Abstract: An electronic device may include a display system and an optical system that are supported by a housing. The optical system may be a catadioptric optical system having one or more lens elements. The optical system may include a wave plate stack with one or more wave plates. The display system may include a polarizer stack with a linear polarizer and one or more wave plates. The optical system and display system may each include a negative dispersion quarter wave plate. A positive C-plate may be positioned adjacent to each quarter wave plate. The optical system may include a quarter wave plate having positive birefringence whereas the display system may include a quarter wave plate having negative birefringence. The optical system and display system may each include a quarter wave plate and a half wave plate.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. The illumination optics may produce illumination that is modulated by the fLCOS panel to produce image light. The waveguide may direct the image light towards an eye box. The fLCOS panel may include a ferroelectric liquid crystal (fLC) layer and a backplane. In order to maximize the reflectance of the fLCOS panel and thus the optical performance of the display, the backplane may be a silver backplane or a dielectric mirror backplane. In addition, the backplane may have a cell gap that is equal to a wavelength divided by four times the birefringence of the fLC layer. In order to further optimize the optical performance of the display module, the wavelength used in determining the cell gap may be a green wavelength between 500 nm and 565 nm.

Abstract: In an embodiment, an electronic device includes a display and processing circuitry. The display includes a plurality of pixels arranged in a plurality of rows, wherein a first grouping of the plurality of rows displays image content during a first portion of an image frame, and wherein a second grouping of the plurality of rows displays image content during a second portion of the image frame. The processing circuitry is operatively coupled to the display and determines a velocity associated with the image content displayed by the first grouping of the plurality of rows moving across the display and adjusts a position of the image content displayed by the second grouping of the plurality of rows during the second portion of the image frame.

Abstract: An electronic device may include a display panel configured to produce light and a lens assembly that receives the light from the display panel. The lens assembly may include a first lens and a second lens. The second lens may be a removable lens that is configured to be selectively attached to the lens assembly. The lens assembly may also include a partially reflective mirror that is interposed between the first lens and the display panel, a reflective polarizer that is interposed between the first lens and the second lens when the second lens is attached to the lens assembly, and a quarter wave plate that is interposed between the reflective polarizer and the second lens when the second lens element is attached to the lens assembly.

Abstract: Electrical shield line systems are provided for openings in common electrodes near data lines of display and touch screens. Some displays, including touch screens, can include multiple common electrodes (Vcom) that can have openings between individual Vcoms. Some display screens can have an open slit between two adjacent edges of Vcom. Openings in Vcom can allow an electric field to extend from a data line through the Vcom layer. A shield can be disposed over the Vcom opening to help reduce or eliminate an electric field from affecting a pixel material, such as liquid crystal. The shield can be connected to a potential such that electric field is generated substantially between the shield and the data line to reduce or eliminate electric fields reaching the liquid crystal.

Abstract: Increasing resolution of liquid crystal displays may result in small distances between adjacent liquid crystal display pixels. This tight pixel spacing may reduce transmission through the liquid crystal display pixels and may result in cross-talk between the liquid crystal display pixels. To increase transmission and, correspondingly, display efficiency, a reflective layer may be included in the liquid crystal display. The reflective layer recycles backlight that may otherwise be absorbed, improving transmittance and efficiency. To reduce color shift and color mixing caused by cross-talk, the pixels may have their pixel electrodes arranged in a zigzag layout. Each pixel electrode may have a height that is less than or equal to the total height of the pixel divided by two. The pixel electrodes in a given row are also alternatingly coupled to first and second gate lines. This zigzag layout results in an increased distance between adjacent pixel electrodes, mitigating pixel cross-talk.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. The illumination optics may include a red, green, and blue light sources. The fLCOS panel may produce image light by modulating a series of image frames onto illumination light. Control circuitry may control the illumination optics to produce the illumination light for each image frame in the series of image frames according to a green-heavy illumination sequence that includes first, second, and third time periods. The green light source may be active during each of the first, second, and third time periods. This may allow the green light source to be driven with a lower current density than the other light sources without significantly reducing image quality at an eye box. The lower current density may match the peak efficiency of the green light source, thereby minimizing power consumption by the display.

Abstract: A display may have display layers that form an array of pixels. An angle-of-view adjustment layer may overlap the display layers. The angle-of-view adjustment layer may include an array of adjustable light blocking structures formed from electrochromic material. The electrochromic material may be interposed between first and second electrode layers. When it is desired to operate the display in a private viewing mode, control circuitry may apply a current to the first and second electrodes that causes the electrochromic material to become more opaque, thereby restricting the angle of view of the display. When it is desired to operate the display in a public viewing mode, control circuitry may apply a current to the first and second electrodes that causes the electrochromic material to become more transparent, thereby opening up the angle of view of the display.

Abstract: An electronic device such as a head-mounted device may have a display that displays computer-generated content for a user. The head-mounted device may have an optical system that directs the computer-generated content towards eye boxes for viewing by a user. The optical system may include a spatially addressable adjustable optical component. The adjustable optical component may have first and second electrodes and an electrically adjustable material between the first and second electrodes. The electrically adjustable material may include a transparent conductive material such as indium tin oxide that includes a pattern of segmented trenches configured to provide the transparent conductive material with electrical anisotropy. Contacts may be coupled to the transparent conductive material. Control circuitry can adjust the electrically adjustable material to form a spatially addressable light modulator or adjustable lens.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. The display may include a temperature sensor that gathers temperature sensor data. Control circuitry may select a non-square wave drive voltage waveform based on the gathered temperature sensor data and/or based on frame history information for the fLCOS display panel. The control circuitry may control the fLCOS panel to produce image light by driving the fLCOS panel using the selected non-square wave drive voltage waveform. The non-square wave drive voltage waveform may be an overdrive waveform or an underdrive waveform. This may serve to optimize the reflectance of the fLCOS display panel and thus the optical performance of the display module regardless of operating temperature and frame history.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. A twisted nematic cell may be optically interposed between the fLCOS panel and the waveguide. A birefringent crystal may be optically interposed between the cell and the waveguide. The cell may have a first state in which the cell transmits the image light with a first polarization and a second state in which the cell transmits the image light with a second polarization. The crystal may transmit the image light within spatially offset beams based on polarization. In another arrangement, a quarter waveplate may be optically interposed between the cell and the waveguide and a geometric phase grating may be optically interposed between the quarter waveplate and the waveguide. Control circuitry may toggle the cell between the first and second states to maximize the effective resolution of images at an eye box.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. The illumination optics may produce linear polarized illumination light that is modulated by the fLCOS panel to produce image light. The illumination optics may include light emitters that emit respective wavelengths of the illumination light. The illumination optics may include an X-plate that outputs the illumination light by combining the light emitted by the light emitters. Polarization recycling structures may be optically interposed between each of the light emitters and the X-plate. The polarization recycling structures may include a reflective polarizer. If desired, the polarizing recycling structures may also include a quarter waveplate. The polarization recycling structures may serve to minimize the amount of light lost in producing linearly polarized illumination light for the fLCOS display panel, thereby maximizing the optical efficiency of the display.

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: An electronic device may have a display with an array of inorganic light-emitting diodes. The array of inorganic light-emitting diodes may be overlapped by a polarizer layer such as a circular polarizer. Alternatively, the display may be a polarizer-free display without any polarizer layer over the array of inorganic light-emitting diodes. Each inorganic light-emitting diode may be surrounded by a diffuser that redirects edge-emissions towards a viewer. A top diffuser, a color filter layer, a microlens, and/or a microlens with color filtering and/or diffusive properties may also optionally overlap each inorganic light-emitting diode. The inorganic light-emitting diodes may have reflective sidewalls to mitigate edge-emissions. In this type of arrangement, the array of inorganic light-emitting diodes may be coplanar with one or more opaque masking layers. To mitigate reflections, the display may include two opaque masking layers having differing properties or a single phase separated opaque masking layer.

Abstract: A display may include illumination optics, a ferroelectric liquid crystal on silicon (fLCOS) panel, and a waveguide. The illumination optics may produce illumination that is modulated by the fLCOS panel to produce image light. The waveguide may direct the image light towards an eye box. The fLCOS panel may include a ferroelectric liquid crystal (fLC) layer and a backplane. In order to maximize the reflectance of the fLCOS panel and thus the optical performance of the display, the backplane may be a silver backplane or a dielectric mirror backplane. In addition, the backplane may have a cell gap that is equal to a wavelength divided by four times the birefringence of the fLC layer. In order to further optimize the optical performance of the display module, the wavelength used in determining the cell gap may be a green wavelength between 500 nm and 565 nm.

Abstract: An electronic device may have a display with an array of inorganic light-emitting diodes. The array of inorganic light-emitting diodes may be overlapped by a polarizer layer such as a circular polarizer. Alternatively, the display may be a polarizer-free display without any polarizer layer over the array of inorganic light-emitting diodes. Each inorganic light-emitting diode may be surrounded by a diffuser that redirects edge-emissions towards a viewer. A top diffuser, a color filter layer, a microlens, and/or a microlens with color filtering and/or diffusive properties may also optionally overlap each inorganic light-emitting diode. The inorganic light-emitting diodes may have reflective sidewalls to mitigate edge-emissions. In this type of arrangement, the array of inorganic light-emitting diodes may be coplanar with one or more opaque masking layers. To mitigate reflections, the display may include two opaque masking layers having differing properties or a single phase separated opaque masking layer.

Abstract: Increasing resolution of liquid crystal displays may result in small distances between adjacent liquid crystal display pixels. This tight pixel spacing may reduce transmission through the liquid crystal display pixels and may result in cross-talk between the liquid crystal display pixels. To increase transmission and, correspondingly, display efficiency, a reflective layer may be included in the liquid crystal display. The reflective layer recycles backlight that may otherwise be absorbed, improving transmittance and efficiency. To reduce color shift and color mixing caused by cross-talk, the pixels may have their pixel electrodes arranged in a zigzag layout. Each pixel electrode may have a height that is less than or equal to the total height of the pixel divided by two. The pixel electrodes in a given row are also alternatingly coupled to first and second gate lines. This zigzag layout results in an increased distance between adjacent pixel electrodes, mitigating pixel cross-talk.

Abstract: A system may have windows. The window may have first and second window layers and a layer of material such as guest-host liquid crystal material between the first and second window layers. Electrodes on the window layers may be used to apply electric fields to the guest-host liquid crystal material to adjust the light transmission properties of the window. To ensure that a desired gap between the first and second window layers is maintained, spacers may be formed between the first and second window layers. The spacers may include key-and-lock spacers that have interlocking portions located, respectively, on the first and second window layers. Spacers such as photoresist posts can be attached using adhesive. Hybrid arrangements may also be used in which key-and-lock spacer structures are attached using adhesive bonds.

Abstract: A system such as a vehicle, building, or electronic device system may have a support structure with one or more windows. The support structure and window may separate an interior region within the system from a surrounding exterior region. Control circuitry may receive input such as user input and may adjust an adjustable layer in the window based on the input. The adjustable layer may have a polymer matrix layer with embedded cells. The cells may include intermixed guest-host liquid crystal cells and liquid crystal cells. The guest-host liquid crystal cells and liquid crystal cells may have different liquid crystal materials and/or different sizes that allow the guest-host liquid crystal cells and liquid crystal cells to electrically switch states at different respective threshold voltages. Based on the user input or other input the control circuitry can adjust a drive signal across the adjustable layer to change light transmittance and haze.

Abstract: An optical system is described. The optical system may include a sensor which may be in a mobile device. The optical system may use the same light source for imaging the display and for providing light to a sensor or sensor device. The optical system may be configured so that randomly polarized light will exit the device for viewing so that a user may view the display in any rotated orientation while wearing polarized eyewear. The optical system may further be configured to mitigate reflections in the mobile device from ambient light entering the system and from reflected and backscattered light from cross-contaminating the imaging light of the display.