Abstract: A projector illumination system includes a tunnel integrator incorporated with a field lens at its output end. One advantage of using the field lens is to form an image of the entrance end of the tunnel integrator at the secondary stop of the illumination system when combined with other relay and/or imager field lenses in the illumination system. This reduces vignetting, resulting in an increased uniformity of illumination, and increased light throughput.

Abstract: LCD projection systems that use reflective LCD imager units commonly use one or more polarization beamsplitters to separate the light incident on the imager from the light reflected by one or more respective imagers. The polarizing beamsplitters introduce astigmatism to the image light from the imagers. According to the present invention, the polarization beamsplitters are adapted to reduce the astigmatism.

Abstract: A tilted polarization splitter (13) for use with a projection lens (15) and a light modulating panel (11) is provided. The polarization splitter has an ultra thin substrate (14) whose thickness is chosen so that the depth of focus of the projection lens in imager space is greater than the astigmatism produced by the splitter at its tilted angle. The polarization splitter can be a wire grid polarizer, polarization coating, or birefringence film carried by or formed on the ultra thin, plane parallel plate substrate.

Abstract: Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have a negative first unit (U1) separated from a positive second unit (U2) by a reflective surface (RS) which folds the lens' optical axis. The lenses are telecentric on the short conjugate side, have a large field of view in the direction of the long conjugate, and have low aberration levels, including, in particular, low levels of lateral color.

Abstract: Glass microspheres and rear projection screens containing glass microspheres, which combine a desirable index of refraction (preferably, no greater than about 1.70) and low levels of defects (e.g., bubbles, visible haziness, frostiness, or opacity, substantially nonspherical shapes) upon formation are provided. Also provided is a coating method of placing microspheres on a film for use in a rear projection screen.

Abstract: Optical bodies, comprising: a plurality of first optical layers comprising a first polymer composition that comprises (i) a polyester portion having terephthalate comonomer units and ethylene glycol comonomer units, and (ii) a second portion corresponding to a polymer having a glass transition temperature of at least about 130° C.; and a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers. Also disclosed are optical bodies comprising: (a) a plurality of first optical layers, each first optical layer being oriented; and (b) a plurality of second optical layers, disposed in a repeating sequence with the plurality of first optical layers, comprising a blend of polymethylmethacrylate and polyvinylidene fluoride. Methods of making the above-described optical bodies, and articles employing such optical bodies are also provided.

Abstract: A polymeric composition includes a first polymeric material, for example, an adhesive material, and a second polymeric material disposed as a plurality of elongated structures within the first polymeric material. Each elongated structure has a major axis and the major axes are substantially aligned. The first polymeric material has an index of refraction that differs by at least 0.01 from an index of refraction of the second polymeric material. In some instances, a pressure sensitive adhesive material is selected as the first polymeric material. The orientation of the elongated structures and the difference in indices of refraction results in the polymeric composition scattering light asymmetrically. The polymeric composition is optionally disposed on a substrate and can be used, for example, to extract light from a light guide or to asymmetrically alter the viewing angle of a display.

Abstract: A light engine (9) for a projection display is provided which employs: 1) at least one light source (25), 2) at least one TIR prism assembly (13), and 3) at least one digital micromirror device (15), wherein: (a) the illumination path (55) between the light source (25) and the prism assembly (13) is unfolded, i.e., the illumination path is free of fold mirrors; and (b) the angle &ggr; between the illumination path (55) and the device's horizontal axis (53) is preferably less than or equal to about 20°.

Abstract: The present invention pertains to an optical device useful in a projection system. The optical device can be designed for easy replacement of selected parts, if necessary, without the need for extensive realignment procedures for the projection system.

Abstract: Illumination systems (11) are disclosed which provide scrolling progressive color change on a liquid crystal panel (21), such as a LCoS panel. The systems use transmissive color filters (30, 31, 33) which form an assembly (13) which is rotated about a rotation axis (37). Incident light from a light source (15, 17) passes through the filters and reflects from a reflecting surface (39). As a result of this reflection, the system's optical axis (41, 43) is turned from an orientation substantially perpendicular to the rotation axis to an orientation which does not intersect a filter. Such turning of the optical axis allows colored light to be easily removed from the assembly and avoids problems with color mixing at boundaries between filters as occurs for systems in which light passes through two filters.

Abstract: Optical filters and their manufacture, as well as the use of the optical filters in optical devices, such as polarizers and mirrors are described. The optical filters typically include a first reflective multilayer film, a second reflective multilayer film, and a lossy element disposed between the first and second reflective multilayer films.

Abstract: A multilayer optical body having improved dimensional stability is disclosed. The optical body includes an optical film, such as an oriented multilayer optical film, and a dimensionally stable layer, such as a transparent polycarbonate layer. In addition, in specific implementations, the invention includes an intermediate layer between the optical film and the dimensionally stable layer. Methods of making the optical body are also disclosed.

Abstract: Generally, the present invention relates to an apparatus for reducing astigmatism in a projection system that is particularly well suited to reducing astigmatism in LCD projection systems. A projection system includes a light source to generate light, conditioning optics to condition the light from the light source and an imaging core to impose on image on conditioned light from the conditioning optics to form image light. The imaging core includes a polarizing beamsplitter and at least one imager, and at least one element in the imaging core is adapted to reduce astigmatism in the image light. The astigmatism may arise in the polarizing beamsplitter. A projection lens system projects the astigmatism-reduced image light from the imaging core.

Abstract: Multilayer polymeric films and other optical bodies are provided. The films, which have at least three layers of different composition in the optical repeating unit, reflect light in a first portion of the spectrum while transmitting light in a second portion of the spectrum, exhibit improved reflectivities at oblique angles, and can be designed to suppress one or more higher order harmonics of the main reflection band.

Abstract: The present invention provides pressure-sensitive adhesives having a refractive index of at least 1.48. The pressure-sensitive adhesives comprise at least one monomer containing a substituted or an unsubstituted aromatic moiety.

Abstract: An optical assembly (11) is formed by individually positioning a plurality of prisms (15) using mechanical reference surfaces (19) which are associated with the prism's diagonal (13) and are preferably formed by extensions of a first sub-prism (17A) beyond a second sub-prism (17B). The mechanical references surfaces and a first side of the prism engage fixed mechanical references (23) associated with a housing. A locking element (21) engages a second side of the prism and forces the mechanical reference surfaces and the first side of the prism against the fixed mechanical references to achieve accurate positioning of the prism's diagonal (13).

Abstract: A multilayered polymer film includes a first set of optical layers and a second set of optical layers. The first set of optical layers is made from a polyester which is often birefringent. The polyesters of the first set of optical layers typically have a composition in which 70-100 mol % of the carboxylate subunits are first carboxylate subunits and 0-30 mol % are comonomer carboxylate subunits and 70 to 100 mol % of the glycol subunits are first glycol subunits and 0 to 30 mol % of the glycol subunits are comonomer glycol subunits, where at least 0.5 mol % of the combined carboxylate and glycol subunits are comonomer carboxylate or comonomer glycol subunits. The multilayered polymer film may be used to form, for example, a reflective polarizer or a mirror.

Abstract: Birefringent optical films have a Brewster angle (the angle at which reflectance of p-polarized light goes to zero) which is very large or is nonexistent. This allows for the construction of multilayer mirrors and polarizers whose reflectivity for p-polarized light decreases slowly with angle of incidence, are independent of angle of incidence, or increase with angle of incidence away from the normal. As a result, multilayer films having high reflectivity (for both planes of polarization for any incident direction in the case of mirrors, and for the selected direction in the case of polarizers) over a wide bandwidth, can be achieved.

Abstract: A dichroic polarizing film is made, for example, by, first combining polyvinyl alcohol and a second polymer, such as, polyvinyl pyrrolidone or a sulfonated polyester, in a solvent. The ratio of polyvinyl alcohol to second polymer is between about 5:1 to 100:1 by weight. The film is coated on a substrate, dried, and then stretched to orient at least a portion of the film. The film incorporates a dichroic dye material, such as iodine, to form a dichroic polarizer. This polarizer may be used in conjunction with a multilayer optical film, such as a reflective polarizer, to form an optical polarizer. The multilayer optical film may contain two or more sets of polyester films, where at least one of the sets is birefringent and orientable by stretching. The polyvinyl alcohol/second polymer film and the multilayer optical film may be simultaneously stretched to orient both polymer films.

Abstract: A polishing system for polishing a surface of a substrate, such as the surface of an optical pin mold, to a desired surface finish and profile under the automated control of a computer during a polishing cycle. The polishing system includes a polishing spindle assembly that holds and rotates a polishing tool that is contacted under pressure with a surface of the mold pin. A torque sensor is associated with the polishing spindle assembly to sense a torque on the polishing tool during the polishing cycle. The polishing system further includes a feedback control system that dynamically adjusts the position of the polishing spindle assembly in response to the torque sensed by the torque sensor to maintain a substantially constant torque on the polishing tool during the polishing cycle.