The Hong Kong University of Science and Technology

Dic Corporation

Other

The Chinese University of Hong Kong

Nano and Advanced Materials Institute Limited

Zedelef Pty Ltd

Vladimir Grigorievich Chigrinov

Hoi Sing Kwok

Abhishek Kumar Srivastava

Hoi-Sing Kwok

Fan Fan

Wing Chiu Yip

Tao Du

Vladimir Markovich Kozenkov

Martin Schadt

Haruyoshi Takatsu

Isa Nishiyama

Yutaka Nagashima

Sayaka Nose

Hirokazu Takada

Wing-Chiu Yip

Sergiy I Valyukh

Elena Karlovna Prudnikova

Vladimir Kozenkov

Evgenii Pavlovich Pozhidaev

Masanao Hayashi

Yasuhiro Kuwana

Tsz Kin Ho

Hitoshi Kondo

Masayuki Iwakubo

Masanobu Fukuda

Yanqing Lu

Amine Bermak

Valerii Vladimirovich Vashchenko

Francois Ladouceur

Alexander Anatolievich Muravsky

Yeuk Lung Jacob Ho

Man Chun Tseng

Wei Hu

Fei Xu

Anatoli Alexandrovich Murauski

Edward Philip John Parrott

Andrew Wing On Poon

Emma MacPherson

Cuiling Meng

Yue Shi

Alexei D Kiselev

Ying Ma

Hongkyu Park

Chenxiang Zhao

Iryna V Valyukh

Evgeny Pavlovich Pozhidaev

Xiaojin Zhao

Linjie Zhou

Hin Yu Mak

Xiaoqian Wang

Zourab Brodzeli

Leonardo Silvestri

Andrew Mark Michie

Eugene Pozhidaev

Wanlong Zhang

Qi Guo

Hoi Song Kwok

A composite photoalignment layer for aligning liquid crystal molecules includes: a monomeric material; a photoinitiator or a thermal initiator; and an azo dye material. A method for preparing a composite photoalignment layer for aligning liquid crystal molecules includes: mixing, in solution form, a monomeric material, a photoinitiator or a thermal initiator, and an azo dye material; coating the mixed solution onto a substrate to form a thin film; exposing the thin film to polarized light; and, with a thermal initiator, heating the thin film to polymerize the monomeric material and form a solid thin film.

Composite photoalignment layer

A low birefringence ferroelectric liquid crystal (FLC) mixture composed of at least two components shows birefringence in the range 0.05 to 0.14, which is suitable for the modern display and photonic devices. The cell gap can be tuned from 1.5 &#x3bc;m to 4 &#x3bc;m to reduces the fabrication complexity and chromatic distortion by electro-optical modulation. The FLC mixtures can be employed in a wide temperature range. The characteristics of the said FLC mixture can be tuned by tuning the concentration of the constituents of the mixture. The helical pitch of the FLC mixtures can be varied from 100 nm to 10 &#x3bc;m. A smectic tilt angle can be varied between 17&#xb0; to 45&#xb0; and the spontaneous polarization can be tuned over a wide range to meet requirements of different electro-optical modes, and the FLC mixture is applicable for a wide variety of electro-optical effects.

Low birefringence ferroelectric liquid crystal mixtures

A photoaligned quantum rod enhancement film (QREF) includes: a substrate (); a photoalignment layer deposited on the substrate (); and a polymer layer deposited on the photoalignment layer, the polymer layer comprises a plurality of quantum rods, the plurality of quantum rods are configured to emit one or more wavelengths of light in response to pumping light, and are aligned to an alignment axis based on the photoalignment layer.

Photoaligned quantum rod enhancement films

Systems and methods for driving a pixel of a liquid crystal pixel array with a driving circuit are provided. An exemplary method includes: providing a data signal (Dm) to a storage element via the first transistor (T); and providing a ramping voltage signal (V) to a gate of a second transistor (T) of the driving circuit to control the on-off status of the second transistor (T); wherein the ramping voltage signal (V) is based on data stored at the storage element; and wherein a duration of an on-state of the second transistor (T) corresponds to a transmitting state for the pixel.

Driving scheme for ferroelectric liquid crystal displays

A standing helix ferroelectric liquid crystal display cell includes: two transparent substrates (A,B); a ferroelectric liquid crystal layer () comprising ferroelectric liquid crystals in a standing helix configuration, the ferroelectric liquid crystal layer () being disposed between the two transparent substrates (A,B), the ferroelectric liquid crystals having a helix axis perpendicular to the two substrates (A,B) and chiral smectic liquid crystal helix pitch shorter than a wavelength of a polarized light normally impinging at least one of the two transparent substrates (A,B); and inter-digital electrodes (), disposed in plane with the two transparent substrates (A,B), configured to apply an electric field to the ferroelectric liquid crystal layer () that provides a driving voltage below a critical voltage for helix unwinding.

Standing helix ferroelectric liquid crystal display cell

A 2D/3D switchable liquid crystal lens device includes: a polarization-dependent lens array, configured to provide a focusing effect for impinging light having a first plane of polarization of the impinging light and to provide no focusing effect for impinging light have a second plane of polarization orthogonal to the first plane of polarization; a switchable polarization rotating stage, comprising bi-stable liquid crystals, wherein the switchable polarization rotating stage is configured to output light having the first plane of polarization to the polarization-dependent lens array while the bi-stable liquid crystals are in a first state, and to output light having the second plane of polarization to the polarization-dependent lens array while the bi-stable liquid crystals are in a second state; and a driving system, configured to switch the bi-stable liquid crystals of the switchable polarization rotating stage between the first state and the second state.

2D/3D switchable liquid crystal lens unit

An electrically suppressed helix (ESH) ferroelectric liquid crystal (FLC) display cell with fast response includes: a liquid crystal layer, disposed between two transparent substrates, wherein helix pitch of chiral smectic liquid crystals of the liquid crystal layer is less than the thickness of the liquid crystal layer; at least one polarizer; and a voltage source, configured to apply electrical driving voltage pulses to electrodes of the display cell with amplitude greater than a critical voltage for helix unwinding of the chiral smectic liquid crystals.

Field sequential color ferroelectric liquid crystal display cell

A liquid crystal Fresnel lens is provided. The liquid crystal Fresnel lens includes a liquid crystal cell and two polarizers. The liquid crystal cell includes: two transparent substrates having conducting layers disposed thereon with alignment layers, wherein an alignment pattern formed by the alignment layers are configured to provide multiple alignment domains in a Fresnel zones pattern, and wherein an easy axis of adjacent alignment domains are oriented at an angle relative to one another; and a ferroelectric liquid crystal layer disposed between the two transparent substrates, wherein the ferroelectric liquid crystal layer has a planar surface orientation and smectic layers perpendicular to the two transparent substrates. The liquid crystal cell is disposed between the two polarizers.

Switchable liquid crystal fresnel lens

A method of measuring fluctuations in electric fields is disclosed, the method comprising the step of: placing a Liquid Crystal Device in communication with the electric field, the device having disparate orthogonal polarization sensitivity to an external electric field; utilizing an optical probe beam having a known polarization state to interrogate the liquid crystal of the liquid crystal device to produce a response beam; and analyzing the polarization state of the response beam to provide an indicator of the corresponding fluctuations in the electric field.

Optically based voltage sensing device and method

A liquid-crystal photo-alignment layer that is composed of polymer stabilized azo dyes is provided, where a polymer network is introduced in the photo-alignment layer for stabilization. The photo-alignment layer is realized based on a two-step irradiation to first achieve molecule alignment to form the photo-alignment layer and then stabilize this layer. To realize the photo-alignment layer, a pre-determined surface of the substrate is first coated with a film of mixture. The mixture comprises an azo dye and a monomer preferably mixed in an optimal concentration of 0.67 wt/wt. The azo dye and the monomer have light-absorption peaks at different wavelengths such that photo-alignment of the azo-dye molecules and stabilization of the photo-alignment layer by polymerization of the monomer are achievable by two separate exposures of light to the film.

Stabilized photo-alignment layer for liquid crystal

A liquid crystal display (LCD) backlight system includes: a light source, configured to generate light; a patterned polarization grating polarization converter (PPG-PC) assembly, configured to convert the generated light from a first polarization state to a second polarization state. The PPG-PC further includes: a patterned polarization grating (PPG) having a plurality of domains, wherein the plurality of domains of the PPG include at least two different types of domains, and wherein each domain of the PPG is configured to diffract incident light into first and second types of light beams corresponding to a first diffraction order; and a patterned retarder (PR), having a plurality of domains, the plurality of domains of the PR including domains corresponding to areas where the first type of light beams output from the PPG and including domains corresponding to areas where the second type of light beams output from the PPG converge.

Patterned polarization grating polarization converter

Provided is a liquid crystal alignment layer of which a constituent member is a polymer represented by the general formula (I). 

Copolymer, and liquid crystal alignment layer including cured product thereof

A liquid crystal cell structure is provided. The liquid crystal cell structure includes: two polarizers; and a liquid crystal diffractive light modulating cell placed between the two polarizers. The cell includes: two transparent substrates treated by photoalignment; and a ferroelectric liquid crystal layer disposed between the two transparent substrates with current conducting layers, the ferroelectric liquid crystal layer comprising ferroelectric liquid crystals. The two transparent substrates treated by photoalignment are configured to provide multiple alignment domains in the ferroelectric liquid crystals with a planar surface orientation. Adjacent domains of the multiple alignment domains are oriented at an angle with respect to each other.

Fast switchable and high diffraction efficiency grating ferroelectric liquid crystal cell

The present invention provides a patterned polarization converter having multiple domains that can be used to convert input linear polarized light to output light with spatially varying polarization states, including domains that produce linearly polarized light and domains that produce circular polarized light based on the patterning of the domains. A patterned polarization converter having multiple domains may be used in a polarization sensor application capable of detecting the polarization state of input light. The present invention further provides patterned radial and azimuthal polarization converters, which have utility in applications such as optical tweezers. Additionally, patterned polarization converters may be used to fabricate more patterned polarization converters having the same pattern using one-step photoalignment to copy the pattern of an existing patterned polarization converter to an unpatterned photoalignment layer.

Patterned polarization converter

A field sequential color (FSC) ferroelectric liquid crystal (FLC) display cell, part of an FSC display, is provided. The FSC FLC display cell includes: two polarizers; an FLC layer, positioned between the two polarizers, the FLC layer comprising FLCs with helix pitch less than the thickness of the FLC layer; and a voltage source, configured to apply an electrical driving voltage to the FLC layer, the electrical driving voltage applied to the FLC layer having an amplitude greater than a threshold voltage for helix unwinding, and wherein the voltage source is further configured to apply electrical driving voltages to light emitting diodes (LEDs) of the FSC display to illuminate pixels of the FSC display. The pixels are illuminated in an FSC manner. The FLC layer is configured to provide a defect-free layer of FLC under the electrical driving voltage applied to the FLC layer.

Growing community of inventors

Hong Kong, China

Vladimir Grigorievich Chigrinov