Abstract: An end cover assembly, an air cylinder, a tread sweeper and a railway vehicle.

Abstract: An optical film having a first surface, an opposing second surface, and a thickness normal to the first and second surfaces is cut. Cutting the film forms a channel at least partially through the thickness of the film. A light control material is printed proximate to a surface of the film. The ink traverses through the channel by capillary motion.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes on a printed circuit board. The backlight unit may include first, second, and third light spreading layers formed over the array of light-emitting diodes. A color conversion layer may be formed over the first, second, and third light spreading layers. First and second brightness enhancement films may be formed over the color conversion layer.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes on a printed circuit board. The backlight unit may include first, second, and third light spreading layers formed over the array of light-emitting diodes. A color conversion layer may be formed over the first, second, and third light spreading layers. First and second brightness enhancement films may be formed over the color conversion layer.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes (LEDs) on a printed circuit board. The display may have a notch to accommodate an input-output component. Reflective layers may be included in the notch. The backlight may include a color conversion layer with a property that varies as a function of position. The light-emitting diodes may be covered by a slab of encapsulant with recesses in an upper surface.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes on a printed circuit board. The backlight unit may include first, second, and third light spreading layers formed over the array of light-emitting diodes. A color conversion layer may be formed over the first, second, and third light spreading layers. First and second brightness enhancement films may be formed over the color conversion layer.

Abstract: A unitary optical film stack comprising a light redirecting film assembly; a light diffusion film assembly; and an optical adhesive; wherein the light redirecting film assembly and the light diffusion film assembly are physically coupled non-continuously to minimize optical coupling.

Abstract: An optical element including an array of microlenses, a pinhole mask, and a wavelength selective filter is described. The pinhole mask includes an array of pinholes with each pinhole in the array of pinholes aligned with a microlens in the first array of microlenses. The wavelength selective filter is adapted to transmit a first light ray having a first wavelength and transmitted from a first microlens in the array of microlenses through a first pinhole in the array of pinholes aligned with the first microlens, and to attenuate a second light ray having the first wavelength and transmitted from the first microlens through a second pinhole in the array of pinholes aligned with a second microlens in the first array of microlenses adjacent to the first microlens.

Abstract: A unitary optical film stack comprising a light redirecting film assembly; a light diffusion film assembly; and an optical adhesive; wherein the light redirecting film assembly and the light diffusion film assembly are physically coupled non-continuously to minimize optical coupling.

Abstract: An optical film having a first surface, an opposing second surface, and a thickness normal to the first and second surfaces is cut. Cutting the film forms a channel at least partially through the thickness of the film. A light control material is printed proximate to a surface of the film. The ink traverses through the channel by capillary motion.

Abstract: An optical film assembly comprises a light redirecting film (110) having a first structured major surface (112) and a second, opposed major surface (114). An optical adhesive layer (120) is disposed on the second major surface of the light redirecting film. A light diffusion film (140) comprises a first major surface (142) comprising a light diffusion surface and a second, opposed major surface (144). A plurality of discrete optical decoupling structures (146) project from the light diffusion surface and contact the optical adhesive layer. An air gap (148) is defined between the first major surface of the light diffusion film and the optical adhesive layer. Embodiments of optical film assemblies described herein are useful, for example, for hiding optical defects and improving the brightness uniformity of light emitted by a light source.

Abstract: An optical film assembly comprising a first optical film, a coupling member, and a second optical film wherein the first optical film comprises a prismatic film, the second optical film comprises a diffuser, wherein the coupling member is bonded to the first optical film and to the second optical film such that the first optical film and second optical film are physically coupled, and the coupling member is bonded to at least one of the first optical film and the second optical film non-continuously such that an optically effective air gap is provided. Also, a method for making such optical film assemblies.

Abstract: Brightness enhancing films with embedded diffusers are described. More specifically, films including a birefringent substrate, a prismatic layer carried by the substrate having linear prisms, and an embedded structured surface disposed between the substrate and the prismatic layer are disclosed. The embedded structured surface may include closely-packed structures. Processes for producing embedded structured surfaces having particular topographies are also disclosed.

Abstract: Optical diffusing films are made by microreplication from a structured surface tool. The tool is made using a 2-part electroplating process, wherein a first electroplating procedure forms a first metal layer with a first major surface, and a second electroplating procedure forms a second metal layer on the first metal layer, the second metal layer having a second major surface with a smaller average roughness than that of the first major surface. The second major surface can function as the structured surface of the tool. A replica of this surface can then be made in a major surface of an optical film to provide light diffusing properties. The structured surface and/or its constituent structures can be characterized in terms of various parameters such as optical haze, optical clarity, Fourier power spectra of the topography along orthogonal in-plane directions, ridge length per unit area, equivalent circular diameter (ECD), and/or aspect ratio.

Abstract: A microreplicated optical film (919) for use in optical displays, backlights, and the like includes a prismatic layer (950) carried by a substrate (920). In use, the optical film may be combined in a system with other components such that the optical film is positioned between an extended light source (902) and a polarizer (904). In such cases, if the substrate has an appreciable birefringence, a subtle but characteristic colored pattern known as substrate color mura (SCM) may be detected by a user of the system. To reduce or eliminate the SCM with little or no adverse effect on brightness enhancement capabilities of the optical film, the optical film may include an embedded structured surface (933) between the substrate and the prismatic layer. In order to avoid another optical artifact known as sparkle, at least 80% of the embedded structured surface is preferably occupied by features such as defocusing lenslets or random planar facets.

Abstract: Brightness enhancing films with embedded diffusers are described. More specifically, films including a birefringent substrate, a prismatic layer carried by the substrate having linear prisms, and an embedded structured surface disposed between the substrate and the prismatic layer are disclosed. The embedded structured surface may include closely-packed structures. Processes for producing embedded structured surfaces having particular topographies are also disclosed.

Abstract: Optical diffusing films are made by microreplication from a structured surface tool. The tool is made using a 2-part electroplating process, wherein a first electroplating procedure forms a first metal layer with a first major surface, and a second electroplating procedure forms a second metal layer on the first metal layer, the second metal layer having a second major surface with a smaller average roughness than that of the first major surface. The second major surface can function as the structured surface of the tool. A replica of this surface can then be made in a major surface of an optical film to provide light diffusing properties. The structured surface and/or its constituent structures can be characterized in terms of various parameters such as optical haze, optical clarity, Fourier power spectra of the topography along orthogonal in-plane directions, ridge length per unit area, equivalent circular diameter (ECD), and/or aspect ratio.

Abstract: Optical diffusing films are made by microreplication from a structured surface tool. The tool is made using a 2-part electroplating process, wherein a first electroplating procedure forms a first metal layer with a first major surface, and a second electroplating procedure forms a second metal layer on the first metal layer, the second metal layer having a second major surface with a smaller average roughness than that of the first major surface. The second major surface can function as the structured surface of the tool. A replica of this surface can then be made in a major surface of an optical film to provide light diffusing properties. The structured surface and/or its constituent structures can be characterized in terms of various parameters such as optical haze, optical clarity, Fourier power spectra of the topography along orthogonal in-plane directions, ridge length per unit area, equivalent circular diameter (ECD), and/or aspect ratio.

Abstract: An optical film assembly comprising a first optical film, a coupling member, and a second optical film wherein the first optical film comprises a prismatic film, the second optical film comprises a diffuser, wherein the coupling member is bonded to the first optical film and to the second optical film such that the first optical film and second optical film are physically coupled, and the coupling member is bonded to at least one of the first optical film and the second optical film non-continuously such that an optically effective air gap is provided. Also, a method for making such optical film assemblies.

Abstract: A display system includes a switchable display screen comprising a first transparent substrate, a first transparent conductive layer disposed upon the first transparent substrate, a second transparent substrate, and a second transparent conductive layer disposed upon the second transparent substrate. The display screen further includes a polymer-stabilized cholesteric texture layer and spacer elements disposed between and in contact with the first transparent conductive layer and the second conductive layer. The display screen comprises a plurality of addressable regions, each region capable of being switched from a transparent state to a diffuse state.