An optical control element according to the invention includes a first polarizer a that is provided on a display screen side of a display apparatus and has a polarization absorption axis 1 set in a horizontal direction, a second polarizer a' that is provided on a viewer side and has a polarization absorption axis 1' set in the horizontal direction or a direction that forms a predetermined angle with the horizontal direction, and at least one retardation film b disposed between the first polarizer a and the second polarizer a'.

The present invention provides an elliptical polarizer with excellent viewing angle characteristics. The elliptical polarizer comprises at least a first polarizer, a first optically anisotropic layer, a second optically anisotropic layer, and a third optically anisotropic layer, laminated in this order, the first optically anisotropic layer satisfying [1] 50≤Re1≤500, [2] 30≤Rth1≤750, and [3] 0.6≤Rth1/Re1≤1.5, the second optically anisotropic layer satisfying [4] 0≤Re2≤20 and [5] -500≤Rth2≤-30, and the third optically anisotropic layer satisfying [6] 100≤Re3≤180, [7] 50≤Rth3≤600, and [8] 0.5≤Rth3/Re3≤3.5, wherein Re indicates the retardation value in the plane of each optically anisotropic layer and Rth indicates the retardation value in the thickness direction of each optically anisotropic layer.

The present invention provides a liquid crystal display device comprising: a first polarizer; a second polarizer; a liquid crystal cell; a first birefringent layer; and a second birefringent layer, the second polarizer having an absorption axis orthogonal to an absorption axis of the first polarizer, the liquid crystal cell being disposed between the first polarizer and the second polarizer, the first birefringent layer being disposed between the first polarizer and the liquid crystal cell, satisfying 0.6 ≤ Nz(550) ≤ 6, and having an in-plane slow axis orthogonal to the absorption axis of the first polarizer, the second birefringent layer being disposed between the liquid crystal cell and the second polarizer, satisfying -5 ≤ Nz(550) ≤ 0.4, and having an in-plane slow axis parallel to the absorption axis of the second polarizer, and at least one of the first and second birefringent layers satisfying |Rxy(450)| ≤ |Rxy(550)| ≤ |Rxy(650)|.

A depolarizing film of the present invention comprises a film containing at least one liquid crystal compound, wherein the liquid crystal compound comprises a liquid crystal compound (1) that satisfies the relation; 0.05≤Δn≤0.5, with the proviso that Δn=ne-no, ne represents an extraordinary-ray refractive index, and no represents an ordinary-ray refractive index, and the film has a haze value of 15% or less and a thickness of 1 µm to 10 µm.

A retardation compensation element (56) is composed of a C-plate (85) and an 0-plate (86). The O-plate (86) is a biaxial birefringent medium made of an obliquely deposited organic material. A fast axis (L6) of the 0-plate (86) is parallel to the orthographic projection of a deposition direction (96) onto the surface of the O-plate (86). Between a liquid crystal display device (51) and a polarization beam splitter (48), the O-plate (86) is arranged such that the fast axis (L6) and a tilt direction (L8) of liquid crystal molecules (75) are parallel to each other, and that the deposition direction (96) and the tilt direction (L8) face the opposite direction with respect to a Z2 axis. The C-plate (86) is disposed together with the O-plate (85) between the liquid crystal display device (51) and the polarization beam splitter (48).

The present invention provides a polarization control system which includes an E-type polarizer and therefore can provide excellent dark state at a wide azimuth and viewing angle. Further, the polarization control system includes a viewing angle control element for controlling a traveling direction of light which has passed through the E-type polarizer and therefore can provide excellent bright state at a wide azimuth and viewing angle. The present invention further provides a display device including such a polarization control system. The polarization control system of the present invention is a polarization control system including a plurality of polarizer, wherein the polarization control system includes an E-type polarizer and a viewing angle control element, and the viewing angle control element controls a traveling direction of light which has passed through the E-type polarizer.

The present invention provides a polarization control system which includes an E-type polarizer and therefore can provide excellent dark state at a wide azimuth and viewing angle. Further, the polarization control system includes a viewing angle control element for controlling a traveling direction of light which has passed through the E-type polarizer and therefore can provide excellent bright state at a wide azimuth and viewing angle. The present invention further provides a display device including such a polarization control system. The polarization control system of the present invention is a polarization control system including a plurality of polarizer, wherein the polarization control system includes an E-type polarizer and a viewing angle control element, and the viewing angle control element controls a traveling direction of light which has passed through the E-type polarizer.

An optical compensation layer-attached polarizing plate of the invention comprises a polarizing plate, an optical compensation layer (1) and another optical compensation layer (2) that are laminated in this order, wherein the optical compensation layer (1) has the relation nx₁>ny₁=nz₁, comprises a resin with a photoelastic coefficient absolute value of at most 2.0x10^-11 m²/N, and has an in-plane retardation (nx₁-ny₁)d₁ in the range of 200 nm to 300 nm, the optical compensation layer (2) has the relation nx₂>ny₂>nz₂, comprises a resin with a photoelastic coefficient absolute value of at most 2.0x10^-11 m²/ N, and has an in-plane retardation (nx₂-ny₂)d₂ in the range of 90 nm to 160 nm, a slow axis of the optical compensation layer (1) makes an angle of 10° to 30° with an absorption axis of the polarizing plate, and a slow axis of the optical compensation layer (2) makes an angle of 75° to 95° with the absorption axis of the polarizing plate. The optical compensation layer-attached polarizing plate can provide viewing angle compensation and broadband circular polarization for a VA mode liquid crystal cell, can form a thin product, and can reduce uneven heat-up.

To provide a retardation film in which the retardation condition is adjusted to achieve a liquid crystal display without coloration over a wide viewing angle range and having a high contrast ratio, and a method of designing the same, as well as a polarizing film and a liquid crystal display using the same. A liquid crystal display comprising a liquid crystal cell and polarizing films in a Cross-Nicol relationship with each other on both sides of the liquid crystal cell; wherein at least one polarizing film includes a retardation film having reverse wavelength dispersion property; and the liquid crystal display further includes a retardation film having a wavelength dispersion property substantially the same as a liquid crystal layer configuring the liquid crystal cell.

A reflective liquid crystal device includes a reflecting electrode (14) provided on the liquid crystal side of a first substrate (10), and a first retardation plate (106), a second retardation plate (116) and a polarizer (105), which are provided on the side of a second substrate (20), which is opposite to the liquid crystal side thereof. The twist angle and Δnd of the liquid crystal are 230 to 260 degrees and 0.70 µm to 0.85 µm, respectively. Δnd of the first retardation plate is 150 ± 50 nm, and Δnd of the second retardation plate is 610 ± 60 nm. The angle formed by the transmission axis or absorption axis of the polarizer and the optical axis of the second retardation plate is 10 to 35 degrees, and the angle formed by the optical axis of the first retardation plate and the optical axis of the second retardation plate is 30 to 60 degrees. As a result, a bright image display having high contrast can be obtained.

A normally white twisted nematic liquid crystal display is disclosed having a pair of retardation films disposed between the liquid crystal layer and an adjacent polarizer, both retardation films being on one side of the liquid crystal layer. Both retardation films, if uniaxial, have retardation values of from about 100 - 200 nm. Optionally, biaxial retarders (n_X > n_Y > n_Z) may be used, such biaxial retarders having retardation values from about Δ_ZX = -100 to -200 nm, and Δ_ZY = -10 to -100 nm. Accordingly, inversion is reduced and contrast rations are improved at large viewing angles.

A reflection liquid crystal display element having only one polarization film. The twist angle of nematic liquid crystal is 45° to 90°. The product of the birefringence of the liquid crystal multiplied by the thickness of the liquid crystal layer is 0.20 to 0.30 µm. The retardation value of the phase difference film on the polarizing film side is 0.23 to 0.28 µm. The retardation value of the phase difference film on the liquid crystal cell side is 0.13 to 0.18 µm. The Z coefficients of the two phase difference films are 0.3 to 1.0. Letting the direction in which the liquid crystal twists toward the lower substrate when viewed from above the upper substrate be positive, and if the angle between the reference line and the direction of the absorption axis of the polarizing film, the angle between the reference line and the direction of the phase retardation axis of the phase difference film on the polarizing film side, and the angle between the reference line and the direction of the phase retardation axis of the phase difference film on the liquid crystal cell side are φ_P, φ_F1, φ₂ respectively, the angle φ_P is 75° to 195°, φ_P-φ_F1 is 105° to 115°, φ_P-φ_F2 is 165° to 175°. Hence, high contrast display is achieved by bright white and achromatic color.

With a liquid crystal display device comprising an STN liquid crystal element (20) comprised of 200° to 260° twist aligned nematic liquid crystal (6) sandwiched between a first substrate (1) thereof, provided with a reflector (7) and first electrodes (3), and a second substrate (2) thereof, provided with second electrodes (4), a retardation film (12), and a polarizing film 11 that are disposed on the outer side of the second substrate (2) of the STN liquid crystal element, black display of low reflectance can be obtained in all wavelength regions, thereby enabling bright display in high contrast to be effected by setting a Δnd value of the STN liquid crystal element 20 indicating a birefringent tendency thereof in a range of 0.7 to 0.8 µm, a retardation value indicating a birefringent tendency of the retardation film (12) in a range of 0.35 to 0.40 µm, and an intersection angle formed by a phase delay axis of the retardation film (12) and an absorption axis or a transmission axis of the polarizing film (11) in a range of 30° to 45°.