WO2009037565A2

WO2009037565A2 - Colour liquid crystal display and patterned compensation panel

Info

Publication number: WO2009037565A2
Application number: PCT/IB2008/002613
Authority: WO
Inventors: Serguei Petrovich Palto; Artur Geivandov
Original assignee: Crysoptix K.K.
Priority date: 2007-09-17
Filing date: 2008-09-17
Publication date: 2009-03-26
Also published as: WO2009037565A3; GB0718154D0

Abstract

The present invention relates to a colour liquid crystal display (LCD) device and, more particularly, to the improvement of colour LCDs aimed to achieving a high contrast ratio and better colour rendering at wide viewing angles. The disclosed colour liquid crystal display comprises first and second polarizing plates facing each other, a liquid crystal cell situated between said first and second polarizing plates, and at least one compensation panel situated between said first and second polarizing plates. The compensation panel comprises at least one matrix of patterned birefringent elements of / kinds having different retardation, wherein / is 3, 4 or 5. The patterned birefringent elements comprise at least one retardation layer comprising at least one polycyclic organic compound with a conjugated p-system and functional groups which are capable of forming non-covalent bonds.

Description

COLOUR LIQUID CRYSTAL DISPLAY AND PATTERNED COMPENSATION PANEL

This invention relates to a colour liquid crystal display (LCD) device and, more particularly, to the improvement of colour LCDs aimed to achieving a high contrast ratio and better colour rendering at wide viewing angles by using of a patterned compensation panel for application in the LCD.

Liquid crystal displays are widely used in watches and clocks, photographic cameras, various instruments, computers, flat television sets, projection screens, and numerous information devices.

Electro-optical modes employed in LCDs include, in particular, the twisted nematic (TN), super twisted nematic (STN), optically compensated bend (OCB), and electrically controlled birefringence (ECB) modes with their various modifications, as well as some other. All these modes use an electric field, which is substantially perpendicular to the substrate and, hence, to the liquid crystal (LC) layer. Besides these modes, there are several electro-optical modes employing an electric field substantially parallel to the substrate and, hence, to the liquid crystal layer, for example, the in-plane switching (IPS).

The IPS and VA (vertically aligned) electro-optical modes are the most frequently used in LCDs for large scale (with the diagonal above 19") modern desktop monitors and TV sets are envisaged for use in future displays for multimedia applications.

'A TN (twisted nematic) mode LCD is a common type of conventional LCD using liquid crystal molecules that have positive dielectric anisotropy and are aligned in a twisted state between two facing substrates. However the TN LCDs cannot display a sufficiently black state at oblique viewing angles because of difficulties of optical compensation of the light leakage caused by the complex distribution of the liquid crystal molecules across the layer thickness. On the other hand, the IPS LCD can display an almost complete black state in an OFF-state because the liquid crystal molecules are uniformly aligned by the substrate surfaces, and this uniform state allows an efficient optical compensation, which suppresses the angular light leakage in the black state. The VA (vertically aligned) mode LCD is also characterized by uniform distribution of LC molecules in the OFF-state. However, for a good-quality optical compensation of VA LCD one needs using at least two different types of the retardation layers. Thus suppressing the light leakage remains a problem to be solved.

In connection with polarizing plates, compensation panel, retardation layers described in the present application, the following definitions of terms are used throughout the text.

The term "optical axis" refers to a direction in which the different linearly polarized components of propagating light have the same phase velocity and do not exhibit mutual retardation.

Any optically anisotropic medium is characterized by its second-rank dielectric permittivity tensor. A dielectric permittivity of any medium is determined by polarizability of particles forming this medium. If medium comprises supramolecules then the dielectric permittivity of the medium is determined by orientation and polarizability of these supramolecules.

The classification of compensator plates is tightly connected to orientations of the principal axes of a particular permittivity tensor with respect to the natural coordinate frame of the plate. The natural xyz coordinate frame of the plate is chosen so that the z-axis is parallel to the normal direction and the xy plane coincides with the plate surface.

Figure 1 (prior art) demonstrates a general case when the principal axes (A, B, C) of the permittivity tensor are arbitrarily oriented relative to the xyz frame. Orientations of the principal axes can be characterized using three Euler's angles (θ, φ, ψ) which, together with the principal permittivity tensor components (ε_Λ, ε_e, ε _c), uniquely define different types of optical compensators. The case when all the principal components of the permittivity tensor have different values corresponds to a biaxial compensator, whereby the plate has two optical axes. For instance, in the case of ε_A ^< ε _B ^< ε _c, the two optical axes are in the plane of C and A axes and oriented symmetrically on both sides from the C axis. In the uniaxial limit, when ε_A= ε _Bl there is a degenerate case when the two axes coincide and the C axis is a single optical axis,

In another example when the two principal axes A and B of the dielectric tensor lie in the layer plane, while the axis C is normal to it. The x, y and z-axes of the laboratory frame can be chosen coinciding with A, B and C axes respectively. If, for instance, the lowest and highest magnitudes of the three principal values ε _A , ε _B of the dielectric permittivity tensor correspond to the A and B axes respectively then ε_A ^< ε_c < ε _Bl and the two optical axes belong to the AB plane. For this reason such retardation layer is named as "A_B" or "β_Λ" type plate (Figure 2, Prior art). The negative A_B plate, when ε_A- ε_B < 0, is equivalent to positive B_A plate (replacing the order of the naming letters changes the sign of the dielectric permittivity difference: ε _B - ε _A > 0). Another fundamentally different case is when the two optical axes belong to the plane orthogonal to the plate surface. This case takes place if the lowest or highest magnitude of one of the principal permittivity corresponds to the C-axis. For instance, in case of ε _c < ε _B < ε _A this retardation layer is named as the negative C_A or positive A₀ plate.

The zenith angle θ between the C axis and the z axis is most important in the definitions of various compensator types. There are several important types of uniaxial retardation layers, which are most frequently used in practice for compensation of LCD.

A C-plate is defined by the Euler angle θ = 0 and ε_A= ε _B ≠ ε _c- In this case, the principal C axis is normal to the plate surface (xy plane). In cases of ε_A = ε _B < ε _c, the plate is called "positive C-plate". On the contrary, if ε _A = ε _B > ε _c, the plate is referred to as the "negative C-plate". Figure 3 (Prior art) shows the orientation of the principal axes of a particular permittivity tensor with respect to the natural coordinate frame of the positive (a) and negative (b) C-plate. The axes OA and OB lodated in a xy plane are equivalent.

If the C axis is normal to plate, but ε_A≠ ε _B =ε_c then the plate is called "A-plate". In this case A- axis is an optical axis, which is parallel to the xy-surface. In case of ε _c = ε _B < ε _A the plate is called "positive A-plate" (Figure 4(a), Prior art). Contrary, if ε_c ⁼ ε _B > ε_A the plate is defined as the "negative A-plate" (Figure 4(b), Prior art).

Generally, for non-magnetic materials, when the permittivity tensor components (ε_Λ, ε_β, and ε_c) are complex values, the principal permittivity tensor components (ε_A, ε_β, and ε c), the refraction indices (na, nb, and nc), and the absorption coefficients (ka, kb, and kc) meet the following conditions: na = Re[(ε_Λ)^1/2], nb = Re[(ε_B)^1/2], nc = Re[(ε _c)^1/2], ka = lm[(ε_A)^1/2], kb = lm[(ε _β)¹'²], kc = lm[(ε _c)^1/2]. The smaller is a refraction index of an environment, the higher is the phase speed of an electromagnetic wave in this environment. Therefore the speed of an electromagnetic wave depends on propagation direction in the anisotropic environment. If light polarized along a chosen principal axis has the highest phase velocity then the axis is called fast principal axis, and, by analogy, a slow principal axis corresponds to direction of polarization for a wave propagating with the lowest speed. Thus the retardation layer may be characterized by two in-plane refractive indices corresponding to a fast principal axis and a slow principal axis (nf and ns), and by one refractive index (nn) in the normal direction. All refractive indices nf, ns and nn have different values in a biaxial plate. As it has been shown above, the A- and C-plates are assigned to the uniaxial plates. In the negative A-plate the refractive indices obey the condition nn = ns > nf. The A-plate may be characterized by the retardation parameter R_A= d-(ns - nf), where d is a thickness of the plate. In the negative C-plate the refractive indices obey the condition nf= ns > nn. The C-plate may be characterized by the retardation parameter R₀= d-|ns - nn\ = d |nf- nn], where d is a thickness of the plate.

It should be noted that herein we distinguish quasi A- and quasi C-plates. The negative quasi A-plate is a slightly biaxial plate, which is characterized by two in-plane refractive indices (nf and ns) corresponding to a fast principal axis and a slow principal axis respectively, and one refractive index (nn) in the normal direction which obey the following conditions for electromagnetic radiation in the visible spectral range: ns >nf, nn >nf, and \nn-ns\l(nn+ns) < 0.1. The negative quasi C-plate is a slightly biaxial plate which is characterized by two in-plane refractive indices (nf and ns) corresponding to a fast principal axis and a slow principal axis respectively, and one refractive index (nn) in the normal direction which obey the following conditions for electromagnetic radiation in the visible spectral range: ns > nf> nn, and (ns-nή/(ns+nή < 0.1.

The optical characteristics of LCD devices can be improved by applying one or more layers having optical birefringence. In all modern types of commercial displays the retardation layers (or retardation films) are used in order to solve the problems of low contrast and light leakage. The typical retardation film consists of at least one homogeneous layer of uni- or biaxial birefringent material, and is disposed between a polarizer and a liquid crystal cell. The retardation film for improving the contrast ratio at oblique viewing angles comprises a negative C-type plate for compensating an in-plane retardation (R₀), and a negative A-type plate for compensating out-of-plane retardation (R_th) which should be placed in a specific order to increase the contrast at wide viewing angles.

However, typical retardation films have a normal dispersion and cannot provide the solution to the above referenced disadvantages in the entire visible spectral range. It can result in the distortion of colour of the displayed picture, especially at wide viewing angles. Usually the optimization of LCD is held in the maximal sensitivity human eye vision range for the light wavelength of 550 nm. Therefore, the maximal distortions may arise in the red and blue parts of the light spectrum. In the present invention it is supposed that the visible spectral range has a lower boundary that is approximately equal to 400 nm, and an upper boundary that is approximately equal to 700 nm.

The present invention provides a compensated colour liquid crystal display with improved optical performance, in particular, higher contrast and better colour rendering at a wide range of viewing angles, and reduced colour shift in an entire visible spectral range. These advantages are provided along with the simplified manufacturing technology.

The design of a colour liquid crystal display with a patterned compensation panel comprising at least one matrix of birefringent elements of i kinds having different retardation, provides an improvement in colour rendering properties and contrast ratio over a wide range of viewing angles.

In a first aspect, the present invention provides a colour liquid crystal display comprising first and second polarizing plates facing each other, a liquid crystal cell situated between said first and second polarizing plates, a colour filter being equipped with /colours, and at least one compensation panel situated between said first and second polarizing plates. The compensation panel comprises at least one matrix of patterned birefringent elements of i kinds having different retardation, wherein / is 3, 4 or 5. The birefringent elements comprise at least one retardation layer comprising at least one polycyclic organic compound with a conjugated π-system and functional groups which are capable of forming non-covalent bonds.

In a second aspect of the present invention there is provided a compensation panel comprising at least one matrix of patterned birefringent elements of / kinds having different retardation, wherein / is equal to 3, 4 or 5. The birefringent elements comprise at least one retardation layer comprising at least one polycyclic organic compound with a conjugated π-system and functional groups which are capable of forming non-covalent bonds.

The general description of the present invention having been made, a further understanding can be obtained by reference to the specific preferred embodiments, which are given herein only for the purpose of illustration and are hot intended to limit the scope of the appended claims.

In one embodiment of the disclosed liquid crystal display, the polycyclic organic compound is forming rod-fike supramolecules via the conjugated π-systems and functional groups. In one embodiment of the disclosed liquid crystal display, the polycyclic organic compound is forming rod-like supramolecules via the conjugated π-systems and functional groups. In still another embodiment of the disclosed liquid crystal display, the polycyclic organic compound is forming planar supramolecules. In still another embodiment of the disclosed liquid crystal display, the polycyclic organic compound is forming planar supramolecules.

In one embodiment of the liquid crystal display, the organic compound has a general structural formula (I)

where Sys is at least partially conjugated substantially planar polycyclic molecular system, X is a carboxylic group -COOH, m is O, 1, 2, 3 or 4; Y is a sulfonic group -SO₃H, n is O, 1, 2, 3 or 4; Z is an amide of a carboxylic acid group, p is O, 1 , 2, 3 or 4; Q is an amide of a sulfonic acid group, v is 0, 1, 2, 3 or 4; K is a counterion; s is the number of counterions providing neutral state of the molecule; R is a substituent selected from the list comprising CH₃, C₂H₅, NO₂, Cl, Br, F, CF₃, CN, OH, OCH₃, C₂H₅, OCOCH₃, OCN, SCN, NH₂, and NHCOCH₃, and w is O, 1 , 2, 3 or 4.

In another embodiment of the liquid crystal display molecular system Sys has a general structural formula from the list comprising structures Il to XLVI given in Table 1. Table 1. Examples of polycyclic molecular systems (Sys)

(XXIII)

)

(XXXI)

(XXXIV)

(XXXVI)

(XXXVII)

(XXXVIII)

(XXXIX)

where/ is 1 , 2, 3, 4, 5, 6, 7 or 8.

In one embodiment of the present invention, the counterion is selected from the list of ions comprising H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Ba⁺⁺, Ca⁺⁺, Mg⁺⁺, Sr⁺⁺, and Zn⁺*.

The structural formulas of some of the organic compounds which might be used for the producing of the retardation layer are presented in Tables 2 to 8.

In one preferred embodiment of the disclosed liquid crystal display, the organic compound is acenaphthoquinoxaline derivative comprising a carboxylic group. Examples of the acenaphthoquinoxaline derivative comprising a carboxylic group and having general structural formulas corresponding to structures 1-7 are given in Table 2.

Table 2. Examples of the structural formulas of acenaphthoquinoxaline derivative

In another preferred embodiment of the disclosed liquid crystal display, the organic compound is acenaphthoquinoxaline derivative comprising a sulfonic group. Examples of the acenaphthoquinoxaline derivative comprising a sulfonic group and having general structural formulas corresponding to structures 8 to 19 are given in Table 3.

Table 3. Examples of the structural formulas of acenaphthoquinoxaline derivative

In yet another preferred embodiment of the disclosed liquid crystal display, the organic compound is a 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative.

In one embodiment the 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative comprises at least one carboxylic group -COOH, and has a general structural formula from the group comprising structures 20 to 32. The examples are given in Table 4. Table 4. Examples of the structural formulas of 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative

In still another embodiment of the disclosed liquid crystal display, the organic compound is a 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative comprising at least one sulfonic group - SO₃H, and having a general structural formula from the list comprising structures 33 to 41. Examples of the structural formulas are given in Table 5.

Table 5. Examples of the structural formulas of 6,7-dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative

In one preferred embodiment of the disclosed liquid crystal display, the organic compound is an oligophenyl derivative. The examples of the oligophenyl derivative of a general structural formula corresponding to structures 42 to 48 are given in Table 6. Table 6. Examples of the structural formulas of oligophenyl derivative

In another preferred embodiment of the disclosed liquid crystal display, the organic compound is an oligobenzimidazole derivative. In one embodiment the oligobenzimidazole derivative comprises at least two carboxylic groups -COOH. The examples of the oligobenzimidazole derivatives of a general structural formula corresponding to structures 49 to 51 are given in Table 7.

Table 7. Examples of the structural formulas of oligobenzimidazole derivatives

In still another embodiment the organic compound is dipyrazinoquinoxaline derivative. In some embodiments the dipyrazinoquinoxaline derivative comprises at least three carboxylic groups -COOH and said derivative has a general structural formula 52 as presented in Table 8.

Table 8. Example of the structural formula of dipyrazinoquinoxaline derivative

The organic compounds used for the retardation layers of the present invention are for illustrative purposes only and do not have a purpose to limit to the list of the compounds for the present invention.

In one embodiment of the liquid crystal display, the retardation layer comprises the organic compound substantially transparent in the visible spectral range.

In one embodiment of the disclosed liquid crystal display, the long axes of rod-like , supramolecules are oriented substantially parallel to the surface of the birefringent elements. In another embodiment of the disclosed liquid crystal display, the planes of planar supramolecules are oriented substantially parallel to the surface of the birefringent elements.

In still another embodiment of the disclosed liquid crystal display, said non-covalent bonds are selected from the list comprising hydrogen bonds, coordination bonds, dipole— dipole interaction, cation-π interaction, van der Waals interaction and π-τr interaction. In yet another embodiment of the disclosed liquid crystal display, at least one said retardation layer of the birefringent elements has at least partially crystalline structure. In one embodiment of the disclosed liquid crystal display, the retardation layer of the birefringent elements is water-insoluble.

In another embodiment of the disclosed liquid crystal display, the number / is equal to 3, and the colour filter includes red, green and blue colours. In one embodiment of the disclosed liquid crystal display, the number i is equal to 3, and the colour filter further comprises complementary colours - cyan, yellow, and magenta. In still another embodiment of the disclosed liquid crystal display, the birefringent element comprises at least one retardation layer of type selected from list comprising negative C-plate, negative A-plate, biaxial negative A₅ plate and biaxial Ac plate.

In yet another embodiment of the disclosed liquid crystal display, birefringent element comprises at least two retardation layers of different types. In yet another embodiment the retardation layers of the same types and belonging to different birefringent elements have equal refractive indices, equal codirectional fast optical axes and slow optical axes, and different thickness.

In one embodiment of the disclosed liquid crystal display, the retardation layers of the same type comprise different polycyclic organic compounds.

In another embodiment of the disclosed liquid crystal display, the colour filter has a pattern which is selected from the list comprising stripe, mosaic, and delta. In still another embodiment of the disclosed liquid crystal display, the at least one matrix of birefringent elements is located inside the liquid crystal cell.

In yet another embodiment of the disclosed liquid crystal display, the compensation panel is located inside the liquid crystal cell. In one embodiment of the disclosed liquid crystal display, the compensation panel is located outside the liquid crystal cell.

In another embodiment of the disclosed liquid crystal display, the compensation panel further comprises at least one homogeneous retardation layer. In one embodiment of present invention, the liquid crystal display further comprises a homogeneous retardation layer located inside the liquid crystal cell. In another embodiment of present invention, the liquid crystal display further comprises a homogeneous retardation layer located outside the liquid crystal cell. In still another embodiment of present invention, the liquid crystal display further comprises two homogeneous retardation layers located on the both sides of the liquid crystal cell. In one embodiment of the disclosed liquid crystal display, the homogeneous retardation layer comprises at least one polycyclic organic compound with a conjugated π-system and functional groups which are capable of forming non-covalent bonds. In another embodiment of the disclosed liquid crystal display, each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose. In still another embodiment of the disclosed liquid crystal display, the transmission axes of said polarizers are perpendicular to each other.

In one embodiment of the disclosed liquid crystal display, the liquid crystal cell is an in-plane switching mode (IPS-mode) liquid crystal cell. In yet another embodiment of the disclosed liquid crystal display, the transmission axes of said polarizers are parallel. In one embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and an uniaxial retardation layer of the negative C-type plate. In still another embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate and a uniaxial retardation layer of the negative C-type plate. In yet another embodiment of the disclosed liquid crystal display with the in-plane switching mode liquid crystal cell, the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and the homogeneous retardation layer is an uniaxial layer of the negative C-type plate. In one embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC). In another embodiment of the disclosed liquid crystal display with the IPS- mode liquid crystal cell, the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC). In still another embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate, and the homogeneous retardation layer is an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the second polarizing plate. In yet another embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose and each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate. In one embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose, a homogeneous retardation layer located between the liquid crystal cell and the second polarizing plate, comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate, and each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate In another embodiment of the disclosed liquid crystal display with the IPS-mode liquid crystal cell, each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose and each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate.

In one embodiment of the disclosed liquid crystal display, the liquid crystal cell is a vertical alignment mode (VA-mode) liquid crystal cell. In another embodiment of the disclosed liquid crystal display with the vertical alignment mode (VA-mode) liquid crystal cell, each of said birefringent elements comprises a uniaxial retardation of the negative C-type plate. In still another embodiment of the disclosed liquid crystal display with the VA-mode liquid crystal cell, each of said birefringent elements comprises a biaxial retardation of the negative A₆ -type plate In yet another embodiment of the disclosed liquid crystal display with the VA-mode liquid crystal cell, each of said birefringent elements comprises a biaxial retardation of the negative A_B -type plate and a uniaxial retardation of the negative C-type plate. In one embodiment of the disclosed liquid crystal display with the VA-mode liquid crystal cell, the fast axis of the uniaxial retardation layer of the negative A_B -type plate is substantially parallel to the transmission axis of the first polarizing plate. In another embodiment of the disclosed liquid crystal display with the VA-mode liquid crystal cell, the fast axis of the uniaxial retardation layer of the negative A₈ -type plate is substantially parallel to the transmission axis of the second polarizing plate. In yet another embodiment of the disclosed liquid crystal display with the VA- mode liquid crystal cell, at least one polarising plate comprises a homogeneous retardation layer is a layer of triacetyl cellulose (TAC). In one embodiment of the disclosed liquid crystal display with the VA- mode liquid crystal cell, the matrix is multilayer matrix comprising at least two layers each comprises the patterned birefringent elements of different kinds. In another embodiment of the disclosed liquid crystal display with the VA-mode liquid crystal cell, the matrix comprises at least one layer comprising i different kinds of the patterned birefringent elements.

The present invention also provides a compensation panel as disclosed hereinabove. In one embodiment of the disclosed panel, the organic compound has a general structural formula (I)

where Sys is at least partially conjugated substantially planar polycyclic molecular system, X is a carboxyiic group -COOH, m is O, 1 , 2, 3 or 4; Y is a sulfonic group -SO₃H, n is O, 1 , 2, 3 or 4; Z is an amide of a carboxyiic acid group, p is O, 1 , 2, 3 or 4; Q is an amide of a sulfonic acid group, v is O, 1 , 2, 3 or 4; K is a counterion; s is the number of counterions providing neutral state of the molecule; R is a substituent selected from the list comprising CH₃, C₂H₅, NO₂, Cl, Br, F, CF₃, CN, OH, OCH₃, OC₂H₅, OCOCH₃, OCN, SCN, NH₂, and NHCOCH₃, and w is O, 1 , 2, 3 or 4.

In another embodiment of the disclosed panel, the molecular system Sys has a general structural formula selected from the list comprising structures Il to XLVI shown in Table 1 , where j is 1 , 2, 3, 4, 5, 6, 7 or 8.

In some embodiments of the disclosed panel the counterion is selected from the list of ions comprising H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Ba⁴⁺, Ca⁺⁺, Mg⁺⁺, Sr⁺⁺, and Zn⁺⁺.

In another embodiment of the disclosed panel, the organic compound is an acenaphthoquinoxaline derivative. In still another embodiment of the disclosed panel, the acenaphthoquinoxaline derivative comprises a carboxyiic group and has a general structural formula corresponding to any of structures 1 to 7 given in Table 2.

In another embodiment of the disclosed panel, the acenaphthoquinoxaline derivative comprises a sulfonic group and has a general structural formula corresponding to any of structures 8 to 19 given in Table 3.

In still another embodiment of the disclosed panel, the organic compound is a 6,7- dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative. In yet another embodiment of the disclosed panel, the 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative comprises at least one carboxyiic group -COOH, and has a general structural formula from the group comprising structures 20 to 32 given in Table 4.

In one embodiment of the disclosed panel, the 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one derivative comprises at least one sulfonic group -SO₃H, and has a general structural formula from the list comprising structures 33 to 41 given in Table 5. In another embodiment of the disclosed panel, the organic compound is an oligophenyl derivative. In still another embodiment of the disclosed panel, the oligophenyl derivative has a general structural formula corresponding to any of structures 42 to 48 shown in Table 6. In yet another embodiment of the disclosed panel, the organic compound is an oligobenzimidazole derivative.

In one embodiment of the disclosed panel, the oligobenzimidazole derivative comprises at least two carboxylic groups -COOH and has a general structural formula corresponding to structures 49 to 51 shown in Table 7.

In one embodiment of the disclosed panel, the organic compound is a dipyrazinoquinoxaline derivative. In another embodiment of the disclosed panel, the dipyrazinoquinoxaline derivative comprises at least three carboxylic groups -COOH and has general structural formula 52 shown in Table 8.

In one embodiment of the disclosed panel, the retardation layer comprising the organic compound is substantially transparent in the visible spectral range.

In another embodiment of the disclosed panel, the polycyclic organic compounds are forming supramolecules.

In still another embodiment of the disclosed panel, said supramolecules have rod-like shapes and the long axes of supramolecules are oriented substantially parallel to the surface of the birefringent elements.

In yet another embodiment of the disclosed panel, said supramolecules have planar shapes and their planes are oriented substantially parallel to the surface of the birefringent elements.

In one embodiment of the disclosed panel, said non-covalent bonds are selected from the list comprising hydrogen bonds, coordination bonds, dipole-dipole interaction, cation-π interaction, van der Waals interaction, and π-π interaction. In another embodiment of the disclosed panel, at least one said retardation layer of the birefringent elements has at least partially crystalline structure.. In still another embodiment of the disclosed panel, at least one said retardation layer is water-insoluble. In one embodiment of present invention, the panel further comprises at least one functional layer selected from the list comprising polarizing layer, conducting layer, planarization layer, and alignment layer.

In another embodiment the compensator panel further comprises at least one functional layer selected from the list comprising polarizing layer, conducting layer, planarization layer, protective layer and alignment layer.

In another embodiment of the present invention, the panel further comprises a substrate. In another embodiment of the disclosed panel, the substrate is made of one or several materials selected from the group comprising diamond, quartz, plastics, glasses, and ceramics.

In still another embodiment of present invention, the panel further comprises a colour filter.

In still another embodiment of the disclosed panel, the colour filter serves as the substrate.

In yet another embodiment of the disclosed panel, the number / is equal to 3, and the colour filter comprises red, green and blue colours. In one embodiment of the disclosed panel, the number ;^" is equal to 3, and the colour filter further comprises complementary colours - cyan, yellow, and magenta.

In another embodiment of the disclosed panel, the retardation layers of the same type have equal refractive indices and codirectional fast optical axes arid slow optical axes, but different thickness. In still another embodiment of the disclosed panel, the birefringent elements are formed of different polycyclic organic compounds. In one embodiment of present invention, the panel further comprises at least one homogeneous retardation layer made from at least one polycyclic organic compound and that serves as a retardation layer of a type selected from list comprising negative C- plate, negative A-plate, biaxial A_B-plate, and biaxial A₀ plate.

In one embodiment of the disclosed compensation panel each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and a uniaxial retardation layer of the negative C-type plate. In another embodiment each of said birefringent elements comprises a biaxial retardation layer of the negative A₆ -type plate and a uniaxial retardation layer of the negative C-type plate. In still another embodiment of the disclosed compensation panel each of said birefringent elements comprises a biaxial retardation layer of the A₀ -type plate.

In one embodiment the panel further comprises at least one homogeneous retardation layer and each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and the homogeneous retardation layer is a uniaxial layer of the negative C-type plate. In still another embodiment the compensation panel further comprises at least one homogeneous retardation layer, and each of said birefringent elements comprises a uniaxial retardation layer of the negative A- type plate and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC). In still another embodiment the disclosed compensation panel further comprises at least one homogeneous retardation layer and each of said birefringent elements comprises a biaxial retardation layer of the negative A_B -type plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC). In still another embodiment the panel further comprising at least one homogeneous retardation layer and each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and the homogeneous retardation layer is a uniaxial retardation layer of the negative A-type plate, wherein the fast axes of said retardation layers are perpendicular to each other.

In one embodiment of the disclosed panel, the birefringent elements contain at least two retardation layers, one of said retardation layers comprises supramolecules having rod-like shapes an the long axes of supramolecules are oriented substantially parallel to the surface of the birefringent elements, and another said retardation layer comprises supramolecules having planar shapes and their planes are oriented substantially parallel to the surface of the birefringent elements.

In another embodiment of the disclosed panel, the matrix is a multilayer matrix comprising at least two layers each comprising the patterned birefringent elements of / different kinds. In another embodiment of the disclosed panel, the matrix comprises at least one layer comprising i different kinds of the patterned birefringent elements.

Other objects and advantages of the present invention will become apparent upon reading the detailed description of the examples and the appended claims provided below, and upon reference to the drawings, in which:

Figures 1 to 4 are described hereinabove as prior art, wherein

Figure 1 shows a general case of the orientation of the principal dielectric tensor axes for the optically anisotropic media;

Figure 2 shows the orientation of the principal dielectric tensor axes and principal values relations for a negative A_B-plate compensator; Figure 3 shows the orientation of the principal dielectric tensor axes and principal values relations (a) for a positive C-plate compensator, and (b) for a negative C-plate compensator; and

Figure 4 shows the orientation of the principal dielectric tensor axes and principal values relations (a) for a positive A-plate compensator, and (b) for a negative A-plate compensator.

Figure 5 schematically shows a colour liquid crystal display according to the present invention.

Figure 6 schematically shows a formation of a biaxial retardation layer of negative biaxial A₀- type plate (Figure 6a) and A-type plate (Figure 6b).

Figure 7 schematically shows a molecular packing for a disk-like molecule of polycyclic organic compound used for a negative C-type plate formation.^"

Figure 8 shows a schematic diagram of a coating device with a slot-die of a special shape; the insert shows the side view of the coating profile.

Figure 9 shows an embodiment for a patterned compensation panel for outside of cell and inside cell designs.

Figure 10 schematically shows a cross-section of the liquid crystal display with the IPS-mode liquid crystal cell.

Figure 11 shows the spectral dependences of the principal refractive indices of a biaxial (negative A_B-type plate) thin birefringent film (TBF).

Figure 12 (a) - (c) shows computer simulated viewing angle diagrams of the liquid crystal display with the IPS-mode liquid crystal cell for different wavelength.

Figure 13 (a) - (c) shows computer simulated viewing angle diagrams of non-compensated IPS-mode liquid crystal display for different wavelength.

Figure 14 schematically shows a cross-section of the liquid crystal display with the VA-mode liquid crystal cell.

Figure 15 (a) - (c) shows computer simulated viewing angle diagrams of the liquid crystal display with the VA-mode liquid crystal cell for different wavelength.

Figure 16 (a) - (c) shows computer simulated viewing angle diagrams of non-compensated VA-mode liquid crystal display for different wavelength.

The colour liquid crystal display according to one of the embodiment of the present invention (Figure 5) comprises:

- first polarizing plate 501 and second polarizing plate 503 facing each other and spaced from each other; a liquid crystal cell comprising:

- front substrate 505 with colour filters 506, black matrix 507 and planarization layer 508;

- liquid crystal layer 504;

- other functional layers 512 comprising electrode and alignment layers;

- a back substrate 513 with electrodes, driving elements and alignment layers;

- a compensation panel 509 situated inside the liquid crystal cell ; and

- a back light unit 502.

The compensation panel comprises at least one matrix of patterned birefringent elements 510 made of thin retardation layer of / kinds having different retardation (in this case /=3, equal to the number of colour subpixels). The isotropic planarization layer 511 is positioned on top of the compensation panel.

The first 501 and second 503 polarizing plates usually have transmission axes which are perpendicular to each other (normally black state).

In one embodiment of the disclosed liquid crystal display, the patterned birefringent elements of the compensation panel comprise at least one retardation layer of supramolecules comprising at least one polycyclic organic compound with a conjugated π-system and functional groups capable of forming non-covalent bonds between said supramolecules.

It is preferable to develop system of ττ-τr-interactions between aromatic rings of the molecules and presence of groups situated in the plane of the molecule and involved into the aromatic system of bonds. The molecules or their molecular fragments possess a substantially planar structure and are forming supramolecules in a solution. Another condition is the maximum overlap of π- orbitals in the stacks of supramolecules.

There are several tasks to perform in process of molecular engineering of the final retardation layer structure. The first task is to design a macroscopic structure that supports desirable optical functions via certain values of the three principal refraction indices. The second task is to design molecules with the required self-assembly properties, which would provide the necessary supramolecular structure with desired orientation and spatial homogeneity of the optical parameters of the retardation layer. The process of retardation layer deposition consists in printing or wet coating of a liquid self-assembling material with a subsequent drying, which converts the liquid coating material into an aligned nanostructural retardation layer.

According to one embodiment of the present invention, the molecules in the solution are assembled in stacks (rod-like supramolecules) and may form a lyotropic liquid crystal. The supramolecules have a rod-like shape and definite long axis (Figure 6). Said rod-like supramolecules have an anisotropic polarizability in plane (uθw) which is perpendicular to their longitudinal axis directed along 0v-axis. The heterocyclic molecular systems and binding groups of the organic compounds suitable for formation of retardation layers of negative A-type plate (Figure 6b) and Biaxial-type plates (Figure 6a) form flat anisometric particles (kinematic units) due to non-covalent chemical bonds between the binding groups of adjacent molecular systems. The examples of such organic compounds include but are not limited to acenaphthoquinoxaline derivative, 6,7- dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative, and oligophenyl derivative. During the deposition, the stacks are oriented under the action of a shear stress along the long axis of the stack. The result is an ordered film with stacks aligned in the substrate plane along the coating direction. Such method can be used for the forming of retardation layers of negative A-type plate (Figure 6b) and negative biaxial A_B -type plate (Figure 6a).

The example of the formation of the retardation layer of the negative C-type plate is shown in Figure 7. The compounds which consist of mostly planar molecules with specific intermolecular interactions and which are aligned by the substrate surface substantially parallel to the surface of the retardation layer. The examples of such organic compounds include but are not limited to bisbenzimidazo[1',2':3_l4;1",2":5,6][1 ,3,5]triazino[1,2-a]benzimidazole-tricarboxylic acids; tricarboxy- 5,11,17-trimethylbis[3,1]benzimidazo[1',2':3,4;1",2":5,6][1,3,5]triazino[1 ,2-a][3,1]benzimidazole- 5,11,17-triium bromides; 1H,1'H-2,2'-bibenzimidazole-dicarboxylic acids; dipyrazino[2,3-f:2',3'- hjquinoxaline-tricarboxylic acid, and other compounds. In the course of preparation of the solution the heterocyclic molecular systems and binding groups form planar supramolecules due to non-covalent chemical bonds between the binding groups of adjacent molecular systems. The supramolecules have a substantially planar shape. During the application of a reaction mixture to a substrate, a certain fraction of these planar supramolecules are destroyed because of the rupture of weak non-covalent bonds. The planes of the planar supramolecules are oriented parallel to the substrate surface due to the hydrophilic properties of the heterocyclic molecular systems, which produces their effective homeotropic alignment. Then, the ruptured non-covalent chemical bonds in the planar supramolecules are restored.

In one preferred embodiment of the present invention, at least one retardation layer of the birefringent elements has at least partially crystalline structure. The thickness of the birefringent elements usually does not exceed approximately 1 micron. The retardation layer thickness can be controlled by changing the content of a solid substance in the applied solution and by varying the applied layer thickness.

In one embodiment of the present invention, the retardation layer of the birefringent elements is water-soluble, For the purpose of the present invention it is usually converted into a water-insoluble form. Some of the used methods of such treatment comprise but are not limited to the film treatment with a solution containing di- or trivalent metals ions and/or by an appropriate heat treatment.

The selection of raw materials for manufacturing the compensation panel should be made with taking into account the spectral characteristics of these compounds and structure of their molecules.

The method of production of matrix of birefringent elements depends on the type of retardation layers. The method of shadow-mask evaporation or the method of printing may be used for forming the compensation panel comprising the matrix of patterned birefringent elements of C-type plate.

The method of printing or the method of applying with slot-die of special (stepped) form may be used for forming the patterned compensation structure comprising the matrix of birefringent elements of negative A- or A₆ -type plates.

Some important units of the coating device are illustrated in the Figure 8 and include a holder 81 for a substrate 82, a container 83 for the dispersion system (a lyotropic liquid crystal in the nematic phase) 84, slot-die of special form for orienting influence. The slot-die is installed with a possibility of motion relative to the substrate such as to provide supply of applying dispersion system over the entire area of the substrate and provide external orienting action on the system. Besides that, there is an option to install elements 85 at a desired distance from the substrate holder. These distances are chosen such as to provide uniform application of the dispersion system onto the substrate, formation of laminar flow in the stream of the solution in process of its application onto the substrate and a uniform orienting action on the supramolecules of the solution through the entire thickness of the applying layer. Depending on the viscosity of the solution and the desired thickness of the anisotropic film, in each particular case, one has to determine the mentioned distances and speed of relative motion of slot-die and the substrate holder. The mentioned operating parameters of the device are calculated according to the known algorithms or determined experimentally.

Another method of manufacturing of the compensation panel (Figure 9) is a successive forming of multilayer matrix of patterned birefringent elements. In this embodiment the retardation layer of desired thickness and/or type is formed either by slot-die or printing. Then the patterned birefringent elements are formed using the applicable patterning process, and the formed birefringent elements are covered with planarization layer. After the planarization layer is affixed, the said process is repeated for residuary layers of matrix. Finally the compensation panel is formed which has birefringent elements of specific thickness and being alternated by planarization layers.

The number i of the different patterned birefringent elements is equal to the number of the colour filter elements and may be equal to 3, 4 or 5.

According to the present invention, the arrangement of the birefringent elements in matrix corresponds to the arrangement of colour filter elements. In one embodiment of the disclosed liquid crystal display, the arrangement of colour filter elements arrangement is selected from the list comprising stripe, mosaic, and delta arrangement types.

In process of forming the elements of definite type the birefringent layer is being etched, and then applied alternated with the birefringent elements of a different type. Application with slot-die of special (stepped) form can be used as well.

The technology also allows forming the birefringent elements of different polycyclic organic compounds. The properties of used materials and characteristic of the technology allow making the compensation panel thin enough to position it inside the LC cell. Depending on the liquid crystal display design the compensation panel or panels may be situated inside the LC cell entirely.

In some embodiments the same compensation panel can be positioned inside or outside of the liquid crystal cell. In other embodiments the compensation panel or panels can be situated outside of the liquid crystal cell exclusively.

In order that the invention may be more readily understood, reference is made to the following examples, which are intended to be illustrative of the invention, but are not intended to be limiting in scope.

Example 1

Example describes the preparation of the polycyclic organic compound of the structural formula 42 of Table 6.

A 4,4'-(5,5-Dioxidodibenzo[b,d]thiene-3,7-diy|)dibenzenesulfonic acid (structural formula 42, Table 6) was prepared by sulfonation of 1 , 1 ':4', 1 ":4", 1 '"-quaterphenyl. ^f^r^M^uaterphenyl (10 g) was charged into 0% - 20% oleum (100 ml). Reaction mass was agitated for 5 hours at heating or at ambient conditions. After that the reaction mixture was diluted with water (170 ml). The final sulfuric acid concentration became approximately 55%. The precipitate was filtered and rinsed with glacial acetic acid (~200 ml). The filter cake was dried in an oven at about 110°C. The process yielded 8 g of 4,4'-(5,5-Dioxidodibenzo[b,d]thiene-3,7-diyl)dibenzenesulfonic acid. The product was analyzed with ¹H NMR (Brucker Avance-600, DMSO-d₆, δ, ppm) and showed the following results: 7.735 (d, 4H, 4CH^Ar (3,3',5,5")); 7.845 (d, 4H, 4CH^Ar (2,2',6,6")); 8.165 (dd,2H, 2CH^Ar (2,8)); 8.34 (m, 4H, 4CH^Ar (1 ,9,4,6)). The electronic absorption spectrum of the product measured in an aqueous solution with spectrometer UVΛ/IS Varian Gary 500 Scan showed the absorption maxima at λ_max1 = 218 nm (ε = 3.42*10⁴), λ_max2 = 259 nm (ε = 3.89*10⁴), and λ_max3 = 314 nm (ε= 4.20*10⁴). The mass spectrum of the product recorded using a Brucker Daltonics Ultraflex TOF/TOF is as follows: molecular ion (M = 529), FW = 528.57.

Example 2

Example 2 describes synthesis of mixture 2-oxo-2,3-dihydro-1'H-1 ,2'-bibenzimidazoledicarboxylic acids, bisbenzimidazo[1',2':3,4;1",2":5,6][1,3,5]triazino[1 ,2-a]benzimidazoletricarboxylic acids and 2- oxo-2,3-dihydro-1 "H-1 ,2': 1 ',2"-terbenzimidazoletricarboxylic acids.

Dry hydrogen chloride was bubbled through 5000 ml of an absolute methanol. 600 g of 3,4- diaminobenzoic acid was added to the obtained solution. This mass was boiled with continuous bubbling of dry HCI and stirring for 6 hours. After cooling the reaction mass was placed on a vacuum filter and the obtained filtrate evaporated until dry. Yield of methyl 3,4-diaminobenzoate dihydrochloride was 476.4 g.

476.4 g of methyl 3,4-diaminobenzoate dihydrochloride was mixed with 237.6 g of urea. The mixture was heated to 150⁰C and was held at temperature for 18 hours. The resulting product was added to 11 liters of water, the suspension was stirred, and pH of the obtained suspension was adjusted to 0.45 by adding HCI. The solid part was isolated by filtering, rinsed with 5 liters of water acidified with HCi (to pH~1.5) and dried at 100⁰C. Yield of methyl 2-oxo-2,3-dihydro-1H- benzimidazole-5-carboxylate was 418.8 g.

250.0 g of the obtained methyl 2-oxo-2,3-dihydro-1 H-benzimidazole-6-carboxylate was charged into 2800 g of fresh distilled phosphorus oxychloride. Dry hydrogen chloride was bubbled through the reaction mass, which was heated to boiling temperature and was held at an elevated temperature and under dry HCI for 20 hours. Then the reaction mass was allowed to cool and then it was added to 12 kg of mixture of ice and water. The resulting liquid was clarified through 1 Dm glass fiber filter.

7500 ml of water and then 4500 ml of 25% aqueous ammonia solution was added to the filtrate. The precipitated matter was filtered out, washed with approximately 60 liters of water and dried at 6O⁰C. Yield of methyl 2-chloro-1 H-benzimidazole-6τcarboxylate was 30.5 g.

30.5 g of methyl 2-chloro-1 H-benzimidazo!e-6-carboxy!ate was charged into a heat-resistant porcelain dish, heated to 195°C (oven) and kept at this temperature for 13 hours. After cooling the solid material was milled and then charged to 300 g of 5% KOH solution. The suspension was heated and stirred at 100⁰C for 3 hours. The obtained liquid was clarified through 1 Gm glass fiber filter. 4000 ml of water and 22.5 g of HCI was added to the clear liquid. This resulted in precipitation of the product, which was isolated by filtering, washed with 12000 ml of water acidified with HCI to pH=2.5 and dried 3 days at 100⁰C. Yield of the product was 21.2 g. Example 3

Example 3 describes the preparation of the retardation layer formed from a lyotropic liquid crystal solution. A 4,4'-(5,5-dioxidodibenzo[b,d]thiene-3,7-diyl)dibenzenesulfonic acid (1g) was obtained as described in Example 1 , then was mixed with 3.8 ml of distilled water and 1.1 ml of 10% aqueous sodium solution and then stirred at room temperature (23⁰C) until a lyotropic liquid solution was formed (for approximately 1 hour).

An LCD-grade Soda Lime glass substrate was prepared for the coating. The substrate was placed in an ultrasonic bath with an aqueous solution of NaOH (w/w 10%) and KMnO₄ (w/w 0.1%) for 30 min, then rinsed with deionized water, and dried with a compressed air stream. The lyotropic liquid crystal solution was applied onto the pretreated glass substrate with Mayer Rod #1.5 moved at linear velocity of 200 mm/s (humidity ~ 30%, temperature 23°C). The coated solution was further dried with the compressed air stream until the retardation layer was formed.

The thickness of the produced retardation layer was 435±15 nm. Said thickness may be regulated by varying the concentration of the organic compound in the water solution or coating conditions. The retardation layer formed is clear (colorless) and transparent in the optical spectral range.

The same quality retardation layer can be produced from the lyotropic liquid crystal solution formed from other compounds described by the present application.

Example 4

Example 4 describes a compensation panel with patterned birefringent elements. Figure 9 shows the compensation panel designed for out-of-cell or in-cell applications. The compensation panel 161 comprises a substrate 162, a first layer of matrix comprising the patterned birefringent elements 163 of the first type, a planarization layer 164, a second layer of matrix comprising the patterned birefringent elements 165 of the second type, a planarization layer 166, a third layer of matrix comprising the patterned birefringent elements 167 of the third type, and a planarization layer 168. The number / of the different patterned birefringent elements is equal to the number of the colour filter elements and may be equal to 3, 4 or 5. The arrangement of the birefringent elements in matrix corresponds to the arrangement of colour filter elements which may be selected from the list comprising stripe, mosaic, and delta arrangement types. Figure 9 shows a compensation panel that can be used for the designs both outside of the liquid crystal cell and inside the liquid crystal cell.

Example 5

Example describes the liquid crystal display with the IPS-mode liquid crystal cell (IPS LCD), design of which is schematically shown in Figure 10

The IPS LCD according to present invention comprises the first polarizing plate 901, the second polarizing plate 902, liquid crystal cell 903 situated between said first and second polarizing plates, the front substrate 904 with colour filter 905 (RGB - type), black matrix 906 and planarization layer 907, other functional layers 908 including electrode and alignment layers, the back substrate 909 with electrodes, driving elements and alignment layers. The compensation panel 910 is located between the liquid crystal layer 903 and the second polarizing plate 902. The first and second polarizing plates have absorption axes, which are perpendicular to each other.

For the liquid crystal display designs equipped with RGB colour filter one pixel comprises three subpixels of red, green and blue colours. In this case the compensation panel comprises birefringent elements 911 of 3 kinds (i=3) having thin retardation layers of the negative A_B-type plate. The thin retardation layers have equal refractive indices and codirectional fast optical axes and slow optical axes, but the elements have different thickness. For the compensation of LCD with thin retardation layers having normal dispersion of refractive indices, it is important that the thin birefringent film layer is thicker for red subpixel than for blue subpixel.

For the A_B-type thin retardation layer, all three principal refractive indices are different: nx=1.49, ny=1.86, nz=1.69 at λ=550nm (Figure 11). The thin retardation layer 911 has principal axis of lowest refraction index (fast axis) lying substantially in the plane of said retardation layer and parallel (or perpendicular) to the transmission axis of the first polarizing plate 901. The optical axis (LC director) of the liquid crystal layer 903 is parallel to the transmission axis of the second polarizing plate 902.

The liquid crystal material has a negative dielectric anisotropy (ε_||-ε j_=-3.5) and low birefringence (Δn≥O.08). The elastic moduli of liquid crystal have typical values: K₁₁=IO pN, K₂₂=5 pN and K₃₃=I 5pN. With such values, the state with maximum transmission coefficient is achieved at an applied voltage of 5 - 8 V. The planar alignment in the IPS-mode liquid crystal cell is achieved using typical polyimide material providing pretilt angle of a few degrees with respect to the substrate plane. The thickness d of the IPS-mode liquid crystal cell is chosen taking into account the LC optical anisotropy Δn in order to provide a liquid crystal cell retardation of Δnc/≤275 nm.

The performance of this optimized IPS LCD design (liquid crystal display with the IPS-mode liquid crystal cell) is illustrated in Figures 12 (a) - (c). Figures show computer simulated dependences compensated IPS LCD design for three wavelength: λ=450nm - Figure 12 (a), λ=550nm - Figure 12 (b), λ=650nm - Figure 12 (a). Figures 13 (a) - (c) show computer simulated dependences for the noncompensated IPS LCD design for. three wavelength: λ=450nm, λ=550nm and λ=650nm accordingly. The data illustrate viewing angle dependencies of the contrast ratio.

The present invention is not limited to using only the aforementioned IPS LCD designs. Table 9 shows the examples of the IPS LCD designs realized according to the present invention.

Here, the notation is as follows: P₄₅ - the polarizer with the transmission axis at 45°; LC₄₅ - planar LC layer aligned with the director at 45°; A_B-₄₅ - the negative biaxial A_B-plate with the fast axis at -45°; A -₄₅- the negative uniaxial A-plate with the fast axis at -45°; TAC - the layer of triacetyl cellulose having retardation Δnd^δOnm. The LC layer retardation is 275 nm. The in-plane driving electric field vector is at an azimuth angle of zero degrees. Δn_xy d_RL =(nχ-ny)d_RL; and Δn^ d_RL = (n_x- n_z)d_RL, where d_RL is the thickness of the retardation layer. Table 9. Examples of the IPS LCD designs and the thicknesses of corresponding retardation layers in compensation panel

r TAG is a protective layer, which is often used as a part of the polarizer. It is assumed that TAC behaves as negative C-plate with retardation of 50 nm.

Example 6

Example 6 describes the VA LCD (liquid crystal display with the vertical alignment mode liquid crystal cell) design according to the present invention which is schematically shown in Figure 14. The VA LCD comprises the first polarizing plate 1301 , the second polarizing plate 1302, liquid crystal cell 1303 situated between said first and second polarizing plates, front substrate 1304 with colour filter 1305 (RGB - type), black matrix 1306 and planarization layer 1307, the compensation panel 1308 located between the liquid crystal layer 1303 and the second polarizing plate 1302 and back substrate 1310 with electrodes, driving elements and alignment layers. The first and second polarizing plates have absorption axes which are perpendicular to each other.

The compensation panel comprises birefringent elements 1309 of 3 kinds (i=3) having thin retardation layers of the negative A₆ -type plate. For the A_B-type thin retardation layer, all three principal refractive indices are different: nx=1.49, ny=1.86, nz=1.69 at λ=550nm (Figure 11). The retardation layers have equal refractive indices and codirectionai fast optical axes and slow optical axes, but the elements of a different thickness. The retardation layer 1309 have principle axis of lowest refraction index disposed substantially in the plane of said retardation layer and parallel to the absorption axis of the second polarizing plate 13O2.The compensation panel comprises an additional planarization layer 1311, and a uniaxial homogeneous retardation layer 1312 of the negative C-type. Table 10 shows some VA LCD designs realized according to the present invention. Table 10. Examples of the VA LCD designs and the thicknesses of corresponding retardation layers in compensation panel

*TAC is a protective layer, which is often used as a part of the polarizer. It is assumed that TAC behaves as negative C-plate with retardation of 50 nm.

**C- is a negative C plate assumed to have Δn=0.2

***VA-mode LC is characterized by retardation (n||-nl)d=275 nm at λ=550 nm.

The performance of the optimized VA LCD design (P₀/TAC/VA LC/C-/A_B0/TAC/P_9O) is illustrated in Figures 15 (a) - (c). Figures show computer simulated viewing angle dependences of contrast ratio for compensated VA design for three wavelengths: λ=450nm (a), λ=550nm (b), and λ=650nm (c).

Figure 16 (a) - (c) shows computer simulated dependences for non-compensated VA design for three wavelength: λ=450nm, λ=550nm, and λ=650nm correspondingly.

The VA LCD may also be compensated using patterned retardation layer of Ac-type plate.

The various designs and modes of LCD with a patterned compensator setup show high contrast in a wide range of viewing angles and excellent colour rendering properties in comparison with the LCD compensated using traditional scheme.

The foregoing descriptions of specific embodiments of the invention have been presented for the purpose of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications, embodiments, and variations are possible in light of the above teaching. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims

CLAIMSWhat is claimed is:

1. A colour liquid crystal display comprising: first and second polarizing plates facing each other, a liquid crystal cell situated between said first and second polarizing plates, and at least one compensation panel situated between said first and second polarizing plates, wherein the compensation panel comprises at least one matrix of patterned birefringent elements of i kinds having different retardation, / is 3, 4 or 5, and the birefringent elements comprise at least one retardation layer comprising at least one polycyclic organic compound with a conjugated π-system and functional groups which are capable of forming non-covalent bonds.

2. A liquid crystal display according to Claims 1, wherein the polycyclic organic compound is capable of forming rod-like supramolecules via the conjugated π-systems and functional groups.

3. A liquid crystal display according to Claim 1 , wherein the polycyclic organic compound is capable of forming planar supramolecules.

4. A liquid crystal display according to any of Claims 1 to 3, wherein the organic compound has a general structural formula (I)

where Sys is at least partially conjugated substantially planar polycyclic molecular system,

X is a carboxylic group -COOH, m is O, 1 , 2, 3 or 4;

Y is a sulfonic group -SO₃H, n is O, 1 , 2, 3 or 4;

Z is an amide of a carboxylic acid group, p is 0, 1 , 2, 3 or 4;

Q is an amide of a sulfonic acid group, v is 0, 1 , 2, 3 or 4;

K is a counterion; s is the number of counterions providing neutral state of the molecule;

R is a substituent selected from the list comprising CH₃, C₂H₅, NO₂, Cl, Br, F, CF₃, CN, OH,

OCH₃, OC₂H₅, OCOCH₃, OCN, SCN, NH₂, and NHCOCH₃, and w is O, 1 , 2, 3 or 4.

5. A liquid crystal display according to Claim 4, wherein the molecular system Sys has a general structural formula from the list comprising structures Il to XLVI:

where j is 1 , 2, 3, 4, 5, 6, 7 or 8.

6. A liquid crystal display according to any of Claims 4 to 5, wherein the counterion is selected from the list of ions comprising H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Ba⁺⁺, Ca⁺*, Mg⁺⁺, Sr⁺*, and Zn⁺⁺.

7. A liquid crystal display according to any of Claims 1 to 6, wherein the organic compound is an acenaphthoquinoxaline derivative.

8. A liquid crystal display according to Claim 7, wherein the acenaphthoquinoxaline derivative comprises a carboxylic group and has a general structural formula corresponding to any of structures 1 to 7:

9. A liquid crystal display according to Claim 7, wherein said acenaphthoquinoxaline derivative comprises a sulfonic group and has a general structural formula corresponding to any of structures 8 to 19:

10. A liquid crystal display according to any of Claims 1 to 6, wherein the organic compound is a 6,7-dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative.

11. A liquid crystal display according to Claim 10, wherein the 6,7-dihydrobenzimidazo[1 ,2- c]quinazolin-6-one derivative comprises at least one carboxylic group -COOH, and has a general structural formula from the group comprising structures 20 to 32:

12. A liquid crystal display according to Claim 10, wherein the 6,7-dihydrobenzimidazo[1 ,2- c]quinazolin-6-one derivative comprises at least one sulfonic group -SO₃H, and has a general structural formula from the list comprising structures 33 to 41:

13. A liquid crystal display according to any of Claims 1 to 6, wherein the organic compound is an oligophenyl derivative.

14. A liquid crystal display according to Claim 13, wherein the oligophenyl derivative has a general structural formula corresponding to any of structures 42 to 48:

15. A liquid crystal display according to any of Claims 1 to 6, wherein the organic compound is an oligobenzimidazole derivative.

16. A liquid crystal display according to Claim 15, wherein the oligobenzimidazole derivative comprises at least two carboxylic groups -COOH and has a general structural formula corresponding to structures 49 to 51.

17. A liquid crystal display according to any of Claims 1 to 6, wherein the organic compound is a dipyrazinoquinoxaline derivative.

18. A liquid crystal display according to Claim 16, wherein the dipyrazinoquinoxaline derivative comprises at least three carboxylic groups -COOH and has a general structural formula 52

19. A liquid crystal display according to any of Claims 1 to 18, wherein the retardation layers are substantially transparent in the visible spectral range.

20. A liquid crystal display according to Claim 2, wherein the long axes of supramolecules are oriented substantially parallel to the surface of the birefringent elements.

21. A liquid crystal display according to Claim 3, wherein the planes of said supramolecules are oriented substantially parallel to the surface of the birefringent elements.

22. A liquid crystal display according to any of Claims 1 to 21 , wherein said non-covalent bonds are selected from the list comprising hydrogen bonds, coordination bonds, dipole-dipole interaction, cation-π interaction, van der Waals interaction and π-π interaction..

23. A liquid crystal display according to any of Claims 1 to 22, wherein at least one retardation layer of the birefringent elements has at least partially crystalline structure.

24. A liquid crystal display according to any of Claims 1 to 23, wherein the retardation layer of the birefringent element is water-insoluble.

25. A liquid crystal display according to any of Claims 1 to 24, further comprising a colour filter.

26. A liquid crystal display according to Claim 25, wherein number / is equal to 3, and the colour filter includes red, green and blue colours.

27. A liquid crystal display according to any of Claims 1 to 25, wherein the birefringent element comprises at least one retardation layer of the type selected from list comprising negative C-plate, negative A-plate, biaxial negative A_B-plate, and biaxial A_c-plate.

28. A liquid crystal display according to Claim 27, wherein the birefringent element comprises at least two retardation layers of different types.

29. A liquid crystal display according to Claim 27, wherein the retardation layers of the same types and which belong to the different birefringent elements have equal refractive indices, equal codirectional fast optical axes and slow optical axes, and different thickness.

30. A liquid crystal display according to Claim 29, wherein the retardation layers of the same type comprise different polycyclic organic compounds.

31. A liquid crystal display according to any of Claims 25 to 30, wherein the colour filter has a pattern which is selected from list comprising stripe, mosaic, and delta.

32. A liquid crystal display according to any of Claims 1 to 31 , wherein at least one matrix of birefringent elements is located inside the liquid crystal cell.

33. A liquid crystal display according to Claim 32, wherein the compensation panel is located inside the liquid crystal cell.

34. A liquid crystal display according to any of Claims 1 to 31, wherein the compensation panel is located outside the liquid crystal cell.

35. A liquid crystal display according to any of Claims 32 to 34, wherein the compensation panel further comprises at least one homogeneous retardation layer.

36. A liquid crystal display according to Claim 35, further comprising a homogeneous retardation layer is located inside the liquid crystal cell.

37. A liquid crystal display according to Claim 35, further comprising a homogeneous retardation layer is located outside the liquid crystal cell.

38. A liquid crystal display according to Claim 37, further comprising two homogeneous retardation layers located on the both sides of the liquid crystal cell.

39. A liquid crystal display according to Claim 35, wherein the homogeneous retardation layer comprises at least one polycyclic organic compound with a conjugated ττ-system and functional groups which are capable of forming non-covalent bonds.

40. A liquid crystal display according to any of Claims 1 to 39, wherein each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose.

41. A liquid crystal display according to any of Claims 1 to 40, wherein the transmission axes of said polarizers are perpendicular to each other.

42. A liquid crystal display according to any of Claims 1 to 41 , wherein the liquid crystal cell is an in-plane switching mode liquid crystal cell.

43. A liquid crystal display according to Claim 42, wherein each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and an uniaxial retardation layer of the negative C-type plate.

44. A liquid crystal display according to Claim 42, wherein each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate and a uniaxial retardation layer of the negative C-type plate.

45. A liquid crystal display according to Claim 42, wherein the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and the homogeneous retardation layer is an uniaxial layer of the negative C-type plate.

46. A liquid crystal display according to Claim 42, wherein the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of said first polarizing plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC).

47. A liquid crystal display according to Claim 42, wherein the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC).

48. A liquid crystal display according to Claim 42, wherein the compensation panel comprises at least one homogeneous retardation layer, each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate, and the homogeneous retardation layer is an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the second polarizing plate.

49. A liquid crystal display according to Claim 42, wherein each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose and each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate.

50. A liquid crystal display according to Claim 42, wherein each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose, a homogeneous retardation layer located between the liquid crystal cell and the second polarizing plate, comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate, and each of said birefringent elements comprises an uniaxial retardation layer of the negative A-type plate, the fast axis of which is substantially parallel to the transmission axis of the first polarizing plate.

51. A liquid crystal display according to Claim 42, wherein each of the first and second polarizing plates comprises at least one layer of triacetyl cellulose and each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate.

52. A liquid crystal display according to any of Claims 1 to 41, wherein the liquid crystal cell is a vertical alignment mode liquid crystal cell.

53. A liquid crystal display according to Claim 52, wherein each of said birefringent elements comprises a uniaxial retardation of the negative C-type plate.

54. A liquid crystal display according to Claim 52, wherein each of said birefringent elements comprises a biaxial retardation of the negative A₈ -type plate.

55. A liquid crystal display according to Claim 52, wherein each of said birefringent elements comprises a biaxial retardation of the negative A_B-type plate and a uniaxial retardation of the negative C-type plate.

56. A liquid crystal display according to any Claims 54 or 55, wherein the fast axis of the uniaxial retardation layer of the negative A_B-type plate is substantially parallel to the transmission axis of the first polarizing plate.

57. A liquid crystal display according to Claim 54, wherein the fast axis of the uniaxial retardation layer of the negative A_B-type plate is substantially parallel to the transmission axis of the second polarizing plate.

58. A liquid crystal display according to any Claims 52 to 57, wherein at least one said polarising plate comprises a homogeneous retardation layer is a layer of triacetyl cellulose (TAC).

59. A liquid crystal display according to any of Claims 1 to 58, wherein the matrix comprises at least two layers, and each said layer comprises the patterned birefringent elements of different kinds.

60. A liquid crystal display according to any of Claims 1 to 58, wherein the matrix comprises at least one layer comprising i different kinds of the patterned birefringent elements.

61. A compensation panel comprising at least one matrix of patterned birefringent elements of ;^" kinds having different retardation, wherein i is equal to 3,^' 4 or 5, and wherein the birefringent elements comprise at least one retardation layer comprising at least one polycyclic organic compound with a conjugated π-system and functional groups which are capable of forming non-covalent bonds.

62. A panel according to Claim 62, wherein the organic compound has a general structural formula (I)

where Sys is at least partially conjugated substantially planar polycyclic molecular system, X is a carboxylic group -COOH, m is 0, 1 , 2, 3 or 4; , Y is a sulfonic group -SO₃H, n is O, 1, 2, 3 or4;

Z is an amide of a carboxylic acid group, p is O, 1 , 2, 3 or 4;

Q is an amide of a sulfonic acid group, v is 0, 1 , 2, 3 or 4; K is a counterion; s is the number of counterions providing neutral state of the molecule; R is a substituent selected from the list comprising CH₃, C₂H₅, NO₂, Cl, Br, F, CF₃, CN, OH, OCH₃, OC₂H₅, OCOCH₃, OCN, SCN, NH₂, and NHCOCH₃, and M/ is^' O, 1 , 2, 3 or 4.

63. A panel according to Claim 62, wherein the Sys molecular system has a general structural formula from the list comprising structures Il to XLVI:

rP (ill)

I TT⁰

(XXXIII)

(XXXIV)

(XXXVI)

(XXXVII)

(XXXVlIl)

(XXXIX)

(XLIII)

H

where j is 1 , 2, 3, 4, 5, 6, 7 or 8.

64. A panel according to any of Claims 62 or 63, wherein the counterion is selected from the list of ions comprising H⁺, NH₄ ⁺, Na⁺, K⁺, Li⁺, Ba⁺⁺, Ca⁺⁺, Mg⁺⁺, Sr⁺⁺, and Zn⁺⁺.

65. A panel according to any of Claims 61 to 64, wherein the organic compound is an acenaphthoquinoxaline derivative.

66. A panel according to Claim 65, wherein the acenaphthoquinoxaline derivative comprises a carboxylic group and has a general structural formula corresponding to any of structures 1 to 7:

67. A panel according to Claim 65, wherein said acenaphthoquinoxaline derivative comprises a sulfonic group and has a general structural formula corresponding to any of structures 8 to 19:

68. A panel according to any of Claims 61 to 64, wherein the organic compound is a 6,7- dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative.

69. A panel according to Claim 68, wherein the 6,7-dihydrobenzimidazo[1 ,2-c]quinazolin-6-ohe derivative comprises at least one carboxylic group -COOH, and has a general structural formula from the group comprising structures 20 to 32:

70. A panel according to Claim 68, wherein the 6,7-dihydrobenzimidazo[1 ,2-c]quinazolin-6-one derivative comprises at least one sulfonic group -SO₃H, and has a general structural formula from the list comprising structures 33 to 41 :

71. A panel according to any of Claims 61 to 64, wherein the organic compound is an oligophenyl derivative.

72. A panel according to Claim 71 , wherein the oligophenyl derivative has a general structural formula corresponding to any of structures 42 to 48:

73. A panel according to any of Claims 61 to 64, wherein the organic compound is an oligobenzimidazole derivative.

74. A panel according to Claim 73, wherein the oligobenzimidazole derivative comprises at least two carboxyϋc groups -COOH and has a general structural formula corresponding to structures 49 to 51.

75. A panel according to any of Claims 61 to 64, wherein the organic compound is a dipyrazinoquinoxaline derivative.

76. A panel according to Claim 75, wherein the dipyrazinoquinoxaline derivative comprises at least three carboxylic groups -COOH and has general structural formula 52:

77. A panel according to any of Claims 61 to 76, wherein the retardation layers comprising the organic compound are substantially transparent in the visible spectral range.

78. A panel according to any of Claims 61 to 77, wherein the polycyclic organic compounds is forming supramolecules.

79. A panel according to Claim 78, wherein said supramolecules have rod-like shapes and the long axes of supramolecules are oriented substantially parallel to the surface of the birefringent elements.

80. A panel according to Claim 78, wherein said supramolecules have planar shapes and their planes are oriented substantially parallel to the surface of the birefringent elements.

81. A panel according to any of Claims 61 to 80, wherein said non-covalent bonds are selected from the list comprising hydrogen bonds, coordination bonds, dipole-dipole interaction, catioή-π interaction, van der Waals interaction, and τr-π interaction.

82. A panel according to any of Claims 61 to 81 , wherein said matrix has at least partially crystalline structure.

83. A panel according to any of Claims 61 to 82, wherein the retardation layer is water-insoluble.

84. A panel according to any of Claims 61 to 83, further comprising at least one functional layer selected from the list comprising polarizing layer, conducting layer, planarization layer, protective layer and alignment layer.

85. A panel according to any of Claims 61 to 84 further comprising a substrate.

86. A panel according to Claim 85, wherein the substrate is made of one or several materials of the group comprising diamond, quartz, plastics, glasses, and ceramics.

87. A panel according to Claim 85, wherein a colour filter serves as the substrate.

88. A panel according to any of Claims 61 to 86, further comprising a colour filter.

89. A panel according to any of Claims 87 or 88, wherein the number / is equal to 3, and the colour filter comprises red, green and blue colours.

90. A panel according to any of Claims 87 or 88, wherein the number / is equal to 3, and the colour filter further comprises complementary colours - cyan, yellow, and magenta.

91. A panel according to any of Claims 61 to 90, wherein the retardation layers of the same type have equal refractive indices, equal codirectional fast optical axes and slow optical axes, and different thickness.

92. A panel according to any of Claims 61 to 91 , wherein the birefringent elements are formed of different polycyclic organic compounds.

93. A panel according to any of Claims 61 to 92, further comprising at least one homogeneous layer made from at least one polycyclic organic compound and serves as a retardation layer selected from the list of types comprising negative C, negative A, biaxial negative A_B and biaxial A_c types of plates.

94. A panel according to any of Claims 61 to 92, wherein each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and a uniaxial retardation layer of the negative C-type plate.

95. A panel according to any of Claims 61 to 92, wherein each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate and a uniaxial retardation layer of the negative C-type plate.

96. A panel according to any of Claims 61 to 92, wherein each of said birefringent elements comprises a biaxial retardation layer of the A₀ -type plate.

97. A panel according to any of Claims 61 to 92, further comprising at least one homogeneous retardation layer and wherein each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and the homogeneous retardation layer is a uniaxial layer of the negative C-type plate.

98. A panel according to any of Claims 61 to 92, further comprising at least one homogeneous retardation layer and wherein each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and the homogeneous retardation layer is a layer of triacetyl cellulose (TAC).

99. A panel according to any of Claims 61 to 92, further comprising at least one homogeneous retardation layer and wherein each of said birefringent elements comprises a biaxial retardation layer of the negative A_B-type plate, and the homogeneous retardation layer is a layer of triacetyl cellulose (TAG).

100. A panel according to any of Claims 61 to 92, further comprising at least one homogeneous retardation layer and wherein each of said birefringent elements comprises a uniaxial retardation layer of the negative A-type plate and the homogeneous retardation layer is a uniaxial retardation layer of the negative A-type plate, wherein the fast axes of said retardation layers are perpendicular to each other..

101. A panel according to Claim 78, wherein the birefringent elements comprise at least two retardation layers, one of said retardation layers comprises supramolecules having rod-like shapes an the long axes of supramolecules are oriented substantially parallel to the surface of the birefringent elements, and another said retardation layer comprises supramolecules having planar shapes and their planes are oriented substantially parallel to the surface of the birefringent elements.

102. A panel according to any of Claims 61 to 101 , wherein the matrix comprises at least two layers, and each said layer comprises the patterned birefringent elements of different kinds.

103. A panel according to any of Claims 61 to 101 , wherein the matrix comprises at least one layer comprising / different kinds of the patterned birefringent elements.