Abstract:
A wavelength selective reflection display (10) comprises a wavelength selective reflection medium (20) and a backing member (30) having a first, non-reflective optical state, and a second, reflective optical state. Both the wavelength selective reflection medium (20) and the backing member (30) are divided into pixels (40, 50, 60), and the backing member (30) is switchable between its first and second optical states on a pixel-by-pixel basis. The pixels of the backing member (30) are substantially aligned with those of the wavelength selective reflection medium (20).
Abstract:
A cholesteric liquid crystal display apparatus according to the present invention comprises: a first liquid crystal panel including a first cholesteric liquid crystal substance that reflects the light of a first color; a second liquid crystal panel including a second cholesteric liquid crystal substance that reflects the light of a second color; a third liquid crystal panel including a third cholesteric liquid crystal substance that reflects the light of a third color; a light absorption layer which is coupled to the lower portion of the third liquid crystal panel; a first double-sided adhesive buffer layer, which is arranged between the first liquid crystal panel and the second liquid crystal panel, for coupling the second liquid crystal panel to the lower portion of the first liquid crystal panel; and a second double-sided adhesive buffer layer, which is arranged between the second liquid crystal panel and the third liquid crystal panel, for coupling the third liquid crystal panel to the lower portion of the second liquid crystal panel.
Abstract:
A full-color reflective display pixel includes first (24, 72) and second (25, 78) independently addressable electro-optic layers, each layer being independently switchable between a first state in which the layer is configured to absorb at least one color region of visible light and a second state in which the layer is configured to transmit the at least one color region of visible light. A reflective color filter (22, 76) is located between the back surface of the first electro-optic layer (24, 72) and the front surface of the second electro-optic layer (25, 78), the reflective color filter (22, 76) being subdivided into a plurality of sub-pixels in which each sub-pixel is configured to transmit a first color region of visible light and reflect a second color region of visible light. A broadband reflective layer (20, 70) is located behind the back surface of the second electro-optic layer (22, 76).
Abstract:
The present invention is related to a method of method of manufacture of a reflective polarizing film that can improve brightness of a liquid crystal display device remarkably by making a liquid crystal film that can over visible light by using cholesteric liquid crystal layers having different selective light-reflection central wavelengths, attaching a quarter wave (1/4 λ) retardation film on top of the liquid crystal film, and adding prism patterns to the opposite side of the liquid crystal film. The reflective polarizing film of the preset invention is characterized by that two or more cholesteric liquid crystal layers having different selective reflection wavelength regions are laminated in order from a shorter wavelength to a longer wavelength, and brightness of a liquid crystal display device is maximized owing to an integrated film manufactured by attaching a ¼ λ retardation film onto cholesteric liquid crystal layers and forming prism patterns onto the opposite side.
Abstract:
The invention relates to an electro-optical cell (1) comprising a first (2) and a second (3) support member, an electro-optical medium (5) between the support members and an electrode arrangement (11, 12) on the support members such that an electric field can be applied, in the electro-optical medium, perpendicular to the support members, aligned with the support members or at an oblique angle (7) with respect to the support members. The electro-optical cell further comprises layers (14) of material with different dielectric constant between the support members in order to reduce the inhomogeneity of the electric field lines in the electro-optical medium. By having a layer of cholesteric liquid crystals between the support members, the electro-optical cell will function as a colour filter for varying applied fields. By introducing a particle suspension in a medium between the support members, an electro-optical cell is created that can be switched between a transmissive, reflective and partly deflective state.
Abstract:
The method of making an optical body includes coating a mixture that includes a plurality of cholesteric liquid crystal compositions, and a solvent on a substrate. Each cholesteric liquid crystal composition is different. A plurality of layers is formed on the substrate. Each layer includes a majority of one of the cholesteric liquid crystal compositions.
Abstract:
Display apparatuses are shown capable of displaying information in a reflective mode using only ambient light and in a transmissive mode using a light source. In one embodiment, the display apparatus includes a reflecting polarizer disposed between a light modulating layer and an isotropic light cavity. The light cavity reflects incident light with a first degree of depolarization. The reflecting polarizer reflects light with a second degree of depolarization for at least one polarization that is greater than the first degree of depolarization. In another embodiment of the display apparatus, a microstructured film is included above a light cavity and below a light modulating system where the microstructured film includes sawtooth formations having at least a tilted surface. In another embodiment of a dual-mode display device, the display includes a cholesteric reflecting polarizer disposed between a light modulating layer and a light cavity where the light cavity causes a polarization phase shift upon reflectance.
Abstract:
The liquid crystal switchable color filter switches between three color bands and is preferably used for time-sequential color devices, as for example projection devices, direct view displays and video cameras. The color filter employs circularly polarizing selective reflection bands of at least four cholesteric filters (cfb1 cfr2) together with three liquid crystal switches (sw1, sw2, sw3) and related retarder layers. The handedness of the second cholesteric filter (cfg1) is equal to the handedness of the third cholesteric filter (cfg2) and opposite to the handedness of the first and fourth cholesteric filter (cfb2, cfr1), and for the blocking state of a color band the optic axis of the corresponding liquid crystal switch is parallel or perpendicular to the polarization direction. This concept leads to an improved, excellent color saturation and requires less stringent production tolerances than in the prior art. Moreover, it advantageously allows overlapping color transmission bands thus improving the light efficiency.
Abstract:
A colour switch for selectively switching between colour bands for use in projection optics and in direct view optics has fewer and thinner layers than in the prior art, but exhibits equal or better colour purity and light efficiency. The filter has a first filter section (2-8) for selectively blocking green light and including a cholesteric filter (2), a quarter wave plate (4) and a liquid crystal switch (6). The filter has a second filter section (10-22) for selectively blocking blue and/or red light including a stack of retarder elements (10, 14, 16, 20) and liquid crystal switches (12, 18), preferably DHF switches. The parameters of the filter are determined by an optimisation process including minimising a cost function G with respect to the parameters of the second filter section. Polarising element (8) may be positioned in front of the stack, and of a type which does not absorb radiation.