Abstract: Polarization modulation with in-plane switching of liquid crystals (LCs) may be used in active retarder stereoscopic display systems where viewers wear passive eyewear to see isolated left and right eye images. Embodiments of the present disclosure may include nematic LC or fast switching ferroelectric liquid crystal (FLC), depending on the desired performance.

Abstract: A polarization conversion system (PCS) is located in the output light path of a projector. The PCS may include a polarizing beam splitter, a polarization rotating element, a reflecting element, and a polarization switch. Typically, a projector outputs randomly-polarized light. This light is input to the PCS, in which the PCS separates p-polarized light and s-polarized light at the polarizing beam splitter. P-polarized light is directed toward the polarization switch on a first path. The s-polarized light is passed on a second path through the polarization rotating element (e.g., a half-wave plate), thereby transforming it to p-polarized light. A reflecting element directs the transformed polarized light (now p-polarized) along the second path toward the polarization switch. The first and second light paths are ultimately directed toward a projection screen to collectively form a brighter screen image in cinematic applications utilizing polarized light for three-dimensional viewing.

Abstract: Curved polarization filters and methods of manufacturing such filters are described in the present disclosure. An exemplary method includes laminating a planar polarization layer to a planar retarder layer at a predetermined orientation and bending the laminate to create a curved filter. The strain on the retarder layer results in stress-induced birefringence, and the predetermined orientation of the retarder substantially compensates for the stress-induced birefringence. In some embodiments, the predetermination is based on mathematical models. In some other embodiment, the predetermination is based on experimental data.

Abstract: A method for providing a projection screen for receiving stereoscopic images may include providing a substrate with a contoured, reflective surface, wherein light reflected from the substrate substantially may undergo no more than a single reflection and may also include coating a first layer on the substrate with a contoured, reflective surface. The first layer may substantially maintain the same optical properties as the substrate without the first layer. The first layer may be substantially conformal to the surface of the substrate and also may be a self assembled monolayer coating which may include at least a functional group that is hydrophobic.

Abstract: Disclosed embodiments include stereoscopic systems having at least one compensator operable to reduce the sensitivity of polarization control over incidence angle of image source optics and analyzer optics. In an exemplary embodiment, the disclosed compensator is operable to compensate polarization changes induced by optics at either or both the image source subsystem and the analyzer subsystem, in which the polarization changes would be operable to cause leakage at the analyzer subsystem if uncompensated. As such, the disclosed compensators and compensation techniques are operable to reduce leakage at the analyzer subsystem even if the disclosed compensator may be located at the analyzer subsystem.

Abstract: Disclosed embodiments relate to eyewear configured to reduce stray light. An exemplary embodiment of the eyewear accounts for various design factors, including the cross sectional profile of the rim, the micro topography of the rim surface, the reflectivity, the theatre or room geometry, proximity of the eye to the lens, lens size, and the screen gain. An exemplary eyewear includes lenses connected to the rims of a frame, and a path may be defined through a maximum height of the outer flange portion of a rim and a maximum height of the inner flange portion of the rim section. The path may be inclined at an angle relative to an angle ? relative to a longitudinal axis defined by the lenses.

Abstract: A polarization conversion system (PCS) is located in the output light path of a projector. The PCS may include a polarizing beam splitter, a polarization rotating element, a reflecting element, and a polarization switch. Typically, a projector outputs randomly-polarized light. This light is input to the PCS, in which the PCS separates p-polarized light and s-polarized light at the polarizing beam splitter. P-polarized light is directed toward the polarization switch on a first path. The s-polarized light is passed on a second path through the polarization rotating element (e.g., a half-wave plate), thereby transforming it to p-polarized light. A reflecting element directs the transformed polarized light (now p-polarized) along the second path toward the polarization switch. The first and second light paths are ultimately directed toward a projection screen to collectively form a brighter screen image in cinematic applications utilizing polarized light for three-dimensional viewing.

Abstract: A polarization conversion system separates light from an unpolarized image source into a first state of polarization (SOP) and an orthogonal second SOP, and directs the polarized light on first and second light paths. The SOP of light on only one of the light paths is transformed to an orthogonal state such that both light paths have the same SOP. A polarization modulator temporally modulates the light on the first and second light paths to first and second output states of polarization. First and second projection lenses direct light on the first and second light paths toward a projection screen to form substantially overlapping polarization encoded images. The polarization modulator may be located before or after the projection lenses. The polarization-encoded images may be viewed using eyewear with appropriate polarization filters.

Abstract: Disclosed herein are systems and related methods for reducing speckle on display screen. More specifically, screen vibration is used to reduce speckle, and in accordance with the disclosed principles, the vibration may be achieved by using wave-based actuation (e.g., acoustic or electromagnetic waves) to vibrate the screen. In an exemplary embodiment, a speckle reducing system may comprise at least one actuating element located proximate to, but not in physical contact with, a display screen. In addition, the at least one actuating element may be configured to generate waves directed towards the display screen. When the waves impact the display screen, the waves impart vibration to the display screen.

Abstract: Generally, this disclosure concerns the angle sensitivity of polarization switch elements and the resulting impact of the ray direction on performance. More specifically, apparatus and techniques for compensating the angular sensitivity of liquid crystal (LC) polarization switches are described that enhance the performance of polarization switches. For example, a polarization switch is disclosed that transforms linearly polarized light of an initial polarization orientation that includes a first and second liquid crystal cell with a compensator located between the LC cells. The compensator layer is operable to enhance the field of view through the polarization switch. Such compensation techniques are particularly useful for short-throw projection environments.

Abstract: Projection systems and methods for providing stereoscopic images viewed through passive polarizing eyewear. The systems relate to projectors that create left and right eye images simultaneously and often as side-by-side images on the image modulator. The systems act to superimpose the spatially separated images on a projection screen with alternate polarization states. The embodiments are best suited to liquid crystal polarization based projection systems and use advanced polarization control.

Abstract: A method for providing a projection screen for receiving stereoscopic images may include providing a substrate with a contoured, reflective surface, wherein light reflected from the substrate substantially may undergo no more than a single reflection and may also include coating a first layer on the substrate with a contoured, reflective surface. The first layer may substantially maintain the same optical properties as the substrate without the first layer. The first layer may be substantially conformal to the surface of the substrate and also may be a self assembled monolayer coating which may include at least a functional group that is hydrophobic.

Abstract: Proposed are various embodiments of projection systems that generally provide stereoscopic images. The projection systems act to split a spatially separated image in a stereoscopic image frame and superimpose the left- and right-eye images on a projection screen with orthogonal polarization states. The embodiments are generally well suited to liquid crystal polarization based projection systems and may use advanced polarization control.

Abstract: Disclosed embodiments relate to eyewear configured to reduce stray light. An exemplary embodiment of the eyewear accounts for various design factors, including the cross sectional profile of the rim, the micro topography of the rim surface, the reflectivity, the theatre or room geometry, proximity of the eye to the lens, lens size, and the screen gain. An exemplary eyewear includes lenses connected to the rim sections of a frame, and a path may be defined through a maximum height of the outer flange portion of a rim section and a maximum height of the inner flange portion of the rim section. The path may be inclined at an angle relative to an angle ? relative to a longitudinal axis defined by the lenses.

Abstract: A polarization conversion system separates light from an unpolarized image source into a first state of polarization (SOP) and an orthogonal second SOP, and directs the polarized light on first and second light paths. The SOP of light on only one of the light paths is transformed to an orthogonal state such that both light paths have the same SOP. A polarization modulator temporally modulates the light on the first and second light paths to first and second output states of polarization. First and second projection lenses direct light on the first and second light paths toward a projection screen to form substantially overlapping polarization encoded images. The polarization modulator may be located before or after the projection lenses. The polarization-encoded images may be viewed using eyewear with appropriate polarization filters.

Abstract: Disclosed herein are systems and related methods for reducing speckle on display screen. More specifically, screen vibration is used to reduce speckle, and in accordance with the disclosed principles, the vibration may be achieved by using wave-based actuation (e.g., acoustic or electromagnetic waves) to vibrate the screen. In an exemplary embodiment, a speckle reducing system may comprise at least one actuating element located proximate to, but not in physical contact with, a display screen. In addition, the at least one actuating element may be configured to generate waves directed towards the display screen. When the waves impact the display screen, the waves impart vibration to the display screen.

Abstract: Polarization preserving front projection screens and diffusers provide optimum polarization preservation for stereoscopic 3D viewing, as well as improved light control for enhanced brightness, uniformity, and contrast for both 2D and 3D systems. Generally, the disclosed screens direct light from a projector toward viewers within a diffusion locus, while maintaining optimum gain characteristics. More specifically, light incident on a region of the front projection screen from a predetermined projection direction is reflected by an engineered surface to a predetermined diffusion locus after undergoing substantially single reflections. The engineered surface, comprised of generating kernels, is used to optimally diffuse illumination light into a range of viewing angles, within the diffusion locus, with suitable gain profile, while optimally preserving polarization for 3D applications.

Abstract: Curved polarization filters and methods of manufacturing such filters. The method includes laminating a planar polarization layer to a planar retarder layer at a predetermined orientation and bending the laminate to create a curved filter. The strain on the retarder layer results in stress-induced birefringence, and the predetermined orientation of the retarder substantially compensates for the stress-induced birefringence. In some embodiments, the predetermination is based on mathematical models. In some other embodiment, the predetermination is based on experimental data.

Abstract: A stiffening strip at selected edges of a screen may enable the use and mounting of a high-elastic modulus substrate screen material. Such screen materials may be engineered to provide polarization-preserving characteristics, and be applied to or part of the high-elastic modulus substrate. Furthermore, the stiffening strip may enable the use of screen vibration techniques to reduce speckle in display applications that use projection screens, particularly those display applications using illumination sources prone to speckle such as laser-based projection. The screen vibration may be provided by a vibrating device attached to the stiffening strip.

Abstract: Polarization preserving projection screens provide optimum polarization preservation for 3D viewing. The projection screens additionally provide improved light control for enhanced brightness, uniformity, and contrast for both 2D and 3D systems. Generally, the disclosed method for providing a projection screen comprises embossing at least a first side of a first substrate to produce an optically functional material and then cutting the optically functional material into pieces to produce a plurality of engineered particles. The plurality of engineered particles may then be deposited on a second substrate to produce a substantially homogeneous optical appearance of the projection screen.