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: An electronic device such as a head-mounted device may have a display that produces a display image. The head-mounted device may have an optical system that merges real-world images from real-world objects with display images. The optical system provides the real-world images and display images to an eye box for viewing by a user. The optical system may use time interleaving techniques and/or polarization effects to merge real-world and display images. Switchable devices such as polarization switches and tunable lenses may be controlled in synchronization with frames of display images. Geometrical phase lenses may be used that exhibit different lens powers to different polarizations of light.

Abstract: An electronic device may have a display that provides image light to a waveguide. First and second liquid crystal lenses may be mounted to opposing surfaces of the waveguide. An coupler may couple the image light out of the waveguide through the first lens. The second lens may convey world light to the first lens. Control circuitry may control the first lens to apply a first optical power to the image light and the world light and may control the second lens to apply a second optical power to the world light that cancels out the first optical power. Each lens may include two layers of liquid crystal molecules having antiparallel pretilt angles. The pretilt angles and rubbing directions of the first lens may be antiparallel to corresponding pretilt angles and rubbing directions of the second lens about the waveguide.

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: 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: An electronic device such as a head-mounted device may have a display that produces a display image. The head-mounted device may have an optical system that merges real-world images from real-world objects with display images. The optical system provides the real-world images and display images to an eye box for viewing by a user. The optical system may use time interleaving techniques and/or polarization effects to merge real-world and display images. Switchable devices such as polarization switches and tunable lenses may be controlled in synchronization with frames of display images. Geometrical phase lenses may be used that exhibit different lens powers to different polarizations of light.

Abstract: To extract light from a light-emitting diode (and thereby improve efficiency of the display), a microlens stack may be formed over the light-emitting diode. The microlens stack may include an array of microlenses that is covered by an additional single microlens. Having stacked microlenses in this way increases lens power without increasing the thickness of the display. The array of microlenses may be formed from an inorganic material whereas the additional single microlens may be formed from an organic material. The additional single microlens may conform to the upper surfaces of the array of microlenses. An additional low-index layer may be interposed between the light-emitting diode and the array of microlenses. A diffusive layer may be formed around the light-emitting diode to capture light emitted from the light-emitting diode sidewalls.

Abstract: An electronic device may have a hinge that allows the device to be flexed about a bend axis. A display may span the bend axis. To facilitate bending about the bend axis without damage, the display may include a display cover layer with a flexible portion. The flexible portion of the display cover layer may be interposed between first and second rigid portions of the display cover layer. The display cover layer may also include a layer with self-healing properties. The layer of self-healing material may be formed across the entire display cover layer or may be formed only in the flexible region of the display cover layer. The display cover layer may include a layer of elastomer in the flexible region of the display cover layer for increased flexibility. Self-healing may be initiated or expedited by externally applied heat, light, electric current, or other type of external stimulus.

Abstract: Display structures and methods of manufacture of display structure including a display panel with a curved three-dimensional film contour are described. In an embodiment, a display panel includes display area with a main body area and a plurality of petals extending from the main body area. The petals are folded into a curved three-dimensional (3D) film contour, and are separated by corresponding trenches between petals. The trenches may be filled with various seam hiding materials to visually obscure the trenches.

Abstract: An electronic device may have a hinge that allows the device to be flexed about a bend axis. A display may span the bend axis. To facilitate bending about the bend axis without damage, the display may include a display cover layer with a flexible portion. The flexible portion of the display cover layer may be interposed between first and second rigid portions of the display cover layer. The display cover layer may also include a layer with self-healing properties. The layer of self-healing material may be formed across the entire display cover layer or may be formed only in the flexible region of the display cover layer. The display cover layer may include a layer of elastomer in the flexible region of the display cover layer for increased flexibility. Self-healing may be initiated or expedited by externally applied heat, light, electric current, or other type of external stimulus.

Abstract: The circular polarizer may be omitted from a display to increase efficiency. A polarizer-free display may use other non-polarizer techniques to mitigate reflections of ambient light and mitigate diffraction reflection artifacts. The polarizer-free display may include a black pixel definition layer that absorbs ambient light. Color filter elements may be included in a black matrix to mitigate ambient light reflections. An intra-anode phase shift layer and/or an inter-anode phase shift layer may be included in the display to mitigate diffractive reflection artifacts. Multiple sub-pixels of the same color may be used in a single pixel to ensure a neutral reflection color. The display may include a cathode layer that is patterned to have openings over the black pixel definition layer to mitigate reflections. The display may include diffusive particles (in the color filter element or in a separate diffuser layer) to mitigate diffractive reflection artifacts.

Abstract: An electronic device may have a hinge that allows the device to be flexed about a bend axis. A display may span the bend axis. To facilitate bending about the bend axis without damage, the display may include a display cover layer with a flexible portion. The flexible portion of the display cover layer may be interposed between first and second rigid portions of the display cover layer. The display cover layer may also include a layer with self-healing properties. The layer of self-healing material may be formed across the entire display cover layer or may be formed only in the flexible region of the display cover layer. The display cover layer may include a layer of elastomer in the flexible region of the display cover layer for increased flexibility. Self-healing may be initiated or expedited by externally applied heat, light, electric current, or other type of external stimulus.

Abstract: An electronic device may have a hinge that allows the device to be flexed about a bend axis. A display may span the bend axis. To facilitate bending about the bend axis without damage, the display may include a display cover layer with a flexible portion. The flexible portion of the display cover layer may be interposed between first and second rigid portions of the display cover layer. The display cover layer may also include a layer with self-healing properties. The layer of self-healing material may be formed across the entire display cover layer or may be formed only in the flexible region of the display cover layer. The display cover layer may include a layer of elastomer in the flexible region of the display cover layer for increased flexibility. Self-healing may be initiated or expedited by externally applied heat, light, electric current, or other type of external stimulus.

Abstract: To extract light from a light-emitting diode (and thereby improve efficiency of the display), a microlens stack may be formed over the light-emitting diode. The microlens stack may include an array of microlenses that is covered by an additional single microlens. Having stacked microlenses in this way increases lens power without increasing the thickness of the display. The array of microlenses may be formed from an inorganic material whereas the additional single microlens may be formed from an organic material. The additional single microlens may conform to the upper surfaces of the array of microlenses. An additional low-index layer may be interposed between the light-emitting diode and the array of microlenses. A diffusive layer may be formed around the light-emitting diode to capture light emitted from the light-emitting diode sidewalls.

Abstract: An optical system may include equipment with a housing that is configured to receive external equipment such as a cellular telephone. The external equipment may include a display. To control the persistence of the display, the optical system may include a light modulating layer. The light modulating layer may switch between a transparent state in which display image light is passed through the light modulating layer to reach the viewer and an opaque state in which display image light is blocked by the light modulating layer from reaching the viewer. The light modulating layer may be placed in the transparent state for a portion of each display frame and the opaque state for the remaining portion of each display frame. The light modulating layer may be formed in the housing of the equipment that receives the external equipment or may be formed with the external equipment directly.

Abstract: An electronic device such as a head-mounted device may have a display that produces a display image. The head-mounted device may have an optical system that merges real-world images from real-world objects with display images. The optical system provides the real-world images and display images to an eye box for viewing by a user. The optical system may use time interleaving techniques and/or polarization effects to merge real-world and display images. Switchable devices such as polarization switches and tunable lenses may be controlled in synchronization with frames of display images. Geometrical phase lenses may be used that exhibit different lens powers to different polarizations of light.

Abstract: An electronic device such as a head-mounted device may have a display that produces a display image. The head-mounted device may have an optical system that merges real-world images from real-world objects with display images. The optical system provides the real-world images and display images to an eye box for viewing by a user. The optical system may use time interleaving techniques and/or polarization effects to merge real-world and display images. Switchable devices such as polarization switches and tunable lenses may be controlled in synchronization with frames of display images. Geometrical phase lenses may be used that exhibit different lens powers to different polarizations of light.

Abstract: An electronic device may have a hinge that allows the device to be flexed about a bend axis. A display may span the bend axis. To facilitate bending about the bend axis without damage, the display may include a display cover layer with a flexible portion. The flexible portion of the display cover layer may be interposed between first and second rigid portions of the display cover layer. The display cover layer may also include a layer with self-healing properties. The layer of self-healing material may be formed across the entire display cover layer or may be formed only in the flexible region of the display cover layer. The display cover layer may include a layer of elastomer in the flexible region of the display cover layer for increased flexibility. Self-healing may be initiated or expedited by externally applied heat, light, electric current, or other type of external stimulus.

Abstract: An electronic device may have a display that provides image light to a waveguide. First and second liquid crystal lenses may be mounted to opposing surfaces of the waveguide. An coupler may couple the image light out of the waveguide through the first lens. The second lens may convey world light to the first lens. Control circuitry may control the first lens to apply a first optical power to the image light and the world light and may control the second lens to apply a second optical power to the world light that cancels out the first optical power. Each lens may include two layers of liquid crystal molecules having antiparallel pretilt angles. The pretilt angles and rubbing directions of the first lens may be antiparallel to corresponding pretilt angles and rubbing directions of the second lens about the waveguide.

Abstract: Aspects of the subject technology relate to display circuitry including pixel overdrive circuitry. The pixel overdrive circuitry includes one more lookup tables of boost values to be applied to pixel display values of a frame to be displayed, for overdrive of that frame. Each lookup table includes a lightness-blur-edge-width-based boost value. The lightness-blur-edge-width-based boost value matches a lightness-blur-edge-width of an intermediate grey-to-grey transition to a lightness-blur-edge-width of a maximum grey-to-grey transition.