摘要:
Multilayer optical film that can be used as a reflective polarizer or mirror is disclosed. The multilayer optical film comprises alternating optical layers of polyesters such as PET and PEN, copolymerized with 4,4′-biphenyl dicarboxylate. The multilayer optical film exhibits a high ratio of in-plane to out-of-plane birefringence.
摘要:
In one embodiment, the invention provides a polyethylene terephthalate film comprising a biaxially oriented and birefringent film polyethylene terephthalate film having at least one layer having a thickness of from 10 mils (0.25 mm) to 25 mils (0.64 mm), wherein the film is formed from a polyethylene terephthalate resin comprising the reaction product of dimethyl terephthalate, terephthalic acid, or a combination thereof ethylene glycol, a diol or triol monomer other than ethylene glycol and from 0.9 to 3 mol percent of a sulfonate monomer having an inorganic counterion based on 100 mol percent dimethyl terephthalate, terephthalic acid, or a combination thereof.
摘要:
Multilayer optical film that can be used as a reflective polarizer or mirror is disclosed. The multilayer optical film comprises alternating optical layers of polyesters such as PET and PEN, copolymerized with 4,4′-biphenyl dicarboxylate. The multilayer optical film exhibits a high ratio of in-plane to out-of-plane birefringence.
摘要:
A reflective film includes microlayers arranged into optical repeat units, each optical repeat unit including a negatively birefringent microlayer. The microlayers are tailored to provide the film with on-axis polarizing properties, such that normally incident light polarized along a block axis is substantially reflected and normally incident light polarized along a pass axis is substantially transmitted. On-axis transmission for the block axis may be 70%. The microlayers also provide the film with angularly dependent polarizing properties: p-polarized light incident in a block plane of incidence is substantially reflected at near-normal angles but substantially transmitted at an oblique angle. The film transmits unpolarized light incident in this plane more strongly at the oblique angle than at normal. The films can be used in direct-lit backlights, luminaires, and similar lighting systems for flux leveling to promote spatial brightness uniformity.
摘要:
An optical stack (400) having a plurality of alternating polymeric layers (401, 402) is described. The alternating layers may be alternating birefringent (syndiotactic polystyrene, sPS) and isotropic (CoPENa) layers, or alternating positively and negatively birefringent layers. Birefringent layers are made using polymers which form optically symmetrical crystallites upon stretching of the polymer. The optical stack has a large refractive index difference in the x-direction (the stretching direction) and small refractive index differences in the y- and z-directions (the non-stretching directions). The optical stack can be made using standard film tentering methods and may be a multilayer reflective polarizer.
摘要:
An optical stack (400) having a plurality of alternating polymeric layers (401, 402) is described. The alternating layers may be alternating birefringent (syndiotactic polystyrene, sPS) and isotropic (CoPENa) layers, or alternating positively and negatively birefringent layers. Birefringent layers are made using polymers which form optically symmetrical crystallites upon stretching of the polymer. The optical stack has a large refractive index difference in the x-direction (the stretching direction) and small refractive index differences in the y- and z-directions (the non-stretching directions). The optical stack can be made using standard film tentering methods and may be a multilayer reflective polarizer.
摘要:
The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthtalate ionomer.
摘要:
A communication article and system comprising a writing member having a dry erasable front surface and a projection member is disclosed. The projection member includes an asymmetric optical diffuser that scatters light in a first direction with a first viewing angle AH, and in a second direction orthogonal to the first direction with a second viewing angle AV. The ratio AH/AV is at least about 2.
摘要:
A light diffusing optical construction is disclosed. The optical construction includes a symmetric optical diffuser that scatters light in a first direction with a first viewing angle AH and in a second direction orthogonal to the first direction with a second viewing angle AV, where AV is substantially equal to AH. The symmetric optical diffuser includes an optically transparent first layer and a plurality of randomly arranged optically transparent beads partially embedded in the first layer leaving portions of the beads exposed. The optical construction also includes a specular reflector that reflects light that is not scattered by the symmetric optical diffuser. The specular reflector has a first average reflectance Ro in the visible at zero incident angle and a second average reflectance R60 in the visible at 60 degree incident angle. Ro/R60 is at least about 1.5. The optical construction also includes a light absorbing layer that absorbs light that is not reflected by the specular reflector.
摘要:
A light diffusing optical construction is disclosed. The optical construction includes a symmetric optical diffuser that scatters light in a first direction with a first viewing angle AH and in a second direction orthogonal to the first direction with a second viewing angle AV, where AV is substantially equal to AH. The symmetric optical diffuser includes an optically transparent first layer and a plurality of randomly arranged optically transparent beads partially embedded in the first layer leaving portions of the beads exposed. The optical construction also includes a specular reflector that reflects light that is not scattered by the symmetric optical diffuser. The specular reflector has a first average reflectance Ro in the visible at zero incident angle and a second average reflectance R60 in the visible at 60 degree incident angle. Ro/R60 is at least about 1.5. The optical construction also includes a light absorbing layer that absorbs light that is not reflected by the specular reflector.