U.S. patent application number 09/880765 was filed with the patent office on 2002-11-07 for optical sheets or overlays.
Invention is credited to Myers, Kenneth J..
Application Number | 20020163728 09/880765 |
Document ID | / |
Family ID | 25297991 |
Filed Date | 2002-11-07 |
United States Patent
Application |
20020163728 |
Kind Code |
A1 |
Myers, Kenneth J. |
November 7, 2002 |
Optical sheets or overlays
Abstract
A field-of-view controlling arrangement for a display screen or
window includes overlay in the form of a single sheet of light
transmitting material having a plurality of parallel, spaced apart
v-shaped grooves, or a plurality of polyhedral, conical, or
frustoconical lens or prism structures, that serve to shift or
expand the field-or-view of an image or scene viewed through the
sheet. Any of the angled or curved surfaces of the resulting lens
or prism structures may be treated to attenuate or scatter light,
thereby providing a privacy screening effect with respect to a
range of angles determined by the orientation of the treated
surfaces.
Inventors: |
Myers, Kenneth J.; (Dobbs
Ferry, NY) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Family ID: |
25297991 |
Appl. No.: |
09/880765 |
Filed: |
June 15, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09880765 |
Jun 15, 2001 |
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09846455 |
May 2, 2001 |
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6443579 |
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Current U.S.
Class: |
359/613 ;
359/529; 359/606 |
Current CPC
Class: |
G02B 5/045 20130101;
G06F 1/1601 20130101; G06F 1/1609 20130101; H01J 29/89 20130101;
H01J 2329/897 20130101 |
Class at
Publication: |
359/613 ;
359/529; 359/606 |
International
Class: |
G02B 005/122; G02B
005/08; G02B 017/00; G02B 027/00 |
Claims
What is claimed is:
1. An overlay, comprising: a single light-transmitting sheet
including a plurality of parallel grooves defined by sets of
intersecting angled surfaces, wherein the grooves are spaced apart
from each other.
2. An overlay as claimed in claim 1, wherein at least one of said
sets of angled surfaces is arranged to attenuate light transmitted
through the overlay.
3. An overlay as claimed in claim 2, wherein two of said sets of
angled surfaces are arranged to attenuate light transmitted through
the overlay.
4. An overlay, comprising a single light-transmitting sheet
including a plurality of polyhedral structures.
5. An overlay claimed in claim 4, wherein said polyhedral
structures are truncated tetrahedral structures arranged in
staggered rows.
6. An overlay as claimed in claim 4, wherein said polyhedral
structures are truncated tetrahedral structures arranged in a grid
pattern.
7. An overlay as claimed in claim 4, wherein said polyhedral
structures are tetrahedral structures arranged in staggered
rows.
8. An overlay as claimed in claim 4, wherein said polyhedral
structures are tetrahedral structures arranged in a grid
pattern.
9. An overlay as claimed in claim 4, wherein said polyhedral
structures are truncated hexahedral structures arranged in a
honeycomb pattern.
10. An overlay as claimed in claim 4, wherein said polyhedral
structures are truncated hexahedral structures arranged in a
honeycomb pattern.
11. An overlay as claimed in claim 4, wherein said polyhedral
structures are hexahedral structures arranged in a honeycomb
pattern.
12. An overlay as claimed in claim 4, wherein selected surfaces of
said polyhedral structures are treated by processes selected from
the group consisting of coating processes, delustering, chemical or
laser etching, casting, and differential polishing of previously
roughened surfaces, to attenuate light passing through the selected
surfaces and thereby form a privacy screen.
13. An overlay, comprising a single light-transmitting sheet
including a plurality of frustoconical structures.
14. An overlay as claimed in claim 13, wherein curved surfaces of
said frustoconical structures are treated by processes selected
from the group consisting of coating processes, delustering,
chemical or laser etching, casting, and differential polishing of
previously roughened surfaces.
15. An overlay, comprising a single light-transmitting sheet
including a plurality of conical structures arranged to control a
field-of-view for an image or scene viewed through the overlay.
16. An overlay, comprising a single light-transmitting sheet
including a plurality of interlocking solids having polygonal
bases.
17. An overlay as claimed in claim 16, wherein said polygonal bases
are hexagonal, thereby forming a honeycomb pattern.
18. An overlay as claimed in claim 17, wherein said interlocking
solids are truncated hexahedra.
19. An overlay as claimed in claim 18, wherein a top surface of
each hexahedron is planar.
20. An overlay as claimed in claim 18, wherein a top surface of
each hexahedron is lens-shaped.
21. An overlay as claimed in claim 20, wherein side surfaces of
each hexahedron are curved.
22. An overlay as claimed in claim 18, wherein side surfaces of
each hexahedron are curved.
23. An overlay as claimed in claim 16, wherein said polygonal bases
are diamond-shaped.
24. An overlay as claimed in claim 23, wherein said interlocking
solids are truncated tetrahedra.
25. An overlay as claimed in claim 24, wherein a top surface of
each tetrahedron is planar.
26. An overlay as claimed in claim 24, wherein a top surface of
each tetrahedron is lens-shaped.
27. An overlay as claimed in claim 26, wherein side surfaces of
each tetrahedron are curved.
28. An overlay as claimed in claim 24, wherein side surfaces of
each tetrahedron are curved.
29. A field-of-view controlling arrangement, comprising: a single
light-transmitting sheet arranged to expand or shift portions of a
field-of-view for an image or scene viewed through the sheet,
wherein the sheet includes a plurality of parallel grooves defined
by sets of intersecting angled surfaces, and wherein the grooves
are spaced apart from each other.
30. A field-of-view controlling arrangement as claimed in claim 29,
wherein at least one of said sets of angled surfaces is arranged to
attenuate light transmitted through the sheet, thereby forming a
privacy screen while maintaining said expanded field-of-view.
31. A field-of-view controlling arrangement as claimed in claim 30,
wherein two of said sets of angled surfaces are arranged to
attenuate light transmitted through the sheet.
32. A field-of-view controlling arrangement, comprising a single
light-transmitting sheet including a plurality of polyhedral
structures arranged to expand, shift, or restrict a field-of-view
for an image or scene viewed through the sheet.
33. A field-of-view controlling arrangement claimed in claim 32,
wherein said polyhedral structures are truncated tetrahedral
structures arranged in staggered rows.
34. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are truncated tetrahedral
structures arranged in a grid pattern.
35. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are tetrahedral structures
arranged in staggered rows.
36. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are tetrahedral structures
arranged in a grid pattern.
37. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are truncated hexahedral
structures arranged in a honeycomb pattern.
38. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are truncated hexahedral
structures arranged in a honeycomb pattern.
39. A field-of-view controlling arrangement as claimed in claim 32,
wherein said polyhedral structures are hexahedral structures
arranged in a honeycomb pattern.
40. A field-of-view controlling arrangement as claimed in claim 32,
wherein selected surfaces of said polyhedral structures are treated
by processes selected from the group consisting of coating
processes, delustering, chemical or laser etching, casting, and
differential polishing of previously roughened surfaces, to
attenuate light passing through the selected surfaces and thereby
form a privacy screen.
41. A field-of-view controlling arrangement, comprising a single
light-transmitting sheet including a plurality of frustoconical
structures arranged to expand, shift, or restrict a field-of-view
for an image or scene viewed through the sheet.
42. A field-of-view controlling arrangement as claimed in claim 41,
wherein curved surfaces of said frustoconical structures are
treated by processes selected from the group consisting of coating
processes, delustering, chemical or laser etching, casting, and
differential polishing of previously roughened surfaces.
43. A field-of-view controlling arrangement, comprising a single
light-transmitting sheet including a plurality of conical
structures arranged to expand, shift, or restrict a field-of-view
for an image or scene viewed through the sheet.
Description
[0001] This application is a continuation-in-part of copending U.S.
patent application Ser. No. 09/846,455, filed May 2, 2001, and
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to single-sheet light transmitting
sheets or overlays, and to arrangements for using such sheets or
overlays.
[0004] The sheets or overlays may, by way of example, be used to
control the field-of-view or range of angles over which an image or
scene can be discerned, by either expanding, shifting, and/or
screening portions of the image or scene, on any side and in any
selected direction.
[0005] Alternatively, the sheets or overlays may be used collect or
capture light, to permit viewing of different images or image
portions at different angles relatively to a display screen, to
separate or combine images, or to serve as retroreflectors.
[0006] 2. Description of Related Art
[0007] Field-of-view expansion overlays made up of
conventionally-shaped microprism or lenticular sheets having
parallel groove or lens structures are disclosed in copending U.S.
Pat. No. 09/780,535, while field-of-view restricting (i.e., privacy
screening) overlays using the same types of conventionally
configured parallel groove or lens structures are disclosed in
copending U.S. patent application Ser. No. 09/481,942.
[0008] The present invention proposes to apply the image expansion
or restriction principles described in the copending applications
to a variety of novel sheet structures, in which the parallel
grooves of the sheet are spaced apart, or are replaced by arrays of
structural elements having polyhedral, frustoconical, or conical
shapes, and/or that are configured as solids arranged in an
interlocking or honeycomb pattern.
[0009] In particular, the present invention proposes to provide a
single-sheet light transmitting overlay for a display screens or
windows in which one surface is formed or cast to include the
above-mentioned spaced apart parallel grooves or polyhedral,
frustoconical, or conical structural elements, and/or solids
arranged in an interlocking or honeycomb pattern, so that the
structural elements shift or expand the field-of-view of an image
viewed through the overlay. Furthermore, by selectively treating
any of the surfaces of the structural elements, a field-of-view
restriction or screening effect may be achieved without affecting
the image shifting or expansion effects of the remaining untreated
surfaces.
[0010] In addition to provide field-of-view controlling the
effects, the novel sheet structures of the prevent invention may be
used to capture light, for example in solar panels, to separate or
combine images, and if provided with a reflective backing, to serve
as retroreflectors.
[0011] By way of background, the following patents are directed to
microprism sheets in general, including microprism sheets having
treated surfaces and surface treatment methods therefor:
[0012] U.S. Pat. Nos. 5,836,096 (Brauer), 5,512,219 (Rowland et
al.) 5,446,594 (Nelson et al.), 5,363,237 (Wakatake), 5,316,359
(Lansinger), 5,208,620 (Mitsutake et al.), 4,708,435 (Yata et al.),
4,309,074 (Granieri), 4,309,073 (Nishimura et al.), 4,206,969 (Cobb
et al.) , 3,971,051 (Baker et al.) , 3,902,787 (Sherlock), and
3,718,078 (Plummer),
[0013] In addition, the following patents disclose use of
microprism sheets having a single treated surface arranged
generally parallel to the direction of image transmission for
purposes of glare reduction:
[0014] U.S. Pat. Nos. 4,911,529 (Van De Ven), 4,756,603 (Ohtani),
4,165,920 (Brown), 2,909,770 (Pugsley); the following patents
disclose use of lenticular or microprism sheets as isotropic light
diffusers in rear projection systems:
[0015] U.S. Pat. Nos. 4,730,897 (McKechnie et al.), 5,400,114
(Yoshida et al.), 5,457,572 (Ishii et al.), 5,581,407 (Mitani et
al.), 5,760,955 (Goldenberg et al.), 6,002,829 (Winston et al.),
6,157,491 (Watanabe et al.), 6,025,897 (Weber et al.), and
6,169,633 (Watanabe); and
[0016] the following patents are directed to use of microprism or
lenticular sheets to increase the field of view in non-projection
or direct sight type LCD systems:
[0017] U.S. Pat. Nos. 5,745,199 and 5,555,476, both to Suzuki et
al.
[0018] While these patents disclose a wide variety of uses for
microprism or lenticular sheets similar to those disclosed in U.S.
patent application Ser. Nos. 09/780,535 and 09/481,942, they do not
disclose the particular structural elements shapes of the present
invention, or use of such shapes in field-of-view controlling
(i.e., expanding, shifting, or restricting) arrangements, image
separating or combining arrangements, light collection devices, or
as retroreflectors.
SUMMARY OF THE INVENTION
[0019] It is accordingly a first objective of the invention to
provide more versatile single-sheet, light-transmitting overlays
that offer enhanced field-of-view control, permitting the
field-of-view of an image or scene to be controlled or restricted
from any side or combination of sides, over any range of angles,
and without substantially increasing the cost or difficulty of
manufacture.
[0020] It is a second objective of the invention to provide
field-of-view controlling arrangements utilizing such single-sheet,
light-transmitting overlays that provide enhanced field-of-view
control.
[0021] It is a third objective of the invention to provide display
screen overlays, for computer monitors, televisions, and the like,
that can provide privacy screening or field-of-view expansion from
any side of the screen, including both sides, the top, and the
bottom, or combinations thereof.
[0022] It is a fourth objective of the invention to provide privacy
screens that may be applied to a window, and which not only serve
as a blind, but also may be arranged to improve the view through
the window, and/or to replace an undesired view with images or
graphics.
[0023] It is a fifth objective of the invention to provide novel
sheet structures that not only can be used for field-of-view
control, but that may also be advantageously adapted for use in
image separating or combining devices, light collectors, and as
retroreflectors.
[0024] These objectives are achieved, in accordance with the
principles of various preferred embodiments of the invention, by
providing an overlay in the form of a single sheet of light
transmitting material having a plurality of parallel, spaced apart
v-shaped grooves, or a plurality of polyhedral, conical, or
frustoconical lens structures, and/or solid (i.e.,
three-dimensional) lens structures arranged in an interlocking or
honeycomb pattern, and that serve to shift or expand the
field-or-view of an image or scene viewed through the sheet, that
direct incident light in a desired manner, or that have the effect
of combining or separating images, depending on the viewing
angle.
[0025] In each of the embodiments of the invention, any angled or
curved surface may be treated to attenuate or scatter light,
thereby providing a privacy screening effect with respect to a
range of angles determined by the orientation of the surfaces. The
surface treatments applied may consist of any surface treatments
that have the effect of absorbing or scattering light and that can
be applied to selected surfaces by means of a mask, control of the
surface treatment tool, or use of an appropriate die, including
application of opaque, light diffusing, or polarizing coatings,
delustering, chemical or laser etching, casting, and differential
polishing of previously roughened surfaces, as well as any other
surface treatment methods described in the above-cited patents or
patent applications, or that are known or may become known to those
skilled in the art.
[0026] In the case of polarizing coatings, a privacy screening
effect can be obtained by providing a polarizing coating on an
entire back surface of the overlay, and by oppositely polarizing
selected surfaces on the front side of the overlay.
[0027] In addition to or instead of including light attenuating or
light scattering coatings, the overlays of the invention may be
provided with non-directional treatments such as reflective
coatings (useful in forming retroreflectors), radiation shielding
coatings, or embedded images or graphics.
[0028] Furthermore, the extremely versatile overlays of the
invention may be arranged to facilitate light collection by
directing light incident light from a relatively wide field of view
into a light guide (which is especially useful for solar
collectors), or the overlays may be provided with polarizing or
other coatings that facilitate image combination or separation.
[0029] When arranged to provide field-of-view control, i.e., as
privacy screens, the overlays of the preferred embodiments of the
invention are especially suitable for use in restricting or
facilitating viewing by persons situated above or below, or to the
side of, a computer monitor or television screen. However, the
field-of-view controlling overlays may be used in any of a variety
of potential applications that might involve restricted or enhanced
viewing of an image or scene, including applications in which the
overlays of the invention are applied to windows to serve as
blinds.
[0030] When applied to a window, the privacy screens of the
invention not only can provide privacy and restrict incoming light,
but also can modify the view through the window by using the prisms
or lenticular structures of the overlay to bend light is selected
directions, or modify the view by adding images or graphics visible
at selected angles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a perspective view of one of the preferred
field-of-view controlling sheets used as a computer display screen
overlay.
[0032] FIG. 2 is a perspective view of a preferred embodiment of
the field-of-view controlling overlay of FIG. 1, in which the
single sheet that makes up the overlay includes parallel, spaced
apart grooves.
[0033] FIG. 3 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including truncated tetrahedral
structures arranged in staggered rows according to the principles
of a second preferred embodiment of the invention.
[0034] FIG. 4 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including truncated tetrahedral
structures arranged in a grid pattern according to the principles
of a third preferred embodiment of the invention.
[0035] FIG. 5 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including tetrahedral structures
arranged in staggered rows according to the principles of a fourth
preferred embodiment of the invention.
[0036] FIG. 6 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including truncated tetrahedral
structures arranged in a grid pattern according to the principles
of a fifth preferred embodiment of the invention.
[0037] FIG. 7 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including truncated hexahedral
structures arranged in a honeycomb pattern according to the
principles of a sixth preferred embodiment of the invention.
[0038] FIG. 8 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including tetrahedral structures
arranged in a honeycomb pattern according to the principles of a
seventh preferred embodiment of the invention.
[0039] FIG. 9 is a plan view of the overlay of FIG. 3, in which no
surfaces are treated to provide a privacy screening effect.
[0040] FIGS. 10-13 are plan views of the overlay of FIG. 3, in
which different surfaces are treated to control the viewing angle
in different directions.
[0041] FIG. 14 is a plan view of the overlay of FIG. 4, in which no
surfaces are treated to provide a privacy screening effect.
[0042] FIGS. 15-18 are plan views of the overlay of FIG. 4, in
which different surfaces are treated to control the viewing angle
in different directions.
[0043] FIG. 19 is a plan view of the overlay of FIG. 5, in which no
surfaces are treated to provide a privacy screening effect.
[0044] FIGS. 20-23 are plan views of the overlay of FIG. 5, in
which different surfaces are treated to control the viewing angle
in different directions.
[0045] FIG. 24 is a plan view of the overlay of FIG. 6, in which no
surfaces are treated to provide a privacy screening effect.
[0046] FIGS. 25-28 are plan views of the overlay of FIG. 6, in
which different surfaces are treated to control the viewing angle
in different directions.
[0047] FIG. 29 is a plan view of the overlay of FIG. 7, in which no
surfaces are treated to provide a privacy screening effect.
[0048] FIGS. 30-39 are plan views of the overlay of FIG. 7, in
which different surfaces are treated to control the viewing angle
in different directions.
[0049] FIG. 40 is a plan view of the overlay of FIG. 8, in which no
surfaces are treated to provide a privacy screening effect.
[0050] FIGS. 41-50 are plan views of the overlay of FIG. 8, in
which different surfaces are treated to control the viewing angle
in different directions.
[0051] FIG. 51 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including frustoconical
structures according to the principles of an eighth preferred
embodiment of the invention.
[0052] FIG. 52 is a plan view of the overlay of FIG. 51, in which
one surface is treated to control the viewing angle in different
directions.
[0053] FIG. 53 is a plan view of the overlay of FIG. 51, in which
no surface is treated to provide a privacy screening effect.
[0054] FIG. 54 is a perspective view of a portion of a single sheet
field-of-view controlling overlay including conical structures in
accordance with the principles of a ninth preferred embodiment of
the invention.
[0055] FIGS. 55-57 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking or honeycomb arrangement of tetrahedral solids
arranged to include a lens surface in accordance with the
principles of a tenth preferred embodiment of the invention.
[0056] FIGS. 58-60 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking or honeycomb arrangement of tetrahedral solids
arranged to include lens-shaped side surfaces in accordance with
the principles of an eleventh preferred embodiment of the
invention.
[0057] FIGS. 61-63 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking or honeycomb arrangement of lens-shaped solids in
accordance with the principles of a twelfth preferred embodiment of
the invention.
[0058] FIGS. 64-66 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking arrangement of truncated non-regular pyramidal
structures in accordance with the principles of a thirteenth
embodiment of the invention.
[0059] FIGS. 67-69 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking arrangement of non-regular pyramidal solids arranged
to include a lens surface in accordance with the principles of a
fourteenth preferred embodiment of the invention.
[0060] FIGS. 70-72 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking arrangement of non-regular pyramidal solids arranged
to include lens-shaped side surfaces in accordance with the
principles of an fifteenth preferred embodiment of the
invention.
[0061] FIGS. 73-75 are respective side, plan, and isometric views
of a single sheet field-of-view controlling overlay including an
interlocking arrangement of lens-shaped solids in accordance with
the principles of a sixteenth preferred embodiment of the
invention.
[0062] FIGS. 76 and 77 are plan views of a single sheet
field-of-view controlling overlay including a honeycomb pattern of
lens-shaped solids in accordance with the principles of respective
seventeenth and eighteenth preferred embodiments of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0063] FIG. 1 illustrates one application of the embodiments
illustrated in FIGS. 2-50. In this embodiment, an overlay 1
designed to be used with the display screen 2 of a computer, to
either expand, shift, or restrict the field-of-view in any desired
direction or directions, or to separate or combine images. For
example, using the embodiment of FIG. 2, the field-of-view could be
restricted in order to prevent eavesdroppers from viewing the
screen from the left or right sides, but expanded to permit viewing
of the screen from above. Alternatively, using the embodiment of
FIGS. 3-77, the field-of-view could be expanded or restricted on
any number of sides, or on any combination of multiple sides, or
the overlay could be arranged such that different images or
portions of an image may be viewed through different facets.
[0064] Alternatively, the sheets or overlays illustrated in FIGS.
2-77 could be arranged to collect light. This is especially useful
in solar panels, since the same principles that permit expansion of
the field-of-view can be applied to increasing the efficiency of
solar light collection, with the goal of directing the light to a
light guide that guides the light to a photo-electric panel, water
heater, or other energy conversion device.
[0065] If the sheets are provided with a reflecting coating on the
surface opposite the lenses or prisms, or on the surfaces of the
lenses or prisms, a retroreflective effect can be obtained, in
which light incident on the sheet is reflected in a particular
direction. Overlays or sheets arranged in this manner are
especially suitable for use in projection screens, but may also be
useful on road signs, nighttime wearing apparel, reflectors for
bicycles or other vehicles, and in any other application in which
retroreflectivity is utilized.
[0066] Turning to the specific structures which make up the
invention, FIG. 2 shows a first preferred embodiment of the
invention arranged to provide modification for any two opposite
sides of field-of-view. This embodiment consists of a sheet 3
having parallel, spaced apart v-shaped grooves formed by angled
surfaces 4 and 5. The presence of angled surfaces 4 and 5 has the
effect of expanding the field-of-view for an image or scene viewed
through the sheet 3. The surfaces 6 connecting the grooves are
planar, although it is possible to modify surfaces 6 to having a
curvature in order to obtain lensing effects.
[0067] As in all of the embodiments of the present invention, in
order to restrict or screen a portion of the field of view, it is
simply necessary to treat at least one of the angled surfaces 4,5
to attenuate or scatter light passing through the treated surfaces.
If just one surface is treated, then the field-of-view expansion
effect of the other surface will still be maintained, although it
is also possible to treat both surfaces, or portions of the
surfaces for a two-sided privacy screening effect.
[0068] The surface treatments applied in this and other embodiments
of the invention may consist of any surface treatments that have
the effect of absorbing or scattering light and that can be applied
to selective surfaces by means of a mask, die, tool, or the like.
In addition to coatings, possible surface treatments include
delustering, chemical or laser etching, casting, and differential
polishing of previously roughened surfaces, as well as any other
surface treatment methods described in the above-cited patents or
patent applications, or that are known or may become known to those
skilled in the art. For example, if the surfaces are treated by
printing, graphic images may be added so that the blocked image or
scene is replaced by a graphic image.
[0069] It will of course be appreciated that the surfaces that are
not "treated" to scatter or attenuate light in order to create a
privacy screening effect may nevertheless be treated to enhance
transmission of light through the surfaces, for example by
polishing, curing, adding transparent protective coatings, and or
printing of portions of the surfaces so as to superimpose graphic
images on the images being viewed through the screen. The term
"untreated" is intended to mean "not altered to diffuse or
attenuate light."
[0070] Furthermore, it will be appreciated that a privacy screening
effect can be obtained not only by light scattering or attenuation,
but also by polarization. In order to obtain privacy screening by
polarization, a back surface of the overlay is polarized in a first
direction, and then selected facets or surfaces on the front side
of the overlay are polarized in the opposite direction so that the
oppositely polarized facets or surfaces effectively prevent
transmission of light through the surfaces. Furthermore, if the
light source itself is polarized, as is the case with a liquid
crystal display, privacy screening could be achieved without
polarizing the back side of the overlay, so long as the selected
facets or surfaces are polarized in a direction opposite the
direction of polarization of the display.
[0071] In addition to treatments that scatter, attenuate, or
polarize light in order to provide a privacy screening effect,
surface treatments may include anti-radiation coatings, polarizing
coatings for purposes other than privacy screening, printing, and
other surface treatments such as the above mentioned reflective
coating, applied either to one or more facets of the prism
structures, but possibly also to the opposite side of the
sheet.
[0072] According to the preferred embodiment of the invention
illustrated in FIGS. 3 and 9-13, the field-of-view controlling
arrangement is made up of a sheet that include staggered rows of
lenticular elements in the form of truncated tetrahedral structures
100 having five sets of mutually parallel surfaces indicated by
reference numerals 101-105. According to the principles of this
embodiment of the invention, the sheet may be used without
treatment of any of the surfaces, in which case the field-of-view
is increased on four sides, or any one or more of surfaces 101-105
may be selectively treated to provide a privacy screening effects,
the range of angles of which is determined by the orientations of
the treated surfaces. For example, in the arrangement of FIG. 9,
none of the surfaces are treated, while in the arrangement of FIG.
10, only surface 101 is treated, and in the arrangements of FIGS.
11-13, surfaces 101 and 105; 101, 104, and 105; and 101 and 104 are
respectively subjected to a light-attenuating or other surface
treatment in the manner described above.
[0073] FIGS. 4 and 14-18 illustrate a field-of-view controlling
arrangement similar to that of FIGS. 14-18 except that the
truncated tetrahedral lenticular elements 200 are arranged in a
grid rather than in staggered rows. Again, any or none of the
surfaces 201-205 may be subjected to a light-attenuating or other
surface treatment in the manner described above.
[0074] FIGS. 5 and 19-23 illustrate further embodiments of the
invention in which the field-of-view controlling elements are
non-truncated tetrahedral structures (300,400) in staggered rows
(FIGS. 5 and 19-23) or non-staggered rows (FIGS. 6 and 25-28) and
in which any set of surfaces 301-304, 401-404 may be subjected to a
light attenuating or other surface treatment, while FIGS. 7, 30-39,
8, and. 40-50 show corresponding arrangements of truncated or
non-truncated hexahedral structures 500,600 forming a honeycomb
pattern and in which any of surfaces 501-507,601-606 may be treated
to create a privacy screening effect, or otherwise treated to
facilitate any of the other effects noted above.
[0075] FIGS. 51-53 show preferred embodiments of the invention in
which the field-of-view controlling elements are
frustoconical-shaped structures 700 having surfaces 701 and 702 in
which the curved surface 701 which forms sides of the structure may
optionally be provided with a light-attenuating surface treatment
to provide a 360.degree. privacy screening effect as shown in FIG.
52, or with other surface treatments as noted above.
[0076] Finally, FIG. 54 shows a preferred embodiment of the
invention in which the field-of-view controlling elements are
conical structures 800 having surfaces 801. This embodiment is
primarily for field-of-view expansion since it would be very
difficult to selectively treat portions of the conical surfaces in
such a way as to still permit viewing of an image through the
overlay, although non-selective treatments may of course be applied
to either side of the sheet or overlay.
[0077] One advantage of using interlocking solids that form
staggered rows or a honeycomb pattern of field-of-view controlling
elements is that the staggering or honeycomb pattern reduces the
so-called "staircase" effect, which results in distortion or
blurring of non-horizontal or vertical lines, caused by the quantum
or discrete nature of aligned microprism or lenticular elements. In
addition, non-truncated discrete elements have the advantage of
providing maximal glare reduction and expansion of the
field-of-view in non-restricted directions.
[0078] Further examples of arrangements utilizing interlocking or
honeycomb patterns are found in FIGS. 55-80. The arrangements of
FIGS. 55-63 are similar to those of FIGS. 29-39 except that the
truncated hexahedral solids depicted in FIGS. 29-39 are modified to
include lens elements 900 (FIGS. 55-57), curved side surfaces 901
(FIGS. 58-60) , or both (FIGS. 61-63) In the arrangements of FIGS.
64-78, the interlocking solids are truncated non-regular
tetrahedra, i.e., tetrahedra with a diamond-shaped rather than
square base, having either a flat top surface 902 (FIGS. 64-66, a
lens-shaped top surface 903 (FIGS. 67-69), lens-shaped side
surfaces 904 (FIGS. 70-72), or both (FIGS. 73-75). Finally, as
illustrated in FIGS. 76 and 77, the interlocking solids may include
more complex shapes, such as the multi-faceted structures shown in
FIG. 76, in which the two traverse vertical cross-sections have
three and four respective sides extending from the plane of the
sheet, or the more continuously curved honeycomb arrangement of
FIG. 77, which includes an semi-annular mid-portion and conical end
portions.
[0079] As indicated above, the single sheet field-of-view
controlling overlays of the invention may be used as overlays for
video displays, for example to restrict eavesdropping with respect
to a computer display. In addition, the overlays of the invention
may be used as privacy screening window coverings in order to
achieve a variety of effects not possible with conventional
mechanical blinds. For example, the prisms or lenticular structures
that make up the overlays may be used to bend incoming light and
improve the view from the window and, if the view from the window
does not include any scenes worth expanding, the entire view may be
replaced by images or graphics.
[0080] The dimensions of the structural elements included in the
overlays of the various embodiments of the invention are
essentially determined by the technology used to form the sheets
and to treat the surfaces, and to the intended application,
although the pitch of the grooves or lenticular elements is
preferably made small enough to eliminate perception of the grooves
or lenticular elements, and/or Moir patterns resulting from
parallel arrangement of light transmitting and diffusing surfaces.
A pitch of less than ten grooves or elements per inch, and
preferably less than twenty grooves per inch, will provide the best
appearance most applications, although the invention is not in
principle limited to particular sheet dimensions or pitches.
[0081] Having thus described a number of preferred embodiments of
the invention in sufficient detail to enable those skilled in the
art to make and use the invention, it will nevertheless be
appreciated that numerous variations and modifications of the
illustrated embodiment may be made without departing from the
spirit of the invention. For example, the illustrated microprism
and lenticular sheet configurations are hardly exhaustive of all of
the possible configurations for such sheets. Accordingly, it is
intended that the invention not be limited by the above description
or accompanying drawings, but that it be defined solely in
accordance with the appended claims.
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