A light guide element includes: a light guide plate; and a diffraction element that is disposed on a main surface of the light guide plate, in which the diffraction element includes a liquid crystal layer that is formed of a liquid crystal composition including a liquid crystal compound and has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, a refractive index of the light guide plate is 1.70 or higher, and in a case where the refractive index of the light guide plate is represented by n.sub.d and a refractive index of the liquid crystal layer is represented by n.sub.k, n.sub.k−n.sub.d≥0 is satisfied.

A method for producing a cholesteric liquid crystal layer is a method that can produce a cholesteric liquid crystal layer whose reflection surface is not parallel to a substrate surface by a simple method. The method includes: a step 1 of forming a composition layer satisfying a condition 1, a condition 2, or a condition 3 on a substrate, using a liquid crystal composition including a liquid crystal compound; and a step 2 of subjecting the composition layer to a treatment for cholesterically aligning the liquid crystal compound in the composition layer to form a cholesteric liquid crystal layer.

Active optical filter adapted for a spectacle lens, the active optical filter being configured so as to filter light radiations over at least one predetermined range of wavelengths, wherein the full width at half maximum of the filtering function of the optical filter is smaller than or equal to 100 nm.

A liquid crystal device comprising a first substrate, a second substrate and a liquid crystal layer sandwiched between said first and second substrate; wherein an electrode structure is deposited on at least one of said first and second substrates, said electrode structure comprising: a first electrode layer; an insulating layer; a second electrode layer; wherein said electrode structure comprises holes extending through said second electrode layer and said insulating layer, such that said insulating layer is discontinuous, and wherein each hole is adapted to generate local fringe fields with azimuthal degenerate direction.

Example display devices include a waveguide configured to propagate visible light under total internal reflection in a direction parallel to a major surface of the waveguide. The waveguide has formed thereon an outcoupling element configured to outcouple a portion of the visible light in a direction normal to the major surface of the waveguide. The example display devices additionally include a polarization-selective notch reflector disposed on a first side of the waveguide and configured to reflect visible light having a first polarization while transmitting the portion of the visible light having a second polarization. The example display devices further include a polarization-independent notch reflector disposed on a second side of the waveguide and configured to reflect visible light having the first polarization and the second polarization, where the polarization-independent notch reflector is configured to convert a polarization of visible light reflecting therefrom.

A liquid crystal writing device is erased by a stylus. The liquid crystal writing device includes a liquid crystal layer including cholesteric liquid crystal material. A user applies pressure to a flexible substrate that changes reflectivity of the cholesteric liquid crystal material to form images on the liquid crystal writing device. The liquid crystal layer is disposed between electrically conductive layers. Writing device terminals are electrically conductive and connected to the electrically conductive layers. The stylus includes stylus electronics adapted to apply an erase voltage or erase voltage waveform to the writing device terminals.

A cholesteric liquid crystal display device includes a solar cell, a first substrate, a shielding layer, a first electrode layer, a cholesteric liquid crystal layer, a second electrode layer and a second substrate stacked sequentially from bottom to top. The solar cell includes a metal wiring pattern layer. The shielding layer corresponds to the upper side of the metal wiring pattern layer, and is used to reduce the reflection of light from the metal circuit pattern layer. In this way, the cholesteric liquid crystal display device replaces the traditional black absorbing layer with the black material of the solar cell, which can not only absorb light, but also display the image with self-sustaining power. The cholesteric liquid crystal display device shields the arrangement of the metal wiring pattern layer through the shielding layer, which can ensure the image quality of the display panel.

A liquid crystal writing device is erased by a stylus. The liquid crystal writing device includes a liquid crystal layer including cholesteric liquid crystal material. A user applies pressure to a flexible substrate that changes reflectivity of the cholesteric liquid crystal material to form images on the liquid crystal writing device. The liquid crystal layer is disposed between electrically conductive layers. Writing device terminals are electrically conductive and connected to the electrically conductive layers. The stylus includes stylus electronics adapted to apply an erase voltage or erase voltage waveform to the writing device terminals.

A backlight module including a circuit substrate, a plurality of light-emitting devices, a first cholesteric liquid-crystal layer, and a second cholesteric liquid-crystal layer is provided. The light-emitting devices are disposed on the circuit substrate and electrically connected to the circuit substrate. The first cholesteric liquid-crystal layer is disposed on the light-emitting devices and overlapped with a light-emitting surface of each of the light-emitting devices. The second cholesteric liquid-crystal layer is disposed on the first cholesteric liquid-crystal layer and overlapped with the first cholesteric liquid-crystal layer. The first cholesteric liquid-crystal layer and the second cholesteric liquid-crystal layer respectively have a first chiral direction and a second chiral direction. A display apparatus adopting the backlight module is also provided.

A writing device includes a liquid crystal layer including cholesteric liquid crystal material. There are electrically conductive layers between which the liquid crystal layer is disposed. There is a front writing surface layer that is transparent and a back support layer between which the electrically conductive layers and the liquid crystal layer are disposed. The cholesteric liquid crystal material changes in texture by application of pressure to the front writing surface layer to create an image. A seal confines the cholesteric liquid crystal material between the front writing surface layer and the back support layer. The electrically conductive layers are adapted to enable a voltage waveform to be applied thereto that erases the image. In one aspect, the resilience to bending the writing device is defined by enabling the writing device to be bent to a radius of curvature of 100.0 millimeters for 10 repetitions of the bending and after each of the repetitions of the bending the voltage waveform completely erases the image. In another aspect, the back support layer comprises a first sublayer formed of a flexible polymeric material adjacent to the back electrically conductive layer, a second sublayer comprising a backer that is flexible and thicker and of a different material than the first sublayer and a bonding layer located between the first sublayer and the second sublayer. In yet another aspect, the seal includes an elastomeric material and wherein the front writing surface layer has a thickness in a range of 0.5 to 4.5 mils and the back support layer has a thickness in a range of 0.6 to 34.5 mils.