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.

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.

Broadband reflectors include a UV-reflective multilayer optical film and a VIS/IR-reflective layer. In various embodiments, the VIS/IR reflective layer may be a reflective metal layer or a multilayer optical film. Concentrated solar power systems and methods of harnessing solar energy using the broadband reflectors and optionally comprising a celestial tracking mechanism are also disclosed.

A reflective optical film includes a reflective light-polarizing unit including a multilayer reflective sheet composed of a plurality of polymer films stacked on top of one another. Each polymer film has a thickness, every two adjacent polymer films are two different materials, and the thicknesses of the polymer films are gradually decreased from two outmost sides of the multilayer reflective sheet to a middle of the multilayer reflective sheet. At least one of the polymer films is a birefringence material layer that conforms to the condition of NXNYNZ, where NX is the index of refraction of light at X direction of the multilayer reflective sheet, NY is the index of refraction of light at Y direction of the multilayer reflective sheet, and NZ is the index of refraction of light at Z direction of the multilayer reflective sheet.

An optical reflective film which includes at least one unit formed by laminating a high refractive index layer and a low refractive index layer on a substrate and is characterized in that at least either of the high refractive index layer or the low refractive index layer contains two or more kinds of polyvinyl alcohols having different degrees of saponification, the high refractive index layer and the low refractive index layer contain polyvinyl alcohols having approximately the same degree of saponification, and an average degree of saponification of polyvinyl alcohols contained in the high refractive index layer and an average degree of saponification of polyvinyl alcohols contained in the low refractive index layer are different from each other.

Articles including post-formed multilayer optical films with layers of at least one strain-induced birefringent material, methods of manufacturing such articles by post-forming multilayer optical films, and multilayer optical films that are particularly well-suited to post-forming operations are disclosed. The articles, methods and multilayer optical films of the present invention allow for post-forming of multilayer optical films including strain-induced index of refraction differentials while retaining the desired optical properties of the multilayer optical films.

An optical film includes a plurality of alternating first and second polymeric layers disposed on a first protective layer. Each of the first and second polymeric layers has an average thickness less than about 500 nm and the first protective layer has an average thickness greater than about 750 nm. An olefin layer can be disposed on the first protective layer opposite the plurality of alternating first and second polymeric layers. The olefin layer includes cyclic olefin copolymer, cyclic olefin polymer, or a blend thereof. The olefin layer can have an unstructured major surface opposite the first protective layer. A bonding layer is disposed between, and bonds together, the olefin layer and the first protective layer. The optical film is integrally formed.

Optical films are described. In particular, optical films including a reflective polarizer portion and an infrared portion, with no adhesive between these two portions, are described. These optical films may be particularly suitable for combiner applications, including automotive heads up display applications with demanding ambient environments.

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.

A light reflective film roll may include a core main body formed in a cylindrical shape and having a length in a width direction of 1.2 m or more; a cushion layer formed by a foamed resin and provided on an outer surface of the core main body; and a light reflective film including a light reflective membrane, which has a reflection unit formed by alternately laminating a high refractive index layer and a low refractive index layer, a pressure sensitive adhesive layer at one outermost layer of the light reflective membrane, and a hard coat layer at the other outermost layer of the light reflective membrane. The light reflective film may be wound up on the outer surface of the cushion layer.