834 results about "Liquid Crystalline Materials" patented technology

A liquid crystal device including a front electrode layer, rear electrode layer, a liquid crystal material located between the front electrode layer and the rear electrode layer. A polarizer is located between the liquid crystal material and the front electrode layer and changing an electrical potential between the rear electrode layer and the front electrode layer modifies portions of the liquid crystal material to change the polarization of the light incident thereon. A plurality of light sensitive elements are located together with the rear electrode layer and a processor determines the position of at least one of the plurality of light sensitive elements that has been inhibited from sensing ambient light.

eSheets create a multitude of different products. One embodiment is a projected capacitive touch sensor created by embedding orthogonal arrays of coated metal wires into the surface of a polymer sheet or onto the back of a projector screen. To increase the capacitance of the electrodes or pixels in the sensor, transparent conductive electrodes can be electrically connected to the wire electrodes. Another embodiment is a reflective, energy-efficient display formed by sandwiching a reflective cholesteric liquid crystal (Ch. LC) material between electroded sheet substrates. The eSheet Ch. LCD is pressure sensitive and can be written on using a finger or stylus. The eSheet Ch. LCD can then be read using the wire electrodes in the eSheet LCD.

A method of operating a liquid crystal cell includes DC-balancing by displaying an inverse image with electric fields of increased magnitude relative to the image producing electric fields. While the inverse image is displayed the image is prevented from being visible by either turning off the light source or re-directing or blocking the light from reaching the viewing area. The image producing electric fields and the inverse image producing electric fields are such that the cumulative time integral of the electric fields that are present in one direction across the liquid crystal material is substantially equal to the cumulative time integral of the electric fields that are present in the opposite direction during the given period of time during the operation of liquid crystal cell. The time duration of the inverse image portion is shorter than the time duration of the image portion by an amount proportional to the increased magnitude of the additional electric fields. Because of the shorter time period when no image is visible, the system brightness is increased.

Embodiments of the present invention relate to a cholesteric liquid crystalline material which may be usable in an electro-active element for providing fail safe operation, polarization insensitivity, low electrical power consumption requirements, and a small number of electrical connections. The cholesteric liquid crystalline material may be usable in an electro-active element for providing a diffractive efficiency or focusing efficiency above 90% in an activated state of the electro-active element and a diffractive efficiency or focusing efficiency below 10% in a deactivated state of the electro-active element.

A light sensitive display that includes a front electrode layer, a rear electrode layer, a liquid crystal material. The display includes a light sensitive element with at least two terminals and a transistor with at least three terminals. A readout system determining when light sensed by the light sensitive element is less than the ambient light and determining the region of the display that the light is less than the ambient light.

A particle is disclosed that comprises a first volume of hydrophobe-rich material with tunable dissolution and solubilization characteristics and a distinct second volume of nanostructured nonlamellar liquid crystalline material, said second volume containing said first domain and being capable of being in equilibrium with said first volume. Preferably, the nanostructured nonlamellar liquid crystalline material is capable of being in equilibrium with a polar solvent or a water-immiscible solvent or both.

Various non-limiting embodiments disclosed herein provide methods of making alignment facilities for optical dyes connected to an optical substrate. For example, one non-limiting embodiment provides a method of making an alignment facility for an optical dye connected to at least a portion of an optical substrate, such as an ophthalmic substrate, by forming at least one at least partial coating comprising an at least partially ordered liquid crystal material on at least a portion of the substrate. Other non-limiting embodiments related to optical elements, such as but not limited to ophthalmic elements, comprising an alignment facility for an optical dye. Still other non-limiting embodiments provide alignment facilities for optical dyes comprising coatings or sheets of an at least partially ordered liquid crystal material.

Transmission and reflection type holograms may be formed utilizing a novel polymer-dispersed liquid crystal (PDLC) material and its unique switching characteristics to form optical elements. Applications for these switchable holograms include communications switches and switchable transmission, and reflection red, green, and blue lenses. The PDLC material of the present invention offers all of the features of holographic photopolymers with the added advantage that the hologram can be switched on and off with the application of an electric field. The material is a mixture of a polymerizable monomer and liquid crystal, along with other ingredients, including a photoinitiator dye. Upon irradiation, the liquid crystal separates as a distinct phase of nanometer-size droplets aligned in periodic channels forming the hologram. The material is called a holographic polymer-dispersed liquid crystal (H-PDLC).

The objective of the present invention is providing a method for fabricating high quality diffractive waveplates and their arrays that exhibit high diffraction efficiency over large area, the method being capable of inexpensive large volume production. The method uses a polarization converter for converting the polarization of generally non-monochromatic and partially coherent input light beam into a pattern of periodic spatial modulation at the output of said polarization converter. A substrate carrying a photoalignment layer is exposed to said polarization modulation pattern and is coated subsequently with a liquid crystalline material. The high quality diffractive waveplates of the present invention are obtained when the exposure time of said photoalignment layer exceeds by generally an order of magnitude the time period that would be sufficient for producing homogeneous orientation of liquid crystalline materials brought in contact with said photoalignment layer. Compared to holographic techniques, the method is robust with respect to mechanical noises, ambient conditions, and allows inexpensive production via printing while also allowing to double the spatial frequency of optical axis modulation of diffractive waveplates.

A liquid crystal display (LCD) exhibiting enhanced optical viewing performance. In a preferred embodiment, the LCD comprises a liquid crystal display panel, the liquid crystal display panel comprising a pair of transparent substrates, liquid crystal material sandwiched between the transparent substrates and transparent electrodes positioned between the liquid crystal material and the transparent substrates. The LCD also comprises a rear polarizer assembly comprising a compensation film, a polarizer mounted on the rear surface of the compensation film, and a first index-matched, pressure sensitive adhesive (PSA) mounted on the front surface of the compensation film, the PSA being adhered to the rear surface of the LCD panel. The LCD also comprises a front polarizer assembly, the front polarizer assembly comprising a front polarizer, a compensation film mounted on the rear surface of the front polarizer and an index-matched PSA mounted on the front surface of the front polarizer. The front polarizer is crossed relative to the rear polarizer. The front polarizer assembly may be adhered to the front of the LCD panel with a second index-matched, optical bonding material or may be spaced therefrom by an air gap. A transparent cover is mounted on the second index-matched PSA. The transparent cover is preferably a plastic plate. The plastic plate may be textured to reduce glare or may have an anti-reflection coating or an anti-reflection film applied to the front surface thereof. Instead of a plastic plate, the transparent cover may be a glass plate or a touch panel.

This invention relates to a number of components, devices and networks involving integrated optics and / or half coupler technology, all of which involve the use of electronically switchable Bragg grating devices and device geometries realized using holographic polymer / dispersed liquid crystal materials. Most of the components and devices are particularly adapted for use in wavelength division multiplexing (WDM) systems and in particular for use in switchable add / drop filtering (SADF) and wavelength selective crossconnect. Attenuators, outcouplers and a variety of other devices are also provided.

A method for preparing electro-optical polymer-liquid crystal photonic crystals, comprising: disposing between at least two optically transparent electrode plates, a polymer-dispersed liquid crystal material that comprises, before exposure:(a) a polymerizable monomer comprising at least one acrylate;(b) a liquid crystal;(c) a chain-extending monomer;(d) a coinitiator;(e) a photoinitiator; and(f) a long chain aliphatic acid;and exposing this polymer-dispersed liquid crystal material to light in an interference pattern.

One aspect of the invention is a bistable cholesteric writing tablet on which an image is formed by applying a suitable voltage while applying writing pressure, which results in a focal conic texture in a reduced gap region of the active layer while not changing the texture of the unreduced gap region of the active layer (e.g., a written portion being in a focal conic texture on a background in the planar texture). Another aspect of the invention is a multi-color stacked writing tablet in which a color of an image is selected by applying a suitable voltage while applying writing pressure using an instrument such as an untethered stylus on the surface of the tablet. The writing tablet includes at least two or three stacked layers of bistable cholesteric liquid crystal material. Selected colors can be additively mixed to achieve intermediate colors as desired. The image can be erased and new images written on the tablet. Gray scale achieved by varying the applied voltage during writing or the writing pressure in some cases, enables the writing tablet to produce a broad range of colors. The writing device is suitable for many applications such as a toy, sketch pad, erasable signage, tags or a large writing board without the mess of chalk or ink.

Transmission and reflection type holograms may be formed utilizing a novel polymer-dispersed liquid crystal (PDLC) material and its unique switching characteristics to form optical elements. Applications for these switchable holograms include communications switches and switchable transmission, and reflection red, green, and blue lenses. The PDLC material offers all of the features of holographic photopolymers with the added advantage that the hologram can be switched on and off with the application of an electric field. The material is a mixture of a polymerizable monomer and liquid crystal, along with other ingredients, including a photoinitiator dye. Upon irradiation, the liquid crystal separates as a distinct phase of nanometer-size droplets aligned in periodic channels forming the hologram. The material is called a holographic polymer-dispersed liquid crystal (H-PDLC).

Reflective color filters using layers of cholesteric liquid crystals with two different center wavelengths and bandwidths per layer are stacked in two layers to provide colored light for displays. With a two layer stack circularly polarized light of one handedness can be provided. With a four layer stack unpolarized colored light can be provided. With a broadband polarizing filter overlapping other filters in the stack a black matrix can be provided by reflecting all colors and transmitting no light in the overlapping areas. When broadband reflective cholesteric liquid crystals are used two primary colors can be reflected in the same pixel of a display making reflective layers with two reflective portions per layer possible. Color displays having three linear sub-pixels with three primary colors or with four sub-pixels of white, blue, green, and red in a pixel with two colors in a top row and two colors on a bottom row can are made with two colors per layer in two layer stacks. The pixels in the display are arranged such that multiple adjacent sub-pixels in a layer, or row in a layer, with the same color makes the color filters easier to manufacture. Displays using these reflective color filters may have a reflective polarizer for viewing the display at wide angles without color distortion. A method of producing cholesteric liquid crystal color filters by polymerizing different portions of cholesteric liquid crystal mixtures at different temperatures and radiations to obtain different central wavelengths and bandwidths of reflection. By masking parts of a layer several portions with different colors are polymerized in a single layer. Further, with radiation which is attenuated in the cholesteric liquid crystal material stacks of different portions reflecting different colors in the same layer are made. Further the cholesteric liquid crystals are polymerized to have other optical properties in the stack such as quarter wave plates and broad band polarizers such that entire optical devices can be made in one layer of cholesteric liquid crystal material making the devices smaller, lighter, more robust, reliable, and easier to make by eliminating gluing and alignment problems. With overlapping reflective cholesteric liquid crystal which together reflect all light stacks with automatic black matrixes built into the layer are made saving light from being blocked by conventional black matrix light absorbing layers in display devices.

A liquid crystal element includes a pair of plates at least one of which is transparent, and a composite layer retained between the plates and including a liquid crystal material in a transparent resin substrate. In the liquid crystal element, (A) the liquid crystal material in the composite layer contains aromatic rings and exhibits a cholesteric phase, the substrate in the composite layer is made of resin and contains aromatic rings, and a ratio of the number of aromatic rings to that of carbon atoms in the main chain of monomer is in a range from 1:5 to 1:12; (B) the liquid crystal material in the composite layer is formed of a mixture of a liquid crystal material exhibiting a nematic phase and a liquid crystal material exhibiting a smectic phase, and exhibits a cholesteric phase as a whole; or (C) the liquid crystal material in the composite layer is formed of a mixture of a tolane liquid crystal material, a biphenyl liquid crystal material and a chiral ingredient, and exhibits a cholesteric phase as a whole.

This invention relates to a number of components, devices and networks involving integrated optics and / or half coupler technology, all of which involve the use of electronically switchable Bragg grating devices and device geometries realized using holographic polymer / dispersed liquid crystal materials. Most of the components and devices are particularly adapted for use in wavelength division multiplexing (WDM) systems and in particular for use in switchable add / drop filtering (SADF) and wavelength selective crossconnect. Attenuators, outcouplers and a variety of other devices are also provided.

A backlight display has improved display characteristics. An image is displayed on the display which includes a liquid crystal material with a light valve. The display receives an image signal and modifies the light for a backlight array and a liquid crystal layer.

A light-scattering film 10 is obtained by subjecting a birefringent material in a resin layer to orientation treatment, in which at least one component selected from a transparent resin 6 and a scattering material 7 is the birefringent material (e.g., a birefringent resin, a liquid crystalline material). According to the light-scattering film, in the case where a linear polarized light in which a vibrating direction and a propagating direction exist in a plane containing a surface-directional axis of the film and a thickness-directional axis of the film is incident at a film surface, the rectilinear transmittance of the incident light shows maximum at an oblique incident direction to the film surface (e.g., incident angle of 20 to 89°). The rectilinear transmittance of the incident light from a direction perpendicular to the film surface is 0 to 30%, and the rectilinear transmittance of the incident light from an oblique direction having an incident angle of 40 to 70° to the film surface is 50 to 100%. Directivity in a light-scattering property of the light-scattering film is improved, and even when an incident light comes from an oblique direction, brightness of the display surface from a front direction is improved. Therefore, the film is useful for employing in combination with a polarized plate of the liquid crystal display apparatus.

A liquid crystal material containing polymer network forming material is microencapsulated by a method utilizing an interfacial polymerization which creates a combination of polyurethane and polyurea polymers or melamine fromaldehyde or urea formaldehyde polymer which form the capsule walls surrounding the discrete liquid crystal droplets. The prepolymer of urethane acrylate and acrylate within the liquid crystal capsules is cured under UV light irradiation to form a web-like structure and induce the formation of polydomain configuration of nematic director. This allows to produce the display having faster switching property and showing significant lower threshold voltage.

An LCD pixel includes a first conductive segment connected to a first bus, a first insulator segment on the first conductive segment, a second conductive segment on the first insulator segment, a liquid crystal material on the second conductive segment, a third conductive segment on the liquid crystal material, and a thin film transistor having a control terminal, a first power terminal and second power terminal connected to a second bus, a third bus and the second conductive segment, respectively. In response to application of a suitable signal on the second bus when reference voltages are present on the first bus and on the third conductive segment, and a voltage is applied to the third bus, the thin film transistor is operative for charging a capacitor formed by the first conductive segment, the first insulator segment and the second conductive segment and for activating the liquid crystal material.

As a compensator for use in an OCB mode liquid crystal display there is provided a compensating film capable of making color compensation and attaining such a viewing angle expansion as has not been attainable heretofore. A compensating film for a liquid crystal display, constituted by at least one layer of a compensating film to be used in an OCB mode liquid crystal display, the compensating film being formed by a discotic liquid crystalline material having a fixed orientation form of a discotic liquid crystal, the compensating film being disposed between a driving liquid crystal cell and a pair of upper and lower polarizing plates, and the orientation form being a hybrid orientation in which the angle between discotic liquid crystal directors near the upper interface of the film and the film plane and the angle between discotic liquid crystal directors near the lower interface of the film and film plane are different from each other.

The invention relates to a negative dielectric anisotropy liquid crystal material composite and a display element containing the liquid crystal composite. The negative dielectric anisotropy liquid crystal material composite contains at least one composite which is composed of compounds and expressed as general formulas (I) and (II) as a first component, at least one composite which is composed ofchemicals and expressed as a general formula (III) as a second component and at least one composite which is composed of chemicals and expressed as general formulas (IV) and (V) as a third component.The composite has significant negative dielectric anisotropy, a wide-enough nematic temperature range and refraction index anisotropy range, low viscosity and very excellent ultraviolet (UV) irradiation resistance performance and can fully satisfy requirements on the liquid crystal materials for high-grade decorative PDLC and simultaneously, in optical and electrical property, satisfy the requirements on the liquid crystal materials for PDLC display light valves with bistability.

The invention discloses a compound. The structure of the compound is shown in a formula I which is shown in the description. The compound can be used as a liquid crystal compound and overcomes the problem that traditional dibenzothiophen liquid crystals are low in solubility, and therefore the compound can be better applied in the field of liquid crystal materials. The invention further disclosesa liquid crystal medium containing the compound and application thereof.

A hand held pointing device for use with a computer system having a graphic interface. The pointing device includes a body, and a communications device within the body for communicating movement signals to the computer system. The pointing device further includes a movement detection device within the body, coupled to the communications device, for detecting movement of the body by a computer user. The pointing device additionally includes a pliant outer shell having at least a portion of the body which dynamically conforms to a computer user's hand when the pointing device is held and manipulated by a computer user, such that the portion of the body which conforms to the computer user's hand provides comfort and efficient ergonomic cushioning to the computer user during computer system pointing device activities. The pointing device further includes at least one user input device for transferring data to the computer system via the pointing device. In addition, the pointing device includes an interior shell which prevents the portion of the body from contacting interior electronics located within the pointing device. The pliant outer shell may also be surrounded by a membrane for preventing the rupture of the portion of the body. The pliant outer shell portion of the body may be composed of a gel based on an elastomer compound. Liquid-crystal material, controlled by a host computer, can also be located on the exterior of the pointing device to provide visual feedback to the computer user.

Embodiments of the present invention relate to a cholesteric liquid crystalline material which may be usable in an electro-active element for providing fail safe operation, polarization insensitivity, low electrical power consumption requirements, and a small number of electrical connections. The cholesteric liquid crystalline material may be usable in an electro-active element for providing a diffractive efficiency or focusing efficiency above 90% in an activated state of the electro-active element and a diffractive efficiency or focusing efficiency below 10% in a deactivated state of the electro-active element.

A window having electrically controllable transmission and reflection includes a layer of liquid crystal material and polarizers on either side thereof. Different combinations of absorptive and reflective polarizers are disclosed. These different combinations can be used in different applications to achieve the desired results. Transparent, conductive layers are provided to apply an electrical field to the liquid crystal material so as to selectively control the rotation of the polarization of light passing therethrough.

In accordance with the present invention, there are provided thermosetting resin compositions with a reduced propensity to shrink in volume upon cure and methods of use therefor. The compositions of the present invention include compounds having aromatic, rigid-rod like spacer groups between the crosslinkable moieties. As such, these compounds impart a degree of liquid crystal-like character to the thermosetting resin composition which results in lower shrinkage upon cure. This effect follows from the well-known expansion that occurs when liquid crystal-like materials pass from a nematic liquid crystal-like state to an isotropic state. Further provided by the present invention are low shrinkage die attach pastes and methods of use therefor.