U.S. patent application number 11/326940 was filed with the patent office on 2006-06-01 for liquid crystal display including o-type and e-type polarizer.
Invention is credited to Yuri A. Bobrov, Alla Y. Sakharova, Pochi Yeh.
Application Number | 20060114384 11/326940 |
Document ID | / |
Family ID | 32396409 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060114384 |
Kind Code |
A1 |
Yeh; Pochi ; et al. |
June 1, 2006 |
Liquid crystal display including O-type and E-type polarizer
Abstract
The disclosure pertains to the devices of information displays,
in particular liquid crystal displays, and could be utilized in
indication devices for various purposes. Liquid crystal displays,
according to this disclosure, contain at least one layer of liquid
crystal placed between two plates, on each plates there has been
formed or applied at least one electrode or a system of electrodes,
or an active matrix, and at least one layer of polarizer; while at
least one polarizing layer is the E-type polarizer and at least one
polarizing layer is an O-type polarizer. The polarizer, according
to the invention, consists of at least two polarizers, at least one
of which is the E-type polarizer and at least one is the O-type
polarizer.
Inventors: |
Yeh; Pochi; (Thousand Oaks,
CA) ; Sakharova; Alla Y.; (Belmont, CA) ;
Bobrov; Yuri A.; (Moscow, RU) |
Correspondence
Address: |
DORSEY & WHITNEY LLP
555 CALIFORNIA STREET, SUITE 1000
SUITE 1000
SAN FRANCISCO
CA
94104
US
|
Family ID: |
32396409 |
Appl. No.: |
11/326940 |
Filed: |
January 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10240531 |
Apr 14, 2003 |
7015990 |
|
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PCT/US01/13189 |
Apr 24, 2001 |
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11326940 |
Jan 7, 2006 |
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Current U.S.
Class: |
349/117 |
Current CPC
Class: |
G02F 1/133565 20210101;
G02B 5/3016 20130101; G02F 1/133528 20130101; G02F 1/13363
20130101 |
Class at
Publication: |
349/117 |
International
Class: |
G02F 1/1335 20060101
G02F001/1335 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 24, 2000 |
RU |
RU 2000110172 |
Claims
1. A liquid crystal display comprising a first plate and a second
plate; and at least one layer of liquid crystal placed between the
first and second plates, wherein on each of the plates there is
formed at least one electrode or a system of electrodes or an
active matrix, wherein the first plate comprises a reflecting
layer, and the second plate comprises at least one layer of O-type
polarizer having negative dielectrical anisotropy and negative
dichroism and at least one E-type polarizer having positive
dielectrical anisotropy and positive dichroism.
2. The liquid crystal display according to claim 1 wherein the
O-type polarizer and the E-type polarizer are applied to different
sides of the second plate.
3. The liquid crystal display according to any of claims 1-2
wherein the O-type polarizer is formed using iodine-polyvinyl,
iodine-polyvinylene or polyvinylene polarizer, and the E-type
polarizer used is a thin film comprised of a plurality of
supramolecular complexes of one or several organic matters, wherein
supramolecular complexes are uniformly oriented in order to
polarize the incident light.
4. The liquid crystal display to claim 1 wherein the function of
the E-type polarizer is played by the dichroic polarizer, which is
realized as a film of oriented molecules of an organic matter, and
characterized by the fact that for the main aces of the ellipsoids
of the real and imaginary part of its anisotropic coefficient of
refraction in the range of at least one band of absorption
wavelengths, the following is true for an area with the linear
dimensions no less than the wavelength: K 1 .gtoreq. K 2 > K 3
.times. .times. and ##EQU4## ( n 1 + n 2 ) 2 > n 3 ##EQU4.2##
where, K.sub.1, K.sub.2, K.sub.3 and n.sub.1, n.sub.2, n.sub.3, are
main values of the real and imaginary part respectively, of the
axes of the ellipsoid, and/or the film is characterized by the fact
that for two films with crossed polarization axes the transmission
of light does not increase for at least a certain range of
wavelengths with its direction declined from the normal to the
polarizer plane.
5. The liquid crystal display according to claim 4 wherein the
directions which correspond to the maximum and minimum values of
the imaginary part of the refraction coefficient lay in the plane
parallel to the plane of the plate.
6. The liquid crystal display according to claim 1 wherein the
E-type polarizer uses at least one organic matter, chemical formula
of which features at least one ionogenic group, which provides its
solubility in polar and non-polar solvents in order to create the
lyotropic liquid crystal phase, and at least one counter-ion, which
in the process of formation of the film either remains in the
structure of the molecule or not.
7. The liquid crystal display according to claim 6 wherein at least
one organic dye, capable of absorption in at least one of the
following ranges: from 200 through 400 nm, or 400 through 700 nm,
or 0.7 through 13 .mu.m, is used as the organic matter of the
polarizer.
8. The liquid crystal display according to claim 1 wherein the
plates are made out of either glass, plastic, semiconductor, metal
or any other material used for their manufacturing, and the same or
different materials are used for either of the plates.
9. The liquid crystal display according to claim 1 wherein at least
one of the plates is optically transparent in the working range of
light spectrum.
10. The liquid crystal display according to claim 1 further
comprising a means of obtaining colored image.
11. The liquid crystal display according to claim 1 wherein a
nematic or smectic or cholesteric or their mixtures is used as the
substance of liquid crystal.
12. The liquid crystal display according to claim 1 further
comprising at least one alignment layer and or at least one
diffuse-reflecting layer and/or at least one phase-shifting layer
and/or at least one birefringent layer and/or at least one
conducting layer and/or at least one protective layer and/or at
least one isotropic layer and/or anisotropic layer and/or at least
one dielectric layer and/or at least one alignment layer and/or at
least one diffuse- or reflecting layer and/or a layer functioning
as at least two of the above layers.
13. The liquid crystal display according to claim 1 wherein the
E-type polarizer is at the same time functioning as a
phase-shifting layer, and/or a birefringent layer, and/or an
alignment layer, and/or a protective layer, and/or a layer
functioning as at least two of the above layers.
14. The liquid crystal display according to claim 1 wherein at
least on one of the plates there are spacers controlling the
distance of separation between the plates.
15. The liquid crystal display according to claim 1 wherein the
reflecting layer is diffuse-reflecting.
16. The liquid crystal display according to claim 1 wherein the
reflecting layer is mirror-reflecting.
17. The liquid crystal display according to claim 2 wherein the
O-type polarizer is applied to the inside of the second plate and
the E-type polarizer is applied to the outside of the second plate.
Description
RELATED APPLICATIONS
[0001] This is a divisional application of U.S. application Ser.
No. 10/240,531, which entered the United States national stage on
Apr. 14, 2003 under 35 U.S.C. .sctn. 371 for PCT/US01/13189 filed
Apr. 24, 2001, which claims priority to RU200110172 filed Apr. 24,
2000, the disclosures of all of which are incorporated herein by
reference.
BACKGROUND
[0002] 1. Field
[0003] The disclosure pertains to the technology of information
displays, in particular to the liquid crystal displays (LCD), and
could be utilized in devices of various configurations.
[0004] 2. Description of the Related Art
[0005] The following references, which are incorporated by
reference are of interest in this disclosure. [0006] 1. L. K.
Vistrin. GVHO, 1983, vol. XXVII, 2nd ed., pp. 141-148 [0007] 2.
U.S. Pat. No. 5,007,942, 1991 [0008] 3. RU 2120651, 1998 [0009] 4.
U.S. Pat. No. 5,739,296, 1998
[0010] These references are now further discussed.
[0011] There are liquid crystal (LC) displays, which are realized
having two parallel flat plates, the inside surfaces of which are
coated with patterns of optically transparent conducting material
and the alignment layer. After the assembly of the plates the space
between them is filled with liquid crystal, which forms a layer
5-20 .mu.m thick and plays the role of the active medium, which
changes its optical qualities (angle of twist of the polarizing
plane) under the influence of electric field. The change in the
optical qualities is registered in the cross-oriented polarizers,
which are usually applied onto the inside surfaces of the plates.
Therefore, the areas of the display, on the electrodes of which
electrical field is not applied, will look bright (open state),
while the areas, the electrodes of which are under the electrical
field, will look dark (closed state) (L. K. Vistrin. GVHO, 1983,
vol. XXVII, 2nd ed., pp. 141-148).
[0012] The main drawback of the described above displays is the
limited viewing angle. This is because the multi-layered structure
of the LC display is effectively controlled by the flux of light
propagating towards the surface of the display within a limited
solid angle. The polarizers in such displays are polymer-based,
such as polyvinyl-alcohol, which is made optically anisotropic by
uniform stretching of a thin film (U.S. Pat. No. 5,007,942, 1991).
The optical anisotropy is obtained as a result of ordering of the
polymer molecules along the direction of stretching. When exposed
to iodine vapor or iodine-containing solution or an organic dye,
the film is colored with the intensity of color depending of the
direction of the vector of the electric field E in the
electromagnetic wave relative to the axis of stretching. Polarizing
effectiveness of such films is determined by the concentration of
iodine or other organic coloring agent and the degree of ordering
of the polymer molecules. Such films feature the so-called positive
dielectric anisotropy and positive dichroism. This means that the
dipole moments of optical transition of molecules, which are
responsible for absorption of light, are oriented along the
direction of stretching. At the same time the ellipsoids of the
angle dependence of the real and imaginary parts of the refraction
coefficient have an extended form. Polarizers obtained from the
described above films are termed O-type, since the "ordinary" wave
will pass through, while the "extraordinary" will not.
[0013] Despite the high polarizing effectiveness, these polarizers
have substantial drawbacks. These are low light and thermal
resistance, large required thickness to achieve high effectiveness.
One of the main drawbacks featured by the two cross-oriented
polarizers is the high transmission of light incident at an angle
(.+-.0.45) to the surface of the polarizers.
[0014] There are LC displays that utilize polarizers on the inside
surfaces of the glass plates (RU 2120651, 1998). The polarizers
used in such displays are thin films with ordered molecular
structure of the liquid crystal polarizer (LCP) (U.S. Pat. No.
5,739,296, 1998). The flat molecules of such LCP are grouped
together into the so-called directionally ordered
bunches--supramolecular complexes. The planes of the individual
molecules, and thus their inherent dipole moments of optical
transition, are oriented perpendicular to the axis of macroscopical
orientation of the produced film. To create such structure one uses
the liquid-crystalline state of the LCP, where the molecules are
already ordered locally, while in one- or two-dimensional blocks
oriented relative to each other. When applied onto a surface with
an additional external alignment force, such substance assumes the
macroscopical orientation, which upon dehydrating not only reins
but could also improve on its own. The resulting axis of
polarization is along the direction of the external aligning
action. In this case the ellipsoids of the angle dependence of the
real and imaginary parts of the refraction coefficient have
disk-like shape,
[0015] The latter polarizers are termed E-type, since
"extraordinary" wave is now transmitted and "ordinary" is
blocked.
[0016] Such polarizer features a number of substantial
disadvantages, which limit its applicability. One of those is the
insufficient polarizing effectiveness, and some transmission of
light has been registered trough two parallel cross-oriented
polarizers of this type with the incident unpolarized light at an
angle to their surfaces. This effect is especially prominent when
at least one of the polarizers has the diffused-reflection coating,
which is used in the majority of LC displays.
SUMMARY
[0017] The technical results herein are: the improvement of the
angle characteristics of polarizers and LC displays, the reduction
of the amount of transmitted unpolarized light by a single as well
as parallel-coupled polarizers while retaining their thickness, the
enhancement of their polarizing effectiveness, improved contract,
widening of the viewing angle as well as elimination of the `gray
field` effect during operation.
[0018] These technical results are achieved by utilizing
combinations of E- and O-type polarizers. Here, the O-type
polarizer provides the high transmission of light during open
state, while E-type polarizer provides the high angle
characteristics in the closed state. The E-type polarizer with the
optimal characteristics, which correspond to the high value of the
coefficient of absorption along the normal to the plane of the
polarizer is obtained by forming a thin film of molecular-oriented
LCP (liquid crystal polarizer) on the surface of O-type polarizer.
The orientation of the molecules is such that their dipole moments
of the optical molecular transit are distributed in the plane
perpendicular to the axis of polarization and the surface of O-type
polarizer.
[0019] The display could be manufactured according to known
techniques and could be produced with a known design not to exclude
the option to utilize some original, and possibly not yet described
methods and arrangement. An aspect of interest in this disclosure
from other disclosed prototypes is in the use of a combination of
different types of polarizers. The disclosed here polarizer
utilizing a composition of at least two layers, one of each is
O-polarizer and another is E-polarizer, could be used in any field
of technology which quires such characteristics, in particular in
the field of liquid crystal displays of different applications.
DRAWINGS
[0020] The present disclosure is illustrated in part by the
enclosed drawings of which:
[0021] FIG. 1 is a diagrammatic depiction of the first
embodiment;
[0022] FIG. 2 is a diagrammatic depiction of the second
embodiment;
[0023] FIG. 3 is a diagrammatic depiction of the third
embodiment.
DETAILED DESCRIPTION
[0024] Envisioned in this disclosure is the following.
[0025] In a first embodiment, as seen in FIG. 1, there is a liquid
crystal display containing at least one layer of the liquid crystal
placed between two plates. On each plate there is disposed or
applied at least one electrode, a system of electrodes, or an
active matrix; and at least one layer of polarizer. At least one
layer of polarizer is an O-type polarizer and at least one layer of
polarizer is an E-type polarizer.
[0026] In a display of the first embodiment, the O-type polarizer
is preferably an iodine-polyvinyl, iodine-polyvinylene or
polyvinylene polarizer. The E-type polarizer is preferably formed
as a thin film comprised of a plurality of supramolecular complexes
of one or several organic materials, the supramolecular complexes
being generally unidirectionally oriented in order to ensure
polarization of incident light.
[0027] A dichroic polarizer is preferably used as the E-type
polarizer, the dichroic polarizer comprising a film of oriented
molecules of an organic compound. In this film, the organic
compound is such that the main axes of the ellipsoids of the real
and imaginary part of the anisotropic refraction coefficient of the
compound forming the film is in the range of at least one band of
absorption wavelength. The following is true for an area with
linear dimensions no less than the wavelength: K 1 .gtoreq. K 2
> K 3 .times. .times. and ##EQU1## ( n 1 + n 2 ) 2 > n 3
##EQU1.2## where, K.sub.1, K.sub.2, K.sub.3 and n.sub.1, n.sub.2,
n.sub.3, are the major or main values of the real and imaginary
part, respectively, of the axes of the ellipsoid. In addition or
alternatively, the film is characterized by the fact that for two
films with crossed polarization axes, the transmission of light
does not increase in at least a certain range of wavelengths, when
its direction departs, deviates, or deflects from the normal to the
polarizer plane. The directions corresponding to the maximum and
minimum values of the imaginary part of the refraction coefficient
lie in the plane parallel to the plane of the substrate.
[0028] The organic compound of which the E-type polarizer is
formed, comprises at least one organic substance which includes at
least one ionogenic group, which provides solubility in polar and
non-polar solvents in order to create the lyotropic liquid-crystal
phase and at least one counter-ion, which in the process of
formation of the film either remains in the structure of the
molecules or does not.
[0029] The organic substance comprises at least one organic dye
capable of absorption in at least one of the following ranges: from
200 through 400 nm, 400 through 700 nm, or 0.7 through 13 .mu.m.
Further, at least one of the polarizers is an internal polarizer
and applied on the internal side of one of the glass plates. The
layers of the polarizers of O- and E-types are applied to the
inside and/or the outside of one plate or inside and/or the outside
of both of the plates. Also, the optical axes of polarizers E- and
O-types are mutually parallel or mutually perpendicular.
[0030] The plates described herein are preferably fabricated out of
glass, plastic, semiconductor material, metal or any other material
suitable for their manufacture. The plates may all be made of the
same materials or different materials. However, at least one of the
plates is preferably optically transparent in the working area of
light spectrum. The display also has the means of obtaining colored
images.
[0031] The liquid crystals are comprised of a nematic, smectic, or
cholesteric liquid crystals or liquid crystals of any other
chemical classes or their mixtures.
[0032] The display also contains at least one alignment layer
and/or at least one diffuse-reflecting layer and/or at least one
phase-shifting layer and/or at least one birefringent layer and/or
at least one conducting layer and/or at least one protective layer
and/or at least one isotropic layer and/or at least one anisotropic
layer and/or at least one insulating layer and/or at least one
alignment layer and/or at least one diffuse- or mirror-reflecting
layer and/or a layer simultaneously functioning as at least two of
the above layers.
[0033] In this disclosure, the E-type polarizer may also function
as a phase-shifting layer, and/or birefringent layer, and/or
alignment layer, and/or protective layer, and/or a layer
functioning as at least two of the foregoing layers.
[0034] The device also includes spacers on at least one of the
plates to limit the distance of separation between the plates.
[0035] The display is of either the transmissive or reflective
type.
[0036] In a second embodiment as seen in FIG. 2, the display
contains at least one layer of liquid crystal placed between two
plates. On each plate, there has been disposed or formed at least
one electrode or a system of electrodes, or an active matrix,
wherein on one of the plates there has been disposed a diffuse- or
mirror-reflecting layer, and on one of the plates there has been
disposed at least one layer of an O-type polarizer and at least one
layer of an E-type polarizer.
[0037] In this second embodiment the layers of polarizers of O- and
E-type are applied to different sides of a plate. In this instance,
the O-type polarizer is formed using iodine-polyvinyl,
iodine-polyvinylene or polyvinylene polarizer, and the E-type
polarizer comprises a thin film comprised of a plurality of
supramolecular complexes of one or several organic compounds,
wherein the supramolecular complexes are unidirectionally oriented
in order to polarize the incident light.
[0038] A dichroic polarizer is preferably used as the E-type
polarizer, the dichroic polarizer comprising a film of oriented
molecules of an organic compound. In this film, the organic
compound is such that the main axes of the ellipsoids of the real
and imaginary part of the anisotropic refraction coefficient of the
compound forming the film is in the range of at least one band of
absorption wavelength. The following is true for an area with the
linear dimensions no less than the wavelength: K 1 .gtoreq. K 2
> K 3 .times. .times. and ##EQU2## ( n 1 + n 2 ) 2 > n 3
##EQU2.2## where, K.sub.1, K.sub.2, K.sub.3 and n.sub.1, n.sub.2,
n.sub.3, are the major or main values of the real and imaginary
part. Accordingly, the axes of the ellipsoid, and/or the film is
characterized by the fact that for two films with crossed
polarization axes the transmission of light does not increase in at
least a certain range of wavelengths when its direction departs,
deviates, or deflects from the normal to the polarizer plane.
[0039] In this embodiment, the directions which correspond to the
maximum and minimum values of the imaginary part of the refraction
coefficient lie in the plane parallel to the plane of the
substrate. Also, the E-type polarizer comprises at least one
organic compound, which comprises at least one ionogenic group,
which provides its solubility in polar and non-polar solvents in
order to create the lyotropic liquid crystal phase, and at least
one counter-ion, which in the process of formation of the film
either remains in the structure of the molecule or does not.
[0040] This embodiment includes at least one organic dye, capable
of absorption in at least one of the following ranges: from 200
through 400 nm, or 400 through 700 nm, or from 0.7 through 13
.mu.m, used as the organic compound of the polarizer. Further, the
plates are fabricated out of glass, plastic, semiconductor, metal
or any other material suitable for their manufacture, and in
addition, the same or different materials could be used for either
of the plates. Also it is preferred that at least one of the plates
is optically transparent in the working range of light
spectrum.
[0041] The display of this embodiment also includes means for
obtaining colored image. Further, the embodiment includes liquid
crystals comprised of a nematic, smectic or cholesteric liquid
crystals, or liquid crystals of any other chemical classes or their
mixtures. This second embodiment also includes at least one
alignment layer and/or at least one diffuse-reflecting layer,
and/or at least one phase-shifting layer, and/or at least one
birefringent layer, and/or at least one conducting layer, and/or at
least one protective layer, and/or at least one isotropic layer
and/or anisotropic layer, and/or at least one insulating layer
and/or at least one alignment layer, and/or a layer simultaneously
functioning as at least two of the above layers.
[0042] The layer of the E-type polarizer in this second embodiment
functions simultaneously as a phase-shifting layer, and/or
birefringent layer, and/or alignment layer, and/or protective
layer, and/or a layer functioning as at least two of the above
layers. Also, at least on one of the plates there are the spacers
to limit the distance of separation between the plates.
[0043] In a third embodiment as seen in FIG. 3, there is a
polarizer, comprising at least two layers, at least one of which is
an O-type polarizer and at least one of the polarizer layers is an
E-type polarizer. In this embodiment, the O-type polarizer is
preferably an iodine-polyvinyl, iodine-polyvinylene or polyvinylene
polarizer, and the E-type polarizer used is a thin film comprised
of a plurality of supramolecular complexes of one or several
organic compounds, wherein the supramolecular complexes are
unidirectionally oriented in a determined direction in order to
polarize the incident light.
[0044] The E-type polarizer is a dichroic polarizer. This dichroic
polarizer comprises a film of oriented molecules of an organic
compound, wherein the main axes of the ellipsoids of the real and
imaginary part of an anisotropic refraction coefficient of the
compound forming the film is in the range of at least one band of
absorption wavelengths. The following is true for an area with the
linear dimensions no less than the wavelength: K 1 .gtoreq. K 2
> K 3 .times. .times. and ##EQU3## ( n 1 + n 2 ) 2 > n 3
##EQU3.2## where, K.sub.1, K.sub.2, K.sub.3 and n.sub.1, n.sub.2,
n.sub.3, are the major or main values of the real and imaginary
part, respectively, of the axes of the ellipsoid, and/or for two
films with crossed polarization axes the transmission of light does
not increase in at least a certain range of wavelengths when its
direction departs, deviates, deflects from the normal to the
polarizer plane.
[0045] The E-type polarizer comprises at least one organic
compound, which includes at least one ionogenic group, which
provides its solubility in polar and non-polar solvents in order to
create the lyotropic liquid crystal phase and at least one
counter-ion, which in the process of formation of the film either
remains in the structure of the molecule or not.
[0046] This embodiment includes as the organic compound at least
one organic dye, capable of absorption in at least one of the
following ranges: from 200 through 400 nm, or 400 through 700 nm,
or from 0.7 through 13 .mu.m. The layer of E-type polarizer is
applied on top of the layer of O-type polarizer and/or vice versa.
The polarizer is preferably multi-layered with any possible
combination of E- and O-type polarizer layers. Preferably, the
thickness of each layer is designed to provide polarizing
effectiveness of 70 to 100%.
[0047] Further, the polarizer may include an additional mirror- or
diffuse-reflecting layer applied onto its surface from the side of
the E- or O-type polarizer layer or both.
[0048] Making use of the methods of assembly of LC displays, one
can list a number of various configurations.
[0049] Design 1. One of the possible LC display designs could be a
transmissive display with internal polarizers. One of the
polarizers in such a display design could be the single-layered
E-type polarizer manufactured according to the method described in
(U.S. Pat. No. 5,739,296, 1998), applied to one of the glass plates
(first plate). This polarizer has a crystalline structure of
oriented supramolecular complexes of an organic matter, most
commonly dyes. Various materials and polarizers of this type are
widely known and used (U.S. Pat. No. 5,739,296, 1998). Such
polarizer has negative dielectrical anisotropy and negative
dichroism; it has inherently high polarizing and operational
characteristics. The other polarizer could be formed by application
onto another glass plate of display, and it is multi-layered, in
particular double-layered. The first of the layers could be, for
example, a layer of O-type polarizer, which features positive
dielectrical anisotropy and positive dichroism. This layer could be
built with the oriented molecules of polyvinyl alcohol colored by
iodine. It is possible, for example, to first obtain this polarizer
as a thin film and then apply it to the inside of the glass plate,
which already has the electrode pattern and the alignment layer
applied on it. However; the method of application and arrangement
of the components other than the polarizer could vary. On top of
the above-mentioned O-type polarizer one could apply a layer of
E-type polarizer, either directly on a O-type polarizer layer or on
an intermediate layer, which could be isotopic as well as
anisotropic. In this example design the E-type polarizer could be
utilized also as the alignment layer and/or as the birefringent
layer, and/or as the phase-shifting layers. This option in addition
to the result achieved by the different designs of the layers in
polarizer and a display also allows decreasing the thickness of the
display.
[0050] The stacking order of O-type and E-type layers, however,
could be other than described above, which will not change the
resultant characteristics. In particular, the E-type polarizer
could be applied onto the display plate where the electrode pattern
or an active matrix along with the alignment layer have already
been applied, and the O-Type polarizer could be applied on top of
that, also by the direct forming of a layer on the surface or by
the gluing of a mediator film formed in advance.
[0051] The described above double-layered polarizers correspond to
the polarizers according to the claims. The mentioned configuration
of layers could be changed according to the requirements--it could
be higher or could be different The layers of O- and E-type
polarizers can alternate as well as double.
[0052] In the described display design the first display plate
could be made of a single-layered O-type polarizer made out of
oriented molecules of polyvinyl-alcohol colored by iodine.
[0053] In a different arrangement of a transmissive LCD with
internal polarizers, each polarizer plate is made out of the
multi-layered polarizers with the same or distinct layering
sequence and combination of E- and O-type polarizers.
[0054] Design 2. Another configuration of a transmissive LC which
can be designed in accordance with the claims of the invention,
could be obtained by applying different sequences of polarizers in
variable combinations on the outside of the plates. Usually
protective coatings fulfill this function for this sort of
structures. However, since the invention does not limit the
configuration of LC display to any one kind, but characterize the
polarizers' structure only, we will not focus on the description of
all structures details of the known LCD designs. These include the
arrangement of spacers, the method of joining of the display
plates, the manufacturing and application of the electrodes and
other elements as well as the choice of materials for them, which
could be a subject of another invention.
[0055] Design 3. A particular attention should be paid to the
design of a transmissive LC display with a "mixed" sequencing of
polarizing layers. The sequencing could be any of the
above-mentioned kinds utilizing different types of polarizers,
which could be applied on either side of the plates. The choice
could vary for different designs and the sequence is determined by
the particular requirements of the intended application. This
flexibility of possible combinations and sequencing of polarizer
layers allows substantial broadening of functional possibilities of
displays.
[0056] Design 4. The most promising, according to the obtained
results, is the reflective LC display, where one of its sides is
non-transparent i.e. a reflecting layer (film or plate) which is
mirror-reflecting or diffusive-reflecting in the working display
range is placed either at the internal or external rear plate.
[0057] The configuration of polarizing layers in the reflective
display could be the same as in the case of the transmitting
display described above. The difference is in the option to place
the polarizer layers on the rear plate side. In case the reflective
layer is placed behind the rear plate then the combination of
polarizers could be any. In case the reflective layer is placed at
the internal side of the rear display plate, or the plate is not
transparent itself and it is reflective itself, in this case rear
plate polarizers could be internal only.
[0058] All the designs of LC displays and the combined polarizer,
despite their variety, do not deplete the list of possible
arrangements determined by the claims of the disclosed invention.
However, according to the experimental results, the use of the
described designs with different polarizer sequences and
combinations allows substantially enhance technical characteristics
of LC displays. Here, all the displays manufactured featured
improved angle characteristics of polarizers as well as the display
as a whole. The displays exhibited negligible amount of transmitted
unpolarized light by a single polarizer as well as by two parallel
polarizers. In addition to that, improvements like substantially
enhanced polarizing effectiveness and contrast ratio; viewing angle
was broadened up to 180.degree. and an absence of the "gray effect"
has been registered. All of the mentioned improvements can be
obtained with various assembly designs. This greatly broadens
functional possibilities of high quality LC displays and allows
unification of the manufacturing process of different displays
hence lowering the cost.
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