Abstract:
This disclosure provides systems, methods and apparatus for light-guiding layers including asymmetrical light-turning features. In one aspect, the asymmetrical light-turning features may include a leading edge oriented at an angle which turns light out of the light-guiding layer, and a near-vertical trailing edge which reduces light leakage from the light-guiding layer. In another aspect, the asymmetrical light- turning features of the light-guiding layer may be oriented in the same or similar direction, and may be distributed with decreasing density adjacent a light source to provide more even illumination.
Abstract:
The disclosed technology relates to methods of patterning elongated structures. In one aspect, a method of forming pillars includes providing a substrate and providing a plurality of beads on a surface of the substrate. Regions of the surface without a directly overlying bead are exposed. The method additionally includes selectively etching the exposed regions of the substrate between the beads such that a plurality of pillars is formed under areas masked by the beads. Selectively etching completely removes at least some of the beads. The pillars that are not covered by beads are etched, thereby leaving some pillars taller than others, with the pillar height pending on the amount of time a pillar was left exposed to etchant by a removed bead.
Abstract:
This disclosure provides systems, methods and apparatus for increasing the efficiency of frontlight systems using thin waveguides (410). In one aspect, a narrowing reflective conduit (460) can be used to condense light from a light source (430) which is thicker than the waveguide (410), and inject it into the waveguide (410). A phosphor strip (470) at the exit aperture of the narrowing reflective conduit can inject light with a diffuse directional profile independent of the directional profile of light within the narrowing reflective conduit (460).
Abstract:
This disclosure provides systems, methods and apparatus for light-guiding layers including light-turning features with multiple reflective surfaces oriented at different angles to the light-guiding layer. In one aspect, the multiple reflective surfaces may be located on each individual light-turning feature, while in another aspect, the multiple reflective surfaces may be located on separate light-turning features. The use of multiple reflective surfaces oriented at different angles can improve the efficiency and appearance of a frontlight system using such a light-guiding layer.
Abstract:
This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for measuring a distance. In one aspect, the method includes actuating or releasing an interferometric modulator having a first surface and a second surface and measuring a distance between the first and second surfaces at a plurality of times during the actuation or release. In another aspect, the method includes illuminating, with a first laser beam having a first wavelength and with a second laser beam having a second wavelength different from the first wavelength, an interferometric modulator having a distance between a first surface which is at least partially reflective and a second surface which is at least partially absorptive, measuring a first intensity of the first laser beam modulated by the interferometric modulator and a second intensity of the second laser beam modulated by the interferometric modulator, and determining the distance based on the measured intensities.
Abstract:
This disclosure provides systems, methods and apparatus for increasing the uniformity of illumination provided by frontlight systems (250) using multiple discrete light sources (230). In one aspect, a phosphor material (236) can be disposed between the discrete light sources and a light-turning waveguide (210), so that at least some of the light emitted by the discrete light sources is absorbed and re-emitted by the phosphor material. The light re- emitted by the phosphor material can have a more diffuse directional profile than the light emitted by the discrete light sources, and injecting this more diffuse light into the waveguide can reduce optical effects which provide non-uniform illumination across the waveguide.
Abstract:
This disclosure provides systems, methods and apparatus for illumination, such as for illuminating displays, including reflective displays. An illumination device (210) includes a light-extracting, diffusive holographic medium (280). The holographic medium may be a holographic film and may be disposed on the surface of a light guide (230), and includes a hologram (282) that both extracts light out of the light guide and diffuses this extracted light for propagation towards the display elements (261) of the display (260). The hologram extracts light by redirecting light, which is propagating within the light guide, so that the light propagates out of the light. The diffusion occurs upon the light being redirected, as the hologram redirects the light towards the light guide in a controlled range of angles.
Abstract:
This disclosure provides an apparatus and method for enhancing the brightness and/or contrast ratio of display devices. In one aspect, the display devices can include a light redirector (403). The light redirector (403) includes a light receiving surface, and a holographic layer including a plurality of transmissive holographic features (403a, 403b) that can receive near-collimated light at non-normal angles with respect to a normal to the light receiving surface and redirect and diffuse the received light along a direction that is within +/- 20 degrees with respect to the surface normal towards a side opposite the light receiving surface.
Abstract:
This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for displaying high bit-depth images using spatial vector screening and/or temporal dithering on display devices including display elements that have multiple primary colors. The systems, methods and apparatus described herein can be configured to select a method of rendering high bit-depth images and/or videos on low bit-depth devices based on the operating speed of the display device.