Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. The interior layers include a first set of layers composed of a first material and a second set of layers composed of a different second material. The first and second sets of layers are both birefringent in the first zone, but at least some of the layers have reduced birefringence in the second zone. The reduced birefringence produces a second reflective characteristic in the second zone that differs from a first reflective characteristic in the first zone, this difference not being substantially attributable to any thickness difference between the first and second zones. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film.

Abstract: A retarder film provides a first light retardation and can be heat processed in one or more selected areas to provide a second light retardation in the selected area(s). The retarder film may have an absorption characteristic such that the heat processing can be carried out by selectively exposing the film to a suitable radiant beam. The retarder film is composed of a stack of contiguous ultrathin layers configured to provide an effective optical medium for visible light. Visible light propagates through the stack as an effective medium having effective refractive indices along principal x-, y-, and z-axes. At least some of the ultrathin layers possess intrinsic birefringence, and the effective indices of the stack are functions of the intrinsic refractive indices of the constituent ultrathin layers. The heat processing is carried out so that the ultrathin layer stack structural integrity is not substantially altered in the processed area(s).

Abstract: A light directing film includes a back major surface having light reflection regions and light transmission regions and being planar, and a front major surface opposing the back surface. The front surface is planar and a plurality of lenses is disposed between the front surface and the back surface. At least selected light transmission regions are registered with selected lens elements. A method for forming the light directing film and illuminated signs utilizing the light directing films are also described.

Abstract: Multi-layer articles are described that are capable of forming color images. The articles may contain at least two layers, a thermally activatable layer and a blocking layer, or at least three layers with two thermally activatable layers and a blocking layer between. The thermally activatable layers absorb light of a write wavelength and have an absorption threshold for activation. The blocking layer blocks light of the write wavelength at certain incident angles or polarization states and permits light of the write wavelength and certain incident angles or polarization states to pass through.

Abstract: A diffusely reflective optical film includes a blended layer extending from a first to a second zone of the film. The blended layer includes first and second polymer materials separated into distinct first and second phases, respectively. The blended layer may have the same composition and thickness in the first and second zones, but different first and second diffusely reflective characteristics in the first and second zones, respectively. The difference between the first and second diffusely reflective characteristics may not be attributable to any difference in composition or thickness of the layer between the first and second zones. Instead, the difference between the first and second diffusely reflective characteristic may be attributable to a difference in birefringence of the first and/or second polymer materials between the first and second zones. The blend morphology of the blended layer may be substantially the same in the first and second zones.

Abstract: Multi-layer articles are described that are capable of forming color images. The articles include at least six layers, four thermally activatable layers (layers 1-4) and two blocking layers (layer 5 and 6). The layers are arranged such that layer 5 is disposed between layers 1 and 2 and layer 6 is disposed between layers 3 and 4. Thermally activatable layers 1 and 2 are activatable upon exposure to light of a first write wavelength, and blocking layer 5 is adapted to at least partially block light of the first write wavelength. Thermally activatable layers 3 and 4 are activatable upon exposure to light of a second write wavelength, and blocking layer 6 is adapted to at least partially block light of the second write wavelength. At least one, and possibly all of the thermally activatable layers include a light to heat convertor composition and a color changing compound.

Abstract: Retarder film combinations generally include a retarder film connected to another optical component such that light transmitted by the retarder film can impinge on the optical component, the combination being configured to allow independent patterning of the retarder film and the optical component by selective birefringence reduction. The patterning can change a first light retardation to a third light retardation in a first zone without substantially changing optical characteristics of the optical component in the first zone. The optical component may be a second retarder film having a second light retardation, and the patterning may change the second light retardation to a fourth light retardation, without substantially changing the first light retardation, in a second zone. The optical component may also be a multilayer optical film, or a diffusely reflective optical film having a blended layer of first and second distinct phases.

Abstract: Certain patternable reflective films are used as masks to make other patterned articles, and one or more initial masks can be used to pattern the patternable reflective films. An exemplary patternable reflective film has an absorption characteristic suitable to, upon exposure to a radiant beam, absorptively heat a portion of the film by an amount sufficient to change a first reflective characteristic to a different second reflective characteristic. The change from the first to the second reflective characteristic is attributable to a change in birefringence of one or more layers or materials of the patternable film. In a related article, a mask is attached to such a patternable reflective film. The mask may have opaque portions and light-transmissive portions. Further, the mask may have light-transmissive portions with structures such as focusing elements and/or prismatic elements.

Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. In the first zone the layers provide a first reflective polarizer characteristic, and in a second zone the layers provide a substantially different reflective polarizer characteristic. The second zone is characterized by at least some of the layers having a reduced birefringence relative to their birefringence in the first zone. In some cases the first reflective polarizer characteristic may have a pass axis that is substantially orthogonal to that of the second reflective polarizer characteristic. The film may have substantially the same thickness in the first and second zones, or a substantially reduced thickness in the second zone relative to the first zone.

Abstract: A reflective film includes a first optical stack that provides a first reflective characteristic and a second optical stack that provides a second reflective characteristic. The optical stacks also have first and second absorptive characteristics that are suitable to absorptively heat the respective stacks upon exposure to light including a write wavelength while maintaining the structural integrity of the stacks. The absorptive heating can change the first and second reflective characteristics to third and fourth reflective characteristics, respectively. A blocking layer that at least partially blocks light of the write wavelength may also be provided between the optical stacks to permit absorptive heating of any selected one of the optical stacks. The reflective characteristics of the optical stacks can thus be independently modified in any desired patterns by appropriate delivery of light beams that include the write wavelength.

Abstract: A reflective film includes interior layers arranged to selectively reflect light by constructive or destructive interference, the layers extending from a first zone to a second zone of the film. The film has a first thickness and the interior layers provide a first reflective characteristic in the first zone; the film has a second thickness and the interior layers provide a second reflective characteristic in the second zone. The difference between the first and second reflective characteristics is not substantially attributable to any difference between the first and second thicknesses, which difference may be zero. Rather, the difference in the reflective characteristics is substantially attributable to reduced birefringence of at least some of the interior layers in one zone relative to the other zone. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film. Related methods and articles are also disclosed.

Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. The interior layers include a first set of layers composed of a first material and a second set of layers composed of a different second material. The first and second sets of layers are both birefringent in the first zone, but at least some of the layers have reduced birefringence in the second zone. The reduced birefringence produces a second reflective characteristic in the second zone that differs from a first reflective characteristic in the first zone, this difference not being substantially attributable to any thickness difference between the first and second zones. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film. Related methods and articles are also disclosed.

Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. In the first zone, the layers operate substantially as a reflective polarizer; in the second zone they operate substantially as a mirror. The layers may thus provide a first reflective characteristic in the first zone wherein normally incident light of one polarization state is substantially reflected and normally incident light of an orthogonal polarization state is substantially transmitted, and a second reflective characteristic in the second zone wherein normally incident light of any polarization state is substantially reflected. The film may have a first thickness in the first zone that is substantially the same as a second thickness in the second zone. Alternatively, the second thickness may be substantially less than the first thickness. Related methods, articles, and systems are also disclosed.

Abstract: A stretcher for substantially uniaxially orienting a film includes a plurality of gripping members to hold opposing edge portions of the film, paths along which the gripping members travel to stretch the film in a stretching region, and a drive mechanism to convey the film and gripping members along a machine direction. At least a portion of the paths in the stretching region define diverging, curvilinear courses disposed in-plane. The paths are configured such that during the stretching an extent of uniaxial character, U, is between zero and unity and a minimum value of an extent of uniaxial character, U, is at least 0.70 over a final portion of the stretching after achieving a TDDR of 2.5. U is defined as U=(1/MDDR?1)/(TDDR1/2?1), wherein TDDR is greater than 4 at an end of the stretching region.

Abstract: A stretcher for substantially uniaxially orienting a film includes a plurality of gripping members to hold opposing edge portions of the film, paths along which the gripping members travel to stretch the film in a stretching region, and a drive mechanism to convey the film and gripping members along a machine direction. At least a portion of the paths in the stretching region define diverging, curvilinear courses disposed in-plane. The paths are configured such that during the stretching an extent of uniaxial character, U, is between zero and unity and a minimum value of an extent of uniaxial character, U, is at least 0.70 over a final portion of the stretching after achieving a TDDR of 2.5. U is defined as U=(1/MDDR?1)/(TDDR1/2?1), wherein TDDR is greater than 4 at an end of the stretching region.

Abstract: An optical low pass filter or blur filter, and method of making the filters, using an article having a birefringent surface for refracting incoming light when used with an image sensor. The birefringent surface of the article, such as a film, is structured or tilted such that, when the blur filter is placed within an optical path between a lens and the image sensor, the birefringent surface causes refraction of a light signal in the optical path into multiple light signals each being incident upon different sub-pixels within the pixels in the image sensor to prevent or reduce artifacts, such as undesirable color moiré effects, in the resulting digital image. The structures on the surface have a variable pitch or angles. The variable pitch can include a periodic, aperiodic, or quasi-aperiodic pitch, to reduce diffractive artifacts in the resulting image.

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: 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: A method of stretching films in which all or a portion of the width of the film is cooled during or just after stretching so as to improve the uniformity of the film. The includes stretching a polymeric film in a tenter that grasps the film with a plurality of clips along the opposing edges of the film and propels the clips to thereby stretch the film. The tenter includes driven clips and idler clips, with at least one idler clip between respective pairs of driven clips. The cooling is done so as to improve the uniformity of the clip spacing relative to the spacing obtained at otherwise identical process conditions without such cooling.