Patent ID: 8917448

Claim:
A combination, comprising: a multilayer optical film having a plurality of microlayers arranged into optical repeat units for reflecting light over an extended wavelength band, adjacent microlayers having refractive index differences that define a first and second in-plane axis, such that the film has a reflectivity of at least 75% for all polarization states of normally incident light, the refractive index differences also being such that for p-polarized light incident on the film in a first plane of incidence that includes the first axis, the film has a reflectivity that decreases by at least half from an initial value at normal incidence to a value R 1 at an incidence angle θoblique measured from a normal of the surface of the multilayer optical film, but for p-polarized light incident on the film in a second plane that includes the second axis, the film has a reflectivity R 2 >R 1 at the incidence angle θoblique; and a polarizer having a pass axis and a block axis, the polarizer and the multilayer optical film being disposed to define an oblique transmission lobe; wherein the optical repeat units have an optical thickness distribution across a thickness of the multilayer optical film, the thickness distribution defining a thin side and a thick side of the multilayer optical film, thinner ones of the optical repeat units being disposed generally towards the thin side and thicker ones of the optical repeat units being disposed generally towards the thick side; and wherein the thin and thick sides of the multilayer optical films are oriented relative to the polarizer to reduce an azimuthal collimation Δφe of the transmission lobe, wherein the azimuthal collimation Δφe is measured in a plane parallel to the surface of the multilayer optical film.