Abstract: An electronic device may be provided with input-output devices and other components such as optical components that emit light and optical components that detect light. An optical component covering structure may be interposed between an interior region of the electronic device and an exterior region that surrounds the electronic device. The optical components may be formed in the interior region of the electronic device. The optical component covering structure may overlap the optical components. The optical component covering structure may be configured to exhibit a flat visible light transmission spectrum. This neutral light transmission characteristic allows the overlapped optical components to emit and/or receive light through the optical component covering structure without imposing an undesired color cast. The optical component covering structure may include first and second layers with complementary light transmission characteristics.

Abstract: A ceramic composite article includes a substrate including a matrix of ceramic material defining a network of interstitial regions and a transparent material occupying at least some of the interstitial regions of the substrate. The transparent material can have a melting point lower than a melting point of the ceramic material. The matrix of ceramic material can be formed by a 3D printing process.

Abstract: A system such as a vehicle may have window that exhibit adjustable transparency. The windows may include liquid crystal devices and polymer dispersed liquid crystal devices that exhibit adjustable amounts of light transmission and haze. An optical property of a window such as window transparency may be modulated using an alternating-current modulation waveform. Modulation of the transparency of the window may be synchronized with modulated light output from a light source. The light source may be located inside the vehicle or may be located outside of the vehicle. By synchronizing the modulation of the transparency of the window with the light source output, privacy may be enhanced or glare may be reduced.

Abstract: An electronic device may include electrical components and other components mounted within an interior of a housing. The device may have a display on a front face of the device and may have a glass layer that forms part of the housing on a rear face of the device. The glass layer may be provided with regions having different appearances. The regions may be textured, may have coatings such as thin-film interference filter coatings formed from stacks of dielectric material having alternating indices of refraction, may have metal coating layers, and/or may have ink coating layers. Textured surfaces may be formed on thin glass layers and polymer films that are coupled to the glass layer. A glass layer may be formed from a pair of coupled glass layers. The coupled layers may have one or more recesses or other structures to visually distinguish different regions of the glass layer.

Abstract: Multiple electronic devices may be used together in a system. The electronic devices may use sensor measurements and other information to detect when an edge of a first electronic device is adjacent to an edge of a second electronic device. In response to detection of adjacency between the edges of the first and second devices, the devices may transition from an independent operating mode in which each device operates separately to a joint operating mode in which resources of the devices are shared. In the joint operating mode, images may extend across displays in the devices, speakers in the devices may be used to play different channels of an audio track, cameras and other sensors may be used in cooperation with each other, and other resources may be shared. Magnetic components may hold devices together in a variety of orientations.

Abstract: An electronic device may have a reconfigurable keyboard. The keyboard may be formed from an array of keys coupled to a housing. Each key may have a movable key member and an associated key display. Control circuitry in the keyboard may direct the key displays to display dynamically adjustable key labels for the keys. Each key movable key member may be formed from a fiber optic plate. The fiber optic plate may be formed from a coherent fiber bundle with opposing first and second surfaces. The first surface may be adjacent to the key display and may receive key label images from the key display. The second surface may face outwardly towards a user and may receive key press input from the fingers of a user while presenting key label images for viewing.

Abstract: An electronic device such as a head-mounted device may have a transparent member supported by head-mounted support structures. Optical sensors such as time-of-flight sensors and other optical sensors may have light-emitting components and light-detecting components. A stray light blocking structure may be formed in the transparent member. The stray light blocking structure may be configured to block stray light that is traveling laterally through an interior portion of the polymer layer. This prevents the stray light from being received by the light-detecting detecting device. The stray light blocking structure may formed by providing the polymer layer with light redirecting structures such as protrusions and/or recesses. Light-absorbing coatings and/or patterned surfaces such as textured surfaces may be incorporated into the stray light blocking structure.

Abstract: A glass sheet having asymmetric chemical strengthening is disclosed and described. The examples described herein are directed to a cover glass for an electronic device and other glass components that may be used as enclosure elements or may form an enclosure. Within the glass component, localized compressive stress regions may be formed on opposite sides of the glass component, which may help arrest or redirect propagating cracks or defects in the glass. The opposing compressive stress regions may also help maintain the overall flatness of the component while increasing strength and/or impact resistance of the component.

Abstract: An electronic device may include electrical components and other components mounted within an interior of a housing. The device may have a display on a front face of the device and may have a glass layer that forms part of the housing on a rear face of the device. The glass layer may be provided with regions having different appearances. The regions may be textured, may have coatings such as thin-film interference filter coatings formed from stacks of dielectric material having alternating indices of refraction, may have metal coating layers, and/or may have ink coating layers. Textured surfaces may be formed on thin glass layers and polymer films that are coupled to the glass layer. A glass layer may be formed from a pair of coupled glass layers. The coupled layers may have one or more recesses or other structures to visually distinguish different regions of the glass layer.

Abstract: An electronic device may have transparent housing structures such as walls formed of glass or sapphire. Housing structures such as transparent housing structures may have a colored coating. The colored coating may include an absorptive layer and a metal layer. The coating may exhibit a color that can be adjusted by adjusting the thickness of the thin absorptive layer. A colored layer such as a layer of colored polymer may be incorporated into the colored coating to further adjust the color of the coating. The colored coating may be formed on an inner or outer housing structure surface. The surface may have a texture to provide the coating with a matte appearance. When formed on an outer surface, a diamond-like carbon layer may protect the colored coating. When formed on an inner surface, a passivation layer may be used to prevent oxidation of the metal layer.

Abstract: Surfaces having structured optical appearances are disclosed. The surface can include substrate, a first optical coating disposed on the substrate having a first refractive index; and a second optical coating disposed on the first optical coating having a second refractive index. The first refractive index is different than the second refractive index. Other surfaces can include a substrate having a visible surface, wherein the visible surface comprises a plurality of structural features, wherein each of the structural features is configured to transmit a light wave that optically interacts with waves of light of other structural features to create a visual appearance. Still other surfaces can include a substrate and an optical coating disposed on the substrate. The optical coating comprising particles in an ordered array within a matrix, wherein the matrix has a first refractive index and the particles have a second refractive index.

Abstract: A system such as a vehicle system or building system may have an enclosing structure such as a wall that surrounds an interior region and separates the interior region from an exterior region. An occupant of the system may be located in the interior region. An adjustable window in the enclosing structure may be located between the interior and exterior regions. Control circuitry in the system may use an exterior sensor system in the exterior region to capture an image of the environment surrounding the system, to locate external objects such as light sources, and to make other measurements. User input can be gathered from the occupant of the system and the location of the occupant and inanimate objects in the interior region can be gathered using an interior sensor system. The control circuitry can adjust the window based on the gathered information.

Abstract: An electronic device has an electrically adjustable optical layer. Displays and other optical components may be supported by a housing structure. The housing structure may form a handheld device housing, a head-mounted housing, or other housing for the electronic device. Control circuitry in the electronic device may adjust the electrically adjustable optical layer. The control circuitry may reduce light transmission for the electrically adjustable optical layer to hide the optical components, may increase light transmission to reveal the optical components while the optical components are being used to receive light or to output light, and may otherwise adjust the electrically adjustable optical layer to exhibit a desired set of optical characteristics depending on the mode of operation of the electronic device.

Abstract: A system such as a vehicle may have window that exhibit adjustable transparency. The windows may include liquid crystal devices and polymer dispersed liquid crystal devices that exhibit adjustable amounts of light transmission and haze. An optical property of a window such as window transparency may be modulated using an alternating-current modulation waveform. Modulation of the transparency of the window may be synchronized with modulated light output from a light source. The light source may be located inside the vehicle or may be located outside of the vehicle. By synchronizing the modulation of the transparency of the window with the light source output, privacy may be enhanced or glare may be reduced.

Abstract: An electronic device or other equipment may include an infrared-transparent one-way mirror. The infrared-transparent one-way mirror may be formed by a layer of material that is supported by a head-mounted support structure or other support structure. The support structure may support the layer of material so that the layer of material separates an exterior region from an interior region. Optical components in the interior region may be overlapped by the layer of material. The optical components may include visible light components such as a visible light camera and infrared components such as an infrared light-emitting device and an infrared light sensor. The optical components may operate through the layer of material while being hidden from view by the reflective appearance of the one way mirror from the exterior region.

Abstract: A window or other component may have glass layers and an interposed polymer layer in which a textured light-scattering layer with a diffuse reflectivity is embedded. The textured light-scattering layer may have a textured polymer carrier film coated with a partially reflective layer such as a metal layer. The polymer carrier film may be textured to cause gaps to form within the partially reflective layer. The gaps may be patterned to form ohmic heating current paths or other signal paths through the partially reflective layer. The partially reflective layer may also serve as an electrode in a light modulator such as a liquid crystal light modulator or other light modulator. Images may be projected onto the textured light-scattering layer. The light-scattering layer may also help extract light from a light guiding layer adjacent to the partially reflective layer.

Abstract: A system such as a vehicle may have windows. A window may have rigid clear layers such as layers of glass or rigid polymer. A polymer layer may be interposed between the rigid clear layers to form a laminated window structure. A conductive layer such as a silver layer or other metal layer in the window may be configured to block infrared light. The conductive layer may be patterned to form signal paths, a radio-transparent region, and other structures in a window. The conductive layer may be formed as a coating on a rigid clear window layer or may be formed on other window structures. The conductive layer may be patterned by removing conductive material from areas of the conductive layer. An insulating layer that visually matches the conductive layer may be formed in these areas without overlapping the conductive area.

Abstract: An electronic device may have a housing in which electrical components such as a display and other components are mounted. Adjustable decoration may be formed on the electronic device. The adjustable decoration may serve as trim for the housing or a component mounted on the housing, may include a logo, or may be used to form other visual elements. The adjustable decoration may have an appearance that is electrically adjustable by control circuitry in the electronic device. The control circuitry may measure sensor data using sensors, may gather user input from input-output devices, and may gather other information with input-output devices to detect events. When an event is detected such as an incoming communication, a calendar reminder, user input, activation of an electrical component such as a camera, or other event, the control circuitry can adjust the appearance of the adjustable decoration.

Abstract: Components of an electronic device, such as glass components, are susceptible to surface damage. Glass components can be strengthened by providing ceramic particles at the exposed surface of the glass. Ceramic particles can also provide optical features, such as color, opacity, and haze to enhance the appearance of the resulting composite article. Where ceramic particles are provided at the exposed surface, the ceramic particles can also produce a desired tactile feature. These features can be provided in various combinations and in different ways across different regions to produce a desired look and feel of the resulting composite article.

Abstract: A system such as a vehicle system may include a window. The window may have glass layers and an interposed polymer layer. Signal paths that contact the polymer layer may be formed within the window. The signal paths may be electrical signal paths formed from wires or patterned conductive traces. The conductive traces may be portions of an infrared-light-blocking layer formed from a conductive film or may be patterned from other conductive thin-film layers. The signal paths may include optical waveguides formed from optical fibers embedded in the polymer or transparent thin-film layers on the glass layers or other substrates. Openings may be formed in the glass layers to allow signal paths to pass to an electrical component. The electrical component may also be wirelessly coupled to the signal paths.