A digital neutral density (DND) filter that provides rapid reconfiguration between discrete density states using electro-optic devices such as liquid-crystal cells. Each filter stage may be dedicated to binary switching between a high-transmission state (giving minimal loss) and one or more prescribed densities in a filtering state. The design prescription may “hard-wire” a stage to produce switching between an all-pass filter and a prescribed filter density. Design parameters can be used to assign specific densities to each stage. Multiple stages can be cascaded to provide a plurality of discrete density values. Such DND filters can sacrifice analog tunability in order to optimize uniformity in color and transmission over a wide range of incidence angles.

The present application relates to a retardation film including a composition or a cured product thereof, the composition comprising: an acrylate-based resin having a glass transition temperature (Tg) of 120° C.; or more; a retardation adjusting agent comprising a styrene monomer; and a triazine-based birefringence adjusting agent, in which the triazine-based birefringence adjusting agent is included in an amount of more than 5 parts by weight and 15 parts by weight or less, based on 100 parts by weight of the acrylate-based resin; a polarizing plate comprising the same, and a liquid crystal display device comprising the same.

An improvement in contrast is achieved by suitably offsetting a phase difference produced by oblique light in a liquid-crystal panel.

An optical compensation apparatus includes a negative C-plate and two O-plates, an amount of a composite phase difference between the two O-plates and the negative C-plate in a tilt-direction cross section is substantially same as an amount of a phase difference produced by light having each of incident angles in a predetermined incident-angle range in the liquid-crystal panel, and a sign of the composite phase difference is opposite to a sign of the phase difference, the tilt-direction cross section being a cross section parallel to a tilt direction of the liquid crystal in a vertical-alignment-type liquid-crystal panel.

A liquid crystal display panel of the present invention includes, sequentially from the viewer side: a first linearly polarizing plate; a first /4-wavelength layer; a first substrate including a color filter, a black matrix, and a second /4-wavelength layer; a liquid crystal layer; a second substrate; and a second linearly polarizing plate, the liquid crystal display panel further including a sealing material disposed so as to surround the liquid crystal layer in a plan view, wherein the second /4-wavelength layer is disposed closer to the liquid crystal layer than the color filter and the black matrix are and such that an outer edge of the second /4-wavelength layer lies inside an arrangement region of the sealing material, and the first /4-wavelength layer and the second /4-wavelength layer are disposed such that their slow axes are perpendicular to each other.

This application relates to a liquid crystal display which comprises: an upper polarizer; a lower polarizer; and a liquid crystal panel provided between the upper polarizer and the lower polarizer, in which the upper polarizer and the lower polarizer are provided so that absorption axes of the upper and lower polarizers are parallel to each other, a first half wave plate, a positive C plate, and a second half wave plate are sequentially comprised between the upper polarizer and the liquid crystal panel, and the liquid crystal panel is a vertical alignment liquid crystal mode.

A switchable privacy display apparatus comprises a polarised output spatial light modulator, and an additional polariser. A reflective polariser, switchable liquid crystal polar control retarder, passive polar control retarders and air gap are arranged between the display output polariser and additional polariser. The passive retarders are arranged to provide no phase difference to polarised light from the spatial light modulator for on-axis light; and simultaneously provide a non-zero phase difference for polarised light in off-axis directions. The polar control retarders are further arranged to achieve low reflectivity for light propagating through the air gap. A switchable privacy display that can be conveniently assembled at low cost can be provided with high contrast images for display users while maintaining high visual security level for off-axis snoopers.

An optical waveplate is provided. The optical waveplate includes a positive-C film including a first liquid crystal (LC) layer. Tilt angles of LC molecules vary along a thickness direction of the first LC layer. The optical wave also includes an LC cell disposed at a first side of the positive-C film and including a second LC layer aligned in an optically compensated bend (OCB) mode. The optical waveplate also includes a positive-A film disposed at a second side of the positive-C film. The optical waveplate further includes a negative biaxial retardation film disposed between the positive-A film and the positive-C film. The LC cell is switchable between at least two predetermined states.

A liquid crystal display device includes an array substrate on which a plurality of thin film transistors are arranged, a counter substrate arranged to face the array substrate, a liquid crystal layer interposed between the array substrate and the counter substrate, and a liquid crystal panel of a transverse field system in which liquid crystal is driven by an electric field generated in a direction parallel to the array substrate and the counter substrate. The liquid crystal panel includes a first alignment film provided on the array substrate side, and a second alignment film provided on the counter substrate side. The first and second alignment films have photo-alignment properties. At least one of the first and second alignment films has a surface on which weak rubbing treatment is performed, of which pushing amount of the rubbing roller in the rubbing treatment is in the range of 0.01 to 0.30 mm.

An optical waveplate is provided. The optical waveplate includes a first birefringent film including optically anisotropic molecules arranged to form a first twist structure. The optical waveplate also includes a second birefringent film including optically anisotropic molecules arranged to form a second twist structure, the second birefringent film being stacked with the first birefringent film. The optically anisotropic molecules at a first portion of the first birefringent film adjacent an interface between the first birefringent film and the second birefringent film are configured with a first azimuthal angle. The optically anisotropic molecules at a second portion of the second birefringent film adjacent the interface are configured with a second azimuthal angle. The first azimuthal angle is substantially the same as the second azimuthal angle.

An optical waveplate is provided. The optical waveplate includes a positive-C film including a first liquid crystal (LC) layer. Tilt angles of LC molecules vary along a thickness direction of the first LC layer. The optical wave also includes an LC cell disposed at a first side of the positive-C film and including a second LC layer aligned in an optically compensated bend (OCB) mode. The optical waveplate also includes a positive-A film disposed at a second side of the positive-C film. The optical waveplate further includes a negative biaxial retardation film disposed between the positive-A film and the positive-C film. The LC cell is switchable between at least two predetermined states.