Abstract: A substrate including a self-supporting tri-layer stack is described. The tri-layer stack includes first and second outer layers and a biaxially oriented layer disposed between and in direct contact with the first and second outer layers. The biaxially oriented layer may include a first polyester having greater than 45 mole percent naphthalate units and greater than 45 mole percent ethylene units. Each of the first and second outer layers includes a second polyester which may include 40 to 50 mole percent naphthalate units, at least 25 mole percent ethylene units, and 10 to 25 mole percent of branched or cyclic C4-C10 alkyl units.

Abstract: A retarder including first and second outer layers and a birefringent layer disposed between and in direct contact with the first and second outer layers is described. The birefringent layer may include a first polyester having greater than 45 mole percent naphthalate units and greater than 45 mole percent ethylene units. Each of the first and second outer layers includes a second polyester which may include 40 to 50 mole percent naphthalate units, at least 25 mole percent ethylene units, and 10 to 25 mole percent of branched or cyclic C4-C10 alkyl units. The retarder has a retardance in a range of 1 micrometer to 100 micrometers.

Abstract: A retarder including first and second outer layers and a birefringent layer disposed between and in direct contact with the first and second outer layers is described. The birefringent layer may include a first polyester having greater than 45 mole percent naphthalate units and greater than 45 mole percent ethylene units. Each of the first and second outer layers includes a second polyester which may include 40 to 50 mole percent naphthalate units, at least 25 mole percent ethylene units, and 10 to 25 mole percent of branched or cyclic C4-C10 alkyl units. The retarder has a retardance in a range of 1 micrometer to 100 micrometers.

Abstract: A light directing film includes a structured major surface with a plurality of microstructures extending along a first direction. Each microstructure has a first region and a second region different from the first region, a substantially constant height in the first region and a non-constant maximum height in the second region greater than the substantially constant height in the first region, and a same lateral cross sectional shape in the first region and the second region.

Abstract: A light directing film includes a structured major surface with a plurality of microstructures extending along a first direction. Each microstructure has a first region and a second region different from the first region, a substantially constant height in the first region and a non-constant maximum height in the second region greater than the substantially constant height in the first region, and a same lateral cross sectional shape in the first region and the second region.

Abstract: A light directing film includes a structured major surface with a plurality of microstructures extending along a first direction. Each microstructure has a first region and a second region different from the first region, a substantially constant height in the first region and a non-constant maximum height in the second region greater than the substantially constant height in the first region, and a same lateral cross sectional shape in the first region and the second region.

Abstract: A backlight includes a light source and one or more light recycling films. The light source generates light that exits the light source with an angular exit distribution. The light recycling films are oriented in relation to the light source so that the prism peaks of the recycling films are oriented away from the light source. The recycling films have a range of optimal incident angles that allow light to pass through the recycling films without recycling. The components of the light source, the characteristics of the recycling films, or both, are configured to control the overlap between the exit distribution of the light source and the optimal incident angle range of the recycling films.

Abstract: An optical film that includes a reflective polarizer and a stretched polymer film is disclosed. The stretched polymer film is laminated to the reflective polarizer, and the stretched polymer film exhibits a refractive index symmetry point at an angle of incidence in air of at least about 60 degrees in a plane of incidence parallel to a direction of greatest stretch.

Abstract: Tags are made from optical films to provide a pattern that is inconspicuous to ordinary observers, but that is detectable by a camera or other imaging device. The pattern is provided by first and second portions of a patterned layer, the first portions selectively filtering at least a portion of blue visible light from other visible light wavelengths. Filtering in the portion of the blue region helps make the pattern inconspicuous. The tags may also include an indicia layer configured to mark a location of the pattern, and a contrast enhancing layer disposed behind the patterned layer and configured to enhance a contrast of the pattern. In some cases, the first portions of the patterned layer may filter optical wavelengths other than blue, such as near-infrared light. The pattern may comprise machine-readable information, e.g., a linear bar code or a 2-D bar code. Associated methods and systems are also disclosed.

Abstract: Edge-lit LCD backlight units having a viewable area comprise (a) a downconversion film element, (b) a light guide comprising extraction elements, (c) a reflector and (d) blue LEDs. The extraction elements extend beyond the viewable area.

Abstract: Tags are made from optical films to provide a pattern that is inconspicuous to ordinary observers, but that is detectable by a camera or other imaging device. The pattern is provided by first and second portions of a patterned layer, the first portions selectively filtering at least a portion of blue visible light from other visible light wavelengths. Filtering in the portion of the blue region helps make the pattern inconspicuous. The tags may also include an indicia layer configured to mark a location of the pattern, and a contrast enhancing layer disposed behind the patterned layer and configured to enhance a contrast of the pattern. In some cases, the first portions of the patterned layer may filter optical wavelengths other than blue, such as near-infrared light. The pattern may comprise machine-readable information, e.g., a linear bar code or a 2-D bar code. Associated methods and systems are also disclosed.

Abstract: Light directing film is disclosed. The light directing film includes a first structured major surface and an opposing second major surface. The first structured major surface includes a plurality of unitary discrete structures. Each unitary discrete structure includes a light directing portion that is primarily for directing light and includes a plurality of first side facets. Each first side facet makes an angle with the plane of the light directing film in a range from about 35 degrees to about 55 degrees. Each light directing portion also includes a first base that is defined by the plurality of first side facets and has a first minimum dimension. Each light directing portion also has a first maximum height. Each unitary discrete structure also includes a bonding portion that is primarily for bonding the light directing film to a surface. The bonding portion is disposed on and between the plurality of first side facets and includes a plurality of second side facets.

Abstract: Light directing film is disclosed. The light directing film includes a first structured major surface and an opposing second major surface. The first structured major surface includes a plurality of unitary discrete structures. Each unitary discrete structure includes a light directing portion that is primarily for directing light and includes a plurality of first side facets. Each first side facet makes an angle with the plane of the light directing film in a range from about 35 degrees to about 55 degrees. Each light directing portion also includes a first base that is defined by the plurality of first side facets and has a first minimum dimension. Each light directing portion also has a first maximum height. Each unitary discrete structure also includes a bonding portion that is primarily for bonding the light directing film to a surface. The bonding portion is disposed on and between the plurality of first side facets and includes a plurality of second side facets.

Abstract: Light directing film is disclosed. The light directing film includes a first structured major surface and an opposing second major surface. The first structured major surface includes a plurality of unitary discrete structures. Each unitary discrete structure includes a light directing portion that is primarily for directing light and includes a plurality of first side facets. Each first side facet makes an angle with the plane of the light directing film in a range from about 35 degrees to about 55 degrees. Each light directing portion also includes a first base that is defined by the plurality of first side facets and has a first minimum dimension. Each light directing portion also has a first maximum height. Each unitary discrete structure also includes a bonding portion that is primarily for bonding the light directing film to a surface. The bonding portion is disposed on and between the plurality of first side facets and includes a plurality of second side facets.

Abstract: Light directing film is disclosed. The light directing film includes a first structured major surface and an opposing second major surface. The first structured major surface includes a plurality of unitary discrete structures. Each unitary discrete structure includes a light directing portion that is primarily for directing light and includes a plurality of first side facets. Each first side facet makes an angle with the plane of the light directing film in a range from about 35 degrees to about 55 degrees. Each light directing portion also includes a first base that is defined by the plurality of first side facets and has a first minimum dimension. Each light directing portion also has a first maximum height. Each unitary discrete structure also includes a bonding portion that is primarily for bonding the light directing film to a surface. The bonding portion is disposed on and between the plurality of first side facets and includes a plurality of second side facets.

Abstract: A backlight includes a light source and one or more light recycling films. The light source generates light that exits the light source with an angular exit distribution. The light recycling films are oriented in relation to the light source so that the prism peaks of the recycling films are oriented away from the light source. The recycling films have a range of optimal incident angles that allow light to pass through the recycling films without recycling. The components of the light source, the characteristics of the recycling films, or both, are configured to control the overlap between the exit distribution of the light source and the optimal incident angle range of the recycling films.

Abstract: A light directing film includes a structured major surface with a plurality of microstructures extending along a first direction. Each microstructure has a first region and a second region different from the first region, a substantially constant height in the first region and a non-constant maximum height in the second region greater than the substantially constant height in the first region, and a same lateral cross sectional shape in the first region and the second region.

Abstract: An approach for making a master tool used to fabricate optical films involves cutting a series of base structures. Modifying features are superimposed with the base structures, producing abruptly discontinuous variations in the shape of the base structures. Diffraction elements may be formed in one or both of the base structures and the modifying features. The modifying features can be formed by moving the cutting tool in the x-direction, in the z-direction, or along a trajectory having both an x component and a z component.

Abstract: An optical film that includes a reflective polarizer and a stretched polymer film is disclosed. The stretched polymer film is laminated to the reflective polarizer, and the stretched polymer film exhibits a refractive index symmetry point at an angle of incidence in air of at least about 60 degrees in a plane of incidence parallel to a direction of greatest stretch.