An optical system for producing electromagnetic radiation with localized increases in irradiance or radiance at the system output includes a first optical mask containing localized regions for producing controlled modifications of phase delays and/or amplitude attenuations and located within the input plane of said optical system. The system also includes at least a single optical component with positive optical power located after the input plane and at least one additional optical mask located after the optical component at non-conjugate locations with respect to the input plane of the system. The additional optical mask contains localized regions for producing controlled modifications of phase delays. Locally increased radiation distributions are produced at the system output.

Provided is a polarizer whereby screen brightness does not become zero regardless of the direction in which a viewer faces when the polarizer is used in a liquid crystal display device capable of displaying three-dimensional images, in which three-dimensional images are visible through a polarizing filter. The polarizer comprises a polarizing film and protective films disposed on both sides of the polarizing film; at least one of the protective films being an oriented film; and the tilt of the orientation axis or an axis orthogonal to the orientation axis of the oriented film relative to the polarization axis of the polarizing film being 1 or more and less than 45.

An optical element includes a three-dimensional structure having a curved surface; and a retardation plate bent along the curved surface. The retardation plate includes a transparent substrate and a liquid crystal layer formed over the transparent substrate. The retardation plate has a slow axis and a fast axis. A glass-transition temperature, Tgne, in a slow axis direction of the retardation plate is higher than a glass-transition temperature, Tgno, in a fast axis direction of the retardation plate.

An object of the present invention is to provide an optical film having an optically anisotropic layer having excellent durability, and a polarizing plate and an image display device using the same. This optical film of the present invention is an optical film at least having an optically anisotropic layer, in which the optically anisotropic layer is a layer obtained by polymerizing a polymerizable liquid crystal composition containing a predetermined liquid crystal compound and a polymerization initiator, and the optically anisotropic layer has a density of 1.20 g/cm.sup.3 or more and a crosslinking point density of 0.0016 mol/cm.sup.3 or more.

Provided is a diffraction element having excellent aligning properties of a liquid crystal compound. The diffraction element includes an optically-anisotropic layer that has a liquid crystal alignment pattern in which an orientation of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, in which a birefringence n of the optically-anisotropic layer is 0.20 or more, the optically-anisotropic layer includes a surfactant, and in a case where components in a depth direction are analyzed by time-of-flight secondary ion mass spectrometry from one surface to another surface of the optically-anisotropic layer, a depth-direction profile of a secondary ion intensity derived from the surfactant is obtained, a position corresponding to a thickness of 20% from the one surface of the optically-anisotropic layer is represented by a position D20, a position corresponding to a thickness of 80% from the one surface is represented by a position D80, and an average value of secondary ion intensities derived from the surfactant between the position D20 and the position D80 is calculated, in a region from the position D20 to the position D80, a peak having a size of 1.1 times or more the average value is observed and a peak having a size of 5 times or more the average value is not observed.

Provided are an optical film, a polarizing plate including same, and a display device including same, the optical film comprising a first layer and second and third layers sequentially formed on the first layer, wherein the first layer and the third layer are each formed directly on the second layer, the first layer is a reverse wavelength dispersive negative A layer, the third layer is a positive C layer, and the ratio of the thickness of the second layer to the thickness of the third layer (the thickness of the second layer/the thickness of the third layer) is about 0.2 to about 2.

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

An optical element includes a three-dimensional structure having a curved surface; and a retardation plate bent along the curved surface. The retardation plate includes a transparent substrate and a liquid crystal layer formed over the transparent substrate. The retardation plate has a slow axis and a fast axis. A glass-transition temperature, Tgne, in a slow axis direction of the retardation plate is higher than a glass-transition temperature, Tgno, in a fast axis direction of the retardation plate.

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

A display apparatus includes a substrate; a light emitting element on the substrate that is configured to emit visible light; and a polarizer including a polarizing object on the substrate and a supporting film on at least one surface of the polarizing object. The polarizing object is configured to absorb ultraviolet light and visible light having wavelengths shorter than a blue light of the visible light emitted from the light emitting element and is configured to transmit the visible light emitted from the light emitting element.