Abstract: Various embodiments of the present invention relate to enhancing the brightness of displays that employ illumination systems. In some embodiments, the illumination systems include light guides, diffractive microstructure, and light-turning features. The diffractive microstructure may be configured to receive ambient light at a first angle and produce diffracted light at a second angle greater than the first angle and greater than the critical angle for of light guide. The light is thereby guided within the light guide. The light-turning features may be configured to turn the light guided within the light guide out of a light guide and onto, for example, a spatial light modulator at near normal incidence.

Abstract: Broad band white color can be achieved in MEMS display devices by incorporating a material having an extinction coefficient (k) below a threshold value for wavelength of light within an operative optical range of the interferometric modulator. One embodiment provides a method of making the MEMS display device comprising depositing said material over at least a portion of a transparent substrate, depositing a dielectric layer over the layer of material, forming a sacrificial layer over the dielectric, depositing an electrically conductive layer on the sacrificial layer, and forming a cavity by removing at least a portion of the sacrificial layer. The suitable material may comprise germanium, germanium alloy of various compositions, doped germanium or doped germanium-containing alloys, and may be deposited over the transparent substrate, incorporated within the transparent substrate or the dielectric layer.

Abstract: In various embodiments described herein, a display device includes a front illumination device that comprises a light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide may include a turning film to deliver uniform illumination from a light source to the array of display elements. For many portable display applications, the light guide comprises the substrate used in fabricating the display elements. The display device may include additional films as well. The light guide, for example, may include a diffuser and/or an optical isolation layer to further enhance the optical characteristics of the display.

Abstract: The invention comprises devices and methods for coupling a light source to a display illumination device. In one embodiment, an illumination device includes a light guide comprising a front surface, a back surface, a light coupling section configured to receive optical energy from a light source in to the light guide through said front surface or said back surface at an angle about normal to the optical energy receiving surface, and further configured to direct light through said light guide, and a light turning section configured to redirect out of the light guide at least a portion of the light received from said light coupling section, said redirected light at an angle about normal to the optical energy receiving surface.

Abstract: Devices for providing illumination to a display and method for manufacturing the same. In one embodiment, a display device includes a reflective display and turning features for turning light propagating from opposite directions in a light guide to the reflective display.

Abstract: Various embodiments of the present invention relate to enhancing the brightness of displays that employ illumination systems. In some embodiments, the illumination systems include light guides, diffractive microstructure, and light-turning features. The diffractive microstructure may be configured to receive ambient light at a first angle and produce diffracted light at a second angle greater than the first angle and greater than the critical angle for of light guide. The light is thereby guided within the light guide. The light-turning features may be configured to turn the light guided within the light guide out of a light guide and onto, for example, a spatial light modulator at near normal incidence.

Abstract: In various embodiments described herein, a display device includes a front illumination apparatus that comprises a first light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide panel is edge illuminated by a light source positioned behind the array display elements. The light from such a light source is coupled to a second light guide disposed behind the array of display elements and positioned laterally with respect to the light source. The light in the second light guide is coupled into the first light guide using a small optical coupling element such as a turning mirror. In some embodiments the second light guide may comprise the backplate of the display device.

Abstract: An edge bar having features that discriminate between light propagating in one direction versus the opposite direction may be configured so as to couple light into a light guide while significantly mitigating against edge shadow artifact.

Abstract: In various embodiments described herein, a display device includes a front illumination apparatus that comprises a first light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide panel is edge illuminated by a light source positioned behind the array display elements. The light from such a light source is coupled to a second light guide disposed behind the array of display elements and positioned laterally with respect to the light source. The light in the second light guide is coupled into the first light guide using a small optical coupling element such as a turning mirror. In some embodiments the second light guide may comprise the backplate of the display device.

Abstract: Interferometric modulators and methods of making the same are disclosed. In one embodiment, an interferometric modulator includes an interferometric reflector having a first reflective surface, a second reflective surface, and an optical resonant layer defined by the first reflective surface and the second reflective surface. The interferometric reflector can be configured to transmit a certain spectrum of light at a transmission peak wavelength such that the interferometric modulator has a diminished reflectance of light at the transmission peak wavelength.

Abstract: A microelectromechanical systems (MEMS) display element may include a photovoltaic structure configured to generate electric energy from incident light. In one embodiment, the display element includes a first layer that is at least partially transmissive of light, a second layer that is at least partially reflective of light, and a photovoltaic element that is formed on the first layer or the second layer or formed between the first layer and the second layer. The second layer is spaced from the first layer and is selectably movable between a first position in which the display element has a first reflectivity and a second position in which the display element has a second reflectivity. The first reflectivity is greater than the second reflectivity. The photovoltaic element is at least partially absorptive of light and is configured to convert a portion of the absorbed light into electric energy, at least when the second layer is in the second position.

Abstract: Various embodiments disclose an illumination apparatus. The apparatus may comprise a light guide supporting propagation of light and having at least a portion of one of its edges comprising an array of microstructures. These microstructures may be incorporated in the input window of the light guide to control the light intensity distributed within the light guide. In certain embodiments, the directional intensity of the light entering the light guide may be modified to achieve a desired distribution across the light guide.

Abstract: A reflective or transmissive hologram may be used to extract light from a waveguide. The hologram may be formed by separately exposing each of a plurality of areas of a holographic medium with object beams and/or reference beams having attributes (e.g., illumination angles) that vary randomly or pseudorandomly over the entire hologram. The areas may be contiguous (e.g., in a tiled pattern) or overlapping. In some embodiments, the spacing and/or orientation of the diffraction gratings may vary from area to area. For example, the spacing and/or orientation of the diffraction gratings may vary randomly or pseudorandomly from area to area. Some parts of the hologram may intentionally be made relatively more or relatively less efficient at extracting light from the waveguide.

Abstract: An illumination apparatus includes a light bar, a plurality of indentations in the light bar on a first side of the light bar, and a contoured reflective surface including a plurality of protruding surface portions, such that the surface portions reflect light transmitted through sloping sidewalls of the indentations. The light bar has a first end for receiving light from a light source. The light bar includes material that supports propagation of the light along the length of the light bar. The turning microstructure is configured to turn at least a substantial portion of the light incident on the first side and to direct the portion of light out the second opposite side of the light bar. The protrusions on the contoured reflective surface and the indentations on the light bar can have complimentary shapes and/or aligned in certain embodiments.

Abstract: In various embodiments described herein, a display device includes a front illumination device that comprises a light guide disposed forward of an array of display elements, such as an array of interferometric modulators, to distribute light across the array of display elements. The light guide panel may include a turning layer to deliver uniform illumination from a light source to the array of display elements. For many portable display applications, the light guide panel comprises the substrate used in fabricating the display elements. The light guide panel may include additional films as well. The light guide panel, for example, may include a diffuser and/or an optical isolation layer to further enhance the optical imaging characteristics of the display.

Abstract: Broad band white color can be achieved in MEMS display devices by incorporating a material having an extinction coefficient (k) below a threshold value for wavelength of light within an operative optical range of the interferometric modulator. One embodiment provides a method of making the MEMS display device comprising depositing said material over at least a portion of a transparent substrate, depositing a dielectric layer over the layer of material, forming a sacrificial layer over the dielectric, depositing an electrically conductive layer on the sacrificial layer, and forming a cavity by removing at least a portion of the sacrificial layer. The suitable material may comprise germanium, germanium alloy of various compositions, doped germanium or doped germanium-containing alloys, and may be deposited over the transparent substrate, incorporated within the transparent substrate or the dielectric layer.

Abstract: Light modulator displays may be illuminated using a light guide comprising diffractive optics that directs light onto an array of light modulators. A holographic light turning element may be included with the light guide to turn light propagating within the light guide onto the light modulators. In some embodiments, the holographic element is configured to distribute a substantially uniform amount of light across the array of modulators. The holographic element may, for example, have a turning efficiency that changes along the length of the holographic element. A holographic element can also be used to function as a light bar. Such a holographic element may receive light from a light source such as a light emitting diode and distribute the light along a light guide disposed in front of an array of light modulators.

Abstract: Various embodiments of a display device described herein include an optical propagation region, at least one optical loss structure, an optical isolation layer, and a plurality of display elements. The propagation region includes a light guide in which light is guided via total internal reflection and turning features configured to redirect the light out of the propagation region. The loss structure would disrupt the total internal reflection of at least some of the light guided within the propagation region if disposed directly adjacent thereto. The optical isolation layer includes a non-gaseous material between the propagation region and the loss structure, and is configured to increase an amount of light that is totally internal reflected in the propagation region. The plurality of display elements are positioned to receive the light redirected out of the propagation region. The loss structure is positioned between the plurality of display elements and the propagation region.

Abstract: Broad band white color can be achieved in MEMS display devices by incorporating a material having an extinction coefficient (k) below a threshold value for wavelength of light within an operative optical range of the interferometric modulator. One embodiment provides a method of making the MEMS display device comprising depositing said material over at least a portion of a transparent substrate, depositing a dielectric layer over the layer of material, forming a sacrificial layer over the dielectric, depositing an electrically conductive layer on the sacrificial layer, and forming a cavity by removing at least a portion of the sacrificial layer. The suitable material may comprise germanium, germanium alloy of various compositions, doped germanium or doped germanium-containing alloys, and may be deposited over the transparent substrate, incorporated within the transparent substrate or the dielectric layer.

Abstract: An illumination device includes a holographic film and a light source, such as a point light source. The point light source is positioned at an edge of the holographic film and has a light emitting face that faces the edge of the holographic film. The holographic film includes a hologram formed of diffractive refractive index structures. The density of the diffractive refractive index structures increases with increasing distance from the light source. Light is propagated from the light source through the holographic film, such as by total internal reflection. The diffractive refractive index structures turn the light, thereby causing the light to propagate out of the holographic film in a desired direction. In some embodiments, the light propagating out of the holographic film has a high uniformity across the surface of the holographic film.