An electrically controlled birefringence liquid crystal display device performs a normally black display. The display device includes a liquid crystal display panel including a liquid crystal layer and a reflective portion to reflect light that is incident through a display surface of the liquid crystal display panel and that passes through the liquid crystal layer, a first polarizing plate on the display surface, and a half-wavelength plate between the liquid crystal display panel and the first polarizing plate. A phase difference Δnd−1 of the liquid crystal layer is less than a half of a phase difference Δnd−2 of the half-wavelength plate. The phase difference Δnd−2 of the half-wavelength plate indicates a positively dispersive wavelength, and a low axis of the half-wavelength plate intersects with an orientation axis of liquid crystal molecules in the liquid crystal layer under no electric field being applied. The liquid crystal layer has a birefringence index Δn indicating a positively dispersive wavelength.

Techniques for changing the presentation of information on a user interface based on presence are described. In an example, a computer system determines, based on an image sensor associated with the system, a first presence of a first user relative to a computing device. The computer system also determines an identifier of the first user. The identifier is associated with operating the computing device. The operating comprises a presentation of the user interface by the computing device. The computer system also determines, based on the image sensor, a second presence of a second person relative to the computing device. The computer system causes an update to the user interface based on the second presence.

The invention relates to a light modulation element comprising a cholesteric liquid crystalline medium sandwiched between two substrates (1), provided with a common electrode structure (2) and a driving electrode structure (3) individually, wherein the substrate with driving and/or common electrode structure is additionally provided with an alignment electrode structure (4) which is separated from the driving and or common electrode structure on the same substrate by a dielectric layer (5), characterized in that it comprises at least one alignment layer (6) directly adjacent to the liquid crystalline medium. The invention is further related to a method of production of said light modulation element and to the use of said light modulation element in various types of optical and electro-optical devices, such as electro-optical displays, liquid crystal displays (LCDs), non-linear optic (NLO) devices, and optical information storage devices.

A pretilt angle of a liquid crystal molecule on the side of an array substrate is formed such that the liquid crystal molecule goes away from the array substrate in a direction to the left when viewed from a position facing a display surface of a liquid crystal panel. The pretilt angle on the side of a counter substrate is formed such that the liquid crystal molecule goes away from the counter substrate in a direction to the right when viewed from a position facing the display surface. The directions to the left and the right define a direction X corresponding to a horizontal direction of the liquid crystal panel. A direction of a delay phase axis of a biaxial phase difference film is arranged in a position rotated anticlockwise in an angular range from over 0° to 1° from the direction X.

Devices and systems to perform optical alignment by using one or more liquid crystal layers to actively steer a light beam from an optical fiber to an optical waveguide integrated on a chip. An on-chip feedback mechanism can steer the beam between the fiber and a grating based waveguide to minimize the insertion loss of the system.

A head-mounted apparatus include an eyepiece that include a variable dimming assembly and a frame mounting the eyepiece so that a user side of the eyepiece faces a towards a user and a world side of the eyepiece opposite the first side faces away from the user. The dynamic dimming assembly selectively modulates an intensity of light transmitted parallel to an optical axis from the world side to the user side during operation. The dynamic dimming assembly includes a variable birefringence cell having multiple pixels each having an independently variable birefringence, a first linear polarizer arranged on the user side of the variable birefringence cell, the first linear polarizer being configured to transmit light propagating parallel to the optical axis linearly polarized along a pass axis of the first linear polarizer orthogonal to the optical axis, a quarter wave plate arranged between the variable birefringence cell and the first linear polarizer, a fast axis of the quarter wave plate being arranged relative to the pass axis of the first linear polarizer to transform linearly polarized light transmitted by the first linear polarizer into circularly polarized light, and a second linear polarizer on the world side of the variable birefringence cell.

Disclosed are dimming assemblies and display systems for reducing artifacts produced by optically-transmissive displays. A system may include a substrate upon which a plurality of electronic components are disposed. The electronic components may include a plurality of pixels, a plurality of conductors, and a plurality of circuit modules. The plurality of pixels may be arranged in a two-dimensional array, with each pixel having a two-dimensional geometry corresponding to a shape with at least one curved side. The plurality of conductors may be arranged adjacent to the plurality of pixels. The system may also include control circuitry electrically coupled to the plurality of conductors. The control circuitry may be configured to apply electrical signals to the plurality of circuit modules by way of the plurality of conductors.

A display device for switching a viewing angle, can include a display panel, a polarizing plate disposed on the display panel, a light path control cell disposed on the polarizing plate and including a liquid crystal layer, and a light path conversion film disposed on the light path control cell and including a plurality of molecules including a polarization alignment dye. An absorption axis of the polarizing plate can be substantially perpendicular to an absorption axis of the light path conversion film. The display device can switch to a shared mode or a shielding mode depending on whether or not a voltage is applied to the light path control cell, thereby providing the display device that switches its viewing angle effectively.

An optical device for illuminating one or more portions of a spatial light modulator includes a waveguide, an array of tunable retarders, and a polarization selective optical element. A respective tunable retarder is optically coupled to receive light from the waveguide. The respective tunable retarder has a first state, which causes the respective tunable retarder to direct light having a first polarization in a first direction, and a second state, which causes the respective tunable retarder to direct light having a second polarization distinct from the first polarization in the first direction. The polarization selective optical element is located adjacent to the array of tunable retarders so that the light having the first polarization propagates from the polarization selective optical element in a second direction and the light having the second polarization propagates from the polarization selective optical element in a third direction distinct from the second direction.

A continuously electronically controlled linear polarization rotator includes a first liquid crystal cell having a first upper substrate, a first lower substrate, and a transparent liquid crystal layer disposed between the first upper substrate and the first lower substrate; and a second liquid crystal cell having a second upper substrate, a second lower substrate, and a transparent liquid crystal layer disposed between the second upper substrate and second lower substrate. The first and second liquid crystal cells satisfy a condition that dΔn/λ is in a range of 1.2 to 1.8, wherein λ is a wavelength of incident light traveling through the first and second liquid crystal cells, d is thickness of the transparent liquid crystal layer, Δn is birefringence of the transparent liquid crystal layer. The first and second liquid crystal cells are applied by voltage to make a linear polarization angle of outgoing light continuously rotate.