756 results about "Liquid Crystalline Materials" patented technology

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.

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.

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 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.

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.

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.

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.

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.

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.

The invention relates to the use of a printable polymerisable liquid crystal material as printable system for the preparation of polymers and pigments, to printable polymerisable liquid crystal materials and pigments and polymers prepared thereof, and to the use of the printable materials, pigments and polymers in optical, electrooptical, semiconductor and electronic applications and as birefringent and optically variable markings for decorative, security, authentification or identification applications.

The invention relates to a polymerizable liquid crystal material containing at least one polymerizable surface-active compound, its use for the preparation of anisotropic polymer films, and the use of the liquid crystal material and the polymer films in optical and electrooptical devices, and for decorative and security applications.

The invention comprises a stacked color photodisplay apparatus using a photosensitive cholesteric liquid crystalline material on which an image can be optically addressed, retained without degradation for an indefinite period of time, electrically erased and a new image addressed. This is similar to a photographic film except that the photodisplay film can be used over and over again similar to digital display but without the cost of addressing electronics. Included is a device for enhancing the brightness of the image and electrooptical devices for optically writing digital images on the photodisplay. Each cell in the stack can be selectively addressed with a different optical image such as the red, green and blue components of a color digital image.

The invention provides a process for the production of a (particulate) luminescent material comprising particles, especially substantially spherical particles, having a porous inorganic material core with pores, especially macro pores, which are at least partly filled with a polymeric material with a first material embedded therein, wherein the process comprises (i) impregnating the particles of a particulate porous inorganic material with pores with a first liquid (“ink”) comprising the first material and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said first material and curable or polymerizable precursor; and (ii) curing or polymerizing the curable or polymerizable precursor within pores of the porous material, as well as a product obtainable thereby. The first material comprises one or more materials selected from a group of materials comprising organic luminescent materials, rare-earth luminescent materials, organic dye materials, inorganic dye materials, thermochromic materials, photochromic materials, liquid crystal materials, magnetic materials, scattering materials, high-refractive index materials, radio-active materials, contrast agents and therapeutic agents.