U.S. patent number 3,647,279 [Application Number 05/040,925] was granted by the patent office on 1972-03-07 for color display devices.
This patent grant is currently assigned to Liquid Crystal Industries, Inc.. Invention is credited to Frederick Davis, Edward N. Sharpless.
United States Patent |
3,647,279 |
Sharpless , et al. |
March 7, 1972 |
COLOR DISPLAY DEVICES
Abstract
A display device for exhibiting a color pattern, said device
comprising container means having a light-transmitting section and
a juxtaposed darker hued or opaque section, a quantity of liquid
crystalline material interposed between said container sections and
encapsulated within said container means, said material having a
characteristic of selective light scattering to exhibit color
patterns within a range of temperatures at which said display
device is normally utilized, and means for peripherally sealing one
of said container sections to the other. Means can also be provided
for applying deformational stress to the liquid crystal to vary its
color pattern.
Inventors: |
Sharpless; Edward N. (Pitcairn,
PA), Davis; Frederick (Penn Hills, PA) |
Assignee: |
Liquid Crystal Industries, Inc.
(Turtle Creek, PA)
|
Family
ID: |
21913749 |
Appl.
No.: |
05/040,925 |
Filed: |
May 27, 1970 |
Current U.S.
Class: |
349/23; 63/32;
D11/131; 40/661; 356/32; 63/40; 40/581; 63/23; 252/299.7; 434/98;
349/185; 349/175; 428/1.1 |
Current CPC
Class: |
G02F
1/13 (20130101); G02F 1/1341 (20130101); C09K
19/36 (20130101); G02F 1/1333 (20130101); Y10T
428/10 (20150115); C09K 2323/00 (20200801) |
Current International
Class: |
G02F
1/13 (20060101); C09K 19/36 (20060101); G02F
1/1341 (20060101); G02F 1/1333 (20060101); G02f
001/40 () |
Field of
Search: |
;356/32 ;350/160
;40/130 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Product Engineering, Dec. 21, 1964, Vol. 35, pp. 56-57. .
Ferguson, "Liquid Crystals," Scientific American, Vol. 211, 8/64,
pp. 76-85. .
Wysooki et al., Molecular Crystals & Liq. Crystals, Vol. 8,
8/68, pp. 471-488. .
Adams et al., Molecular Crystals & Liq. Crystals, Vol. 8, 8/68,
pp. 9-18. .
Klein et al., Rev. of Sci. Instr., Vol. 41, No. 2, 2/70, pp.
238-239. .
Garn, J. of Amer. Chem. Soc., Vol. 91, No. 19, 9/69, p. 5382. .
Lehmann, Thermodynamics, Vol. I, 1966, pp. 2-5. .
Fergason et al., Electro-Technology, 1/70, pp. 41-50..
|
Primary Examiner: Wibert; Ronald L.
Assistant Examiner: Rothenberg; J.
Claims
We claim:
1. A display device for exhibiting a varying color pattern, said
device comprising container means having a light transmitting
section, a quantity of cholesteric liquid crystalline material
encapsulated within said container means, said material having
characteristics of selective visual light scattering to exhibit
color patterns within a range of temperatures at which said display
device is normally utilized, and of transmitting a substantial
quantity of impinging visual light, light absorbing means supported
by at least one of said liquid crystalline material and said
container means for absorbing at least a substantial proportion of
said transmitted light, said container means being configured so as
to permit substantial volumetric flow of said liquid crystalline
material within said container means, said material having an
additional characteristic of a selective light frequency scattering
which is variable in accordance with applied deformational
stresses, the color patterns exhibited by said material being
substantially insensitive to a wide range of temperature
variations, and means coupled to said container means for
displacing said container means to apply said deformational
stresses to said material in a direction to induce said volumetric
flow, said displacing means comprising a relatively thin portion of
said container means adjacent said light-transmitting section, said
portion including deformable constriction and expansion areas for
displacing and accommodating said flow respectively so that
pronounced color changes are effected in said material as a result
of said flow.
2. The combination according to claim 1 wherein said displacing
means further includes an arm member engageable with an external
surface of said container portion, means for retaining said
external surface and said arm member in bearing engagement, and
means for moving said arm member across said external surface while
in bearing engagement therewith.
3. The combination according to claim 1 wherein said
light-transmitting section is a substantially flat transparent
member of about one-eighth inch in thickness.
4. The combination according to claim 1 wherein said liquid
crystalline material includes at least one of the group consisting
of alkyl carbonate and alkanoic cholesteric esters of cholesterol,
B-sitosterol, stigmasterol, and ergosterol.
5. The combination according to claim 4 wherein said liquid
crystalline material is a cholesteryl compound.
6. The combination according to claim 4 wherein a quantity of
cholesteryl halide is admixed with said liquid crystalline
material.
7. The combination according to claim 6 wherein said halide is
selected from the group consisting of cholesteryl chloride,
cholesteryl bromide, and cholesteryl iodide.
8. The combination according to claim 6 wherein said halide
consists of cholesteryl chloride.
9. The combination according to claim 6 wherein said halide is
present in the amount of about 15 to about 40 percent of the
resulting composition.
10. The combination according to claim 4 wherein said cholesteric
esters include at least one of the group consisting of the oleyl
carbonates and the nonanoates, together with a quantity of
cholesteryl halide.
11. The combination according to claim 10 wherein said oleyl
carbonates include high cholesteryl oleyl carbonate and low
cholesteryl oleyl carbonate.
12. The combination according to claim 11 wherein said cholesteryl
halide is present in the amount of about 22 percent to about 27
percent, said high cholesteryl oleyl carbonate is present in the
amount of about 50 percent to about 75 percent, said low
cholesteryl oleyl carbonate is present in the amount of about 0
percent to about 23 percent, and said cholesteryl nonanoate is
present in the amount of about 0 percent to about 15 percent.
13. The combination according to claim 1 wherein said light
absorbing means are supported on said displacing means.
14. The combination according to claim 1 wherein said displacing
means include a flexible membrane sealed to said container means so
that a portion thereof can be displaced toward said container means
while another portion thereof can be displaced away from said
container means.
15. A display device for exhibiting a color pattern, said device
comprising container means having a light-transmitting section and
containing a thin sandwich of cholesteric liquid crystalline
material within said container means, said material having
characteristics of selective visual light scattering to exhibit
substantially temperature insensitive color patterns within a range
of temperatures at which said display device is normally utilized
and of transmitting a substantial quantity of impinging visual
light, light-absorbing means supported by at least one of said
liquid crystalline material and said container means for absorbing
at least a substantial proportion of said transmitted light, said
container means being configured so as to permit substantial
volumetric flow of said material within said container means, said
material including a quantity of cholesteryl halide and having an
additional characteristic of a selective light frequency scattering
which is variable in accordance with applied deformational
stresses, and means coupled to said container means for applying
said stresses.
16. The combination according to claim 15 wherein said halide is
selected from the group consisting of cholesteryl chloride,
cholesteryl bromide and cholesteryl iodide.
17. The combination according to claim 15 wherein said halide
consists of cholesteryl chloride.
18. The combination according to claim 15 wherein said halide is
present in the amount of about 15 percent to about 40 percent of
the resulting composition.
19. The combination according to claim 15 wherein said cholesteric
material includes at least one of the group consisting of high and
low oleyl carbonates and the nonanoates.
20. The combination according to claim 19 wherein said cholesteryl
halide is present in the amount of about 22 percent to about 27
percent, high cholesteryl oleyl carbonate is present in the amount
of about 50 percent to about 75 percent, low cholesteryl oleyl
carbonate is present in the amount of 0 percent to about 23
percent, and cholesteryl nonanoate is present in the amount of 0
present to about 15 percent.
Description
The present invention relates to variable color display or
aesthetic devices and to means for enhancing the variable color
patterns produced by the device for entertainment, advertising,
aesthetic or decorative effects or purposes.
Devices for displaying color patterns for various purposes are
legion. These devices usually employ various colored materials or
surfaces, color filters or simply lights of various colors. Many of
these devices are capable only of displaying colors or color
patterns of a fixed or invarying nature, and their usefulness is
thereby limited. Particularly in displays for decorative or
aesthetic purposes, the "novelty wears off" all too soon.
Color display devices in the form of various kinds of
light-projecting machines are likewise available for use in
advertising, entertainment and in the purely decorative field. For
the most part, these machines rely on solid crystalline or plastic
colored materials, photographic slides, systems of mirrors with
color filters attached, movable arrays of color filters, or simply
lights of various colors which may be movably disposed or otherwise
sequenced to illuminate the object or area with the intended color
pattern or patterns. While some of these machines work reasonably
well in a limited range of applications and furnish a number of
fixed color patterns, the machines usually are complex in
construction owing to mechanical repetition of various components.
The total number of available color patterns or color variation is
severely limited in most cases and the sense of variety is soon
lost. The colors or color patterns are usually overly brilliant,
cold, or otherwise unnatural in their hues and intensities.
In many color display devices there is the frequent requirement
that several such devices or systems be used to approach the
desired aesthetic or decorative effects. The number of moving
components of these systems are thereby multiplied, leading to
maintenance problems. When several such light systems are utilized,
a time synchronization is often required, particularly when one
attempts to associate music with a changing color display or an
analogous dynamic lighting system. This objective is difficult to
accomplish with conventional systems owing to large numbers of
moving parts and other practical difficulties. Moreover, the
potential variation in color patterns has been severely limited for
the reasons pointed out above.
In many other fields of endeavor, it is desired to illuminate
relatively large areas in varying color patterns. For example, in
the fields of theatrical and nightclub lighting, various means have
been utilized for providing colored illuminational patterns, for
backdrop or other environmental effects. Frequently, a subdued
character is desired of these environmental effects. This is
accomplished by rather complex lighting systems, as alluded to
above, requiring, where moving patterns are desired, the services
of a skilled operator to arrange the necessary combination of
lighting components, to achieve a desired sequence of colors or
color patterns. Conventionally theatrical lighting systems for this
purpose include a light source with a plurality of
solenoid-operated color filters for selective orientation in front
of the light source for varying the color saturation with which the
stage is illuminated. Such equipment may require several hundred
color panels, and numerous light sources, all of which must be
operated by skilled personnel. Other arrangements involve
complicated arrays of mirrors and/or projectors, none of which is
capable of changing color patterns with smooth transitions between
colors and hues.
Certain of these problems have been alleviated to some extent by
projection and display devices disclosed in the U.S. Pats. to
Clark, III No. 3,431,044; Lane et al. No. 3,315,391; and Billings
No. 2,600,962. The Clark device inherently involves a number of
moving parts but limited color variation. The potential color
variations achieved by the Clark device are limited by employment
of a solid double refractive member. The polarizing panels of the
Clark arrangement, when crossed, would considerably reduce light
transmittance.
A similar arrangement is shown in the Lane et al. reference in
which the intermediate solid member is additionally deformed to
simulate motion. The Billings device is analogous, except that a
stress-responsive birefringent crystal is employed. The Billings
arrangement, moreover, is not directed to the problem of aesthetic
or decorative lighting, as it is arranged to pass very narrow
optical bands.
In general, the variety of color patterns attainable with devices
such as disclosed by Lane et al. and Clark is limited, owing to the
employment of birefringent solid members. The cited references
require the use of various light polarizing structures, which are
not essential to our invention. Our color display device, which can
be more or less permanently and directly applied to large surface
areas, such as walls, ceilings, stage backdrop, and furniture
surfaces, in many cases obviates the need for colored lights or the
optical projection of color patterns.
We overcome these disadvantages of the prior art by providing a
unique optical display device capable of producing an infinite
variety of color variations and patterns. The solution of this
perennial problem is realized by introducing a liquid crystalline
material into a display device of novel construction. Desirably the
liquid crystalline material is selected which has a characteristic
of variable light scattering at room temperature or at least at
those environmental temperatures under which the device is
employed. For example, a liquid crystalline material can be
selected, which is capable of variable light scattering at
operating temperatures in the region of an illuminating light
source, for example one utilized in an advertising sign, area
lighting, or other display arrangement. The selected liquid
crystalline material desirably but not necessarily exhibits a
variable scattering characteristic which is further modified when
subjected to mechanical deformation, such as occasioned by shear or
flow stresses.
Accordingly, our novel display device or liquid crystal cell is
provided firstly with a light transmitting wall to permit viewing
of the contained liquid crystalline material. Secondly, the liquid
crystalline cell is desirably associated with means for inducing
deformational stresses within the contained liquid crystalline
material. This can be accomplished in a variety of ways: For
examples, the liquid crystalline cell can be constructed with means
permitting the displacement of one wall structure thereof relative
to another. Various mechanical means can be associated with the
cell or display device for inducing flow and attendant shear
stresses within the liquid crystalline material.
Our display device as thus far described is capable of a large
number of applications, for example as an aesthetic novelty,
decorative wall, floor and ceiling panels, backdrops for stages and
other illuminated areas, toys, book and album covers, place mats,
paper weights, clock faces, displays for table tops and other
furniture surfaces, and numerous analogous applications. For many
of these applications a subdued background or environmental
illumination is sufficient for viewing the infinite variety of
color patterns resulting from a stress manipulation of my display
device. Deformational stresses can be applied manually or through
the operation of suitable mechanical, electromechanical, or
electrohydraulic means. Owing to the pressure sensitivity of many
liquid crystalline materials, useful in our invention, stresses can
be applied by vibratory or minor shock energies. For example,
certain forms of the display device can be suspended or stretched
over loudspeaker, or the like, such that color pattern changes are
effected by sonic vibrations. An analogous application involves
incorporation of my display device on piano tops or in connection
with other musical instruments.
In many other applications, our liquid crystal display devices find
utilization where it is desirable to show visually strain patterns,
or patterns of stress application. For example, components of our
display devices can be applied to such items as glass or metal
sheets to demonstrate physical stresses therein.
Conventionally, the usefulness of cholesteric liquid crystalline
materials has been severely limited owing to their greaselike
nature. There has been no adequate conventional means for
protecting the liquid crystalline material from a hostile
environment such as dirt, dust, oil and accidental removal of the
material from the surface to which it is applied. Various means for
encapsulating liquid crystals have been proposed from time to time.
According to one such attempt, the liquid crystalline material is
encapsulated as minute balls or droplets in a gelatin matrix. The
form of encapsulation, however, does not permit the visual stress
phenomenon to be observed and greatly diminishes the
light-scattering characteristic of the liquid crystal. Other
attempts, involving a simple overlay with a protective material,
have met with failure in the absence of an adequate sealing means
for excluding elements of a hostile environment.
With the application of deformational stresses to the liquid
crystalline material, a distinct and abrupt change in the color of
the selectively scattered light is observed. The greatest color
change is observable in the area of greatest mechanical force. A
deformational force as small as 0.5 gram per square centimeter can
be registered as shear phenomenon by appropriate liquid crystalline
materials. The sensitivity of these materials is illustrated by the
fact that a liquid crystal encapsulation according to our invention
and of suitable length (several feet, for example) can be used to
register a sound wave.
The color patterns produced by the deformational stresses have a
relaxation time, that is to say the time for the visible effects of
the deformation to return to their "relaxed" form after the
deformational stress is removed. The deformational stress is most
advantageously applied normally of the liquid crystal
encapsulation. The pressure can be applied for a smaller or greater
interval of time, but preferably for a minimum of 0.2 second. The
deformation stresses can be applied by means of an auxiliary member
either incorporated in or separate from the encapsulation and
having a message, aesthetic design, or the like embossed thereon. A
plurality of such auxiliary members can be provided, if desired,
for use with a single encapsulation to provide a variety of
messages or designs. By pressing the design or message member
against a flexible portion of the liquid crystal encapsulation the
message or design is delineated by lines or areas of darker color
in the ensuing color pattern.
The clear or transparent member of the encapsulation can be made
from two or more associated materials of differing refractive
indicies for a further enhancement and a variety of the color
pattern display.
Therefore, we also contemplate the use of various novel container
means to enhance or modify the color patterns and to protect the
liquid crystalline material from hostile environments. At least one
section of the container is light-transmitting for viewing purposes
and a second container section is secured thereto to enclose a
quantity of the liquid crystal. The second container section
desirably is closely disposed to the first-mentioned container
section to conserve liquid crystalline material, which in most
applications can be utilized in the context of film thicknesses.
The liquid crystal container can be substantially flat, or
otherwise as described more fully below, and can be made
sufficiently large to cover entire desk or table top surfaces or
wall and ceiling surfaces, for example. The liquid crystalling
areas of such panels can be continuous or discontinuous depending
on the application and character of the container. Light-absorbing
means are associated with the liquid crystal material to absorb
transmitted light, which would otherwise substantially mask that
light which is also variably scattered from the liquid crystal. The
light absorber can be incorporated directly in the liquid crystal
as a dark dye or suspended material. Alternatively, the second
container section can be dark opaque or otherwise dark hued to
absorb part or all of the transmitted light to enhance the light
scattering characteristic of the liquid crystalline material.
Optimally the light absorber is black for maximum enhancement. At
least one of the container sections desirably is flexible or
resilient so that the aforementioned deformational stresses can be
applied to the liquid crystal externally of the package.
Alternatively, deformational stresses can be applied internally of
the container, for example in accordance with certain modifications
of the invention described and claimed in a copending, coassigned
application of Edward N. Sharpless entitled "Variable Color Display
Device and Projection Means Therefor," Ser. No. 40,899, filed
concurrently herewith.
Desirably, the light-transmitting section is of a certain minimal
thickness to enhance an illusion of depth in the color pattern of
the liquid crystal. In such case, the light-transmitting panel
preferably is transparent. The use of a relatively thick
light-transmitting section for enhancement purposes is particularly
desirable in relatively small decorative objects or panels, which
may be viewed from a number of angles or positions. We also
contemplate the formation of the liquid crystal container in a
variety of shapes and forms, for example as a cube,
parallelopipedon, prism, various types of pyramidal forms,
hemisphere, hexahedron, octahedron, and other geometric forms. In
the multifaceted forms, we contemplate further the application of
liquid crystalline material and corresponding second container
sections of two or more faces or facets of the form. Obviously, the
invention is equally applicable of nongeometric or random shapes
which may be faceted or nonfaceted.
The aforementioned forms and shapes desirably are of
light-transmitting and preferably transparent material so that an
interesting array of reflections and refractions of color patterns
are seen within the shape. An unexpected feature of this form of
the invention is the fact that the various reflections or
refractions may be of widely differing basic colors, as the viewing
angle is effectively different for each reflection or refraction of
the liquid crystal surface. Our invention utilizes, therefore, in
an unobvious manner, another aspect of the selective scattering
characteristic of the liquid crystalline material.
In the latter feature of our invention the forms or shapes can be
molded from a transparent plastic and various types of coins,
models, fossils, precious and semiprecious stones and the like can
be molded within the plastic and viewed against the variable and
colored background of the encapsulated liquid crystalline material.
The last-mentioned display devices can be utilized as various
decorative objects for desk and table tops or as part of ink
stands, pen and calendar holders and similar utilitarian
articles.
In another arrangement of our invention, a synchronous motor can be
provided for operating the aforementioned stress-varying means in
accordance with a timed or rythmic sequence for synchronizing our
color display device with music or other rythmic operation. Our
novel display device is capable of an infinitely variable sequence
of color patterns for aesthetic, decorative, and entertainment
purposes. A large number of applications of our inventions in the
advertising field for various types of eye-catching signs and
displays will become readily apparent.
Our display device is capable of producing nonrepetitive color
patterns which are a mixture of natural hues and intensities. The
effects achieved are warm, relaxed, and psychologically subdued and
are therefore particularly desirable for decorative and other
aesthetic purposes.
Besides its aesthetic values, our display device is useful in
depicting, as a color display, relative motions between or among a
number of objects. Such relative motions can be comparatively
slight and even of a vibratory nature. Of greater significance is
the capability of simultaneous indication of a number of forces
applied externally to our display device at a given time.
We are aware, of course, of a number of United States Patents
relating to various applications of liquid crystalline materials.
For example, Fergason et al., U.S. Pat. No. 3,114,836 depicts an
imaging device, which exhibits a color pattern on a film of liquid
crystal upon focusing a heat or thermal pattern thereon. Fergason
U.S. Pat. No. 3,409,404 discloses a liquid crystalline device in
which variation in selective scattering of liquid crystalline
materials is employed for identifying unknown materials. Williams
U.S. Pat. NO. 3,322,485 utilizes a threshold characteristic of
liquid crystalline material to scatter light selectively in the
presence of a given electric field. Freund et al. U.S. Pat. No.
3,364,433 employs a frequency-shifting characteristic of liquid
crystalline materials in the presence of an electric and/or
magnetic field. None of these references, however, discloses a
color display device utilizing liquid crystalline materials in
which an infinite or non-repetitive pattern is exhibited by a
liquid crystalline material applied by attendant variation in
applied mechanical stresses.
We accomplish these desirable results by providing a display device
for exhibiting a color pattern, said device comprising container
means having a light-transmitting section and a juxtaposed opaque
section, a quantity of liquid crystalline material interposed
between said container sections and encapsulated within said
container means, said material having a characteristic of selective
light scattering within a range of temperatures at which said
display device is normally utilized, and means for peripherally
sealing one of said container sections to the other.
We also desirably provide a similar display device wherein said
material has an additional characteristic of a selective light
scattering which is variable in accordance with applied
deformational stresses, and means are provided for the application
of said deformational stress to said material.
We also desirably provide a similar display device wherein flow
effecting means include means for displacing at least one of said
container sections relative to the other of said sections to effect
flow of said material within said container.
We also desirably provide a similar display device wherein the
juxtaposed surface of said opaque section is provided with a dark
color.
We also desirably provide a similar display device wherein said
light-transmitting member is a transparent hemispheroidal member,
and said opaque container section is peripherally joined and sealed
to a substantially flat surface of said hemispheroidal member, at
least some of the faces of said multifaceted member are disposed
for reflection and/or refraction of the color pattern of said
liquid crystal.
We also desirably provide a similar display device wherein said
light-transmitting section is a transparent multifaceted member
having container means encapsulating a quantity of liquid
crystalline material and secured to at least one face of said
multifaceted member.
We also desirably provide a similar display device wherein said
light-transmitting section is a substantially flat transparent
member of about one-eighth inch in thickness.
We also desirably provide a similar display device wherein said
light-transmitting section in a transparent member and said opaque
section is peripherally sealed to a surface of said transparent
member to encapsulate said liquid crystalline material, a stand is
provided for said display device, said stand being shaped to
receive at least those portions of said transparent member adjacent
said surface, said opaque section is relatively flexible, and said
stand includes indicia means engageable with said opaque section
when said device is seated in said stand for applying deformational
stress to said opaque section to outline said indicia within a
color pattern of said material which is visible through said
transparent member.
During the foregoing discussion, various objects, features and
advantages of the invention have been set forth, or alluded to.
These and other objects, features and advantages of the invention
together with structural details thereof will be elaborated upon
during the forthcoming description of certain presently preferred
embodiments of the invention and presently preferred methods of
practicing the same.
In the accompanying drawings we have shown certain presently
preferred embodiments of the invention and have illustrated certain
presently preferred methods of practicing the same, wherein:
FIG. 1 is an isometric view, partially broken away, of one form of
liquid crystal display device arranged in accordance with our
invention;
FIG. 2 is a cross-sectional view of the device as shown in FIG. 1
and taken along reference line II--II thereof;
FIG. 3 is a partial isometric view of another form of our novel
display device in conjunction with mechanical means for the
application of deformational stresses;
FIG. 4 is an isometric view of still another form of our display
device configured in the context of a common geometric form.
Illustrated also are pressure-sensitive means for applying indicia
to the liquid crystal;
FIG. 5 is an isometric view of still another form of our display
device showing a multifaceted and multicontainer geometric
form;
FIGS. 6-8 are isometric views representing the incorporation of our
novel display device as still other geometric forms. FIGS. 7 and 8
show the incorporation of other decorative objects within the
liquid crystal container structure;
FIG. 9 is a similar view of another form of our novel display
device configured nongeometrically;
FIG. 10 is an isometric view of our novel display device
incorporated in a surface of an article of furniture or the
like;
FIG. 10A is an enlarged partial, isometric view showing a modified
form of the light-transmitting member shown in FIG. 10;
FIG. 11 is a partial isometric view of one form of wall structure
incorporating our novel display device;
FIG. 12 is an isometric view of another form of our novel display
device;
FIG. 13 is a cross-sectional view of the display device of FIG. 12
and taken along reference line XIII--XIII thereof;
FIG. 14 is an isometric view of still another form of our novel
display device;
FIG. 15 is a similar view of still another modification of our
display device;
FIGS. 16 and 16A are top plan views of an advertising novelty
arranged in accordance with our invention;
FIG. 17 is an isometric view of a further modification of our
display device, arranged here as a paper weight or the like;
FIG. 18 is an isometric view of the modified form of the invention
as shown previously in FIG. 15;
FIG. 18A is a cross-sectional view of the display device shown in
FIG. 18 and taken along reference line XVIIIA--XVIIIA thereof;
FIG. 19 is a similar view of another form of the novel display
device;
FIG. 19A is a cross-sectional view of the device as shown in FIG.
19 and taken along reference line XIXA--XIXA thereof;
FIG. 20 is an isometric view of a further modification of the
display device of our invention;
FIG. 20A is a cross-sectional view of the device as shown in FIG.
20 and taken along reference line XXA--XXA thereof;
FIG. 21 is a similar view of a further modification of our novel
display device;
FIG. 21A is a cross-sectional view of the device as shown in FIG.
21 and taken substantially along reference line XXIA--XXIA
thereof;
FIG. 22 is an isometric view of still another modification of our
invention, presented here as a display device capable of exhibiting
color patterns on both sides thereof;
FIG. 22A is a cross-sectional view of the display device of FIG. 22
and taken along reference line XXIIA--XXIIA thereof;
FIG. 22B is a similar view of a modified form of the device as
shown in FIGS. 22 and 22A, but incorporating novel message
means;
FIG. 22C is a similar view of our novel display device but
incorporating modified light absorption means, in which the color
pattern is visible through a flexible section of the display device
container;
FIG. 22D is a cross-sectional view similar to FIG. 13 but
illustrating a sheet form modification of our invention, in which
the display device container is completely flexible;
FIG. 23 is a side elevational view of a further modification of our
novel display device and incorporating another form of deformation
producing means according to our invention;
FIG. 23A is a cross-sectional view of the device as shown in FIG.
23 and taken along reference line XXIIIA--XXIIIA thereof;
FIG. 24 is an exploded isometric view of still another modification
of our novel display device;
FIG. 24A is an assembled isometric view of the display device shown
in FIG. 24;
FIG. 24B is a cross-sectional view of the display device as shown
in FIG. 24A and taken along reference line XXIVB--XXIVB
thereof;
FIG. 24C is an isometric view similar to FIG. 22 and to others of
the preceding Figures, but illustrating the use of multiple
encapsulations;
FIG. 24D is a cross-sectional view of the display device shown in
FIG. 24C and taken along reference line XXIVD--XXIVD thereof;
FIG. 25 is an isometric view of a modification of our novel display
device similar to that illustrated previously in FIG. 4;
FIG. 25A is a cross-sectional view of the display device as shown
in FIG. 25 and taken along reference line XXVA--XXVA thereof;
FIG. 25B is a similar view of a modified form of the display device
as shown in FIGS. 25 and 25A;
FIG. 25C is a similar view of a modified form of the display device
as shown in FIGS. 25 and 25A;
FIG. 25D is a similar view of a modified form of the display device
as shown in FIGS. 25 and 25A;
FIG. 26 is an isometric view of still another modification of our
novel display device;
FIG. 26A is a cross-sectional view of the display device of FIG. 26
and taken along reference line XXVIA--XXVIA thereof;
FIG. 27 is an isometric view of still another form of our novel
display device;
FIG. 27A is a cross-sectional view of the display device as shown
in FIG. 27 and taken along reference line XXVIIA--XXVIIA
thereof;
FIG. 28 is an isometric view of still another form of our novel
display device;
FIG. 28A is a cross-sectional view of the display device as shown
in FIG. 28 and taken along reference line XXVIIIA--XXVIIIA
thereof;
FIG. 29 is a bottom plan view of a further modification of our
novel display device incorporating another form of our
deformational means;
FIG. 29A is an elevational view, partly in section, of the display
device of FIG. 29;
FIG. 30 is an isometric view of still another form of our novel
display device, incorporating in this case novel illumination means
therefor; and
FIG. 30A is a cross-sectional view of the display device as shown
in FIG. 30 and taken along reference line XXXA--XXXA thereof.
With reference now to FIG. 1 of the drawings, a display device 10
in the form of a liquid crystalline support 12 is illustrated
therein. In this arrangement, the support 12 in the form of a flat
container having opposed container wall sections or structures
14,16 of any suitable size and shape. In the arrangement shown, the
wall sections 14, 16 are substantially coextensive although this is
not an essential requirement. In point of fact, one of the wall
structures 14, 16 can be significantly smaller than the other wall
structure (FIG. 3), as long as one wall structure is joined about
its periphery to the other wall structure, for example in the
manner described below. Likewise, the wall structures 14, 16 need
not be of flat configuration as illustrated but can be of some
other configuration for example parallelopipedon or hemispherical
as illustrated in FIGS. 4 and 5. It is contemplated however, that
any geometrical or nongeometrical, symmetrical or nonsymmetrical
shape or form can be employed for either or both of the wall
structures 14, 16. As noted previously, the wall structures 14, 16
need not be coterminus. Further, the wall structures 14, 16 need
not be planar as shown in FIGS. 1 and 2 but instead one or both
sides thereof can be dished as indicated in the aforementioned
copending application, or they can be otherwise configured as
described below.
Depending on the manner in which the wall structures 14, 16 are
joined, the resilience and hence the thickness of either or both of
the wall structures 14, 16 may or may not be critical. Such
criticality, whether encountered depends on the manner in which
deformational stresses are to be applied to a liquid crystalline
material 18 confined between the wall structures 14, 16. In the
arrangement of our novel display device as illustrated in FIGS. 1
and 2, at least one of the wall structures 14, 16 is sufficiently
thin or is made of a suitably plastic material as to lend a
resilient or flexible character to the wall structure. Thus, the
wall structure, such as the wall structure 16 can be bent or
otherwise deformed toward the wall structure 14 when a force is
applied more or less transversely thereto as denoted by arrow 20.
Such force can be applied at various locations on the wall 16 as
denoted by dashed arrows 21.
By thus bending one of the wall structures 14, 16 relative to the
other, the liquid crystalline material 18, which is supported, in
this example, between the wall structures 14, 16 in filmlike form,
is caused to flow generally away from the region of applied force
(arrows 20, 21) to other regions of the volume confined within the
liquid crystal container 12. The application of the force 20 and
the resultant flow of the liquid crystal 18 develops shear and
other deformational stresses within the liquid crystal 18. Such
stresses modify the light scattering and attendant transmittance
characteristics of the liquid crystal material 18 and result in an
endless variety of color changes and patterns.
In order to observe these aesthetic color changes one of the
container sections, for example the section 14, is light
transmitting, and desirably transparent, to permit the display
device 10 to be observed from a side away from the application of
deformational forces 20 or 21. The clear container section 14 can
be fabricated from polyacrylic, polycarbonate, polybutyrate, glass
or other suitable material.
At least a portion of the other wall structure 16 can be made dark
opaque or of a more or less transparent but darker hued material
for optimum visual characteristics, which result from viewing only
the light scattered from the display device 10, in particular from
its liquid crystal layer 18. The darker hued container section 16
may be a buff gray or other neutral color although desirably a
darker coloration will make the color patterns of a liquid crystal
more obvious. A particular color may be selected or several colors
can be provided on that side of the container section 16 facing the
liquid crystalline material 18. Use of such coloring, particularly
a darker color or mixture of colors, lends an interesting and
subtle shading to the color patterns produced in the liquid
crystals. For maximum light-scattering characteristics of the
liquid crystal, the background "coloration" desirably is black,
which, as in the case of the aforementioned colors can be coated at
17 on the container section 16 or incorporated therein. The terms
"dark-opaque" or "dark-hued" are inclusive of black for the
purposes of this specification and claims. Similarly, "dark-hued"
is inclusive of colored but transparent or translucent materials of
low light transmittance. Desirably, whatever coloration is provided
for the container section 16 is made at least coextensive with the
area of the liquid crystalline material 18. The dark colored, black
and/or dark opaque layer can be applied at the interface of the
liquid crystal 18 and container section 16 as shown or
alternatively on the juxtaposed outer surface of the container
section 16, if the container section 16 is otherwise clear or
transparent. Alternatively the light-absorbing means can be
physically incorporated in the liquid crystal 18, as described
below in reference to FIG. 22A.
As noted previously, at least one of the container sections 14, 16
is joined about its periphery to a surface of the other wall
structure. In the FIG. 1 arrangement, such joining means are
further arranged to peripherally seal one wall structure to a
surface of the other. In the display device 10, such joining and
sealing means include a pressure-sensitive tape 22, which is
compatible with the material of the wall structures 14, 16 and
covers their coextensive peripheral edges. The liquid crystal 18 is
thereby sealed in the context of film thicknesses within the space
defined by the slightly separated wall structures 14, 16 and the
peripheral tape 22. It will be understood, of course, that the
separation between the wall structures 14, 16 can be different from
that illustrated, depending upon the relative quantity of liquid
crystal 18 which is used, the desired intensity of color patterns,
and the background coloration of the dark-opaque or dark-hued
container section 16. Generally, a relatively thin film of liquid
crystal 18 should be enclosed between the wall structures 14, 16 in
conservation of the liquid crystalline material.
In those cases wherein the joining and sealing tape 22 is quite
flexible and more or less loosely applied at the wall edges or is
at least somewhat elastic, one or both of the wall structures 14,
16 can be made thicker and hence less resilient. In such cases, an
eccentric application of the deformational force 20 will cause one
of the wall structures to become slightly canted or angulated or
otherwise displaced relative to the other in order to induce
deformational flows in the liquid crystalline material. Such
deformational flows are, of course, aided by the elasticity and/or
edge slackness of the joining and sealing tape.
In any event it is desirable to provide the light transmitting
section 14, particularly when transparent, with appreciable
thickness to enhance the variable color patterns of the liquid
crystal 18 and to create an illusion of depth. When the display
device is substantially planar as in FIGS. 1, 2, 10 and 11, the
container section 14 should be in the neighborhood of about
one-eighth inch or more in thickness although such thickness is not
essential to the invention and can be varied depending upon a
specific application of the display device. When the device is
incorporated into a relatively small decorative object, a
transparent container section of at least this thickness is
desirable as the object is more readily viewed from different
angles or positions. When supplied in greater thicknesses or when
multifaced or faceted, the variable color display is even further
enhanced as described below.
The liquid crystalline material 18 is selected from one or more of
those materials which exhibit variation in light-scattering and
attendant transmittance characteristics under deformational
stresses. Desirably, such variations are within the visible range
at room temperatures or at whatever ambient temperature conditions
prevailing in the area of utilization of the display device 10. As
an example of the latter situation, the liquid crystalline material
18 can be one of those which exhibit visual stress variation in the
aforementioned characteristics at or near body temperature, and is
therefore useful when the display device is held in the observer's
hand. Larger display devices 10 can of course be bathed with
infrared radiation, if their liquid crystals are not of the
room-temperature-visual variety.
On the other hand, display devices for outdoor use, as for signs
and other advertising situations, require liquid crystalline
materials exhibiting stress indicia at correspondingly lower
temperatures.
There are a considerable number of substances which exhibit the
characteristics required of the liquid crystalline material 18. In
general the category of materials known as cholesteric liquid
crystals are suitable for use with my invention and exhibit an
optical phenomenon known as selective scattering of white light.
The appellation of this categorization of liquid crystals
originates in the frequent use of cholesterol as the starting
material in synthesizing these organic substances. The derivatives
of cholesterol usually are liquid crystalline in character and
demonstrate the characteristic of selective light scattering.
Liquid crystalline substances fall additionally into the general
chemical classifications of esters, carbonic esters, ethers, schiff
bases, and related classes. Nominally, the cholesteric liquid
crystals are not limited to the use of cholesterol as a base
material. Many steroids exhibit similar optical characteristics
when synthesized into the general classifications of organic
compounds, as mentioned above. These and other "cholesteric" liquid
crystals are useful for the purposes of our invention as long as
their molecular arrangement exhibits the necessary anisotropic and
optical characteristics.
For the purposes of our invention, we employ a cholesteric liquid
crystalline material which exhibits a relative optical phenomenon
attendant to the selective scattering characteristic of this
category of liquid crystal. The latter characteristic is the stress
or shear sensitivity of certain cholesteric materials whereby the
selective (light frequency) scattering characteristic is varied
upon the application of deformational stresses.
Cholesteric materials will selectively and visibly scatter white
light, at or near room temperature conditions, when two or more of
these substances are admixed in proper proportions. Mixtures of
liquid crystals can be selected or varied to obtain visual
responses at other temperatures for the purposes mentioned
previously. It is observed that a physical deformation of the
liquid crystal will shift the frequency of the observed cholesteric
color display or pattern, when viewed at a given angle, toward the
blue or shorter wave length end of the visible spectrum. The amount
of color shift, measured in wave length units, can be employed to
indicate quantitatively the physical stress applied to the
cholesteric material, when a given liquid crystalline material has
been properly calibrated.
A constant pressure applied to the liquid crystalline material will
not, after its initial application, thereafter appreciably effect
the then observed color patterns. Instead, the great variety of
color changes or patterns exhibited by our display device are
produced by changes in applied forces and attendant deformational
stresses. With acceleration of changing deformational stresses, in
either direction, changes in the observed color patterns become
more pronounced.
It has also been observed that the application of a constant
deformational stress over a significant period of time will
initially induce an observable change in the cholesteric color
pattern, which despite continued stress, will revert to the
unstressed or original cholesteric color in time. That is to say,
there is a relaxational effect in the liquid crystalline structure,
owing to its nature.
It is contemplated that the liquid crystalline material may have a
single basic color or that a mixture of liquid crystalline
materials having differing basic colors can be employed. For
example, liquid crystalline materials I, V, and/or VI, tabulated
below, can be employed in the package 10 or in others of the
packages described below. It is also contemplated that liquid
crystalline materials of differing basic coloration can be employed
in differing areas of the package 10 but within the same liquid
crystalline layer 18 to enhance the variety of color patterns.
Owing to the viscous nature of the liquid crystals, the differing
colored materials will not readily admix although the flexible or
resilient backing layer (if used) of the package is manipulated a
relatively large number of times.
It will be understood herein that a cholesteric substance is one
which exists in the cholesteric state at a certain temperature. The
cholesteric state of such mesomorphic substance exists in the
region between the temperature at which the substance behaves as a
true liquid and the temperature at which the substance is a solid.
In the cholesteric state, the substance is optically negative, has
a strong rotatory power, selectively scatters light to give vivid
colors (or monochromatic light to give areas of darkness and
brightness), and exhibits circular dichorism. Such a physical state
is especially notable in derivatives of cholesterol and like
materials, although a relatively few other substances such as
optically active amylcyanobenzylidineaminocinnamate and the
aforementioned steriods exhibit the cholesteric state.
The liquid crystalline substances herein contemplated will be in
the cholesteric state within at least a certain temperature range,
but as the temperature is raised above or depressed below this
range the substances will pass into another mesomorphic state or
into a normal liquid or solid state. Thus, the cholesteric
substance will be in the cholesteric state at a first temperature
and will change its phase into some other state at a second
temperature. The range of temperatures within which a visible color
display is exhibited as a result of scattering of white light can
be determined by a proper selection of cholesteric substances and
will be referred to as the color play range.
Cholesteric substances used according to the present invention can
be chosen from a wide range of compounds exhibiting the cholesteric
phase. Derivatives of cyclopentanophenanthrene are desirably used.
There are a number of factors to be considered in selecting such
derivatives: All of the ring systems should be in the trans
configuration, the 3-substituent (on the A ring) should be in the
B-configuration, and there should be no more than two axial methyl
groups. Unsaturation at the 5, 6 carbon atom bond can have an
effect on the melting point, but otherwise has little effect on the
formation of the cholesteric phase. Thus, derivatives of such
cyclopentanophenanthrenes as cholesterol, compesterol, ergosterol,
B-sitosterol, stigmasterol, and like materials can be used.
It is preferred in the present invention to utilize alkyl and aryl
derivatives of the cyclopentanophenanthrene materials, particularly
those derivatives which are esters of alkanoic or aralkanoic acids,
or mixed alkyl esters of the cyclopentanophenanthrene material and
carbonic acid. The alkanoic acids used can contain from one to 24
or more carbon atoms in the molecule, and can be saturated or
unsaturated and straight or branched chain. It is preferred to
utilize esters comprising higher fatty acids, containing from nine
to 22 carbon atoms or lower saturated or unsaturated phenalkanoic
acids having one to three carbon atoms. Mixed carbonate esters
comprising alkanols having from one to 22 carbon atoms and
cholesterol are also among the preferred cholesteric
substances.
Such derivatives of cholesterol are presently preferred in certain
aspects of the invention. Thus, useful cholesteric substances
include cholesteryl nonanoate, cholesteryl caprylate, cholesteryl
laurate, cholesteryl palmitate, cholesteryl stearate, cholesteryl
arachidate, cholesteryl behenate, cholesteryl oleate, cholesteryl
linoleate, and cholesteryl linolenate, cholesteryl benzoate,
cholesteryl cinnamate, cholesteryl dihydrocinnamate, and the like.
Carbonate esters such as oleyl cholesteryl carbonate, stearyl
cholesteryl carbonate, methyl cholesteryl carbonate, ethyl
cholesteryl carbonate, pentyl cholesteryl carbonate, and the like
carbonates are very useful in the present invention.
It will be appreciated by those skilled in the art that a pure
cholesteric substance may have only a very limited color play
range. HOwever, where this color change does not occur at the
temperature of interest, several stratagems permit coverage of a
broad range of temperatures from 0.degree. C., and even down to
-40.degree. C., up to and above 250.degree. C. One method of
varying the color play temperature range is to prepare a substance
at a desired purity level, as increased impurities usually lower
the temperature range. One convenient method of carrying out this
adjustment is to admix a plurality of chemically distinct
cholesteric substances having different color play temperature
ranges until the desired temperature range is obtained. Another
method of adjusting the color play range is to prepare the
substance in a highly purified form and to admix enough of a less
refined aliquot or aliquots of the substance with the purer
material until the desired change of color play range is obtained.
For instance, in this latter aspect, a 99.99% pure cholesteryl
oleyl carbonate can be prepared and admixed with less refined
material. Those skilled in the art will have no difficulty in
providing a desired transition temperature for use in the
compositions and articles of the present invention. All parts,
proportions, percentages and ratios herein are by weight unless
otherwise stated.
The following tabulation will exemplify a few of the many color
play regions obtained with the cholesteric substance or substances:
##SPC1##
It will accordingly be appreciated that one, two or more
cholesteric substances can be mixed to obtain the requisite color
play temperature range, and that both the temperature and the range
of temperatures can be widely varied. It is desirable that the
cholesteric substance(s) not crystallize at the lowest temperature
at which they are held before use.
As disclosed above, a desired melting range can also be obtained by
varying the purity of cholesteric substances. It is usually found
that increasing the purity raises the temperature of the color play
region and a narrowing of the range is also frequently obtained. It
will, of course be appreciated that the presence of excessive
quantities of impurities will ultimately entirely prevent obtaining
of the cholesteric phase, especially if the impurities themselves
are not cholesteric substances. The cholesteric substance(s) can
also comprise up to 5 percent or so of miscible materials such as
fatty acid triglycerides to lower the range. As disclosed
hereinafter, it is most desirable to protect the cholesteric
substance from the milieu to obviate the inhibition of impurities
by the cholesteric substances and thereby to maintain the desired
color play temperature.
As an illustration, cholesteryl oleyl carbonate is prepared as
described in "Detection of Liquid Crystals," AD 620 940, U.S.
Department of Commerce Aug. 1965). A portion of the cholesteryl
derivative is purified by solvent extraction and washed with
methanol. The purified cholesteryl material is found to have a
color play temperature of 21.degree.-22.degree. C. Admixing 80
parts of this material with 20 parts of an unpurified material
provides a color play temperature of 15.degree.-16.degree. C.
The cholesteric materials for use with this invention can also
include a cholesteryl halide. Although cholesteryl fluoride can be
prepared, the desired halides for use herein are cholesteryl
chloride, cholesteryl bromide, cholesteryl iodide, and mixtures of
these halides. The preferred halide for use herein is cholesteryl
chloride.
The cholesteryl halide serves to provide a uniform color over a
broad range of temperatures in which the cholesteric substance or
substances are in the cholesteric phase. Thus, in such case, our
novel display device shows a single color below transition to the
condition wherein the liquid crystal does not scatter visible
light, i.e., the condition in which it becomes colorless. The color
below the transition point can be selected according to the amount
of cholesteryl halide used. As the quantity of halide is increased
from about 15 percent of the composition up to above 40 percent,
the color usually varies from deep violet to deep red. The quantity
of halide used will also vary according to the particular
cholesteric substances utilized.
These halides are conveniently prepared by refluxing the
cholesterol with an excess (twice or more, stoichiometrically) of a
thionyl halide for 48-72 hours and distilling the mixture
thereafter to remove unreacted material. Generally, the purity of
the halides is sufficient to permit the desired change of phase
from the cholesteric. It is preferred that the halides be at least
90 percent pure. Such halides usually have a tendency to broaden
the color play temperature range of the cholesteric
substance(s).
Depending upon a particular application of our display device a
cholesterol halide may or may not be used depending on whether a
single or multiple color display is desired.
Specific examples of liquid crystalline compositions useful for our
present invention appear below, wherein all amounts are in parts,
"ChCl" is cholesteryl chloride melting at 94.degree.-95.degree. C.;
"High ChOlC" is cholesteryl oleyl carbonate showing a color play at
20.degree.-22.degree. C.; "Low ChOlC" is cholesteryl oleyl
carbonate showing a color play at 5.degree.-6.degree. C.; "ChNo" is
cholesteryl nonanoate; and the upper temperatures are those at
which the compositions become colorless. ##SPC2##
Other alkanoic esters of cholesterol or alkyl carbonate esters of
cholesterol can be used in the foregoing Examples to provide a
broad variety of temperatures and temperature ranges for the liquid
crystalline material 18. Likewise, other cholesteric materials such
as corresponding derivatives of B-sitosterol, stigmasterol,
ergosterol, and the like can be substituted with comparable
results.
In the display device 10 of FIGS. 1 and 2 it is contemplated that
the forces 20, 21 can be applied manually, for example by pressing
or stroking the container section 16 with the fingers. A single
force can be applied as designated by arrow 20 or alternatively
multiple forces can be applied as desired as denoted by arrows 21.
The edge-sealing tape 22 can be of the pressure-sensitive variety,
desirably of the light-transmitting or transparent type, in the
illustrate embodiment. It will be understood, of course, that other
means can be utilized for joining and sealing the container section
16 to the container section 14. For example the joining means
illustrated in the aforementioned copending application or herein
in subsequent figures can be utilized, depending upon the
application of the invention.
Alternatively the container sections can be joined as illustrated
in FIG. 3. The latter arrangement of our invention demonstrates
also that the container sections need not be coterminus. In the
container 12' of the display device 10' of FIG. 3, container
section 16' is of appreciably smaller area than that of the
container section 14'. In this example the section 14' is
relatively rigid and light-transmitting or transparent in contrast
to the resiliency and opaqueness of the section 16' for the reasons
set forth above. Where the joining and sealing tape 24 is of a
character, for example, inherent elasticity, to permit, of itself,
relative displacement of the container sections 14', 16', the
container section 16' can also be made rigid. The container
sections 14', 16' enclose a quantity of liquid crystalline material
18' therebetween, and the periphery of the smaller container
section 16' (in this case) is sealed and joined to the juxtaposed
surface of the larger container section 14', by means of the
aforementioned tape 24. The tape 24 also is of the
pressure-sensitive variety, and can be light-transmitting or
transparent to render its presence less obvious. The structure of
FIG. 3 exhibits the practical advantage of an inobvious joining
means, when the display device 10' is viewed from its
light-transmitting surface.
The color patterns of the liquid crystal 18' can be varied manually
in the manner set forth above with respect to the display device 10
of FIGS. 1 and 2. Alternatively, various mechanical means can be
provided in conjunction with the display device 10' for the
application of deformational stress of the liquid crystal 18'. One
form of such means includes contacting means 26 including in this
example roller 28 positioned to engage the external surface of the
opaque wall structure 16'. Means are provided for reciprocating the
contacting device 26-28 across the exposed surface of the container
section 16'. One arrangement of such means includes a link 30
pivoted at 32 to the contacting means 26 and to crank 34. Although
the crank 34 is illustrated for manual actuation by hand wheel 36,
suitable motive means (not shown) can be substituted. The roller 28
of the contacting device is held in bearing engagement with the
container section 16' by means of a pair of slotted brackets 38, 40
which engage the projecting ends 42 of the roller axle.
The varying color patterns of the display device 10' can be set to
music or other rhythmic activity by rotation of the crank 34 in
accordance with a predetermined timed sequence, as by use of a
synchronous drive motor (not shown) and suitable gearing or other
transmission, arrangements of which are disclosed in the
aforementioned copending application.
The force applying arrangement of FIG. 3 is particularly useful for
varying the color patterns of large-area devices such as the wall
panel illustrated in FIG. 11 or other relatively nonportable
display devices.
As pointed out in the description of FIGS. 1 and 2 and previously
it is contemplated that the light-transmitting or transparent
container section can be provided with appreciable thickness to
enhance the variable color display made possible by our device. For
example display device 44 of FIG. 4 is furnished in the form of a
container 46 including in this example a hemispheroidal container
section 48 and a substantially flat container section 50 adhered to
the flat face 52 of the container section 48. In the modification
of FIG. 4 the substantially flat container section 50 can be
applied as shown in FIG. 3 except that the container section 50
desirably is made circular. The hemispheroidal container section 48
provides an interesting magnification and refraction of color
patterns 54 of the liquid crystalline material enclosed between the
flat face 52 of the hemispheroidal section 48 and the flat
container section 50.
The display device 44 can be utilized, for example, as an
entertaining and ornamental novelty for a table or desk top. A
relatively slight pressure upon the rounded surface of the
hemispheroidal container section 48 will apply compressional forces
to the resilient or displaceable container section 50 resting, for
example, directly upon the table or desk top. This in turn will
cause various flow patterns within the liquid crystal 54 depending
upon the magnitude and location of the applied forces. As a result
an interesting and entirely unexpected variable color display is
produced.
We contemplate also that localized forces can be applied to the
external surface of the container section 50. One arrangement for
effecting such force application includes a stand 56 adapted for
the display serve 44 and likewise shown in FIG. 4. The stand 56 in
this example includes a retaining rim 58, shaped to receive the
peripheral surface of the display device 44 adjacent its flat face
52. The bottom of the stand 56 desirably includes a number of
contact surfaces arranged in the form of a design, message, various
geometrical configurations, or other indicia. For example, the
bottom area 60 of the stand 56 may incorporate the owner's initials
denoted in this example by reference numeral 62. The design,
message item, or indicia 62 can be fabricated from any suitable
structural material, plastic or metallic, and desirably are
arranged such that their undersurfaces seat flushly against the
table or desk top. The upper surfaces of the design or message
items 62 project sufficiently above the remainder of the bottom
structure 60 and are supported in this example by connecting links
64. In consequence only the message items 62 are engaged by the
container section 50 when the display device 44 is seated in the
stand 58. When so arranged the message items or indicia 62 depress
the flexible container section 50 at their top surface areas with
the result that the items appear as a discrete and contrasting
coloration within the color pattern 54 of the liquid crystal. A
variety of stands 58 can be furnished with a single display device
44 to display a variety of message or design motifs of this
character. When the several stands, similar to the stand 56, are
thus changed corresponding changes in the overall color patterns of
the liquid crystal patterns likewise occur owing to differing
distribution of applied base or bottom forces at the flexible
container section 50.
Other geometric shapes can be utilized in addition to the
hemisphere or hemispheroid of FIG. 4. For example, FIG. 5
illustrates another geometric, transparent member 66, exemplarily
in the form of a cube, forming part of display device 68. One or
more faces of the cube 66 can be utilized as a component container
section of a corresponding number of liquid crystal containers or
cells. In the illustrated display device 68 two such cells 70 are
afforded, although obviously a different number can be furnished.
Each of the cells 70 include, in this example, a substantially flat
container section or structure 72 of about the same size as the
adjacent face of the cubic member 66. The container structures 72
can be secured to the corresponding face of the member 66 by means
of pressure-sensitive tape 74, after the manner of FIG. 3 or FIG. 1
depending upon whether the container structure 72 is desired to be
of the same size (FIG. 1) or correspondingly smaller than the
juxtaposed face of the cubic member 66 (FIG. 3). Quantities 76 of
liquid crystal enclosed between the container sections 72 and the
juxtaposed faces of the cubic member 66 are visible within the
transparent cubic member 66. The facets or faces of the cubic
member 66 provide an interesting array of reflections and
refractions of the variable color patterns of the liquid crystal
portions 76. With only a liquid crystal encapsulation at only one
cubic face, for example, up to about 13 reflections and refractions
(including secondary images) can be seen. An endless variety of
color patterns, therefore, can be obtained by application of forces
to the container sections 72 after the manner of FIG. 2 or FIG. 3,
or as set forth in the aforesaid copending application, and/or by
changing viewing angles.
Similar geometric shapes are illustrated in FIGS. 6, 7 and 8 which
respectively show parallelopiped, pyramidal, and prismatic shapes.
The transparent members 78, 80 and 82 of these figures each have
liquid crystalline material 84, 86 or 88 confined against one face
thereof after the manner of FIG. 4 or FIG. 5. Liquid crystalline
material (not shown) similarly can be applied to additional faces
of each transparent member 78, 80 or 82 if desired. The display
devices 90, 92, 94 of FIGS. 6-8 provide interesting and respective
arrays of reflections and refractions of the color patterns of the
contained liquid crystalline material. For example in FIG. 6 the
several refractions and reflections of the liquid crystal patterns
are denoted by the reference characters 84' and will of course vary
depending upon the direction from which the display device 90 is
viewed. Similarly, refractions and reflections 86' appear in the
display device 92 of FIG. 7 and a reflection 88' in the display
device 94 of FIG. 8. These and additional reflections and
refractions will appear or disappear depending upon the viewing
angle, all of which heightens the interest engendered by the
display devices. Moreover, the basic color of the associated liquid
crystal pattern and its reflections and/or refractions will vary
depending on the viewing angle. Of equal importance, the several
reflections and/or refractions will differ in color from each other
and from that of the liquid crystal itself, as the viewing angle is
effectively different for each reflection or refraction, although
the display device is viewed from a single position.
The aforementioned liquid crystal color patterns (which can be
varied by the application of deformational stress as described
previously or as set forth in the aforementioned copending
application) can be employed as unexpectedly decorative and
entertaining backgrounds for items such as coins, models, fossils,
precious and semiprecious stones, specimens and the like embedded
in the transparent member. In furtherance of this purpose a molded
plastic such as plexiglass or one of the polyacrylic resin is
employed for the transparent member. In the display devices 92 and
94 (FIGS. 7 and 8) coins 96 and 98 are so used. Other items (not
shown) can be employed with or substituted for the coins 96, 98. In
FIG. 7, one such coin 96 has been molded within the transparent
member 80, while several coins, in differing positions have been so
included in FIG. 8. A reflection 96' (FIG. 7) or reflections of
these items may appear depending again on the viewing angle.
The display devices according to this feature of our invention are
not limited, of course, to geometric shapes. For example display
device 100 of FIG. 9 incorporates a faceted but nongeometric or
irregular transparent solid 102 against at least one face or facet
of which is contained a quantity of liquid crystalline material.
The last-mentioned liquid crystalline material preferably is
encapsulated against the juxtaposed facet of the transparent member
102 in the manner described previously. A color pattern 104 of the
liquid crystal appears in a number of additional faces 104' of the
transparent member 102. The shaded facets 106 denote areas of
mirror-type reflections, which, when combined with the liquid
crystal color pattern 104 and its various reflections or
refractions 104', again provide an unexpected decorative and
entertaining display.
The display devices of FIGS. 4-9, as in the case of the devices 10
and 10' of FIGS. 1-3 are made of any convenient or suitable size.
Primarily, the display devices of FIGS. 4-9 are intended for
relatively small ornamental items for various decorative
purposes.
In FIG. 10, however, the adaption of our novel display device to
relatively large surface areas is exemplified. The latter form of
our display device 108 is incorporated in an article of furniture,
in this example table 110. For maximum effect the display device
108 is applied to top structure 112 of the table 110. The display
device 108 further includes a light-transmitting member 114 which
conforms in contour and extent to the shape of the table top 112.
The table top 112 and the light-transmitting member 114 are flat
although this is not necessarily the case.
A quantity of liquid crystal 115 is enclosed between the
light-transmitting member or sheet 114 serving as one container
component and a preferably opaque structure including sheet 116
which serves as the other liquid crystal component. The sheet 116
is adhered about its peripheral edges to the undersurface or
periphery of the light-transmitting member 114. The sheet 116 can
of itself be opaque, or if transparent, the table top 112
preferably is opaque.
The container components 114, 116 can be secured and sealed
together after the manner of FIGS. 1 or 3. Desirably also the
light-transmitting or transparent member 114 is relatively thin
such that forces applied to the upper surfaces thereof, either
manually as by individuals utilizing the table 110 for various
purposes or by various utilitarian objects placed upon the
light-transmitting member 114, produce an endless and unexpected
variety of color patterns within the liquid crystalline material
115 as a result of its variable light-scattering and
pressure-sensitive characteristics.
To heighten the observers interest still further a lens or
refractive configuration 118 can be molded in the
light-transmitting sheet 114 of the display device 108', as shown
alternatively in FIG. 10A.
The display arrangement 108 or 108' can, as noted previously, be
applied to other furniture surfaces, disposed either vertically or
horizontally or at some other inclination as desired. An
interesting application of this arrangement of our invention is to
a piano top (not shown) or other surface subject to sonic
vibrations. Alternatively, a display device, such as the device 108
or 108' can be stretched over a loudspeaker cone (not shown) in an
analogous arrangement. In this latter application the display
device including its container components desirably is made
relatively thin for maximum sensitivity of the liquid crystal
contained therebetween to sonic vibrations. Other applications
subject to vibratory forces will suggest themselves.
The display device as shown in FIG. 10 or 10A can likewise be
applied to room surfaces and for this purpose can be furnished in
the form of conveniently sized panels fabricated after the manner
of the display panel 108 or 108' in FIG. 10 or 10A. These can be
applied to floor, wall, ceiling and/or door surfaces of a
conventional room or as a stage or auditorium backdrop. One
arrangement of such panels is illustrated in FIG. 11, where display
device 120 is shown as a wall panel and will be presently
described. Deformational forces can be applied to the
aforementioned panels by manual pressures exerted against the
accessible surfaces of the panel, or by mechanical means such as
illustrated in FIG. 3 in this application or in various Figures of
the aforementioned copending application.
With the incorporation of display device 120 in a room structure as
shown in FIG. 11, the device 120 desirably includes
light-transmitting sheet 122 which preferably faces the interior
124 of the room structure 126. The sheet 122 can be provided with
cove 128, baseboard 130 and base shoe 132 moldings where
appropriate to conform to conventional wall structures which may be
used elsewhere in the room. The light-transmitting panel 122 can be
secured to studs 134 or other structural members conventionally
used in bearing and nonbearing walls as the case may be.
The rear of the light-transmitting panel 122, i.e., the side away
from the interior 124 of the room structure 126, is substantially
covered by encapsulating means for retaining a relatively thin
layer of liquid crystal against the rear surface. In the
illustrated arrangement the encapsulating means are extended
generally between adjacent pairs of the studs 134 or other wall
support members. One form of such encapsulating means includes one
or more container sections 136 secured to the rear surfaces of the
light-transmitting panels 122 and disposed between each associated
pair of the studs 134. In the illustrated example three such
container sections 136 are utilized between each pair of studs,
although a different number can be employed.
The container sections 136 desirably are relatively stiff but
resilient plastic sheets adhered about their peripheries to the
juxtaposed surfaces of the light-transmitting panel 122 after the
manner of FIGS. 1 and 3 and related figures described above, or
after the manner of FIGS. 12-16 described below. The container
sections 136 can be colored or coated as described previously and
each encloses a quantity of liquid crystal against the adjacent
surface of the light-transmitting panel 122. Any rear surfaces of
the light-transmitting panel 122 which are not covered by the
container sections 136 can be suitably masked by various types or
colors of coatings. For example, the masked areas, such as denoted
by reference characters 130, can be colored to blend more or less
with the color patterns produced by the several liquid crystalline
areas as defined by the container section 136 and visible through
the front surfaces of the light-transmitting
Another arrangement of our novel display device is exemplified by
display container 140 of FIGS. 12, 13. The display container 140 or
aesthetic novelty includes a light-transmitting member 142, which
can be fabricated from a polyacrylic resin in sufficient thickness
to give the aesthetic novelty 142 sufficient rigidity or structural
strength. For example, if the aesthetic novelty 140 is of the order
of about 4 inches square, the light-transmitting member 142 can be
of the order of about one-eighth inch in thickness, although a
greater or lesser thickness can be employed as evident from FIGS.
16, 16A described below. Desirably, the light-transmitting member
142 is fabricated from a fully transparent polyacrylic resin to
enhance the color patterns of the liquid crystal material 144
encased between the light-transmitting member 142 and a desirably
darker-hued or dark-opaque film or sheet 148 adhered to the upper
surface (as viewed in FIGS. 12 and 13) of the flexible film 146.
Other light-absorbing means can be substituted such as described
with reference to FIG. 22A and other figures hereof. In this
arrangement, the film 146 can be formed from a sheet of PVC plastic
or the like to which a coating of pressure sensitive adhesive is
applied entirely over one surface thereof. The PVC sheet or film
146 and the application of the adhesive thereto can be formed by
conventional techniques.
The area occupied by the liquid crystalline material 144 can be
demarcated by a sheet of heavy paper or cardboard or by a second
plastic film or sheet 148, which can be pressed into adhesive
engagement with the central area of the adhesive film 146. Use of
the film layer 148 prevents the juxtaposed surfaces of the film 146
from adhering to the underside of the light-transmitting member 142
and thus delineates a shallow pocket for the liquid crystalline
material 144.
The film layer 148 can be coated or formed from a material having a
dark or other contrasting color relative to the predominating color
of the liquid crystalline material 144. Printed messages (not
shown) or various designs, e.g., the design 150 (FIG. 12) or 152
(FIG. 14) or 154 (FIG. 15), can be applied to the film or sheet
layer 148. Such designs, for example the designs 150, 152 can be
printed in darker colors or shades upon a light background or
alternatively as evident from the design 154 in FIG. 15, the design
can be delineated in lighter colors against a darker background.
Also, the designs can be more or less geometrical as shown in FIG.
12 or random as shown in FIG. 14 or pictorial as shown in FIG. 15.
The unique cooperation of the contrasting colors of the film layer
148, when provided with a design of some sort such as those
described above, is evident when the flexible film 146 is depressed
in the area of the film layer 148 to apply deformational stresses
to the liquid crystalline material 144. The alternate thinning and
thickening of the liquid crystalline layer considerably enhances
the varying color patterns resulting from deformational flows in
the liquid crystal. Interest in the liquid crystalline patterns is
heightened, with the variation in thickness or depth of the liquid
crystalline material above the various contrasting colors or shades
of the designs imparted to the film layer 148.
The area of contained liquid crystal, such as the area 156 in FIGS.
12, 13 can be similar in shape to that of the light-transmitting
member 142 or can be of a different shape or series of shapes (not
shown) as denoted by the liquid crystal areas 158 of FIG. 14 or 160
of FIG. 15. Similarly, the light-transmitting member 142 of FIGS.
12-14 can be of geometrical contour or can be of some other contour
as denoted by the light-transmitting member 162 of FIG. 15. The
film 164 adhered to the light-transmitting member 162 desirably is
of similar shape.
It is contemplated that the film layer 148 can be omitted, and that
the aforementioned pressure-sensitive adhesive layer can be
confined to the peripheral areas of the film 146 or 164 to
delineate the container sections or areas 156, 158, 160 of FIGS.
12-15 respectively. In such case, the designs 150, 152 and 154 can
be printed or embossed directly upon the uncoated central areas of
the films 146 or 164. As a further alternative either the film
layer 148 (FIG. 13) or the central region of the films 146 or 164
can be coated or otherwise provided with a uniformly dark or black
material for a uniform enhancement of the liquid crystalline color
patterns, as mentioned previously. Alternatively again, the designs
150, 152 and 154 of FIGS. 12-14 can be replaced with random color
patterns, or with messages of various kinds printed in contrasting
colors or shades upon darker-hued or opaque films 146, 164, or on
the overlying film layer 148, when used (FIG. 13), or on the
transparent member 142.
As a further enhancement of the color pattern variation and
interest therein, an air bubble 166 (FIG. 12) can be introduced
into the liquid crystal area 156, along with the liquid crystalline
material. The air bubble 166 operates to thin the juxtaposed
portions of the contained liquid crystalline material, and such
thinning provides an interesting variation in the resulting color
patterns. Also, interesting differences in reflection occur at the
air bubble, depending on viewing angle. In addition, as the
flexible backing member 146 is depressed or deformational stresses
are otherwise applied thereto, the bubble 166 tends to break up
into a number of smaller bubbles exhibiting variable patterns,
depending on the amount and area of pressure application, to
further increase the viewer's interest in the color patterns. The
use of the bubble 166 is particularly fascinating in conjunction
with the aforedescribed designs 150, 152, 154 and equivalents, as
the presence of the air bubble enhances the delineation of those
portions of the design which are juxtaposed thereto. The
correspondingly thicker regions of the liquid crystal 144 removed
outwardly from the bubble 166 tend to subdue the design
delineations. The sharper delineations of the design 150 are
denoted in FIG. 12 by shaded areas 150a of the design 150. The air
bubble 166, whenever broken up into a number of discrete smaller
air bubbles, tends to reform as a single air bubble after removal
of the deformational stresses. Similar air bubbles 168 (FIG. 14)
and 170 (FIG. 15) can be employed in conjunction with the designs
152 and 154 of these figures respectively. The air bubbles 166-170
can be of differing relative sizes than as illustrated, as long as
the area normally occupied by the bubble is substantially smaller
than that of the liquid crystal.
In FIGS. 16 and 16A, another form of our novel color display device
172 is illustrated with optional commercial aspects. The display
device 172 can be fabricated from relatively thin material, for
example in the shape of a calling card or the like. In this case
the liquid crystalline material 174 is encapsulated between a
darker hued or opaque film 176 and a light-transmitting or fully
transparent film 178, which are otherwise assembled after the
manner illustrated in FIG. 13 or in accordance with the
encapsulating technique described and claimed in a copending,
coassigned application of Frederick Davis filed Mar. 19, 1969, Ser.
No. 803,319 entitled "Thermometric Articles and Methods for
Preparing Same." The liquid crystalline material 174 can be
selected to exhibit the requisite color play temperature at room
temperature as in the case of the display devices described
previously. In that case the display device 172 will normally
exhibit the appearance of FIG. 16A. It will be understood, of
course, that some other design motif can be substituted in place of
the spherical portions 180a, 180b and the commercial message 180c,
all of which are delineated by the encapsulated liquid crystalline
material.
Alternatively, and to add a note of intrigue to the brilliant color
pattern of the liquid crystalline material 174, the liquid
crystalline material can be selected with a different color play
temperature range, in the manner discussed previously, commencing
above the normal room temperature range but, for example, below the
temperature of the human body. Thus, the liquid crystalline pattern
will assume the base color of the base film 176, which desirably is
made a dark color or black for this purpose. In consequence, the
display device 172 will assume a uniform dark or black color as
evident from FIG. 16, against which the delineations of the liquid
crystalline material (shown in dashed outline in FIG. 16 for
illustrative purposes) are not visible at all, until the display
device 172 is warmed to the requisite color play temperature range,
for example by holding in the individual's hand.
A further modification of our novel display device 182 is shown in
FIG. 17 and is arranged in this example as a largely transparent
novelty such as a paper weight or the like. The display device 182
includes in this example a solid block 184 of transparent material,
such as one of the polyacrylic resins. The transparent block 184 is
provided in accordance with this aspect of our invention with a
first embedment 186 of liquid crystalline material and a second
embedment 188 of a design or lettering such as a slogan, motto, the
owner's name or initials or the like. The second embedment 188 can
be formed in the transparent block 184 for example by printing or
lettering the design or message with opaque dark-hued ink on a
transparent support or a support of darker transparent hues, as
required.
The liquid crystalline embedment 186 can be provided after the
manner described in connection with FIGS. 16, 16A with the
exception that two transparent films are employed to permit viewing
of the second embedment therethrough. The first embedment 186, as
in the case of the second or conventional embedment 188, can then
be suspended within the transparent block 184, when the latter is
molded, by conventional techniques. When the liquid crystal
embedment 186 is viewed through top face 190 of the transparent
block 184 the design or message of the second embedment 188 is
viewed through the color display afforded by the color patterns of
the liquid crystalline material located in the first embedment 186.
To enhance the color display, the bottom face 192 of the
transparent block 184 can have a relatively dark hue, or a black
coating can be applied. Alternatively the design or message of the
second embedment 188 can be applied in lighter colors against a
darker background, which can be opaque or more or less transparent
as desired.
Means, (not shown) can be provided for the application of
deformational stresses to the first or liquid crystal embedment
186, for example in accordance with the teachings of a copending
and coassigned application of Edward N. Sharpless, filed
concurrently herewith entitled Variable Color Display Device and
Projection Means Therefor, Ser. No. 40,889. In the absence of such
deformational means, the liquid crystal embedment 186 still yields
an interesting variety of color patterns depending, for example,
upon the character of light falling upon the transparent block 184,
incident angle of illumination, and individual viewing angles.
It is contemplated further that the liquid crystalline material 186
can be embedded by forming the insulating block 184 from bipartite
transparent container sections, which are shallowly dished to
encapsulate the liquid crystalline material 186 therebetween. The
bipartite transparent member can be permanently joined after the
liquid crystalline material 186 is injected therebetween, by heat
or solvent welding, use of adhesive or cement, etc.
From FIG. 18, it is apparent that our novel display device 190 is
similar to that of FIG. 15, in that a design, message, logo,
artwork, or trademark 192 is incorporated in the package 190 and
juxtaposed to the light-absorbing means 194 (FIG. 18A) thereof.
Liquid crystalline material 196 is encapsulated after the manner of
FIG. 13 between a relatively rigid transparent member 142' and an
adhesive sheet 146'. The light-absorbing member 194 which is, in
this example, adhered to the adhesive sheet 146' to define the
encapsulating area of the display device 190 is a transparent
plastic sheet of polyvinyl material having a photoemulsion 198
thereon.
The emulsive layer 198 is exposed save for the areas defining the
logo or other mark 192. The transparent areas 192 in the absorption
means 194 provide a considerably enhanced delineation of the
design, advertising message, logo, or the like 192 of the display
device 190. This follows from use of a somewhat translucent
adhesive sheet 146' such that a limited amount of transmitted light
passes through the liquid crystalline material 196 at the
transparent areas 192 in the absorption means 194. Other
arrangements can, of course, be employed to enhance the design 192
by affording a limited light transmittance, for example, that
disclosed in FIGS. 24, 24A and 24B described below.
A modification of the message means of FIG. 18 is illustrated by
the display device 200 shown in FIGS. 19 and 19A. The display
device 200 can be assembled in a similar manner, save that the
light absorption means or sheet or film 202 is uniformly black or
dark-hued. A message or design bearing member 204 is suspended
within the body of the contained liquid crystal 206. As better
shown in FIG. 19, the suspended member 204 can carry a design,
logo, or message 207, which can be commercial or otherwise. The
message 207 can, for example, be displayed against a background
area 208 of the suspended member 204, which background can be the
same, or a different color or texture from that of the light
absorbing member 202. In the event that the suspended member 204 is
provided with a dark or black background, the member 204 itself
becomes an auxiliary light absorbing means.
In the package 200, depending upon the basic color of the liquid
crystal 206 being utilized and on the color of the message or
design 207, the liquid crystal material may partially or completely
obscure the message 207 when the display device 200 is in its
quiescent state. That is to say, the suspended member 204,
fabricated in this example from a piece of polyvinyl plastic sheet,
will gradually settle to the bottom of the display device 200,
i.e., against the light absorption means 202 thereof. Under these
conditions, a substantial thickness of the liquid crystal 206
covers the message or design 207. With this construction, the
message or design 207 only becomes evident when the flexible
container portion 146' is depressed to move the suspended member
204 against the juxtaposed face of the relatively rigid container
member 142'. This obscuration is enhanced by making the same color
as the basic coloration of the liquid crystal. The design, then,
becomes evident when the angle of incident illumination is changed,
which changes the apparent basic coloration of the liquid crystal.
Alternatively, the message or design 207 can be made more or less
evident, as the case may be, by manipulating the container section
146' to position air bubble 210 over the design or message 207 or
to displace the bubble 210 therefrom.
We contemplate, of course, that the package or display device
construction of FIGS. 18, 19 and related figures need not be
confined to flat or planar display devices. For example a display
device of FIGS. 20, 20A demonstrates the principles of our novel
container construction as applied to a hollow, cylindrical display
device 212. In this arrangement, the display device 212 includes an
outer cylindrical container section 214 of a clear or transparent
material such as glass or polyacrylic resin. An inner container
section 216 is formed from a rectangular sheet of a suitable
plastic coated with pressure sensitive adhesive. The inner
container section 216 can be rolled as better shown in FIG. 20A and
lapped at 218. The major portion of the container section 216, in
this example, is covered with a rectangular sheet 220 of
light-absorbing material of a black or dark hue. The
light-absorbing sheet can be likewise rolled and lapped, as denoted
at 222.
A quantity of liquid crystal 224 is inserted between the light
absorbing sheet 220 and the juxtaposed surfaces of the cylindrical
outer container section 214. The sheet 216 desirably is provided
with a coating of pressure-sensitive adhesive for adhering to the
inner surfaces of the outer container section 214 adjacent the ends
thereof as denoted by reference characters 226, 228 respectively
(FIG. 20). Desirably, the internal diameter of the display device
212 is sufficient to afford access to an individual's finger or
other means for applying deformational stresses to the flexible
container section 216.
Alternatively, the flexible container section can be of clear
material and applied to the exterior of the tubular member 214
after the manner of FIGS. 22, 22A. In such case, the liquid crystal
224 can be provided with a contained light-absorbing means as
described below in connection with the latter figures.
Still other forms of hollow display devices can be made after the
manner of the display device 230 illustrated in FIGS. 21-21A. In
this arrangement, the display device 230 includes a container
section 232 of exemplary, pyramidal configuration, although a
differing geometric or nongeometric shape can be utilized. One face
of the pyramid shape 232, for example the bottom face, is provided
with a liquid crystal package 234, of which the adjacent surface of
the pyramidal shape 232 forms a part, after the manner of FIGS.
6-9. Alternatively, two or more liquid crystalline packages can be
provided after the manner of FIG. 5. The precise construction of
the liquid crystal package 234 can be modified in accordance with
one of several of the accompanying figures, for example after the
manner of FIG. 22A or 22B, substituting, of course, the pyramidal
shape of FIG. 21 for the planar, rigid member of the latter
figures.
The several reflections and refractions within the transparent
pyramidal shape 232 are multiplied by the provision of a hollow
core 236 within the solid transparent member 232. The core 236 can
be sealed as shown in FIG. 21 or in the alternative conduit means
238 and 240 (FIG. 21A) can be coupled thereto. In any event, the
core 236 can be filled with a gas or liquid having a differing
refractive index from that of the material comprising the
transparent block 232. The differences in refractive indices and
the several interfaces between the gas or liquid within the core
236, multiplies the number of reflections and refractions of the
liquid crystalline pattern 238 and enhances the visual aspects of
the display.
For further variety and enhancement of interest in the display
device 230, we contemplate the partial filling of the core 236 as
denoted by chain line 240 in FIG. 21A. In such case, the core 236
contains a liquid portion 242 with an air pocket 244 thereover.
Alternatively, the air pocket 244 can be replaced by an immiscible
liquid portion having a lower specific gravity than that of the
liquid portion 242. For further variety in interest, the liquids
244 and 242 can be dyed with differing colors.
FIG. 21A also illustrates alternative means for filling or changing
or circulating the fluid or fluids contained within the hollow core
236. Such means includes the aforementioned connecting conduits
238, 240, a pump 246 and suitable connecting conduits. Valved
conduit sections 248, 250 can be coupled to a suitable source or
sources (not shown) of appropriate fluids for filling the core 236.
In the event that the core 236 is filled with two liquids 242, 244,
the core can first be completely filled with the lighter liquid
244, from which subsequently a portion is displaced by circulation
of a heavier liquid 242, to provide a liquid-liquid interface
(chain line 240).
Another arrangement for packaging liquid crystalline materials for
display purposes is illustrated by display device 252 in FIGS. 22,
22A. In this modification of our invention, the display device 252
exhibits a variable color pattern of liquid crystal 254 from both
sides of the device 252. This is accomplished by utilizing a
relatively rigid light transmitting or clear container section 256
and a resilient or flexible container section 258 of
light-transmitting or clear plastic 258. A peripheral portion of
the plastic sheet 258 is provided with pressure sensitive adhesive
at 260 for peripheral sealing of the sheet to the container section
256 to encapsulate liquid crystal 254 therebetween. The liquid
crystal 254 desirably is of the pressure-sensitive variety
described previously.
To permit viewing of the color pattern of the liquid crystals from
either side of the display device 252, under normal conditions and
without the use of auxiliary viewing devices such as crossed
nichols, we have unexpectedly found that light-absorbing means can
be incorporated within the liquid crystalline material 254. Such
light-absorbing means permit viewing of the liquid crystal patterns
from either side of the device 252 by means of variably scattered
light from the liquid crystalline material, while eliminating all
or a substantial portion of the otherwise interfering transmitted
light.
One form of such light-absorbing means includes the use of a black
or dark-hued dye, for example a nigrazine dye. The nigrazine dye is
miscible with the liquid crystalline material 254 and can be used
in the range of about two percent to about 10 percent by volume.
Alternatively, the light-absorbing means can comprise carbon black
or other finely divided light absorbing material suspended within
the liquid crystal, in an amount (in the case of carbon black) of
from about 1 to about 30 percent by weight.
Another form of our display device 262 is illustrated in FIG. 22B.
The display device 262 presents a variable color pattern visible
through flexible container section 258', which in this case is a
transparent plastic sheet material such as Mylar. The other
container section 256', which in this example is more or less
rigid, is likewise transparent. The package 262 as described thus
far is assembled after the manner of the display device 252 of FIG.
22A. To facilitate assembly a nonadhesive clear plastic sheet 264
can cover a central portion of the adhesive clear sheet 258' to
demarcate the area occupied by the liquid crystal 266. In the case
of the display device 262, however, the liquid crystalline material
266 does not have a self-contained light-absorbing means such as
the dye or carbon black mentioned above with reference to FIGS. 22,
22A. Instead, the light absorbing means is applied to the outer
face of the more or less rigid container section 256'. The
light-absorbing means can be applied as a black or dark-hued
coating 268 on such outer face. Alternatively, an opaque black or
dark-hued plastic sheet provided with a coating of pressure
sensitive adhesive can be substituted for the coating 268. The use
of the dark-hued or black coating or sheet 268 eliminates or
reduces substantially the reflection of transmitted light back
through the liquid crystal 266, after the manner of the light
absorption means 16 of FIGS. 1 and 2.
In FIG. 22C, a somewhat similar package construction or display
device 270 is illustrated which incorporates packaging components
256', 258', at least one of which is clear or transparent. Inserted
between the packaging component 256' and a nonadhesive area of the
flexible packaging component 258' is a discrete liquid crystal
package 272 which can be fabricated after the manner described
above in connection with FIGS. 16, 16A. If the liquid crystal
encapsulating members or sheets forming part of the package 272 are
both clear or transparent, a black or dark-hued coating 274 can be
applied to an adjacent face of the packaging component 256' or
258'. Alternatively the coating 274 can be omitted, and space 276
can be filled with a black or dark-hued dye or other
light-absorbing material, such as mentioned above. In such case,
the liquid crystal pattern will be visible through the clear
container section 258' and the juxtaposed transparent sheet of the
package 272.
Alternatively, the preencapsulation 272 of FIG. 22C can be
fabricated in accordance with the package or display device 272' of
FIG. 22D. In this arrangement, the liquid crystal 278 is
encapsulated between a pair of flexible sheets 280, 282 at least
one of which, for example the sheet 280, is clear or transparent. A
light-absorbing sheet 284 defines the liquid crystalline area and
for this purpose is black, dark-opaque, or otherwise dark-hued for
light absorption. The display device 272' of FIG. 22D can be used
per se as a display device independently, or alternatively, the
display device can be incorporated in the FIG. 22C structure. In
the latter case, the coating 274 or the dye or other
light-absorbing means 276 as the case may be would be
eliminated.
In our novel display device 286 of FIGS. 23, 23A liquid crystalline
material 288 is contained within tubular member 290, the lower end
292 of which is closed. A light-absorbing member 294 is loosely
inserted into the container tube 290 for the purpose of absorbing
light transmitted through the liquid crystal 288. The plunger can
be blackened or dark-hued or alternatively can be of a transparent
red or blue material or other color equivalent to the overall body
color of the particular liquid crystalline material 288 employed.
Thus, the light-absorbing member 294 absorbs the light transmitted
through the liquid crystalline material 288 so that the color
display thereof is enhanced, as the viewer sees substantially only
the light scattered by the liquid crystalline material.
In the illustrated arrangement of the display device 286, the
light-absorbing member 294 is arranged additionally as a plunger
for the purpose of imparting deformation stresses to the liquid
crystalline material 288. In furtherance of this purpose the
light-absorbing member or plunger 294 protrudes slightly at 296
from the open end of container tube 290. The plunger 294 is
suspended for reciprocatory motion generally between biasing spring
298 and a flexible cap 300, which is shaped to snap over a
circumferential lip 302 or the like at the open end of the
container tube 290. The flexible cap 300 and container tube 290,
therefore, may be said to be assembled in "eyedropper" fashion.
The outward flexible end of the cap 300 can be depressed (arrow
304) to move the plunger 294 slightly into the container tube 290
against the action of the biasing spring 298. Even a very limited
extent of such movement causes deformational flows within the
liquid crystalline material 288 and a resulting endless variety of
color patterns. A similar display results when the pressure on the
flexible cap 300 is released to permit the plunger 294 to move in
the opposite direction. Desirably the flexible cap 300 is of
sufficient flexibility to absorb the small amount of liquid
crystalline material displaced from the tubular container 290 when
the plunger is moved into the container.
Alternatively, as pointed out in connection with FIGS. 22, 22A, the
light-absorbing function of the plunger 294 can be eliminated,
whereupon the plunger can be manufactured from a clear, white, or
light-colored material. The light-absorbing means, then, is admixed
with the liquid crystalline material 288, as set forth in the
description of the liquid crystalline material 254 of FIG. 22A.
In FIGS. 24, 24A, 24B a display device 190' is illustrated which is
somewhat similar to that described above with reference to FIGS.
18, 18A. The liquid crystalline material 196' is encapsulated as
described above, along with a light-absorbing sheet 306 between
container sections 142' and 146' of which at least the upper
section 142' is clear or transparent. The assembled form of the
package 190' is shown in FIG. 24A. An air bubble 308 can be
introduced during the assembly procedure to heighten the interest
in the display device 190'.
In the package 190' a message or design means or the like 310 is
incorporated in the light-absorbing means 306, for example by
aperturing the absorber or sheet member 306. The juxtaposed surface
of the lower container section 146' (FIG. 24) desirably is covered
completely on one face with a pressure sensitive adhesive layer. In
one arrangement of the package 190' the design elements of the
message or design 310 are separated sufficiently widely that the
sheet member 146' can be adhered to the juxtaposed surface of the
upper container section 142', which can be a rigid material such as
glass or polyacrylic resin, as shown in FIG. 24B. Under these
conditions, portions of the flexible backing sheet 146' protrude
through the apertured portions of the design or message 310 to
adhere to the juxtaposed face of the ridged encapsulating member
142' as denoted by reference characters 311 (FIG. 24B).
A similar display package 190" is illustrated in FIG. 24C. In this
arrangement discrete areas 311' of the flexible backing member 146"
are adhered about discrete encapsulations 312 and 314 of liquid
crystalline material. The discrete portions of liquid crystalline
material are defined by light-absorbing means 316, 318 of black or
dark-hued coloration and adhered to the adhesive side of the
flexible container section 146". The individual light-absorbing
members 316, 318 (FIG. 24D) can be fabricated in accordance with
similar light-absorbing members of the preceding figures.
Alternatively the encapsulations 312, 314 can be delineated by
marking off similar positions of the adhesive coating of section
146". Light-absorbing means, such as noted above, can then be
admixed with the liquid crystal. By manipulation of the flexible
encapsulating member 146' the liquid crystalline material 196'
and/or the air bubble 308 can be forced between the elements of the
design or message 310 to increase further the interest in the
display device 190'.
Another modification 320 of our novel message or design bearing
display device is illustrated in FIG. 25 and related figures. The
display device 320 is arranged somewhat after the manner of FIG. 4
described above, and includes a light-transmitting block 320 having
in this example a planar face 324 forming one component of an
encapsulation for a quantity of liquid crystalline material 326.
The other component of the encapsulation includes a flexible sheet
member 328 which is adhered in this example to the underside of the
light-transmitting component 322 by one of the assembly
arrangements described previously. Either the flexible container
section 322 or the container liquid crystal 326 itself can be
provided with light-absorbing means after the manner of any of the
preceding figures.
The display device 320 can be employed as a desk top novelty or
decoration, or alternatively can be incorporated in one of the
utilitarian devices or decorative devices disclosed herein. In this
arrangement the display device 320 is provided with a relatively
low profile, with the device 320 in this example further including
a relatively shallow casing 330 into which a message or design
bearing member 332 is inserted. For example, the member 332 can be
substantially flat as evident from FIG. 25A but is provided on its
upper face with a message or design embossment 334. The embossment
334 can, for example, spell out a name or a greeting such as
illustrated in FIG. 25.
In certain applications the weight of the light-transmitting or
clear member 322 is adequate to press the liquid crystalline
encapsulation including its flexible member 328 into bearing
engagement with the embossment 334 of the message member 332. In
other applications manual pressure exerted against the upper
surface of the light-transmitting member 322 (arrow 336), as by a
weight or some other object placed thereon, is required.
Alternatively one or more relatively light springs (not shown) or
other biasing means can be inserted between the liquid crystalline
encapsulation and the message member 332 of the device 320 to
maintain these items apart until pressure is exerted on the
light-transmitting member 322.
Alternatively the message or design embossment can be provided on
the lower surface of the light-transmitting member, as denoted by
the embossment 334' of the light-transmitting member 322' of FIG.
25B. On the other hand, and owing to the rather extreme pressure
sensitivity of certain liquid crystalline materials, a design or
message embossment 334" can be provided on the flexible membrane
328" as shown in FIG. 25C. As a further alternative a design or
message embossment 334'" can be provided on a separate
light-absorbing and masking member 338 as shown in FIG. 25D. In the
arrangements of FIGS. 25B and 25C the light-absorbing means can be
incorporated in the liquid crystalline material itself or coated on
either the upper encapsulating member 322' or 322" or on the lower
encapsulating member 328' or 328" depending on whether the display
device is viewed from the upper or lower side thereof.
A more utilitarian form 340 of our novel display device is shown in
FIGS. 26, 26A and is arranged here as a desk blotter, writing pad,
place mat, or the like. The display device 340 includes a
transparent or light-transmitting upper container section 342 (as
viewed in the drawings), to the bottom of which an encapsulating
container sheet member 344 is adhered. The container section 344
which is adhered peripherally to the upper container section 342
encapsulates a quantity of liquid crystalline material 346
therebetween. Suitable light absorption means can be incorporated
in or adhered to the encapsulating sheet or flexible member 344 or
in the liquid crystalline material itself. If the display device
340 be inverted such that the flexible member 344 becomes the upper
surface, the latter can be furnished as clear or transparent
material, and the light absorption means, conversely, can be
incorporated in or on the container section 342.
The container section 342 can be fabricated from a resilient
material, such as a relatively heavy sheet of transparent plastic
(in the arrangement as shown) or as a relatively thin sheet of
polyacrylic resin. With this arrangement the display device 340
possesses sufficient overall flexibility for insertion of its
corners into corner pockets 348 of a suitable casing or support 350
for the display device.
Another form 352 of our novel display device, with utilitarian
overtones, is illustrated in FIGS. 27, 27A. In the instant
modification, the display device 352 includes a relatively heavy
block 352 of clear or light-transmitting material, which is
provided with an ellipsoidal or equivalent rocking surface 356.
With a liquid crystal encapsulation 358 covering at least the major
proportion of the rocking surface 356 an interesting variety of
color patterns is produced in the liquid crystal, which is
preferably visible through the supporting block 354, as the block
rocks to and fro upon a suitable supporting surface, such as a desk
or table top. The display device 352 can thus be set in motion
manually or by other suitable means. If desired, as better shown in
FIG. 27A, the display device 352 can be used as an ink blotting
device, and in furtherance of this purpose a strip of blotting
paper 360 can be adhered to the bottom of the display device 352
for example to the flexible container section 362 thereof.
Another utilitarian form of our novel display device 364 as
illustrated in FIGS. 28, 28A. The display device 364 is arranged in
this example as a stand 366 for either a ballpoint or fountain-type
pen 368. The stand 366 includes a lower, desirably rigid container
section 370 for which an upper section or cover 372 is provided.
The sections 370, 372 can be joined and sealed by various means for
example by heat or solvent welding, use of a suitable cement or the
like. The peripheral lip 373 of the bottom container section is
thus sealed to the adjacent surfaces of the upper container section
372. At least the upper container section 372 is clear or
transparent, through which the changing color patterns of a
quantity of contained liquid crystal 374 are visible.
The lower container section 370 can be of a dark opaque or dark
hued material for absorption of light transmitted through the
liquid crystal 374. Alternatively the adjacent surfaces 376 of the
container section 370 can be coated with a dark-hued material. As a
further alternative the aforementioned light-absorbing material can
be admixed with the liquid crystal 374.
The pressure-sensitive characteristic of the aforementioned liquid
crystalline materials is utilized with the provision of a movably
mounted pen holder 378 having a flanged portion 380 which overlies
an appreciable but desirably minor proportion of the area of the
contained liquid crystal 374. The holder 378 is further provided
with a stem 382 movably inserted into aperture 384 of the upper
container section 372. The stem 382 is apertured at 386 to receive
the inserted end of the pen 368. Suitable clearances are provided
between the stem 382 and the display device aperture 384 such that
the pen holder 378 is subjected to movement when the pen is removed
or inserted.
Desirably the flange portion 380 of the pen holder 378 is movably
sealed to the under surface of the upper container section 372 by
means of a peripheral strip of tape 388, or by a more typical form
of bellows (not shown), or the like. If it is desired to overlay
the flanged portion 380 with liquid crystal material the peripheral
seal can be moved inboard of the flanged portion 380 as denoted
alternatively by similar sealing means 390. The sealing means 388
or 390 prevents the liquid crystalline material 374 from exuding
through the necessary clearances between the pen holder stem 382
and the display device aperture 384.
A modified form of our mechanistic means for effecting a changing
color pattern in a liquid crystal encapsulation are illustrated in
FIGS. 29, 29A. Our novel and automated display device 392 includes
in this example one of the planar display packages 394, such as
illustrated in certain of the preceding figures. The package 394
desirably has a relatively ridged light-transmitting, container
section 396, desirably of transparent material, and a relatively
flexible container section 398 peripherally adhered to the ridged
section 396 to contain a quantity of liquid crystal material.
Flow deformational stresses are applied to the contained liquid
crystal by movable contact arm 400 which is supported against the
flexible container section 398. At its inward end the arm 400 is
joined to output shaft 402 of a suitable driving means such as
electric motor 404. Suitable speed reduction means (not shown) can
be incorporated between the motor and shaft. The arm 400 can be
lightly or heavily constructed as required, and can be urged
against the display package 394 with greater or lesser force,
depending upon the particular aesthetic effect which is desired by
revolution of the arm 400. The motor 404 and the contact arm 400
can be supported against the display package 394 by a casing or
housing 406 on which the motor 404 and the display package 394 are
mounted as shown.
To minimize abrasion of the flexible container section 398 the
contact arm 400 desirably is formed from a spaced array of washers
408 each of which is individually and rotatably mounted on
supporting rod 410 which defines the length of the contact arm 400.
The washers 408 desirably are made from a solid polyamide material,
tetrafloroethylene, or other self-lubricating material. As an
alternative, the washers can be alternated with washers of smaller
diameter to reduce contacting surfaces. The washers 408 permit
differential contact speeds between various parts of said arm with
the container section 398.
It will be understood, of course, that the washers 408 can be
omitted, if desired, particularly where contact pressures are
rather light. In such case, the contact arm 400 can take the form
of an elongated member having a smooth edge shaped for contingent
engagement with the display package 394.
The contact arm 400 can be rotated fast or slow depending upon the
particular aesthetic effect desired. For example, the contact arm
400 can be incorporated into a clock mechanism, the motion of which
would be visible as a moving and predominating color line in the
revolving color patterns produced by revolution of the contact arm
400.
Means for enhancing appropriate ones of our novel display packages
are illustrated in FIGS. 30, 30A wherein display device 412
includes a liquid crystal encapsulation 414, which is generally
similar to that shown in FIG. 5. In FIGS. 30, 30A the encapsulation
414 includes a desirably transparent viewing block 416 to the
bottom surface of which, in this example, a quantity of liquid
crystalline material 418 is confined by a substantially planar
container section 420 which may take the form of that shown in FIG.
5 or other appropriate figures of the drawings. The container
section 420 may or may not be flexible depending whether it is
desired to apply external deformation stresses to the encapsulation
414. A design can, of course, be incorporated on a stand or
platform 422 of the display device 412, for example after the
manner of FIGS. 4 and 25A and related Figures. Thus, the stand or
platform 422 can be provided with message means or design 424.
As set forth previously, the basic color of the liquid crystalline
material 418 changes with variation in viewing angle, i.e., with
changes in the angle of incidence of illumination. In accordance
with this feature of our invention, we provide means for variably
or alternately illuminating the liquid crystal material visible
through the transparent block 416. Such variable illumination
enhances the variety of color patterns already available from the
several reflections and refractions within the transparent block
416 itself, as pointed out above in connection with FIG. 5 and
related Figures. It is also contemplated that other geometric or
nongeometric shapes can be substituted for the block 416 in keeping
with the teachings inherent in FIGS. 30, 30A.
One form of such variable illumination means includes the use of a
plurality of illumination sources, with two such sources or lamps
426, 428 being utilized in this example of the invention. The lamps
426, 428 can be of the "wheat grain" variety which are frequently
used in model railroading or automotive layouts. The lamps 426, 428
are mounted on the transparent block 416 such that the illumination
from each of the lamps strikes the liquid crystalline material 418
from a different angle. Desirably, the lamps 426, 428 are embedded
in the transparent block 416, which can be fabricated from a
polyacrylic resin for this purpose. A miniaturized battery 430 for
each of the lamps 426, 428 can be electrically connected to the
lamps and embedded therewith as shown in FIG. 30. For a longer
lived display device, only the lamps 426, 428 are embedded, as in
FIG. 30A, but are connected through external leads 432 to an
external power supply 434, which can be mounted on an exterior
surface of the block 416.
Returning to FIG. 30, a miniaturized blinker or flasher element 436
can be connected between each battery 430 and the associated lamp
426, or 428 and likewise embedded within the block 416. As it is
extremely unlikely that the flashers 436 will flash on and off in
synchronization, owing to manufacturing tolerances, one of the
lamps 426, 428 will be on and the other off for a substantial
proportion of any given period. Thus, the liquid crystal 418 will
be illuminated part of the time solely by illumination of normal
incidence from lamp 426, another part of the time by illumination
of angular incidence from lamp 428, another part of the time by
both of these, and probably a remaining part in which both lamps
426, 428 are off. Thus, at least two and probably three basic color
patterns, owing to the variable scattering property of the liquid
crystal, will be evident as the lamps 426, 428 are flashed on and
off. Interest in the device 412 will be further enhanced as the
individual observer moves either himself or the device to change
his viewing angle in conjunction with the aforementioned changes in
illumination angles.
In the alternative circuit arrangement shown in FIG. 30A, the power
supply 434 can incorporate a suitably sized battery and a capacitor
operated switching arrangement, whereby lamp 426 is always switched
on when lamp 428 is switched off and vice versa. Alternatively, the
lamps 426, 428 can be energized and deenergized by means of manual
switches (not shown) coupled in the leads 432. Where a limited life
of the illumination means of the display device is not a problem,
the power supply 434 and leads 432 likewise can be embedded within
the polyacrylic resin or other suitable material used to fabricate
the block 416.
From the foregoing it will be apparent that our novel display
device is capable of a wide variety of applications, some of which
are illustrated in this application and others of which have been
alluded to. Many analogous applications will occur to those skilled
in the art in the entertainment, interior decorating, indoor and
outdoor advertising, novelty, decorative utilitarian devices, and
related fields. Our display devices are capable of presenting an
interesting and unexpected color pattern even without manipulation
of deformation of their liquid crystalline materials. However, the
color display is enhanced and the attention-gathering
potentialities are multiplied many times, when the display device
is arranged for the application of deformational stresses, either
manually or otherwise, to the contained liquid crystalline
material.
Owing to the wide variety of shapes and sizes which can be imparted
to the display device, pursuant to the various features of my
invention, the decorative, entertaining, picturesque utilitarian,
and advertising possibilities are virtually unlimited. For example,
when the display device is incorporated in an advertising sign, the
advertising message can be applied to the device pursuant to the
teachings ingerent in FIGS. 4, 12-19A, 22B, 24-24C, and 25-25D. The
message can be applied to the outer of inner (FIG. 25B) surface of
the light transmitting member, or in contrasting colors to the
opaque container section of the display device, if, in the latter
case, the layer of liquid crystalline material is sufficiently
thin. In any event, when means are associated with the display
device for the application of deformational stresses to the liquid
crystal a most unusual and eye-catching sign results. For purely
decorative objects used per se or as a part of wall surfaces or
articles of furniture (such as FIGS. 4-9 and FIGS. 10 and 11
respectively) or other utilitarian devices (such as FIGS. 26, 26A,
27, 27A, 28, and 28A) various designs can be superimposed upon the
variable color pattern of the liquid crystal pursuant again to the
teachings of FIG. 4, 12-19A, 22B, 24-24C, or 25-25D; or by applying
various designs, geometric or otherwise, to the light transmitting
members (such as FIGS. 4-9, 10A, 25B, 25C). The color patterns
inherent in the liquid crystals, can be modified by manual
manipulation or by various deformation means (e.g., FIGS. 3, 11,
21A, 23, 23A, 27, 28, 28A, 29, 29A).
It will be apparent, then, that we have disclosed novel and
efficient forms of Color Display Devices. While we have shown and
described certain presently preferred embodiments of the invention
and have illustrated presently preferred methods of practicing the
same it is to be distinctly understood that the invention is not
limited thereto but may be otherwise variously embodied and
practiced within the spirit and scope of the invention.
* * * * *