Abstract: A hollow light-recycling backlight has a “semi-specular” component providing a balance of specularly and diffusely reflected light improving the uniformity of the light output. The component may be arranged on the reflectors (1021), (1014) or inside the cavity (1016). This balance is achieved by designing the component's “transport ratio” defined by (F?B)/(F+B), (F and B are the amounts of incident light scattered forwards and backwards respectively by the component in the plane of the cavity) to lie in a certain range. Furthermore, the product of the front and back reflector “hemispherical” reflectivities should also lie in a given range. Alternatively, the “cavity transport value”, a measure of how well the cavity can spread injected light from the injection point to distant points in the cavity should lie in a further range and the “hemispherical” reflectivity of the back reflector should be >0.7.

Abstract: A broadband mirror, polarizer, or other reflector includes separate stacks of microlayers. Microlayers in each stack are arranged into optical repeat units, and the stacks are arranged in series. At a design angle of incidence such as normal incidence, the second stack provides a second 1st order reflection band and a distinct second 2nd order reflection band with a second spectral pass band therebetween. The first stack provides a first 1st order reflection band that fills the second spectral pass band such that a single wide reflection band is formed that includes the first 1st order reflection band, the second 1st order reflection band, and the second 2nd order reflection band. In some cases, the single wide reflection band can include a first 2nd order reflection band of the first stack. In some cases, the first and second stacks may have apodized portions which monotonically deviate from respective baseline portions.

Abstract: An edge-lit backlight comprises a front and back reflector forming a hollow light recycling cavity having a cavity depth H and an output region of area Aout, and one or more light sources disposed proximate a periphery of the backlight to emit light into the light recycling cavity. The light sources have an average plan view source separation of SEP collectively having an active emitting area Aemit, wherein a first parameter equals Aemit/Aout and a second parameter equals SEP/H. The first parameter is in a range from 0.0001 to 0.1, and by the second parameter is in a range from 3 to 10. The front reflector has a hemispherical reflectivity for unpolarized visible light of Rfhemi, and the back reflector has a hemispherical reflectivity for unpolarized visible light of Rbhemi, and Rfhemi*Rbhemi is at least 0.70.

Abstract: A backlight that includes a front reflector and a back reflector that form a hollow light recycling cavity including an output surface is disclosed. The backlight further includes one or more light sources disposed to emit light into the light recycling cavity. The front reflector includes an on-axis average reflectivity of at least 90% for visible light polarized in a first plane, and an on-axis average reflectivity of at least 25% but less than 90% for visible light polarized in a second plane perpendicular to the first plane.

Abstract: 3D stereoscopic viewing enabled by the use of an LCD panel, dynamic backlight, and glasses. The system utilizes an LCD panel with an LED backlight having a 4-color red-green-blue-yellow pixel array and wavelength selective glasses to isolate each channel by color. The system is based on alternating left and right image frames on an LCD panel. One of the frames is illuminated by the red-green-blue LEDs, and the other frame is shown in gray scale and illuminated by the yellow LEDs. The viewer wears glasses where the left lens or filter passes only the spectrum of light used for the left channel of data, and the right lens or filter passes only the spectrum of light used for the right channel of data.

Abstract: A film construction (330) includes a broad band reflective polarizing film (312) that may be immersed in an ultra low refractive index medium (332, 334). The reflecting polarizing film is characterized by a pass axis and a block axis, and its reflectivity for white light of the pass state polarization increases with increasing incidence angle to provide a compressed or narrowed viewing cone selectively in one plane of incidence. In some embodiments, the plane of incidence associated with the compressed viewing cone is aligned with the pass axis. In other embodiments it is aligned with the block axis.

Abstract: A projection system is disclosed, in which a screen may have improved rejection of ambient light by having a high reflectivity at low angles of incidence for a polarization parallel to that of the projector, a low reflectivity at high angles of incidence for a polarization parallel to that of the projector, and a low reflectivity at both low and high angles of incidence for a polarization perpendicular to that of the projector. In some embodiments, for p-polarized light polarized parallel to the projector, the power reflectivity is high at low angles of incidence and decreases to a low value at high angles of incidence. In some embodiments, for p-polarized light polarized perpendicular to the projector, the power reflectivity is low at low angles of incidence. In some embodiments, for s-polarized light polarized perpendicular to the projector, the power reflectivity remains low at all angles of incidence.

Abstract: A film construction (610) includes a group of microlayers that reflect normally incident light polarized along a first axis more than normally incident light polarized along a second axis. The microlayers are arranged into optical repeat units (ORUs) that have a layer thickness distribution along a thickness axis perpendicular to the first and second axes that provides the group of microlayers with an intermediate reflectivity over an extended reflection band for a given incidence condition. The ORUs include thinner ORUs whose thicknesses are less than an average thickness, and thicker ORUs whose thicknesses are greater than the average thickness. The group of microlayers is optically immersed in a medium having a refractive index greater than air, such that “supercritical light” can propagate through the microlayers. The microlayers are oriented such that, on average, the thinner ORUs are closer than the thicker ORUs to an output surface of the construction.

Abstract: A hybrid polarizer includes an absorbing element having a first major surface and a second major surface. The hybrid polarizer also includes a first birefringent reflective polarizer disposed on the first major surface of the absorbing element, the first birefringent reflective polarizer having a first pass axis and a first block axis. The hybrid polarizer further includes a second birefringent reflective polarizer disposed on the second major surface of the absorbing element, the second reflective polarizer having a second pass axis and a second block axis.

Abstract: A hybrid polarizer includes an absorbing element having a first major surface and a second major surface. The hybrid polarizer also includes a first birefringent reflective polarizer disposed on the first major surface of the absorbing element, the first birefringent reflective polarizer having a first pass axis and a first block axis. The hybrid polarizer further includes a second birefringent reflective polarizer disposed on the second major surface of the absorbing element, the second reflective polarizer having a second pass axis and a second block axis.

Abstract: Multilayer reflective polarizers are disclosed that utilize a thick film multilayer stack and that are suitable for use in liquid crystal display devices. The disclosed polarizers can be mechanically stiff and suitable for use as a plate or substrate for other light control films within the display. The polarizers can also include diffusing means to scatter transmitted light of the pass state, reflected light of the block state, or both.

Abstract: Multilayer optical films are disclosed that exhibit high reflectivity at normal incidence for all polarizations but preferentially transmit high angle rays in one or two orthogonal planes of incidence. Both symmetrical and asymmetrical constructions are disclosed. The films can be used in direct-lit backlights and in lighting systems other than direct-lit backlights, such as edge-lit backlights, and non-backlight lighting systems such as systems intended for general illumination without the need for any graphic component, such as luminaires and task lights.

Abstract: 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 <20%, and on-axis transmission for the pass 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.

Abstract: A film includes microlayers arranged into optical repeat units. Adjacent microlayers have in-plane refractive index mismatches ?nx, ?ny tailored to provide mirror-like on-axis properties, such that the film has a reflectivity for normally incident light in an extended wavelength band of at least 75% for any polarization. Adjacent microlayers also have a refractive index mismatch ?nz that provides the film with reduced reflectivity R1 and increased transmission for p-polarized light in the extended wavelength band incident on the film in a first plane of incidence at an angle ?blique, where R1 is no more than half of the minimum of on-axis reflectivity. Further, ?nx and ?ny are different enough so that for light incident on the film in a second plane of incidence orthogonal to the first plane, the film has a reflectivity R2 of at least 75% for such light that is p-polarized and incident at any angle.

Abstract: Illumination devices having a partially transmissive front reflector, a back reflector, and a cavity between them are disclosed. At least one light injector including a baffle and a light source is disposed in the cavity. The light injector is capable of injecting partially collimated light into the cavity. The output area of the illumination device can be increased by disposing light injectors progressively within the cavity, without sacrificing uniformity of the light emitted through the output area.

Abstract: A hybrid polarizer includes an absorbing element having a first major surface and a second major surface. The hybrid polarizer also includes a first birefringent reflective polarizer disposed on the first major surface of the absorbing element, the first birefringent reflective polarizer having a first pass axis and a first block axis. The hybrid polarizer further includes a second birefringent reflective polarizer disposed on the second major surface of the absorbing element, the second reflective polarizer having a second pass axis and a second block axis.

Abstract: Multilayer optical films having one or more reflection bands are provided. The films include alternating polymeric layers configured to selectively reflect and transmit visible light at a design angle of incidence, where the selective reflection includes first and second visible reflection bands. At least one of the first and second visible reflection bands is a first-order reflection.

Abstract: A hybrid polarizer includes an absorbing element having a first major surface and a second major surface. The hybrid polarizer also includes a first birefringent reflective polarizer disposed on the first major surface of the absorbing element, the first birefringent reflective polarizer having a first pass axis and a first block axis. The hybrid polarizer further includes a second birefringent reflective polarizer disposed on the second major surface of the absorbing element, the second reflective polarizer having a second pass axis and a second block axis.

Abstract: A hollow light-recycling backlight has a “semi-specular” component providing a balance of specularly and diffusely reflected light improving the uniformity of the light output. The component may be arranged on the reflectors (1021), (1014) or inside the cavity (1016). This balance is achieved by designing the component's “transport ratio” defined by (F?B)/(F+B), (F and B are the amounts of incident light scattered forwards and backwards respectively by the component in the plane of the cavity) to lie in a certain range. Furthermore, the product of the front and back reflector “hemispherical” reflectivities should also lie in a given range. Alternatively, the “cavity transport value”, a measure of how well the cavity can spread injected light from the injection point to distant points in the cavity should lie in a further range and the “hemispherical” reflectivity of the back reflector should be >0.7.

Abstract: A display device includes a display panel and a biaxial reflective polarizer having a plurality of layers characterized by a varying optical thickness. A majority of the layers of the biaxial reflective polarizer having a smaller optical thickness are disposed closer to the display panel than the layers having a larger optical thickness.