LCD panels and LCD display devices

Abstract

A liquid crystal panel (101) includes a liquid crystal unit (20), a first polarizer (30), a second polarizer (40), and an optical anisotropic component (50). The liquid crystal unit includes a liquid crystal layer containing liquid crystal molecules that are horizontally oriented in a non-electric field state, and a color filter (22) disposed on a first main surface of the liquid crystal layer. The retardation axis direction (53) of the optical anisotropic component (50) is parallel to the absorption axis direction (45) of the second polarizer. The thickness direction retardation of the optical anisotropic component and the thickness direction retardation of the color filter of the liquid crystal unit satisfy a specific relationship at a wavelength of 550 nm and a wavelength of 650 nm, respectively.

Description

[0001] This application is a divisional application of the Chinese patent application with the application date of May 17, 2019, application number 201980039432.4, and name “Liquid Crystal Panel and Liquid Crystal Display Device”. Technical Field

[0002] The present invention relates to a liquid crystal panel having an optically anisotropic element between a liquid crystal cell and a polarizer, and also to a liquid crystal display device using the liquid crystal panel. Background Art

[0003] A liquid crystal panel has a liquid crystal cell between a pair of polarizers. This cell has a liquid crystal layer between a pair of substrates. In a typical liquid crystal cell, a color filter is provided on the substrate (color filter substrate) positioned on the visual confirmation side of the liquid crystal layer, while pixel electrodes and TFT components are provided on the substrate (TFT (thin-film transistor) substrate) positioned on the light source side.

[0004] In-Plane Switching (IPS) liquid crystal cells, in the absence of an electric field, the liquid crystal molecules are horizontally aligned, roughly parallel to the substrate surface. Applying a lateral electric field causes the liquid crystal molecules to rotate within a plane parallel to the substrate surface, controlling light transmission (white display) and light blocking (black display). Like IPS, IPS-based LCD panels, where the liquid crystal molecules are horizontally aligned in the absence of an electric field, offer excellent viewing angle characteristics.

[0005] IPS liquid crystal display devices are broadly classified into O-mode and E-mode, depending on the relationship between the alignment direction of the liquid crystal molecules in the liquid crystal cell's no-electric-field state (hereinafter referred to as the "initial alignment direction") and the absorption axis direction of the polarizers placed on the front and back sides of the liquid crystal cell. In O-mode, the absorption axis direction of the polarizer placed on the light source side of the liquid crystal cell is parallel to the initial alignment direction of the liquid crystal. In E-mode, the absorption axis direction of the polarizer placed on the light source side of the liquid crystal cell is orthogonal to the initial alignment direction of the liquid crystal.

[0006] IPS-mode liquid crystal display devices experience significant light leakage from black displays when viewed obliquely at a 45-degree angle (azimuth angles of 45, 135, 225, and 315 degrees) relative to the polarizer's absorption axis, which can lead to reduced contrast and color shift. This light leakage occurs when the polarizers placed on the front and back sides of the liquid crystal cell deviate from the 90-degree angle formed by their apparent absorption axis when viewed obliquely.

[0007] To reduce light leakage during oblique viewing, a method has been proposed to place an optically anisotropic component (retardation plate) between a liquid crystal cell and a polarizer. For example, Patent Document 1 proposes placing an optically anisotropic component with a refractive index anisotropy of nx>nz>ny between a liquid crystal cell and a polarizer. nx is the refractive index in the direction of the in-plane slow axis, ny is the refractive index in the direction of the in-plane fast axis, and nz is the refractive index in the thickness direction (normal direction).

[0008] From the perspective of compensating for the angular shift in the absorption axis direction exhibited by the polarizer, it is ideal that the retardation of the optically anisotropic element is 1 / 2 of the wavelength and the Nz coefficient represented by Nz = (nx - nz) / (nx - ny) is 0.5 (see Figure 5 The retardation of an optically anisotropic component varies depending on wavelength. In optical compensation for liquid crystal display devices using an optically anisotropic component, the optical design is typically designed to minimize light leakage from green light (wavelength around 550nm), which has a high luminosity function. Therefore, to compensate for the axial angular deviation exhibited by the polarizer, an optically anisotropic component with a retardation of approximately 275nm at a wavelength of 550nm is sufficient.

[0009] In addition to the axial misalignment exhibited by the polarizer, the characteristics of other optical components can also contribute to light leakage during black display. For example, Patent Document 2 proposes adjusting the optical properties of the optically anisotropic element used for optical compensation by taking into account the birefringence of a triacetylcellulose (TAC) film provided as a protective film on the liquid crystal cell side of the polarizer. Patent Document 3 proposes using a low-birefringence film, such as a norbornene-based resin film, as a protective film provided on the surface of the polarizer.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 4-371903

[0013] Patent Document 2: Japanese Patent Application Laid-Open No. 2001-258041

[0014] Patent Document 3: Japanese Patent Application Laid-Open No. 2004-4641 Summary of the Invention

[0015] Problems to be solved by the invention

[0016] The color filter placed on the liquid crystal cell substrate has approximately zero in-plane retardation, but exhibits retardation of several to tens of nanometers in the thickness direction. As mentioned above, if the optical component placed between the polarizer and the liquid crystal cell exhibits birefringence, adjusting the optical properties of the optically anisotropic element in consideration of this optical property can further reduce light leakage during oblique viewing.

[0017] As mentioned above, the LCD panel's optical compensation is optimized for green light (wavelength around 550nm), which has a high luminosity function. Therefore, when displaying black, light of wavelengths that deviate significantly from the optimal optical design leaks out, tinting the image and causing it to appear visually. Optical design makes it difficult to achieve a completely neutral hue when viewed from an angle. Therefore, when displaying black, the image appears slightly tinted, depending on the wavelength of the light leaking. Blue (wavelength around 450nm) has a lower luminosity function than red (wavelength around 650nm), so the hue of black displays tends to lean toward the bluish side.

[0018] According to the inventors' research, in a liquid crystal panel with a specific structure, when the optical anisotropic element is designed to minimize green light leakage by taking into account the influence of the thickness-direction retardation of the color filter, there is a tendency for red light leakage to be greater, and when viewed from an oblique angle, the black display appears to have a reddish hue. Specifically, the inventors discovered that, when the absorption axis of the polarizer positioned on the light source side of the liquid crystal cell is orthogonal to the slow axis of the optical anisotropic element, if the optical design is designed to minimize green light leakage by taking into account the influence of the thickness-direction retardation of the color filter, red light leakage also tends to be suppressed. On the other hand, when the absorption axis of the polarizer positioned on the light source side of the liquid crystal cell is parallel to the slow axis of the optical anisotropic element, if the optical design is designed to minimize green light leakage by taking into account the influence of the thickness-direction retardation of the color filter, red light leakage is greater, and the black display tends to have a reddish hue.

[0019] An object of the present invention is to provide an image display device, in which, in a liquid crystal panel in which the absorption axis direction of the polarizer on the light source side is parallel to the slow phase axis direction of the optical anisotropy component, the light leakage of the black display when visually confirmed from an oblique direction is reduced by taking into account the influence of the color filter, and the red coloration during the black display is reduced, thereby achieving excellent visual confirmation.

[0020] Technical means to solve the problem

[0021] The liquid crystal panel of the present invention comprises: a liquid crystal cell having a liquid crystal layer containing liquid crystal molecules aligned horizontally in the absence of an electric field, and a color filter disposed on a first principal surface (visual recognition side) of the liquid crystal layer; a first polarizer disposed on the first principal surface (visual recognition side) of the liquid crystal cell; and a second polarizer disposed on the second principal surface (light source side) of the liquid crystal cell. The absorption axis direction of the first polarizer is orthogonal to the absorption axis direction of the second polarizer.

[0022] The color filter has at least a green transmission region and a red transmission region. The green transmission region of the color filter preferably has a thickness direction retardation Ct of 550 nm. 550 The red region of the color filter preferably has a thickness direction retardation Ct at a wavelength of 650 nm. 650 Below 50nm. 550 and Ct 650 All are greater than 0. Ct 550 and Ct 650 For example, it may be 1 nm or more, 3 nm or more, or 5 nm or more.

[0023] The liquid crystal panel of the present invention comprises an optical anisotropic element disposed between a first polarizer and a second polarizer. The slow axis direction of the optical anisotropic element is parallel to the absorption axis direction of the second polarizer. The front retardation Re of the optical anisotropic element at a wavelength of 650 nm is 650 Thickness direction delay Rt 650 Rt 650 / Re 650 It is 0.2 to 0.8.

[0024] Preferably, the thickness direction retardation Rt of the optically anisotropic element at a wavelength of 650 nm is 650 (nm) Thickness retardation Ct of the color filter at a wavelength of 650nm in the red transmission region 650 (nm) satisfies the following formula (1a) or (2a):

[0025] Rt 650 ≥0.37(Ct 650 )+116...(1a)

[0026] Rt 650 ≤-0.44(Ct 650 )+116...(2a).

[0027] The first embodiment of the present invention employs an O-mode liquid crystal panel. In the liquid crystal cell's no-electric-field state, the alignment direction (initial alignment direction) of the liquid crystal molecules is parallel to the absorption axis of the second polarizer. In an O-mode liquid crystal panel, an optically anisotropic element is positioned between the liquid crystal cell and the first polarizer, i.e., on the viewing side of the liquid crystal cell.

[0028] In the first embodiment, it is preferable that the thickness direction retardation Rt of the optically anisotropic element at a wavelength of 550 nm is 550 (nm) Thickness retardation Ct of the green transmission wavelength of the color filter at 550nm 550 (nm) satisfies the following formula (3a):

[0029] 0.97(Ct 550 )+73≤Rt 550 ≤0.49(Ct 550 )+205...(3a).

[0030] The second embodiment of the present invention employs an E-mode liquid crystal panel, in which the initial alignment direction of the liquid crystal molecules in the liquid crystal cell is perpendicular to the absorption axis of the second polarizer. In an E-mode liquid crystal panel, an optically anisotropic element is positioned between the liquid crystal cell and the second polarizer, i.e., on the light source side of the liquid crystal cell.

[0031] In the second embodiment, the thickness direction retardation Rt of the optically anisotropic element at a wavelength of 550 nm is preferably 550 (nm) Thickness retardation Ct of the green transmission wavelength of the color filter at 550nm 550 (nm) satisfies the following formula (8a):

[0032] 0.69(Ct 550 )+70≤Rt 550 ≤1.35(Ct 550 )+200...(8a).

[0033] The liquid crystal display device of the present invention includes a light source disposed on the second main surface side of the liquid crystal panel.

[0034] Effects of the Invention

[0035] According to the present invention, a liquid crystal display device can be provided which, by optically designing in consideration of the birefringence of a color filter, can reduce the brightness of black when viewed from an oblique direction and suppress red coloration in black display, thereby achieving excellent visibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a conceptual diagram of the structure of the liquid crystal panel (O mode) according to the first embodiment.

[0037] Figure 2 is a schematic cross-sectional view of the liquid crystal display device (O mode) according to the first embodiment.

[0038] Figure 3 This is a conceptual diagram showing the structure of a liquid crystal panel (E mode) according to the second embodiment.

[0039] Figure 4 is a schematic cross-sectional view of a liquid crystal display device (E mode) according to the second embodiment.

[0040] Figure 5 This is an explanatory diagram illustrating how an axial deviation of a polarizer is optically compensated by an optically anisotropic element using the Poincare sphere.

[0041] Figure 6 This is a conceptual diagram of the structure of a liquid crystal panel (O mode) of a reference example.

[0042] Figure 7 This is a conceptual diagram of the structure of a liquid crystal panel (E mode) of a reference example.

[0043] Figure 8 This is an explanatory diagram for explaining the optical compensation state of an O-mode liquid crystal panel using the Poincare sphere.

[0044] Figure 9 This is an explanatory diagram for explaining the optical compensation state of an E-mode liquid crystal panel using the Poincare sphere.

[0045] Figure 10 This is a simulation result of the chromaticity of the black display of an O-mode liquid crystal display device.

[0046] Figure 11 This is a simulation result of the chromaticity of black display of an E-mode liquid crystal display device.

[0047] Figure 12 This is a graph plotting conditions under which the chromaticity u' of the black display of an O-mode liquid crystal display device reaches a specific value.

[0048] Figure 13 This is a graph plotting conditions under which the luminance of black display of an O-mode liquid crystal display device reaches a specific value.

[0049] Figure 14 This is a graph plotting conditions under which the chromaticity u' of the black display of an E-mode liquid crystal display device reaches a specific value.

[0050] Figure 15 This is a graph plotting conditions under which the luminance of black display of an E-mode liquid crystal display device becomes a specific value or less. DETAILED DESCRIPTION

[0051] [Overview of the entire LCD panel]

[0052] Figure 1 This is a conceptual structural diagram showing the arrangement of optical components in the liquid crystal panel 101 according to the first embodiment. Figure 2 2 is a schematic cross-sectional view of a liquid crystal display device 201 including a liquid crystal panel 101 and a light source 110 . Figure 3 This is a conceptual structural diagram showing the arrangement of optical components in the liquid crystal panel 102 according to the second embodiment. Figure 4 is a schematic cross-sectional view of a liquid crystal display device 202 including a liquid crystal panel 102 and a light source 110 .

[0053] The liquid crystal panel includes a first polarizer 30 disposed on the first principal surface (visual confirmation side) of the liquid crystal cell 20, and a second polarizer 40 disposed on the second principal surface (light source side) of the liquid crystal cell 20. The absorption axis direction 35 of the first polarizer 30 is orthogonal to the absorption axis direction 45 of the second polarizer 40.

[0054] The liquid crystal panel 101 and the liquid crystal display device 201 of the first embodiment are in O mode, and the absorption axis direction 45 of the second polarizer 40 disposed on the light source 110 side of the liquid crystal cell 20 is parallel to the initial alignment direction 11 of the liquid crystal molecules in the liquid crystal layer 10. The liquid crystal panel 102 and the liquid crystal display device 202 of the second embodiment are in E mode, and the absorption axis direction 45 of the second polarizer 40 disposed on the light source 110 side of the liquid crystal cell 20 is orthogonal to the initial alignment direction 11 of the liquid crystal molecules in the liquid crystal layer 10.

[0055] The liquid crystal panel of the present invention includes an optically anisotropic component between the first polarizer 30 and the second polarizer 40. The O-mode liquid crystal panel 101 of the first embodiment includes an optically anisotropic component 50 between the liquid crystal cell 20 and the first polarizer 30. The E-mode liquid crystal panel 102 of the second embodiment includes an optically anisotropic component 60 between the liquid crystal cell 20 and the second polarizer 40. In either embodiment, the absorption axis 45 of the second polarizer 40 is parallel to the slow axis directions 53 and 63 of the optically anisotropic components 50 and 60.

[0056] Furthermore, in this specification, "orthogonal" refers not only to completely orthogonal but also to substantially orthogonal, and the angle thereof is generally within the range of 90±2°, preferably 90±1°, and more preferably 90±0.5°. Similarly, "parallel" refers not only to completely parallel but also to substantially parallel, and the angle thereof is generally within the range of ±2°, preferably within the range of ±1°, and more preferably within the range of ±0.5°.

[0057] [Liquid crystal unit]

[0058] The liquid crystal cell 20 includes a liquid crystal layer 10 between a first substrate 21 and a second substrate 25. A color filter 22 is provided on the first substrate 21 (color filter substrate), which is positioned on the viewing side of the liquid crystal layer. The color filter 22 includes at least a green-transmitting region 22G and a red-transmitting region 22R. A switching element (typically a TFT element) for controlling the alignment of the liquid crystal is provided on the second substrate 25 (TFT substrate), which is positioned on the light source side of the liquid crystal layer 10.

[0059] A green filter having relatively high transmittance for light with a wavelength of approximately 500 to 600 nm is provided in the green-transmitting region 22G of the color filter 22. The green filter preferably has a maximum transmittance in the wavelength range of 500 to 600 nm. The transmittance in the green-transmitting region at a wavelength of 550 nm is, for example, 30% or greater. The transmittance in the green-transmitting region at a wavelength of 450 nm is preferably 10% or less. The transmittance in the green-transmitting region at a wavelength of 650 nm is preferably 10% or less, and more preferably 5% or less.

[0060] The red-transmitting region 22R is provided with a red filter having relatively high transmittance for visible light with wavelengths longer than 600 nm. The transmittance of the red-transmitting region at a wavelength of 650 nm is, for example, 30% or greater. The transmittance at a wavelength of 550 nm and at a wavelength of 450 nm is preferably 10% or less, and more preferably 5% or less.

[0061] The color filter 22 may include regions other than the green-transmitting region 22G and the red-transmitting region 22R. Typically, it includes a blue-transmitting region 22B. The blue-transmitting region 22B includes a blue filter having relatively high transmittance for visible light with wavelengths shorter than 500 nm. The transmittance of the blue-transmitting region at a wavelength of 450 nm is, for example, 30% or greater. The transmittance of the blue-transmitting region at a wavelength of 550 nm and at a wavelength of 650 nm is preferably 10% or less, and more preferably 5% or less.

[0062] The color filter may further include a light-transmitting region having a relatively high light transmittance in a specific wavelength region other than the above-mentioned regions. A black matrix is ​​preferably provided at the boundary between adjacent light-transmitting regions.

[0063] The liquid crystal layer 10 contains liquid crystal molecules that are horizontally aligned in the absence of an electric field. Horizontally aligned liquid crystal molecules are those in which the alignment vectors of the liquid crystal molecules are parallel and uniformly aligned relative to the substrate plane. Furthermore, the alignment vectors of the liquid crystal molecules may be slightly tilted relative to the substrate plane (pretilt). The pretilt angle of the liquid crystal cell is typically 3° or less, preferably 1° or less, and more preferably 0.5° or less.

[0064] Examples of liquid crystal cells containing horizontally aligned liquid crystal molecules in an electroless state include lateral field effect (IPS) mode, fringe field switching (FFS) mode, and ferroelectric liquid crystal (FLC) mode. Liquid crystal molecules can be nematic or smectic liquid crystals. Generally, nematic liquid crystals are used in IPS and FFS mode liquid crystal cells, while smectic liquid crystals are used in FLC mode liquid crystal cells.

[0065] [Polarizer]

[0066] A first polarizer 30 is disposed on the first principal surface side of the liquid crystal cell 20, and a second polarizer 40 is disposed on the second principal surface side. The polarizer converts natural light or any polarized light into linear polarized light. Any appropriate polarizer can be used as the first polarizer 30 and the second polarizer 40, depending on the purpose. For example, a polarizer obtained by adsorbing a dichroic substance such as iodine or a dichroic dye onto a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified film of an ethylene-vinyl acetate copolymer and then uniaxially stretching the film; and a polyene-based alignment film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride.

[0067] Among these polarizers, polyvinyl alcohol (PVA) polarizers are preferably used because they have higher polarization brightness. Polyvinyl alcohol films such as polyvinyl alcohol and partially formalized polyvinyl alcohol are adsorbed with a dichroic substance such as iodine or a dichroic dye, and oriented in a specific direction. For example, a PVA polarizer can be obtained by dyeing a polyvinyl alcohol film with iodine and then stretching it.

[0068] As a PVA-based polarizer, a thin polarizer with a thickness of 10 μm or less can also be used. Examples of thin polarizers include thin polarizing films described in Japanese Patent Application Laid-Open No. 51-069644, Japanese Patent Application Laid-Open No. 2000-338329, WO2010 / 100917, Japanese Patent No. 4691205, and Japanese Patent No. 4751481. Such thin polarizers are obtained, for example, by a method comprising stretching a PVA-based resin layer and a stretching resin substrate as a laminate, followed by iodine dyeing.

[0069] [Optically anisotropic components]

[0070] Optically anisotropic elements 50 and 60 are retardation films whose refractive index nx in the in-plane slow axis direction, refractive index ny in the in-plane fast axis direction, and refractive index nz in the thickness direction satisfy nx>nz>ny. Polarizers 30 and 40, positioned above and below liquid crystal cell 20, are arranged so that their absorption axes 35 and 45 are orthogonal to each other. However, when the liquid crystal panel is viewed from an angle, the angle formed by the absorption axes of polarizers 30 and 40 is greater than 90° (causing a shift from the crossed polarization), resulting in light leakage.

[0071] By placing a retardation film satisfying nx>nz>ny between the liquid crystal cell 20 and the polarizers 30 and 40, the polarizer's axis misalignment is compensated, reducing light leakage when viewing the screen from an oblique angle. In particular, the black brightness at an angle of 45 degrees relative to the polarizer's absorption axis (azimuth angles of 45 degrees, 135 degrees, 225 degrees, and 315 degrees) is reduced, improving contrast.

[0072] In the O-mode liquid crystal panel 101 of the first embodiment, an optical anisotropic element 50 is disposed between the liquid crystal cell 20 and the first polarizer 30 on the visual confirmation side. In the E-mode liquid crystal panel 102 of the second embodiment, an optical anisotropic element 60 is disposed between the liquid crystal cell 20 and the second polarizer 40 on the light source side.

[0073] The front retardation Re of the optically anisotropic components 50 and 60 at a wavelength of 550 nm is 550 It is preferably 150 to 400 nm, more preferably 180 to 370 nm, and even more preferably 200 to 350 nm. The thickness direction retardation Rt of the optically anisotropic element at a wavelength of 550 nm is 550 It is preferably 75 to 200 nm, more preferably 90 to 185 nm, and even more preferably 100 to 175 nm. In addition, the front retardation Re and the thickness direction retardation Rt are defined by the following formula using the refractive index nx in the slow axis direction, the refractive index ny in the fast axis direction, and the refractive index nz in the thickness direction:

[0074] Re=(nx-ny)×d

[0075] Rt=(nx-nz)×d.

[0076] The ranges of Re and Rt of the optically anisotropic element taking into account the retardation in the thickness direction of the color filter will be described in detail below.

[0077] The optically anisotropic elements 50 and 60 preferably have an Nz coefficient defined as Nz = (nx - nz) / (nx - ny) of 0.2 to 0.8. Based on the above definitions of Re and Rt, it can also be expressed as Nz = Rt / Re. In this specification, the Nz coefficient is calculated based on the refractive index at a wavelength of 650 nm. That is, the Nz coefficient is the front retardation Re at a wavelength of 650 nm. 650 Thickness direction delay Rt 650 Rt 650 / Re 650 Therefore, the optically anisotropic component is preferably, Rt 650 / Re 650 It is 0.2 to 0.8. In the retardation film produced by stretching a polymer film, the Nz coefficient calculated from the refractive index at a wavelength of 550 nm is generally substantially the same as the Nz coefficient calculated from the refractive index at a wavelength of 650 nm.

[0078] The Nz coefficient of the optically anisotropic element is more preferably 0.3 to 0.7, and even more preferably 0.4 to 0.6. There is a tendency that the closer the Nz coefficient is to 0.5, the less light leakage occurs in a wide viewing angle range.

[0079] Examples of materials constituting the optically anisotropic element include polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyarylate resins, sulfone resins such as polysulfone and polyethersulfone, sulfur resins such as polyphenylene sulfide, polyimide resins, cyclic polyolefin (polynorbornene) resins, polyamide resins, polyolefin resins such as polyethylene and polypropylene, and cellulose esters. Liquid crystal materials can also be used as materials for the optically anisotropic element.

[0080] When using polymer materials, stretching or shrinking the polymer film in at least one direction can enhance molecular orientation in a specific direction, thereby producing an optically anisotropic element (retardation film). By laminating a polymer film with a heat-shrinkable film, stretching the film in one direction while shrinking it in a direction perpendicular to the stretching direction using the shrinkage force of the heat-shrinkable film, an optically anisotropic element with a refractive index anisotropy of nx>nz>ny can be obtained.

[0081] The thickness of the optically anisotropic element can be appropriately selected depending on the material constituting the optically anisotropic element. When using a polymer material, the thickness of the optically anisotropic element is generally about 3 μm to 200 μm. When using a liquid crystal material, the thickness of the optically anisotropic element (the thickness of the liquid crystal layer) is generally about 0.1 μm to 20 μm.

[0082] The optically anisotropic element only needs to have specific Re and Rt, and the material, thickness, and manufacturing method of the optically anisotropic element are not limited to those described above.

[0083] [Optical compensation principle of optically anisotropic components]

[0084] In the present invention, by setting the optical properties of the optically anisotropic element based on the birefringence of the color filter, it is possible to optically compensate for both the axial offset exhibited by the polarizer and the influence of the birefringence of the color filter, thereby achieving a liquid crystal display device with minimal light leakage when viewed from an oblique direction and a neutral black hue. Specifically, the optical properties of the optically anisotropic element are set such that the thickness-direction retardation Ct of the green-transmitting region 22G of the color filter 22 at a wavelength of 550 nm is 1:1. 550 , and the thickness direction retardation Rt of the optically anisotropic components 50 and 60 at a wavelength of 550 nm 550 and the thickness direction delay Ct of the red transmission region 22R of the color filter 22 at a wavelength of 650nm 650 , and the thickness direction retardation Rt of the optically anisotropic components 50 and 60 at a wavelength of 650 nm 650 Satisfy a specific relationship.

[0085] Optical compensation without considering color filter birefringence

[0086] First, refer to Figure 5 The principle of compensating for the axial deviation of a polarizer by using an optically anisotropic element having a refractive index anisotropy of nx>nz>ny is described below. Figure 5 In the example, the Poincare sphere is used to illustrate the compensation of the optical anisotropy component 50. Figure 1 The polarizers 30 and 40 of the liquid crystal panel 101 in the O mode are shown to be misaligned in the axial direction.

[0087] Light passing through the light source side polarizer 40 is linearly polarized. When the liquid crystal display device is viewed from the front, the light passing through the polarizer is represented by point P0 on the equator of the Poincare sphere. Since the absorption axis direction 35 of the viewing side polarizer 30 is orthogonal to the absorption axis direction 45 of the light source side polarizer 40, the light passing through the viewing side polarizer 30 is represented by point P1 on the equator of the Poincare sphere.

[0088] The initial alignment direction 11 of the liquid crystal molecules in the liquid crystal cell 20 is parallel to the absorption axis direction 45 of the polarizer 40. Therefore, the polarization state of light passing through the polarizer 40 does not change after passing through the liquid crystal cell. In other words, the polarization state of light passing through the liquid crystal cell does not shift from point P0 on the Poincare sphere. Since the light P0 passing through the liquid crystal cell 20 and the light P1 passing through the polarizer 30 on the viewing side are linearly polarized and orthogonal to each other, all the light passing through the liquid crystal cell 20 is absorbed by the polarizer 30 on the viewing side, achieving a black display.

[0089] When the liquid crystal display device is visually observed from an azimuth angle of 45° with respect to the absorption axis of the polarizer and a slope (polar angle) θ with respect to the normal direction of the screen, the axis direction of the polarizer 40 on the light source side shifts from P0 to P'0, and the axis direction of the polarizer 30 on the visual confirmation side shifts from P1 to P'1. The larger the polar angle θ, the greater the change in the axis direction of the polarizer.

[0090] The light P'0 passing through the light source side polarizer 40 and the light P'1 passing through the visual confirmation side polarizer 30 are not orthogonal to each other, so light leakage occurs in the black display. In order to prevent light leakage caused by such an axial deviation, it is necessary to make the polarization state of the light after passing through the liquid crystal cell 20 linearly polarized light P'1 orthogonal to the light P'1 passing through the visual confirmation side polarizer 30. A .

[0091] Figure 1 In the illustrated O-mode liquid crystal panel 101, the absorption axis direction 45 of the light source-side polarizer 40 is parallel to the initial alignment direction 11 of the liquid crystal cell 20. Therefore, the initial alignment direction 11, as observed from an oblique angle, shifts in the same direction as the absorption axis direction 45 of the light source-side polarizer. Consequently, the polarization state of light passing through the polarizer 40 remains unchanged even after passing through the liquid crystal cell, and does not shift from point P'0 on the Poincare sphere.

[0092] The light passing through the liquid crystal unit 20 is incident on the optical anisotropic component 50. The optical anisotropic component 50 with an Nz coefficient of 0.5 does not change the direction of the optical axis regardless of the angle from which it is visually confirmed, and there is a delayed phase axis on the line connecting P0 and P1. The front retardation (delay of light relative to the normal direction) Re of the optical anisotropic component 50 is 1 / 2 of the wavelength λ. When Nz = 0.5, even if the transmission direction of the light changes, the delay shown does not change and is fixed at λ / 2. The delay of λ / 2 corresponds to the phase difference π, so the light P'0 passing through the liquid crystal unit 20 rotates 180° clockwise on the Poincare sphere with the axis P0-P1 as the center by passing through the optical anisotropic component 50, and moves to point P A .

[0093] As mentioned above, linear polarization P A Since the light P′1 is linearly polarized light that is perpendicular to the light P′1 that has passed through the visual confirmation side polarizer 30, the light P′1 whose polarization state is changed by the optical anisotropic element 50 is linearly polarized light. A The light is absorbed by the polarizer 30 on the visual confirmation side, thereby realizing a black display.

[0094] like Figure 6 As shown, in the O-mode liquid crystal panel 106 in which the absorption axis direction 45 of the second polarizer 40 is orthogonal to the slow phase axis direction 53 of the optical anisotropic component 50, the conversion of the polarization state by the optical anisotropic component 50 becomes a half-turn clockwise on the Poincare sphere. Figure 5 As shown by the single dotted line, the trajectory on the Poincare sphere passes through the southern hemisphere. Since the rotation angle is 180°, Figure 1 Similarly to the case of the liquid crystal panel shown in FIG, the polarization state of light passing through the optical anisotropic element 50 is determined by the point P on the Poincare sphere. A is indicated and is absorbed by the visual confirmation side polarizer 30, so a black display can be achieved.

[0095] exist Figure 3 In the illustrated E-mode liquid crystal panel 102, the initial alignment direction 11 of the liquid crystal molecules in the liquid crystal cell 20 is orthogonal to the absorption axis direction 45 of the light-source-side polarizer 40. Therefore, when viewed from an oblique angle, the initial alignment direction 11 and the absorption axis direction 45 of the light-source-side polarizer 40 are offset from 90°. Therefore, an optical anisotropic element 60 is disposed between the light-source-side polarizer 40 and the liquid crystal cell 20, so that the linearly polarized light P'0 transmitted through the light-source-side polarizer 40 passes through the optical anisotropic element 60 and moves to a point P on the Poincare sphere. A In this way, the linear polarization P'0 from the light source side polarizer 40 is converted into the linear polarization P by the optical anisotropic element 60. A Then it is incident on the liquid crystal unit 20, and the polarization state of the light passing through the liquid crystal unit does not change from P to A The change is absorbed by the polarizing element 30 on the visual confirmation side, thereby achieving a black display.

[0096] like Figure 7 As shown, in the E-mode liquid crystal panel 107 in which the absorption axis direction 45 of the second polarizer 40 is orthogonal to the slow phase axis direction 63 of the optical anisotropic element 60, the trajectory of the polarization state conversion performed by the optical anisotropic element 60 on the Poincare sphere is different in that it becomes the northern hemisphere or the southern hemisphere, but the principle of optical compensation is the same as Figure 3 The liquid crystal panels 102 shown are identical.

[0097] As described above, without considering the influence of the birefringence of the color filter, the optical design of the optically anisotropic component does not depend on the angle between the optical axis of the optically anisotropic component and the optical axis of the polarizer (parallel or orthogonal), nor on the angle between the initial alignment direction of the liquid crystal unit and the optical axis of the polarizer (O mode or E mode).

[0098] <Retardation in the thickness direction of color filters>

[0099] As described above, the in-plane delay of the color filter 22 provided on the visual confirmation side of the liquid crystal layer 10 in the liquid crystal unit 20 is approximately 0, but there is a delay of several nm to several tens of nm in the thickness direction. In the green transmission area 22G, the thickness direction delay relative to the light of the wavelength of 550nm with the highest transmittance affects the visual confirmation. For the same reason, in the red transmission area 22R, the thickness direction delay relative to the light of the wavelength of 650nm with higher transmittance affects the visual confirmation. Therefore, when evaluating the thickness direction delay of the color filter, it is appropriate to use the thickness direction delay Ct of the wavelength of 550nm for the green transmission area (green color filter). 550 For evaluation, for the red transmission area (red color filter), the thickness direction retardation Ct at a wavelength of 650nm was used. 650 Conduct an assessment.

[0100] In order to suppress light leakage when viewing from an oblique direction, it is preferable that the thickness direction retardation of the color filter is small. The thickness direction retardation Ct of the green transmission region at a wavelength of 550nm 550 The thickness direction retardation Ct of the color filter in the red region at a wavelength of 650 nm is preferably 50 nm or less, more preferably 40 nm or less, further preferably 35 nm or less, and particularly preferably 30 nm or less. 650 It is preferably 50 nm or less, more preferably 40 nm or less, further preferably 35 nm or less, and particularly preferably 30 nm or less. The thickness direction retardation of the color filter is ideally 0, but it is difficult to completely reduce the thickness direction retardation of the color filter to 0. Therefore, Ct 550 and Ct 650 Greater than 0. Ct 550 and Ct 650 For example, it may be 1 nm or more, 3 nm or more, or 5 nm or more.

[0101] <Principle of Optical Compensation Taking Color Filter Birefringence into Account>

[0102] First, refer to Figure 8 A, yes Figure 1The influence of the thickness direction retardation of the color filter of the O-mode liquid crystal panel 101 shown in FIG. 1 and the optical compensation taking this influence into account will be described. When viewed from an oblique direction, the polarization state of light after passing through the liquid crystal layer 10 of the liquid crystal cell 20 is represented by point P'0 on the Poincare sphere, which is different from the case where the birefringence of the color filter is not taken into account ( Figure 5 )same.

[0103] Light passing through the liquid crystal layer enters the color filter 22. The color filter has a front retardation of approximately 0 and a specific thickness-direction retardation, so it can be approximated as a negative C-plate with a refractive index anisotropy of nx=ny>nz. Light traveling in an oblique direction changes its polarization state due to the thickness-direction retardation of the negative C-plate, and moves southward from point P'0 to point P along the meridian on the Poincare sphere. C .

[0104] and Figure 5 Similarly, when the phase difference of the optical anisotropic element is π (rotated 180° on the Poincare sphere), the polarization state of light passing through the optical anisotropic element is changed from Figure 8 Point P' of A A In order to make the light after passing through the optical anisotropic component 50 become point P on the equator, A The linear polarization represented by must be such that the rotation angle on the Poincare sphere caused by the optical anisotropic element is greater than 180°. In other words, if the influence of the birefringence of the color filter is taken into account, Figure 1 In the O-mode liquid crystal panel 101 shown, in order to make the light transmitted through the optically anisotropic element 50 linearly polarized, the phase difference of the optically anisotropic element 50 must be larger than π.

[0105] Figure 8 B represents that the absorption axis direction 45 of the second polarizer 40 is orthogonal to the slow axis direction 53 of the optical anisotropic component 50. Figure 6 The optical compensation status of the O-mode liquid crystal panel 106. The polarization state of the light after passing through the color filter 22 which is similar to the negative C plate is different from Figure 8 Similarly, the point P in the southern hemisphere of the Poincare sphere C Indicates that when the phase difference of the optical anisotropic component is π, if the phase difference of the optical anisotropic component is π, then the optical anisotropic component is C If you rotate half a circle clockwise on the Poincare sphere and rotate 180°, you will pass through the equator and reach point P' in the northern hemisphere. A In order to make the light after passing through the optical anisotropic element 50 be AThe linear polarization represented by must be such that the rotation angle on the Poincare sphere caused by the optical anisotropic element is less than 180°. In other words, if the influence of the birefringence of the color filter is taken into account, Figure 6 In the O-mode liquid crystal panel 106 shown, in order to make the light transmitted through the optically anisotropic element 50 linearly polarized, the phase difference of the optically anisotropic element 50 must be smaller than π.

[0106] Figure 9 A represents that the absorption axis direction 45 of the second polarizer 40 is orthogonal to the slow axis direction 63 of the optical anisotropic component 60. Figure 7 The optical compensation status of the E-mode liquid crystal panel 107. Figure 8 A and Figure 8 Similarly to the case of B, if the light P after passing through the liquid crystal unit L After passing through the color filter 22 which is similar to a negative C plate, the polarization state of the light changes and it moves southward along the meridian on the Poincare sphere. A And it is absorbed by the visual confirmation side polarizer 30, and it is necessary to make the light P after passing through the liquid crystal unit L The Northern Hemisphere lies on the Poincare sphere.

[0107] and Figure 5 Similarly, if the phase difference of the optical anisotropic element is π, and the linear polarized light P'0 passing through the light source side polarizer passes through the optical anisotropic element and moves to the point P on the Poincare sphere, A , the polarization state of the light passing through the liquid crystal unit does not change from P A However, the light that has passed through the liquid crystal cell moves southward along the meridian on the Poincare sphere due to the influence of the thickness-direction retardation of the color filter. Therefore, the light that has passed through the color filter becomes elliptically polarized light located in the southern hemisphere, and the light that is not absorbed by the polarizer 30 on the visual confirmation side is visually recognized as leakage light.

[0108] Figure 7 In the E-mode liquid crystal panel 107 shown, Figure 9 As shown in A, by making the phase difference of the optical anisotropic element 60 smaller than π (making the rotation angle on the Poincare sphere caused by the optical anisotropic element smaller than 180°), appropriate optical compensation can be performed. The polarization state of light passing through the optical anisotropic element with a phase difference smaller than π is determined by point P on the southern hemisphere of the Poincare sphere. R The polarization state is transformed by the phase difference of the liquid crystal layer 10, with the axis P A -P'1 is the center and rotates clockwise on the Poincare sphere. Therefore, the polarization state of the light after passing through the liquid crystal layer 10 is determined by the point P on the northern hemisphere of the Poincare sphere. L As mentioned above, if the light P after passing through the liquid crystal unitL Through the color filter 22, it goes south along the meridian on the Poincare sphere and reaches point P on the equator. A Therefore, the light P after passing through the color filter A The polarizing member 30 on the visual confirmation side absorbs light appropriately, thereby preventing light leakage.

[0109] Figure 9 B indicates that the absorption axis direction 45 of the second polarizer 40 is parallel to the slow axis direction 63 of the optical anisotropic component 60. Figure 3 The optical compensation status of the E-mode liquid crystal panel 102. In the liquid crystal panel 102, if the phase difference of the optical anisotropic element 60 is set to be greater than π (the rotation angle on the Poincare sphere caused by the optical anisotropic element is set to be greater than 180°), the polarization state of the light after passing through the optical anisotropic element is located at point P on the southern hemisphere of the Poincare sphere. R . Later, with Figure 9 Similarly, the point A moves to point P on the northern hemisphere by passing through the liquid crystal layer 10. L , passing through the color filter 22 and reaching point P on the equator A , so the light P after passing through the color filter A It was visually confirmed that the side polarizer 30 absorbed light appropriately.

[0110] As described above, in order to compensate for the effects of the color filter's birefringence by using an optically anisotropic element, it is necessary to adjust the phase difference of the optically anisotropic element according to the thickness-direction retardation of the color filter. When the absorption axis of the polarizer on the light source side is parallel to the retardation axis of the optically anisotropic element, that is, Figure 1 The O-mode liquid crystal panel 101 shown (see Figure 8 A), and Figure 3 The E-mode liquid crystal panel 102 shown (see Figure 9 In B), in order to perform appropriate optical compensation, the phase difference of the optical anisotropic element must be greater than π (the delay must be greater than λ / 2). On the other hand, when the absorption axis direction of the polarizer on the light source side is orthogonal to the slow axis direction of the optical anisotropic element, that is, Figure 6 The O-mode liquid crystal panel 106 shown (see Figure 8 B), and Figure 7 The E-mode liquid crystal panel 107 shown (see Figure 9 In A), in order to perform appropriate optical compensation, the phase difference of the optically anisotropic element must be smaller than π (the retardation must be smaller than λ / 2).

[0111] [Optical Design of Optically Anisotropic Components]

[0112] Hereinafter, the preferred optical characteristics of an optically anisotropic element corresponding to the thickness-direction retardation of a color filter of a liquid crystal cell will be described, along with the results of an optical simulation study.

[0113] In the optical simulation, the LCD MASTER Ver.8.1.0.3 emulator for liquid crystal displays manufactured by Shintec was used, and the extended function of LCD Master was used to calculate the brightness of black display at an azimuth angle of 45° and a polar angle of 60°, and the chromaticity (u', v') of black display in the CIE1976 color space.

[0114] In the simulation of the O-mode LCD device, as shown in Figure 2 As shown in FIG. 1 , a model in which a light source side polarizer 40, an IPS liquid crystal cell 20 having a color filter 22 on the visual confirmation side of the liquid crystal layer 10, an optical anisotropic element 50, and a visual confirmation side polarizer 30 are stacked in this order from the light source 110 side is used as a simulation model. In the simulation of the E-mode liquid crystal display device, as shown in FIG. Figure 4 As shown, a model in which a light source side polarizer 40, an optical anisotropic element 60, an IPS liquid crystal cell 20 having a color filter 22 on the visual confirmation side of the liquid crystal layer 10, and a visual confirmation side polarizer 30 are stacked in this order from the light source 110 side is used as a simulation model.

[0115] In the simulation, the front retardation of the liquid crystal layer of the IPS liquid crystal cell was set to 339 nm, the pre-tilt angle was set to 0°, the Nz coefficient of the optical anisotropic component was set to 0.5, and the wavelength dispersion of the retardation was set to Re 650 / Re 550 =Rt 650 / Rt 550 =0.95, Rt 650 The color filter can be changed to various values ​​in the range of 0 to 60 nm in 5 nm increments. The thickness direction retardation Ct of the green transmission region at a wavelength of 550 nm is 550 , and the thickness direction retardation Ct of the red transmission region at a wavelength of 650nm 650 .

[0116] In the O-mode LCD panel, Ct 650 and Rt 650 The chromaticity of black display when changing to various values ​​is shown in Figure 10 A and Figure 10 In the E-mode LCD panel, Ct 650 and Rt 650 The chromaticity of black display when changing to various values ​​is shown in Figure 11 A and Figure 11 B.

[0117] Figure 10 A is as follows Figure 1 The absorption axis direction 45 of the light source side polarizer 40 is parallel to the slow phase axis direction 53 of the optical anisotropic component 50 (for the principle of optical compensation, refer to FIG. Figure 8 A) Simulation results. Figure 10 B is as follows Figure 6 The absorption axis direction 45 of the light source side polarizer 40 is orthogonal to the slow axis direction 53 of the optical anisotropic component 50 in the liquid crystal panel 106 (for the principle of optical compensation, refer to FIG. Figure 8 B) Simulation results. Figure 11 A is as follows Figure 7 The absorption axis direction 45 of the light source side polarizer 40 is orthogonal to the slow axis direction 63 of the optical anisotropic component 60 in the liquid crystal panel 107 (for the principle of optical compensation, refer to FIG. Figure 9 A) Simulation results. Figure 11 B is as follows Figure 3 The absorption axis direction 45 of the light source side polarizer 40 is parallel to the slow phase axis direction 63 of the optical anisotropic component 60 (for the principle of optical compensation, refer to FIG. Figure 9 B) Simulation results.

[0118] like Figure 10 B and Figure 11 As shown in A, when the absorption axis direction of the polarizer on the light source side is perpendicular to the slow axis direction of the optical anisotropic element, it is found that the retardation Ct in the thickness direction of the red transmission area of ​​the color filter increases. 650 Increased, making the thickness direction retardation Rt of the optically anisotropic component 650 The maximum value of u' tends to decrease when it changes. 650 In the range of 0 to 60 nm, regardless of the thickness direction retardation Rt of the optical anisotropic element 650 In other words, when the absorption axis direction of the polarizer on the light source side is perpendicular to the slow axis direction of the optical anisotropic component, Figure 6 The O-mode liquid crystal panel 106 and Figure 7 In any of the liquid crystal panels 107 in the E mode shown, the black screen is not noticeably colored red when viewed from an oblique direction.

[0119] On the other hand, Figure 10 A and Figure 11 As shown in B, when the absorption axis of the polarizer on the light source side is parallel to the slow axis of the optical anisotropic element, it is found that the thickness direction retardation Ct of the red transmission area of ​​the color filter increases. 650 Increased, making the thickness direction retardation Rt of the optically anisotropic component650 The maximum value of u' tends to increase when it changes. Figure 10 A and Figure 11 In B, with Figure 10 B and Figure 11 Compared with A, u' is delayed Ct in the thickness direction of the red transmission area of ​​the color filter. 650 and thickness direction retardation Rt of optically anisotropic components 650 However, it varies greatly, and some cases exceeding 0.35 are also found.

[0120] From these results, it can be seen that when the absorption axis direction of the light source side polarizer is parallel to the slow axis direction of the optical anisotropic element, Figure 1 The O-mode liquid crystal panel 101 and Figure 3 In all of the E-mode liquid crystal panels 102 shown, the black display appears red when viewed from an oblique angle due to the birefringence of the red-transmitting region of the color filter. This indicates that in a liquid crystal panel where the absorption axis of the light-side polarizer is parallel to the slow axis of the optical anisotropic element, when optically compensating for the birefringence of the color filter, in addition to reducing green light leakage and improving contrast, the optical design of the optical anisotropic element must also be designed to minimize the coloration of the black display caused by red light leakage.

[0121] <First Embodiment: Optical Design of O-Mode Liquid Crystal Panel>

[0122] (Adjustment of chroma)

[0123] Figure 12 is based on Figure 1 The simulation results of the O-mode liquid crystal panel 101 are plotted in a graph showing the conditions under which the chromaticity of the black display reaches a specific value. The horizontal axis is the thickness direction retardation Ct of the red transmission region of the color filter at a wavelength of 650nm. 650 The vertical axis is the thickness direction retardation Rt of the optical anisotropic component at a wavelength of 650nm. 650 In each Ct 650 The points where the chromaticity u' of the black display in the direction of azimuth angle 45° and polar angle 60° becomes 0.35 are indicated by black circle and black triangle. 650 When the image is located between the black circle mark and the black triangle mark, u' exceeds 0.35, and the black display is colored red and visually recognized. 650 When located above the black circle mark or below the black triangle mark, u' is less than 0.35, and red coloration of black display can be suppressed.

[0124] Depend on Figure 12It can be seen that both the upper and lower limits of the boundary of u' = 0.35 can be approximated by straight lines. The straight lines in the graph are represented by the following equations (1) and (2):

[0125] Rt 650 =0.37(Ct 650 )+116...(1)

[0126] Rt 650 =-0.44(Ct 650 )+116...(2).

[0127] Therefore, the thickness direction retardation Ct of the red transmission region 22R of the color filter 22 at a wavelength of 650 nm is 650 , and the thickness direction retardation Rt of the optical anisotropic element 50 at a wavelength of 650 nm 650 When the following formula (1a) or (2a) is satisfied, u' becomes 0.35 or less, and black display with reduced red tint can be achieved.

[0128] Rt 650 ≥0.37(Ct 650 )+116...(1a)

[0129] Rt 650 ≤-0.44(Ct 650 )+116...(2a).

[0130] Figure 12 The white circle and white triangle indicate the point where the chromaticity u' of the black display becomes 0.314. 650 When it is between the white circle mark and the black circle mark, u' is 0.314 to 0.35, and Rt 650 When the value is located above the white circle, u' is less than 0.314. 650 When it is located between the white triangle mark and the black triangle mark, u' is 0.314 to 0.35, and Rt 650 When located below the white triangle mark, u' is less than 0.314.

[0131] The boundary of u'=0.314 indicated by the white circle can be expressed as a straight line parallel to the above formula (1): Rt 650 =0.37(Ct 650 )+121 approximation. The boundary of u'=0.314 indicated by the white triangle mark can be expressed by a straight line parallel to the above formula (2): Rt 650 =-0.44(Ct 650 )+108 approximately.

[0132] Therefore, the retardation Ct in the thickness direction at a wavelength of 650 nm in the red transmission region of the color filter is 650 Thickness direction retardation Rt of optically anisotropic component at wavelength 650nm 650 When the following formula (1b) or (2b) is satisfied, u' becomes 0.314 or less, and black display with a further reduced red tint can be achieved.

[0133] Rt 650 ≥0.37(Ct 650 )+121...(1b)

[0134] Rt 650 ≤-0.44(Ct 650 )+108...(2b).

[0135] According to the above results, it can be considered that Figure 1 In the O-mode liquid crystal panel shown, the Ct 650 With Rt 650 When the following formula (1c) or (2c) is satisfied, a black display with reduced red tint can be realized.

[0136] Rt 650 ≥0.37(Ct 650 )+C1...(1c)

[0137] Rt 650 ≤-0.44(Ct 650 )+C2...(2c).

[0138] As described above, when u'=0.35 is used as the boundary, C1 in formula (1c) is 116nm, and C2 in formula (2c) is 116nm. In other words, when the conditions are set so as to satisfy u'≤0.35, as in the above formulas (1a) and (2a), C1=116nm and C2=116nm can be set. Based on the same viewpoint, when the conditions are set so as to satisfy u'≤0.314, as in the above formulas (1b) and (2b), C1=121nm and C2=108nm can be set. In order to further reduce u' for black display, C1 can be set larger and C2 can be set smaller.

[0139] C1 in formula (1c) can be any number greater than 116. C1 can be 116 nm, 121 nm, 124 nm, 126 nm, 128 nm, 130 nm, 132 nm, 134 nm, 136 nm, 138 nm, or 140 nm. Similarly, C2 in formula (2c) can be any number less than 116. C2 can be 116 nm, 112 nm, 108 nm, 105 nm, 102 nm, 100 nm, 98 nm, 96 nm, 94 nm, 92 nm, or 90 nm.

[0140] From the viewpoint of reducing the chromaticity u' of the black display when viewed from an oblique direction, the Rt of the optical anisotropic element 50 at a wavelength of 650 nm is 650 If the above formula (1c) or (2c) is satisfied, the upper and lower limits are not particularly limited. However, as described below, if Rt is considered to reduce the black brightness, 550 Range and wavelength dispersion Rt of retardation of the optical anisotropic component 50 650 / Rt 550 , then Rt 650 The upper and lower limits are automatically determined.

[0141] (Brightness adjustment)

[0142] As described above, by delaying Ct in the thickness direction of the color filter 650 Adjusting the Rt of the optical anisotropy component 650 By suppressing red light leakage, u' of black display can be reduced. On the other hand, in order to reduce the amount of light leakage during black display (black brightness), it is preferable to perform optical design so as to reduce the light leakage of green light with a high luminosity function.

[0143] Figure 13 is based on Figure 1 The simulation results of the O-mode liquid crystal panel 101 are plotted in a graph showing the conditions under which the black brightness reaches a specific value. The horizontal axis is the thickness direction retardation Ct of the green transmission region of the color filter at a wavelength of 550nm. 550 The vertical axis is the thickness direction retardation Rt of the optical anisotropic component at a wavelength of 550nm. 550 In each Ct 550 , the black brightness in the direction of azimuth angle 45° and polar angle 60° has the same Ct 550 , and the points that become half of the liquid crystal display device without using an optical anisotropic element are indicated by black circle marks and black triangle marks. 550 In the case of being located between the black circle mark and the black triangle mark, the black brightness when viewed from an oblique direction is reduced to less than half compared to the case without the optically anisotropic element.

[0144] Depend on Figure 13 It can be seen that the upper and lower limits of the region where the black brightness is halved can be approximated by straight lines compared to the case where no optical anisotropic element is used. The straight lines in the graph are expressed by the following equations (3) and (4):

[0145] Rt 550 =0.97(Ct 550 )+73...(3)

[0146] Rt 550 =0.49(Ct 550 )+205...(4).

[0147] Therefore, the green transmission region 22G of the color filter 22 has a retardation Ct in the thickness direction at a wavelength of 550 nm. 550 The thickness direction retardation Rt of the optical anisotropic element 50 at a wavelength of 550 nm is 550 When the following formula (3a) is satisfied, the black brightness in an oblique direction becomes 1 / 2 or less compared to the case where no optically anisotropic element is used.

[0148] 0.97(Ct 550 )+73≤Rt 550 ≤0.49(Ct 550 )+205...(3a).

[0149] Figure 13 The white circle mark and the white triangle mark indicate the point where the black brightness becomes 1 / 5 of the black brightness of the liquid crystal display device without using an optical anisotropic element. 550 In the case of being located between the white circle mark and the white triangle mark, the black luminance is reduced to less than 1 / 5 compared to the case without the optically anisotropic element.

[0150] The boundary indicated by the white circle can be drawn by a straight line parallel to the above formula (3): Rt 550 =0.97(Ct 550 ) + 98 approximation. The boundary indicated by the white triangle mark can be drawn with a straight line parallel to the above formula (4): Rt 550 =0.49(Ct 550 ) + 180 approximation. Therefore, the thickness direction delay Ct of the green transmission region of the color filter at a wavelength of 550nm is 550 Thickness direction retardation Rt of optically anisotropic component at wavelength 550nm 550 When the following formula (3b) is satisfied, the black brightness can be reduced to 1 / 5 or less compared to the case where no optical anisotropic element is used, thereby achieving a display with a high contrast ratio.

[0151] 0.97(Ct 550 )+98≤Rt 550 ≤0.49(Ct 550 )+180...(3b).

[0152] According to the above results, it can be considered that Figure 1 In the O-mode liquid crystal panel shown, the Ct 550 With Rt 550 When the following formula (3c) is satisfied, the influence of the birefringence of the color filter can be eliminated, and a display with reduced black brightness in an oblique direction can be achieved.

[0153] 0.97(Ct 550 )+C3≤Rt 550 ≤0.49(Ct 550 )+C4...(3c)

[0154] As described above, when the black brightness is set to less than 1 / 2 of the black brightness of a liquid crystal display device that does not use an optical anisotropic component, it is sufficient to set C3 = 73nm and C4 = 205nm as in the above formula (3a). Based on the same viewpoint, when the black brightness is set to less than 1 / 5 of the black brightness of a liquid crystal display device that does not use an optical anisotropic component, it is sufficient to set C3 = 98 and C4 = 180nm as in the above formula (3b). In order to further reduce the black brightness in the oblique direction, C3 is set to be large and C4 is set to be small. C3 in formula (3c) can be any number greater than 73. C3 can be 73nm, 88nm, 98nm, 108nm, 113nm, 118nm, 123nm, or 128nm. Similarly, C4 in formula (3c) can be any number less than 205. C4 may be 205 nm, 190 nm, 180 nm, 173 nm, 168 nm, 163 nm, 158 nm, 153 nm, or 148 nm.

[0155] like Figure 13 As shown, the thickness direction retardation Ct of the color filter 550 The larger the Rt value of the optically anisotropic element, the lower the black brightness when viewed from an oblique direction. 550 The larger the optimal value of Figure 8 The principle of optical compensation shown in A is understood. The thickness direction retardation Ct of the color filter 550 Big, this corresponds to Figure 8 P'0 and P in A C The distance is large (P C P CThe further south the latitude is from the equator, the greater the phase difference of the optical anisotropic element must be in order to move the light after passing through the optical anisotropic element 50 to the equator of the Poincare sphere. Figure 13 As shown, Ct 550 The larger the Rt is, the lower the black brightness must be. 550 The bigger.

[0156] (Balance between black brightness reduction and chromaticity)

[0157] In order to reduce the black brightness when visually confirmed from an oblique direction, the thickness direction retardation Ct of the color filter is adjusted. 550 , the Rt of the optically anisotropic component is set to satisfy the above formula (3c) 550 , and the Rt of the optically anisotropic element is set so as to satisfy the above formula (1c) or (2c) 650 However, Rt 550 and Rt 650 Cannot be set individually, Rt 650 / Rt 550 It is a fixed value corresponding to the wavelength dispersion of the retardation of the optically anisotropic component.

[0158] For example, the retardation Ct in the thickness direction of the green transmission area of ​​the color filter is 550 When the optical anisotropic component has a thickness of 10 nm, if Rt 550 If the thickness is 130nm, the black brightness is small when visually confirmed from an oblique direction, and a high contrast display can be achieved. 650 / Rt 550 = 0.95 wavelength dispersion, if Rt 550 =130nm, then Rt 650 =124nm.

[0159] Since the red color filter and the green color filter are made of different materials, their Rth is different. 650 Greater than the Ct of the green color filter 550 For example, if the thickness direction delay Ct of the red transmission region 22R of the color filter 22 is 650 is 30nm, then Rt 650 =124 nm, neither the above formula (1a) nor the formula (1b) is satisfied, the chromaticity u' when viewed from an oblique direction exceeds 0.35, and the black display is visually colored red.

[0160] From the above example, we can see that Figure 1In the O-mode liquid crystal panel shown, even if the optical anisotropic element is optically designed so that the black brightness is reduced, the chromaticity u' of the black display may increase, and the black display may be tinted red. 550 and Ct 650 , and wavelength dispersion Rt of the retardation of the optically anisotropic component 650 / Rt 550 The thickness direction delay of the optically anisotropic component can be set in a manner that satisfies the above-mentioned formula (3c) (here, C3 is greater than 73 nm and C4 is less than 205 nm) and satisfies the above-mentioned formula (1c) or (2c) (here, C1 is greater than 116 nm and C2 is less than 116 nm).

[0161] Furthermore, the wavelength dispersion Rt of the retardation in the thickness direction of the retardation film is 650 / Rt 550 Usually related to the wavelength dispersion Re of the front retardation 650 / Re 550 are roughly equal and are within the range of 0.8 to 1.2. If the range of normal wavelength dispersion is considered, then in Ct 650 When the Rt is 10nm or more, 550 Satisfies formula (3c), and Rt 650 The cases satisfying formula (2c) are rare. Therefore, it is preferable to make Rt 550 Satisfies the above formula (3c), and Rt 650 The retardation of the optically anisotropic element is set so as to satisfy the above-mentioned formula (1c).

[0162] Front retardation Re of the optically anisotropic component 50 550 and Re 650 To make Rt 550 and Rt 650 As described above, the ratio Nz=Rt / Re of the thickness direction retardation Rt of the optical anisotropic element 50 to the front retardation Re is 0.2 to 0.8. Therefore, under this constraint, the thickness direction retardation Rt of the optical anisotropic element is set to 550 and Rt 650 , and Nz coefficient to set the front retardation Re 550 and Re 650 .

[0163] Specifically, the front retardation Re of the optically anisotropic component 50 at a wavelength of 650 nm is 650 Preferably Rt 650 Therefore, Re 650 It is preferable to satisfy the following formula (1d) or (2d).

[0164] Re 650 ≥0.74(Ct 650 )+C 11 ...(1d)

[0165] Re 650 ≤-0.88(Ct 650 )+C 12 ...(2d).

[0166] C 11 is twice that of C1. Specifically, C 11 Above 232nm. 11 It can be 232nm, 236nm, 242nm, 248nm, 252nm, 256nm, 260nm, 264nm, 268nm, 272nm, 276nm, or 280nm. 12 is twice that of C2. Specifically, C 12 Below 232nm. 12 It can be 232nm, 224nm, 216nm, 210nm, 204nm, 200nm, 196nm, 192nm, 188nm, 184nm, or 180nm. If the wavelength dispersion of the retardation of the optical anisotropic element is taken into account, the Re of the optical anisotropic element 50 is 650 It is preferable to satisfy the above-mentioned formula (1d).

[0167] The front retardation Re of the optically anisotropic component 50 at a wavelength of 550 nm is 550 Preferably Rt 550 Therefore, Re 550 It is preferred to satisfy the following formula (3d):

[0168] 1.94(Ct 550 )+C 13 ≤Re 550 ≤0.98(Ct 550 )+C 14 ...(3d).

[0169] C 13 is twice that of C3. Specifically, C 13 It is above 146nm. 13 It can be 145nm, 175nm, 185nm, 215nm, 225nm, 235nm, 245nm, or 255nm. 14 is twice that of C4. Specifically, C 14 Below 410nm. 14It may be 410 nm, 380 nm, 360 nm, 345 nm, 335 nm, 325 nm, 315 nm, 305 nm, or 295 nm.

[0170] <Second Embodiment: Optical Design of E-Mode Liquid Crystal Panel>

[0171] Figure 14 is based on Figure 3 The simulation results of the E-mode liquid crystal panel 102 shown in FIG. 1 are graphs showing conditions under which the chromaticity of black display becomes a specific value. Figure 12 Similarly, points where the chromaticity u' of black display is 0.35 in the direction of azimuth angle 45° and polar angle 60° are indicated by black circles and black triangles, and points where the chromaticity u' of black display is 0.314 are indicated by white circles and white triangles.

[0172] and Figure 12 The same is true for Figure 14 The boundary of u'=0.35 can also be approximated by the straight lines represented by the following equations (6) and (7):

[0173] Rt 650 =0.37(Ct 650 )+116...(6)

[0174] Rt 650 =-0.44(Ct 650 )+120...(7).

[0175] Therefore, in the liquid crystal panel 102, the retardation Ct in the thickness direction of the red transmission region 22R of the color filter 22 at a wavelength of 650 nm is 650 The thickness direction retardation Rt of the optical anisotropic element 50 at a wavelength of 650 nm is 650 When the following formula (6a) or (7a) is satisfied, u' becomes 0.35 or less, and black display with reduced red tint can be achieved.

[0176] Rt 650 ≥0.37(Ct 650 )+116...(6a)

[0177] Rt 650 ≤-0.44(Ct 650 )+120...(7a).

[0178] It should be noted that the equation (6) is the same as the equation (1) for the O-mode liquid crystal panel 101. The equation (7) is expressed by a straight line parallel to the equation (2) for the O-mode liquid crystal panel 101. Figure 14 In FIG, as a reference, the straight line of equation (2) is represented by a dotted line.

[0179] The boundary of u'=0.314 indicated by the white circle can be represented by a straight line parallel to the above formula (6): Rt 650 =0.37(Ct 650 )+121 approximation. The boundary u'=0.314 indicated by the white triangle mark can be drawn by a straight line parallel to the above formula (2): Rt 650 =-0.44(Ct 650 )+108 approximately.

[0180] Therefore, the retardation Ct in the thickness direction at a wavelength of 650 nm in the red transmission region of the color filter is 650 Thickness direction retardation Rt of optically anisotropic component at wavelength 650nm 650 When the following formula (6b) or (7b) is satisfied, u' becomes 0.314 or less, and black display with a further reduced red tint can be realized.

[0181] Rt 650 ≥0.37(Ct 650 )+121...(6b)

[0182] Rt 650 ≤-0.44(Ct 650 )+108...(7b).

[0183] According to the above results, it can be considered that Figure 3 In the E-mode liquid crystal panel 102 shown, at Ct 650 With Rt 650 When the following formula (6c) or (7c) is satisfied, a black display with reduced red tint can be realized.

[0184] Rt 650 ≥0.37(Ct 650 )+C6...(6c)

[0185] Rt 650 ≤-0.44(Ct 650 )+C7...(7c).

[0186] When the conditions are set so that u' ≤ 0.35, as in equations (6a) and (7a) above, C6 = 116 nm and C7 = 120 nm are sufficient. When the conditions are set so that u' ≤ 0.314, as in equations (6b) and (7b) above, C6 = 121 nm and C7 = 108 nm are sufficient. To further reduce u' for black display, C6 can be set larger and C7 can be set smaller.

[0187] C6 in formula (6c) can be any number greater than 116. C6 can be a numerical value equivalent to the above-mentioned C1, and C6 can be 116nm, 118nm, 121nm, 124nm, 126nm, 128nm, 130nm, 132nm, 134nm, 136nm, 138nm, or 140nm. Similarly, C7 in formula (7c) can be any number less than 120. C7 can be a numerical value equivalent to the above-mentioned C2, and can also be 121nm, 116nm, 112nm, 108nm, 105nm, 102nm, 100nm, 98nm, 96nm, 94nm, 92nm, or 90nm. If the wavelength dispersion of the delay of the optical anisotropic component is taken into account, the Rt of the optical anisotropic component 60 is 650 It is preferable to satisfy the above formula (6c).

[0188] From the viewpoint of reducing the chromaticity u' of black display when viewed from an oblique direction, the Rt of the optical anisotropic element 60 at a wavelength of 650 nm is 650 If the above formula (6c) or (7c) is satisfied, the upper and lower limits are not particularly limited. However, as described above with respect to the first embodiment, if Rt is considered to reduce the black brightness, 550 The range of the wavelength dispersion Rt of the retardation of the optical anisotropic element 60 650 / Rt 550 , then Rt 650 The upper and lower limits are automatically determined.

[0189] Figure 15 is based on Figure 3 The simulation results of the E-mode liquid crystal panel 102 shown in FIG. 1 are graphs showing conditions under which the black luminance reaches a specific value. Figure 13 Similarly, the points where the black brightness in the direction of an azimuth angle of 45° and a polar angle of 60° is half of that of a liquid crystal display device that does not use an optical anisotropic component are represented by black circle marks and black triangle marks, and the points where the black brightness is 1 / 5 of that of a liquid crystal display device that does not use an optical anisotropic component are represented by white circle marks and white triangle marks.

[0190] and Figure 13 The same is true for Figure 15 In the graph, the boundary of the region where the black brightness is 1 / 2 can be approximated by a straight line compared to the case where no optical anisotropic element is used. The straight line in the graph is expressed by the following equations (8) and (9):

[0191] Rt 550 =0.69(Ct 550 )+70...(8)

[0192] Rt 550 =1.35(Ct550 )+200...(9).

[0193] Therefore, in the liquid crystal panel 102, the green transmission region 22G of the color filter 22 has a retardation Ct in the thickness direction at a wavelength of 550 nm. 550 The thickness direction retardation Rt of the optical anisotropic element 50 at a wavelength of 550 nm is 550 When the following formula (8a) is satisfied, the black brightness is reduced to 1 / 2 or less compared to the case where no optical anisotropic element is used.

[0194] 0.69(Ct 550 )+70≤Rt 550 ≤1.35(Ct 550 )+200...(8a).

[0195] The points indicated by the white triangles can be drawn with a straight line parallel to the above formula (8): Rt 550 =0.69(Ct 550 )+98 approximation. The points indicated by the white circles can be expressed by a straight line parallel to the above formula (9): Rt 550 =1.35(Ct 550 )+180 approximation. Therefore, in Ct 550 With Rt 550 When the following formula (8b) is satisfied, the black brightness is 1 / 5 or less compared to the case where no optically anisotropic element is used.

[0196] 0.69(Ct 550 )+98≤Rt 550 ≤1.35(Ct 550 )+171...(8b).

[0197] According to the above results, it can be considered that Figure 3 In the E-mode liquid crystal panel 102 shown, at Ct 550 With Rt 550 When the following formula (8c) is satisfied, the influence of the birefringence of the color filter can be eliminated, and a display with reduced black brightness when viewed from an oblique direction can be achieved.

[0198] 0.69(Ct 550 )+C8≤Rt 550 ≤1.35(Ct 550 )+C9...(8c).

[0199] To reduce the black level in the oblique direction to less than half the value when the optical anisotropic element is not used, C8 = 70 nm and C9 = 200 nm can be used, as in equation (8a). Based on the same idea, to reduce the black level in the oblique direction to less than one-fifth the value when the optical anisotropic element is not used, C3 = 98 and C4 = 171 nm can be used, as in equation (8b). To further reduce the black level in the oblique direction, C8 can be set larger and C9 can be set smaller.

[0200] C8 in formula (8c) can be any number greater than 70. C8 can be 78 nm, 88 nm, 98 nm, 108 nm, 113 nm, 118 nm, 123 nm, or 128 nm. Similarly, C9 in formula (8c) can be any number less than 200. C9 can be 200 nm, 190 nm, 180 nm, 173 nm, 168 nm, 163 nm, 158 nm, 153 nm, or 148 nm.

[0201] like Figure 15 As shown, the thickness direction retardation Ct of the color filter 550 The larger the Rt value of the optically anisotropic element, the lower the black brightness when viewed from an oblique direction. 550 The larger the optimal value of Figure 9 The principle of optical compensation shown in B is understood.

[0202] exist Figure 3 In the E-mode liquid crystal panel 102 shown, in order to reduce the black brightness when viewed from an oblique direction, the thickness direction retardation Ct of the color filter is adjusted. 550 , and set the Rt of the optically anisotropic component in a manner that satisfies the above formula (8c) 550 , and the Rt of the optically anisotropic element is set so as to satisfy the above formula (6c) or (7c) 650 That's it.

[0203] As described above for the example of the O-mode liquid crystal panel, if the wavelength dispersion Rt of the optically anisotropic element is considered, 650 / Rt 550 , then in Ct 650 When the Rt is 10nm or more, 550 Satisfies formula (8c), and Rt 650 There are few cases where formula (7c) is satisfied. Therefore, it is preferable to make Rt 550 Satisfies the above formula (8c), and Rt 650 The retardation of the optically anisotropic element 60 is set so as to satisfy the above-mentioned formula (6c).

[0204] The front retardation Re of the optically anisotropic component 60550 and Re 650 To make Rt 550 and Rt 650 The front retardation Re of the optical anisotropic element 60 at a wavelength of 650 nm may be set so as to fall within the above range. 650 Preferably Rt 650 Therefore, Re 650 It is preferred to satisfy the following formula (6d) or (7d):

[0205] Re 650 ≥0.74(Ct 650 )+C 16 ...(6d)

[0206] Re 650 ≤-0.88(Ct 650 )+C 17 ...(7d).

[0207] C 16 is twice that of C6. Specifically, C 16 Above 232nm. 16 It can be 232nm, 236nm, 242nm, 248nm, 252nm, 256nm, 260nm, 264nm, 268nm, 272nm, 276nm, or 280nm. 17 is twice that of C7. Specifically, C 17 Below 240nm. 12 It can be 240nm, 232nm, 224nm, 216nm, 210nm, 204nm, 200nm, 196nm, 192nm, 188nm, 184nm, or 180nm. If the wavelength dispersion of the retardation of the optical anisotropic element is taken into account, the Re of the optical anisotropic element 60 is 650 It is preferable to satisfy the above formula (6d).

[0208] The front retardation Re of the optically anisotropic component 60 at a wavelength of 550 nm is 550 Preferably Rt 550 Therefore, Re 550 Preferably, the following formula (8d) is satisfied:

[0209] 1.38(Ct 550 )+C 18 ≤Re 550 ≤2.70(Ct 550 )+C 19 ...(8d).

[0210] C 18 is twice that of C8. Specifically, C18 More than 140nm. 18 It can be 155nm, 175nm, 185nm, 215nm, 225nm, 235nm, 245nm, or 255nm. 19 is twice that of C9. Specifically, C 19 Below 400nm. 19 It may be 400 nm, 380 nm, 360 nm, 345 nm, 335 nm, 325 nm, 315 nm, 305 nm, or 295 nm.

[0211] [Arrangement of Optical Components]

[0212] As described above, the liquid crystal panel 101 of the first embodiment is configured such that the optically anisotropic element 50 disposed on the visual confirmation side of the liquid crystal cell 20 corresponds to the retardation Ct in the thickness direction of the color filter 22. 550 and Ct 650 The liquid crystal panel 102 of the second embodiment is optically designed so that the optical anisotropic element 60 disposed on the light source side of the liquid crystal cell 20 corresponds to Ct 550 and Ct 650 Optical design is performed in a way that has specific optical characteristics.

[0213] The liquid crystal panel 101 of the first embodiment may also include an optically isotropic film as a polarizer protective film between the visual confirmation side polarizer 30 and the optically anisotropic element 50, or between the light source side polarizer 40 and the liquid crystal cell 20. The liquid crystal panel 102 of the second embodiment may also include an optically isotropic film as a polarizer protective film between the visual confirmation side polarizer 30 and the liquid crystal cell 20, or between the light source side polarizer 40 and the optically anisotropic element 60. Providing a polarizer protective film on the surface of the polarizer can improve the durability of the polarizer.

[0214] An optically isotropic film used as a polarizer protective film is a film that substantially does not change the polarization state of light transmitted in either the normal or oblique direction. Specifically, the optically isotropic film preferably has a front retardation Re of 10 nm or less, and a thickness retardation Rt of 20 nm or less. The front retardation of the optically isotropic film is more preferably 5 nm or less. The thickness retardation of the optically isotropic film is more preferably 10 nm or less, and even more preferably 5 nm or less.

[0215] The liquid crystal panel may also include optical layers or other components other than those described above. For example, it is preferred that a polarizer protective film be provided on the outer surface of the polarizers 30 and 40 (the surface not facing the liquid crystal unit 20). The polarizer protective film provided on the outer surface of the polarizer may be optically isotropic or optically anisotropic. On the other hand, the polarizer protective film provided on the surface of the liquid crystal unit 20 side of the polarizer 30 on the visual confirmation side and the polarizer protective film provided on the liquid crystal unit 20 side of the polarizer 40 on the light source side are required to be optically isotropic as described above.

[0216] The liquid crystal panel 101 of the first embodiment preferably includes no optically anisotropic component other than the optically anisotropic component 50 between the visual confirmation-side polarizer and the liquid crystal cell 20, and preferably includes no optically anisotropic component between the light source-side polarizer 40 and the liquid crystal cell 20. The liquid crystal panel 102 of the second embodiment preferably includes no optically anisotropic component other than the optically anisotropic component 60 between the light source-side polarizer and the liquid crystal cell 20, and preferably includes no optically anisotropic component between the visual confirmation-side polarizer 30 and the liquid crystal cell 20.

[0217] The liquid crystal panel is formed by stacking the liquid crystal unit and the above-mentioned optical components. During its formation process, each component can be stacked on the liquid crystal unit in sequence, or a structure in which several components are stacked in advance can be used. The stacking order of these optical components is not particularly limited. The polarizer and the optically anisotropic component can also be stacked to pre-form a stacked polarizing plate, and the stacked polarizing plate can be attached to the liquid crystal unit via an adhesive (not shown). As mentioned above, a polarizer protective film can also be provided on the surface of the polarizer. An optically isotropic film can also be provided between the polarizer and the optically anisotropic component as a polarizer protective film.

[0218] In laminating the components, an adhesive or pressure-sensitive adhesive may be preferably used. As the adhesive or pressure-sensitive adhesive, an adhesive or pressure-sensitive adhesive having a base polymer such as an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyvinyl ether, a vinyl acetate / vinyl chloride polymer, a modified polyolefin, an epoxy polymer, a fluorine polymer, or a rubber polymer may be appropriately selected.

[0219] [Liquid Crystal Display Devices]

[0220] A liquid crystal display device is formed by disposing a light source 110 on the second principal surface side (polarizer 40 side) of the liquid crystal panel. A brightness enhancement film (not shown) may also be provided between the liquid crystal panel and the light source. The brightness enhancement film may also be provided integrally with the light source-side polarizer. For example, a structure may be used in which the brightness enhancement film is adhered to the outer surface (light source-side surface) of the second polarizer via an adhesive layer. In addition, a polarizer protective film may also be provided between the polarizer and the brightness enhancement film.

[0221] Label Description

[0222] 10 Liquid crystal layer

[0223] 11 Initial orientation direction

[0224] 20 liquid crystal cells

[0225] 21 Color filter substrate

[0226] 22 TFT substrate

[0227] 30, 40 polarizer

[0228] 35, 45 absorption axis (direction)

[0229] 50, 60 optical anisotropic components (phase difference plates)

[0230] 53, 63 delayed phase axis (direction)

[0231] 101, 102 LCD panels

[0232] 110 Light Source

[0233] 201, 202 Liquid Crystal Display Devices

Claims

1. A liquid crystal panel comprising: A liquid crystal cell comprising a liquid crystal layer and a color filter, wherein the liquid crystal layer includes liquid crystal molecules that are horizontally aligned in the absence of an electric field, and the color filter is disposed on a first main surface of the liquid crystal layer and has at least a green-transmitting region and a red-transmitting region; a first polarizer, which is disposed on a first main surface of the liquid crystal unit; a second polarizer, disposed on the second main surface of the liquid crystal unit; and an optically anisotropic component, disposed between the first polarizer and the second polarizer, The pre-tilt angle of the liquid crystal cell is less than 1°, The absorption axis direction of the first polarizer is orthogonal to the absorption axis direction of the second polarizer. The slow axis direction of the optical anisotropic component is parallel to the absorption axis direction of the second polarizer. For the optically anisotropic component, the front retardation Re at a wavelength of 650 nm is 650 Thickness direction delay Rt 650 Rt 650 / Re 650 0.4~0.6, For the green transmission region of the color filter, the thickness direction retardation Ct at a wavelength of 550 nm 550 Below 50nm, For the red transmission region of the color filter, the thickness direction retardation Ct at a wavelength of 650 nm is 650 Greater than 0 and less than 50nm, The alignment direction of the liquid crystal molecules in the liquid crystal unit in the no-electric-field state is orthogonal to the absorption axis direction of the second polarizer. The optical anisotropic component is disposed between the liquid crystal unit and the second polarizer. Thickness direction retardation Rt of the optically anisotropic component at a wavelength of 550 nm 550 With the Ct 550 Satisfies the following formula (8a): 0.69(Ct 550 )+70≤Rt 550 ≤1.35(Ct 550 )+200...(8a) wherein Rt 550 and the Ct 550 The unit is nm, The Rt 650 With the Ct 650 Satisfies the following formula (6a) or (7a): Rt 650 ≥0.37(Ct 650 )+116...(6a) <h2 style=";text-align:left;direction:ltr">Rt<h2 style=";text-align:left;direction:ltr"> 650 <h2 style=";text-align:left;direction:ltr"> ≤-0.44(Ct<h2 style=";text-align:left;direction:ltr"> 650 <h2 style=";text-align:left;direction:ltr"> )+120...(7a) wherein Rt 650 and the Ct 650 The unit is nm.

2. The liquid crystal panel according to claim 1, wherein The Rt 550 With the Ct 550 Satisfies the following formula (8b): 0.69(Ct 550 )+98≤Rt 550 ≤1.35(Ct 550 )+171...(8b)。 3. The liquid crystal panel according to claim 1 or 2, wherein: The Rt 650 With the Ct 650 Satisfies the following formula (6b) or (7b): Rt 650 ≥0.37(Ct 650 )+121...(6b) Rt 650 ≤-0.44(Ct 650 )+108...(7b)。 4 . A liquid crystal display device comprising: the liquid crystal panel according to claim 1 ; and a light source arranged on the second main surface side of the liquid crystal panel.

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