates and propagating along the second direction has a fourth
set of color coordinates, a difference between the third and fourth
sets of color coordinates being less than a difference between the
first and second sets of color coordinates.
[0225] Embodiment 152 is a retroreflective system, including:
a retroreflective sheet for retroreflecting light; and a light
control film disposed on the retroreflective sheet, such that for a
first wavelength, light incident on the light control film at each
of a first and second angles of incidence is retroreflected, and
for a second wavelength, light incident on the light control film
at the first, but not the second, angle of incidence is
retroreflected.
[0226] Embodiment 153 is the retroreflective system of Embodiment
152, wherein the light control film includes a greater first
viewing angle for the first wavelength and a smaller viewing angle
for the second wavelength.
[0227] Embodiment 154 is the retroreflective system of Embodiment
152, wherein the first angle of incidence is substantially equal to
zero relative to a line normal to a plane of the light control
film.
[0228] Embodiment 155 is the retroreflective system of Embodiment
152, wherein the retroreflective sheet includes at least one of
microsphere beads and corner cubes.
[0229] Embodiment 156 is the retroreflective system of Embodiment
152, wherein the light control film includes a plurality of spaced
apart first regions, each first region having a substantially low
transmission at the second, but not the first, wavelength.
[0230] Embodiment 157 is the detector system of Embodiment 38,
wherein the detector includes a photovoltaic device.
[0231] Embodiment 158 is the detector system of Embodiment 38,
wherein the detector includes a solar battery, a solar cell, or a
solar detector.
[0232] Embodiment 159 is the detector system of Embodiment 38,
wherein the detector is a detector in a camera.
[0233] Embodiment 160 is a camera including the detector system of
Embodiment 38.
[0234] Embodiment 161 is the light source system of Embodiment 148,
wherein the light source includes a light emitting diode (LED), a
laser light source, a halogen light source, a metal halide light
source, a tungsten light source, a mercury vapor light source, a
short arc xenon light source, or the sun.
[0235] Unless otherwise indicated, all numbers expressing feature
sizes, amounts, and physical properties used in the specification
and claims are to be understood as being modified by the term
"about." Accordingly, unless indicated to the contrary, the
numerical parameters set forth in the foregoing specification and
attached claims are approximations that can vary depending upon the
desired properties sought to be obtained by those skilled in the
art utilizing the teachings disclosed herein.
Although specific embodiments have been illustrated and described
herein, it will be appreciated by those of ordinary skill in the
art that a variety of alternate and/or equivalent implementations
can be substituted for the specific embodiments shown and described
without departing from the scope of the present disclosure. This
application is intended to cover any adaptations or variations of
the specific embodiments discussed herein. Therefore, it is
intended that this disclosure be limited only by the claims and the
equivalents thereof.
* * * * *