National Sun Yat-sen University of Kaohsiung

Brilliant Optronics Co., Ltd.

Li-Min Chang

Tsung-Hsien Lin

Cheng-Chang Li

Kuan-Wu Lin

Heng-Yi Tseng

Hung-Chang Jau

Duan-Yi Guo

Chun-Ta Wang

Yu-Chieh Li

Cheng-Kuan Wu

Yi-Han Tseng

A cholesteric liquid crystal polarizing grating includes two substrates, two alignment layers, and a liquid crystal layer. An interlayer space is formed between the two substrates. The two alignment layers are respectively located on inner surfaces of the two substrates facing the interlayer space. Alignment directions of the alignment layers are periodically arranged. An alignment plane of each alignment layer is divided into a plurality of rows. The alignment directions in a same row are the same, and the alignment directions in adjacent rows rotate relative to each other. The plurality of rows with the alignment directions rotated by 180 degrees defines a grating period. The liquid crystal layer is located in the interlayer space. Liquid crystal molecules adjacent to the two alignment layers are arranged following the alignment direction of each alignment layer to form a polarizing grating with the grating period.

Cholesteric liquid crystal polarizing grating

An intelligent window includes two substrates and a dimming layer. Each substrate is electrically connected to a voltage source. A switchable electric field is formed between the two substrates. The dimming layer is formed by filling a liquid crystal material between the two substrates. The liquid crystal material is formed by mixing a chiral molecule, a dichroic dye, and a salt ion in a nematic liquid crystal. A weight percentage concentration of the chiral molecule in the liquid crystal material is determined according to a limitation formula (I). C is the weight percentage concentration, n is a birefringence index of the liquid crystal material, p is a chiral force of the chiral molecule in micrometer, D is a thickness of the dimming layer in micrometer, mis a constant of multiaxial absorption condition in micrometer, and mis a constant of normally transparent condition.

Intelligent window

A light reflecting device includes two substrates and a liquid crystal layer. The two substrates are parallel to each other and respectively electrically connected to a voltage source to generate an electric field therebetween. Each of the two substrates has an inner surface having a horizontal orientation. The liquid crystal layer is formed by liquid crystal materials filled between the two substrates. The liquid crystal materials include liquid crystal molecules and ions of salt species. The liquid crystal molecules are at least formed by negative liquid crystals and chiral molecules. The liquid crystal layer is respectively switched to a diffuse reflection state and a specular reflection state by applying the electrical field generated by the voltage source in a first frequency and a second frequency. The second frequency is higher than the first frequency.

Light reflecting device and switching method thereof

An electrically controlled polarization rotator is disclosed. The electrically controlled polarization rotator includes two substrates and a liquid crystal layer located between the two substrates. The two substrates have a homogeneous alignment and a homeotropic alignment respectively. A distance between the two substrates is a liquid crystal thickness. A switching electric field which is adjustable is provided between the two substrates. A polarized light is incident on the substrate having the homogeneous alignment. A polarization direction of the polarized light is orthogonal or parallel to an alignment direction of the substrate having the homogeneous alignment. A birefringence of the liquid crystal layer multiplied by the liquid crystal thickness and further divided by a wavelength of the polarized light is greater than 10. The polarization direction of the polarized light is rotated corresponding to an intensity of the switching electric field in the liquid crystal layer.

Electrically controlled polarization rotator

A one-way glass with switching modes includes an absorbing layer located on a weak light side, a reflecting layer located on an intense light side, and a converting layer stacked between the absorbing layer and the reflecting layer. The absorbing layer absorbs first polarized light and allows second polarized light to pass through. The reflecting layer reflects the first polarized light and allows the second polarized light to pass through. Unpolarized light incident from the weak light side or from the intense light side is respectively converted into the polarized light. During the process of gradually adjusting the converting layer from a twisted state to a vertical state, rotated angles of polarization directions of the first polarized light and the second polarized light gradually decrease.

One-way glass with switching modes

A projection type transparent display includes a polarization modulator and a reflective layer. The polarization modulator is stacked in sequence by a linear polarizer, a liquid crystal layer and a phase retarder. The reflective layer is stacked on the phase retarder. A projection light is incident on the linear polarizer to form a linearly polarized light. The liquid crystal layer changes a polarization direction of the linearly polarized light. Two kinds of linearly polarized projection lights with polarization directions orthogonal to each other are respectively formed and pass through the phase retarder to respectively form two kinds of circularly polarized projection lights with opposite rotation directions. A background light is incident on the reflective layer. A circularly polarized background light with the same spiral direction is reflected, and the circularly polarized background light opposite to the spiral direction passes through the reflective layer and is incident on the polarization modulator.

Projection type transparent display

A smart window includes two transparent substrates and a liquid crystal layer. The two transparent substrates are opposite to each other and are electrically connected to a voltage supply. A first pulse voltage or a second pulse voltage is provided between the two transparent substrates by the voltage supply. The liquid crystal layer is located between the two transparent substrates and has a liquid crystal material. The liquid crystal material has a pitch of at most 250 nanometers or at least 500 nanometers. The liquid crystal material includes a nematic liquid crystal, a rotatory molecule, and a photochromic dye mixed with each other. The liquid crystal material changes a transmittance corresponding to a specific light wavelength range when receiving a light. The liquid crystal material is switched between a planar texture and a focal-conic texture respectively according to the first pulse voltage and the second pulse voltage.

Smart window and method for switching the same

A reflective display apparatus includes three liquid crystal modules stacked in sequence for an incident light to enter from top to bottom sequentially. Each liquid crystal module includes a liquid crystal layer disposed between two substrates. A switchable electric field and a vertical alignment force are provided by the two substrates to the liquid crystal layer. The three liquid crystal modules are respectively: a blue light liquid crystal module located at a top layer, a green light liquid crystal module located in a middle layer and having the liquid crystal layer doped with a dichroic dye for absorbing a light within a blue light wavelength range, and a red light liquid crystal module located at a bottom layer and having the liquid crystal layer doped with a dichroic dye for absorbing a light within a green light wavelength range. A method for controlling the reflective display apparatus is also disclosed.

Reflective display and control method thereof

A transmittable lighting device is provided. The transmittable lighting device includes two substrates, a transmittable layer, two polarizers and a light source. The two substrates are respectively electrically connected to a voltage supply. A switchable electric field is provided between the two substrates, and two alignment directions of the two substrates are orthogonal to each other. The transmittable layer is located between the two substrates and has a plurality of liquid crystal molecules. Each of the plurality of liquid crystal molecule is arranged along the alignment direction of the substrate nearby, and the plurality of liquid crystal molecules is arranged in a 90-degree twisted arrangement. The two polarizers are located at two outer surfaces of the two substrates, respectively. Each polarizer has a polarization direction parallel to the alignment direction of the substrate on the same outer surface. The light source emits a lateral light entering the transmittable layer laterally.

Transmittable lighting device

A multi-function light-adjusting glass includes first and second substrates delimiting an intermediate space therebetween, a light-adjusting layer disposed in the intermediate space, and a first polarizing board located at an outer side of the first substrate away from the intermediate space, and a second polarizing board located at an outer side of the second substrate away from the intermediate space. Each substrate includes an electrically conductive film on an inner surface of the substrate facing the intermediate space, and an alignment film disposed between the electrically conductive film and the intermediate space. The two alignment films respectively have two alignment directions orthogonal to each other. The light-adjusting layer includes liquid crystal molecules and salt-in ions. When the two electrically conductive films apply a voltage to the light-adjusting layer, the liquid crystal molecules are in a discontinuous and chaotic arrangement and cause an incident light to scatter in the light-adjusting layer.

Growing community of inventors

Kaohsiung, Taiwan

Li-Min Chang