Abstract: A process for making an optical film includes stretching a polyolefin film in a first direction and stretching the polyolefin film in a second direction different than the first direction forming a biaxially stretched polyolefin film. At least a portion of the stretching of the polyolefin film in the second direction occurs simultaneous with the stretching of the polyolefin film in the first direction. The biaxially stretched polyolefin film has a length and a width and substantially non-absorbing and non-scattering for at least one polarization state of visible light. The biaxially stretched polyolefin film has x, y, and z orthogonal indices of refraction where at least two of the orthogonal indices of refraction are not equal, an in-plane retardance being 100 nm or less and an out-of-plane retardance being 50 nm or greater.

Abstract: An optical stack includes a first liquid crystal layer and a j-retarder disposed on the liquid crystal layer. The j-retarder includes a simultaneous biaxially stretched polymeric film being substantially non-absorbing and non-scattering for at least one polarization state of visible light. The j-retarder has x, y, and z orthogonal indices of refraction where at least two of the orthogonal indices of refraction are not equal, an in-plane retardance being 100 nm or less and an absolute value for an out-of-plane retardance being 55 nm or greater.

Abstract: Stretched polymeric films can be used in a variety of applications, including optical applications. The stretching conditions and shape of the stretching tracks in a stretching apparatus can determine or influence film properties. Methods and stretching apparatuses can include adjustable or zone-defined stretching regions.

Abstract: Illumination systems are disclosed that include a light source or a bank of light sources having a non-radially symmetrical aperture having a longer dimension and a shorter dimension, such that the light source or bank of light sources produces illumination with a non-radially symmetrical angular intensity distribution having a larger angular dimension and a smaller angular dimension. The illumination systems include an integrator having an entrance end optically connected to the bank of light sources, an exit end, and a dimension that experiences a larger increase from the entrance end to the exit end. The integrator is disposed so that the dimension experiencing the larger increase is substantially aligned with the larger angular dimension of the illumination produced at the entrance end of the integrator.

Abstract: Compensation of a liquid crystal display can be achieved using a compensation structure, having, in the following order: a) a first o-plate; b) a first retarder; c) a liquid crystal cell; d) a second retarder; and e) a second o-plate. The first and second retarders can be c-plates or biaxial retarders.

Abstract: Multi-directional optical elements are disclosed that include a body having a first side having a first curvature, a second side having a second curvature, a third side having a third curvature, and a fourth side having a fourth curvature. The second side is disposed generally opposite the first side along a first direction and a fourth side is disposed generally opposite the third side along a second direction, the second direction being different from the first direction. Also disclosed are optical systems utilizing such multi-directional optical elements.

Abstract: A film that includes a first reflective polarizer substantially reflecting light having a first polarization state and substantially transmitting light having a second polarization state, a polarization rotating layer or depolarizing layer (or both) positioned to receive light passing through the first reflective polarizer, and a second reflective polarizer positioned to receive light passing through the polarization rotating layer or depolarizing layer, the second reflective polarizer substantially reflecting light having a third polarization state back through the polarization rotating layer or depolarizing and substantially transmitting light having a fourth polarization state. Articles containing the film can be formed.

Abstract: Dental articles including at least one optical surface formed of a multilayer optical film including layers of at least one strain-induced birefringent material are disclosed. The multilayer optical films included in the dental articles is preferably post-formed into desired non-planar shapes in manners that result in some deformation of the optical stack of the multilayer optical films. A variety of dental implements can be constructed with multilayer optical film including dental mirrors, light guides for use in connection with photo-curing dental materials, and matrix bands for use in molding photo-curing dental restoratives.

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: The invention provides a cholesteric liquid crystal composition that includes at least one cholesteric liquid crystal precursor, and at least one non-liquid crystalline additive that is a non-liquid crystalline compound of formula I The invention also provides cholesteric liquid crystal films and optical bodies formed from cholesteric liquid crystal compositions of the invention. The invention further provides an optical display that includes a display medium, and a reflective polarizer including a cholesteric liquid crystal composition in accordance with the invention.

Abstract: A transflective assembly includes an absorbing polarizer and a first reflective polarizer disposed to reflect at least a portion of light transmitted through the absorbing polarizer. A second reflective polarizer is disposed between the absorbing polarizer and the first reflective polarizer. The second reflective polarizer reflects light transmitted through the first reflective polarizer having a polarization absorbable in the absorbing polarizer, and transmits light transmitted through the absorbing polarizer towards the first reflective polarizer.

Abstract: Lighting devices are disclosed that include optical laminated bodies. An exemplary optical laminated body includes a polarizing layer, a first transparent film disposed closely to a front surface of the polarizing layer and a second transparent film disposed closely to a back surface of the polarizing layer. The polarizing layer includes a reflective polarizing film, and both of the first transparent film and the second transparent film are diffusive films. The lighting devices further include a light source supplying light to the optical laminated body through a light entry surface of the first transparent film of the optical laminated body and a lens film disposed between the light source and the optical laminated body. The lighting device provides diffused-polarized light emitted from a light emitting surface of the second transparent film of the laminated body.

Abstract: An optical film includes a layer of simultaneous biaxially stretched polyolefin film that is substantially non-absorbing and non-scattering for at least one polarization state of visible light. The layer has x, y, and z orthogonal indices of refraction where at least two of the orthogonal indices of refraction are not equal. The layer has an in-plane retardance of 100 nm or less and an out-of-plane retardance of 50 nm or greater.

Abstract: Stretched polymeric films can be used in a variety of applications, including optical applications. The stretching conditions and shape of the stretching tracks in a stretching apparatus can determine or influence film properties. Methods and stretching apparatuses can include adjustable or zone-defined stretching regions.

Abstract: A process for stretching films is described. The process preferably stretches films in a uniaxial fashion. Preferably, optical films are stretched including multilayer optical films. Other aspects of the invention include a roll of stretched film and an apparatus for stretching films.

Abstract: Stretched polymeric films can be used in a variety of applications, including optical applications. The stretching conditions and shape of the stretching tracks in a stretching apparatus can determine or influence film properties. Take-away systems can be used to receive the film after stretching. The configuration of the take-away system can, in at least some instances, influence final film properties.

Abstract: Optical devices using reflective polarizers and, in particular, diffusely reflective polarizers are provided. Many of the optical devices utilize the diffusely reflecting and specularly transmitting properties of diffusely reflecting polarizers to enhance their optical characteristics. The optical devices include a lighting system which uses a reflector formed from a diffusely reflecting polarizer attached to a specular reflector. Another optical device is a display apparatus which uses a diffusely reflecting polarizer layer in combination with a turning lens which folds shallow angle light toward a light modulating layer. Other optical devices exploit the depolarizing characteristics of a diffusely reflecting polarizer when reflecting light. Still other optical devices use diffusely reflecting polarizers to recycle light and improve display illumination.

Abstract: The present invention provides a unique polarizing beam splitter (PBS) that is suitable for use in projection systems and displays. The PBS contains at least one prism having at least one major surface and having a refractive index of at least about 1.6 and a birefringent film disposed on the major surface of the prism. The birefringent film is a multi-layer film having at layers of at least a first material and a second material. After uniaxial stretching, the film exhibits a refractive index difference of less than about 0.15 units in the stretched direction.

Abstract: Compensation of a liquid crystal display can be achieved using a compensation structure, having, in the following order: a) a first o-plate; b) a first retarder; c) a liquid crystal cell; d) a second retarder; and e) a second o-plate. The first and second retarders can be c-plates or biaxial retarders.

Abstract: An optical body includes a substrate and a cholesteric liquid crystal layer disposed on the substrate. The cholesteric liquid crystal layer has a non-uniform pitch along a thickness direction of the layer and comprises a crosslinked polymer material that substantially fixes the cholesteric liquid crystal layer. The crosslinking hinders diffusion of cholesteric liquid crystal material within the cholesteric liquid crystal layer. In other methods of making an optical body, a reservoir of chiral material is provided during the process over a first cholesteric liquid crystal layer to diffuse into the layer and provide a non-uniform pitch. Alternatively, two coating compositions can be disposed on a substrate where the material of the first coating composition is not substantially soluble in the second coating composition.