Abstract: An electronic device may have a display system with a module that produces image light and a waveguide that directs the image light towards an eye box. The module may include a light source, spatial light modulator, and collimating lens between the lens and modulator. The lens may direct illumination from the light source to the modulator, which modulates the illumination to produce the image light. The lens may have a geometry that illuminates the modulator with a non-uniform illumination pattern to mitigate subsequent brightness non-uniformity introduced by the waveguide. The light source may include one or more LEDs that are independently driven by control circuitry over one or more drive lines to help mitigate the non-uniformity introduced by the waveguide and/or to operate the display in a heads-up display mode.

Abstract: A device may include an electronic display to display image frames. The display may include illuminators that generate light and mirrors that selectively direct the light to pixel locations based bitplanes that set the arrangement of the mirrors. Additionally, the device may include duty cycle balancing circuitry that generates and provides duty cycle balancing signals to the electronic display. In response to the duty cycle balancing signals, the electronic display is implements balancing on bitplanes during at least a first portion of off periods during the image frames and implements balancing off bitplanes during at least a second portion of the off periods such that, in the aggregate, a ratio of respective on times of the mirrors to respective off times of the mirrors is balanced across the image frames during the off periods.

Abstract: Systems, methods, and devices for reducing or eliminating image artifacts due to motion are provided. An electronic display may include an electronic display panel having a display pixel, an optical combiner that directs light from the display pixel toward a viewing area, and display driver circuitry. The display driver circuitry may receive image data that defines a total pulse width for one image frame. The display driver circuitry may cause the display pixel to emit light in in multiple pulses totaling to the total pulse width for the display pixel for one image frame.

Abstract: A display may include illumination optics, a spatial modulator, and a waveguide. The illumination optics may produce illumination that is modulated by the spatial modulator to produce image light. The waveguide may direct the image light towards an eye box. The illumination optics may include light source sets that produce the illumination. Each set may include a low power light source and a high power light source. In a first state, the high and low power light sources may be active. In a second state, the low power light sources may be active. Control circuitry may adjust between the first and second states based on image data. The second state may be used when virtual objects in the image data are confined to a peripheral region of the field of view of the eye box.

Abstract: An electronic device may have a display with an array of display pixels. To increase the efficiency of the display, the display may also include an array of microlenses. Each microlens may overlap and focus light from a respective pixel. Pixels for one of the colors of light may have a high aspect ratio. These pixels may be covered by two microlenses or a single cylindrical microlens. The microlens dimensions may be tuned to mitigate non-uniformities in the brightness profiles of the pixels. The microlens edges may be laterally shifted towards or away from the center of the light-emitting areas to either reduce or increase the focusing power of the microlens. The microlenses and color filter elements in each pixel may also be shifted to account for the chief ray angle of the display.

Abstract: Methods and apparatus for combining or separating spectral components by means of a polychromat. A polychromat is employed to combine a plurality of beams, each derived from a separate source, into a single output beam, thereby providing for definition of one or more of the intensity, color, color uniformity, divergence angle, degree of collimation, polarization, focus, or beam waist of the output beam. The combination of sources and polychromat may serve as an enhanced-privacy display and to multiplex signals of multiple spectral components. In other embodiments of the invention, a polychromat serves to disperse spectral components for spectroscopic or de-multiplexing applications.

Abstract: Methods and apparatus for combining or separating spectral components by means of a polychromat. A polychromat is employed to combine a plurality of beams, each derived from a separate source, into a single output beam, thereby providing for definition of one or more of the intensity, color, color uniformity, divergence angle, degree of collimation, polarization, focus, or beam waist of the output beam. The combination of sources and polychromat may serve as an enhanced-privacy display and to multiplex signals of multiple spectral components. In other embodiments of the invention, a polychromat serves to disperse spectral components for spectroscopic or de-multiplexing applications.

Abstract: Methods and apparatus for combining or separating spectral components by means of a polychromat. A polychromat is employed to combine a plurality of beams, each derived from a separate source, into a single output beam, thereby providing for definition of one or more of the intensity, color, color uniformity, divergence angle, degree of collimation, polarization, focus, or beam waist of the output beam. The combination of sources and polychromat may serve as an enhanced-privacy display and to multiplex signals of multiple spectral components. In other embodiments of the invention, a polychromat serves to disperse spectral components for spectroscopic or de-multiplexing applications.

Abstract: Methods and apparatus for reducing or eliminating reflection at the interface between a binary or multi-level diffractive element and a surrounding medium. A non-planar diffractive surface of a diffractive optical element is coated forming a plurality of nanostructures on the non-planar diffractive surface and, in certain embodiments, on a planar surface as well. The nanostructures are chosen for providing adiabatic refractive index matching at the optical interface between the non-planar diffractive surface and a surrounding medium subject to matching tangential fields at surface discontinuities.