57results about How to "Increased birefringence" patented technology

A method of producing a hologram element is disclosed that is able to prevent spread of a polymerization reaction and light leakage during exposure with interference light, and improve productivity in mass production. The hologram element is for transmitting, reflecting, diffracting, or scattering incident light, and includes a pair of substrates, an isolation member between the substrates that forms an isolated region, and a photo-sensitive recording material sealed in the isolated region. The hologram element includes a periodic structure formed by exposing the recording material to interference light. The interference light is generated by two or more light beams, or by using a master hologram. The recording material is formed from a composite material including a polymerized polymer or a polymerized liquid crystal. The periodic structure is formed by exposing the recording material to the interference light to induce the polymerization reaction and phase separation in the composite material.

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.

The nature of a volume hologram limits its use in security and sensing applications. Accordingly, a volume hologram segregated into a first and second region recording a first and second image, respectively, and wherein the second region is responsive to stimulus while the first region is protected physically from stimulus is provided. Also provided is a volume hologram with a functional cover disposed thereon to regulate how the volume hologram interacts with the stimulus when in the presence of stimulus. A volume hologram with a removable cover disposed thereon to permit a first recorded image to be viewed, to protect the volume hologram from physical damage, to prevent the volume hologram from interacting with the stimulus, and to be removed, thereby permitting the volume hologram to interact with the stimulus is provided as well. In these ways, the usability of volume holograms in security and sensing applications is increased.

A method for controlling positive birefringence in an optical compensation film (positive C-plate) having high positive birefringence throughout the wavelength range 400 nm<λ<800 nm is provided. The method includes selecting polymers with optically anisotropic subunits (OASUs) that exhibit the buttressing effect, wherein the OASUs may be disks, mesogens or aromatic rings substituted with birefringence enhancing substituents. The method further includes processing the polymer by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. These optical compensation films may be used in LCDs, particularly IPS-LCDs.

Optical compensation films (positive C-plate) with anisotropic subunits (OASUs) that are aromatic rings substituted with birefringence enhancing substituents (BES) and have high positive birefringence throughout the wavelength range 400 nm<λ<800 nm are provided. The optical compensation films may be processed by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. Such optical compensation films are suitable for use as a positive C-plate in LCDs, particularly IPS-LCDs.

An optical film comprising a thermoplastic resin, which is such that the slow axis direction in the film plane differs from the film tilt direction and the birefringence of a sliced section of the film that contains the tilt direction and the thickness direction in the plane varies in the thickness direction of the film.

Optical compensation films (positive C-plate) with disk anisotropic subunits (OASUs) that have high positive birefringence throughout the wavelength range 400 nm<λ<800 nm are provided. The optical compensation films may be processed by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. Such optical compensation films are suitable for use as a positive C-plate in LCDs, particularly IPS-LCDs.

An optical film comprising a thermoplastic resin and having a tilt direction, which is such that, when a sliced section of the optical film having both a tilt direction and the thickness direction of the film in the sliced plane thereof is placed between two polarizers set in a crossed Nicols configuration, and the two crossed Nicols polarizers are rotated from 0° to 90° while irradiated with light in the direction perpendicular to the polarizer plane, and when the sliced section is analyzed sequentially from one end to the other end in the thickness direction, then all the detected extinction positions are from more than 0° to less than 90° and the birefringence varies in the thickness direction.

The present invention relates to an eigenmode completely separate type degenerated multimode fiber. The degenerated multimode fiber comprises a birefringence fiber core, a stress region and a cladding. The birefringence fiber core provides the shape structure birefringence, and adopts an elliptical-core/elliptical ring-shaped fiber core structure. The stress region provides a stress additional birefringence and adopts a circular (panda type) or fan ring-shaped (bow-tie/butterfly-shaped) structure. The shape structure birefringence and the stress additional birefringence are superposed, so that the multi-channel eigenmode is enabled. Meanwhile, the difference among the effective refractive indexes of all eigenmodes is larger than 1*10-4 simultaneously. As a result, all eigenmodes are completely separated and degenerated. According to the technical scheme of the invention, the number of optical fiber degenerated eigenmodes is increased, and the crosstalk among the eigenmodes is reduced. The degenerated multimode fiber can be applied to the optical fiber multi-channel eigenmode multiplexing communication, while the multiple-input and multiple-output digital signal processing technique is not required. Based on the manufacturing process of panda type/bow-tie type/butterfly type elliptic-core polarization-preserving fibers and ring-shaped optical fibers, the eigenmode completely separate type degenerated multimode fiber is convenient for actual drawing.

The present invention relates to a nematic liquid crystal compound and a liquid crystal composition exhibiting a fast response time over a wide temperature range comprising the same, and more particularly, to a liquid crystal composition with fast response characteristics, and having a high phase transition temperature of liquid crystal, and having a low driving voltage and a nematic phase in a wide temperature range, comprising a nematic liquid crystal compound having an isothionate group and at least one fluorine atom in an aromatic ring of a terminal group.

The present invention provides materials and methods that make liquid crystal phases accessible with relatively short β-peptides in aqueous solvents.

A nematic liquid crystal composition includes a compound of formula (1) and a host mixture:

wherein ‘R’ is chosen from C_nH_2n+1O, C_nH_2n+1, C_nH_2n+1S or C_nH_2n−1; ‘n’ is an integer of 1 to 15; ‘A’ is

‘a’ is 0 or 1; ‘B’ is —CH₂CH₂—, —C═C—, —C≡C— or

‘b’ is 0 or 1; ‘D’ is

—CH₂CH₂—, —C═C— or —C≡C—; ‘d’ is 0 or 1;‘X’ is H, F, Cl, Br, NCS or CN; and ‘Y’ is from NCS, SCN or F. A liquid crystal display apparatus employing the nematic liquid crystal composition has a high response speed and a high phase transition temperature. In addition, the nematic liquid crystal composition has an augmented birefringence and a dielectric anisotropy. The liquid crystal display apparatus using the nematic liquid crystal composition may have an enhanced brightness.

The invention is directed to a method for processing and annealing metal fluoride single crystals. Among other steps, the method includes of removing the as-grown surfaces of the crystals after they emerge from the growth furnace, processing the surfaces in such way that all the crystal surfaces have the same thermal properties, and then placing the crystals in a secondary annealing furnace to further anneal the crystals to release the residual stresses resulting from the primary annealing process. The invention is suitable for metal fluoride crystals of general formula MF₂, where M is calcium, magnesium, barium and strontium, and mixtures thereof.

Described herein are novel azo-benzene type chromophores. The chromophores are useful in photochromic compositions comprising a polymer matrix and a chromophore, wherein the chromophore is a novel azo-benzene type structure. The photochromic composition is photoresponsive upon irradiation by at least one wavelength of laser light across the visible light spectrum. Photochromic devices which comprise the novel azo-benzene type chromophore compound show significantly higher photoinduced birefringence, higher diffraction efficiency, and brighter images than devices that comprise well known azo-benzene chromophores. The photochromic composition may include a liquid crystal.