Abstract:
An electronic device may generate content that is to be displayed on a display. The display may have an array of liquid crystal display pixels for displaying image frames of the content. The display may be operated in at least a normal viewing mode, a privacy mode, an outdoor viewing mode, and a power saving mode. The different view modes may exhibit different viewing angles. In one configuration, the display may include a backlight unit (42) that generates a collimated light source and that includes a switchable diffuser film (200) for selectively scattering the collimated light source depending on the current viewing mode of the display. In another configuration, the display may include a backlight unit that generates a scattered light source that includes a switchable microarray structure such as a switchable mirror structure or a tunable microlens array for selectively collimating the scattered light source depending on the current viewing mode.
Abstract:
Displays such as liquid crystal displays may be provided with structures that minimize curtain mura. A display may have upper (22) and lower (24) polarizers. A color filter layer (12) and a thin film transistor layer (14) may be located between the upper and lower polarizers. A liquid crystal layer (16) may be interposed between the color filter layer and the thin film transistor layer. A first optical film layer (18) that includes a birefringent compensating layer (62) may be located between the upper polarizer and the color filter layer. A second optical film layer (20) that is devoid of birefringent compensating layers may be located between the thin film transistor layer and the lower polarizer. A grid of metal signal lines (66) may be used to distribute signals to thin film transistors on the thin film transistor layer. A black mask (68) may be interposed between the grid of signal lines and the thin film transistor layer.
Abstract:
A display may be formed by an array of light-emitting diodes mounted to the surface of a display substrate. The light-emitting diodes may be inorganic light-emitting diodes formed from separate crystalline semiconductor structures. An array of pixel control circuits may be used to control light emission from the light-emitting diodes. Each pixel control circuit may be configured to control one or more respective passive matrices. To control partial pixel cells in the display, a donor pixel control circuit in a partial pixel cell may control the pixels in a receptor partial pixel cell without a pixel control circuit. To mitigate the size of an inactive area of the display, fanout signal lines for the display may be formed in the light-emitting active area of the display. The fanout signal lines may be formed between a row of pixel control circuits and a bottom edge of the light-emitting active area.
Abstract:
An electronic device may contain components such as a processor, video circuitry, camera flash, communications circuitry, and other components that may generate heat during operation. The device may have a display with a backlight unit that contains light -emitting diodes.
Abstract:
An electronic device such as a wearable electronic device may have a band. The band may form a stand-alone device or a strap for a wristwatch unit or other device. Electrical components may be mounted on flexible printed circuit substrates. A substrate may be encapsulated by elastomeric polymer material or other material forming the band. The elastomeric polymer material may form cavities that receive the electrical components. Components such as light-emitting diodes may be mounted to the flexible printed circuit substrates so that the light-emitting diodes are located in the cavities. Reflective sidewalls in the cavities may reflect light from the light-emitting diodes outwardly through a thinned portion of the band. Light-diffusing material in the cavities may be formed from clear polymer with light-scattering particles.
Abstract:
An electronic device is provided with a display (14) having a backlight (88) with light sources (82-1..82-N) of different colors. The electronic device includes a color ambient light sensor (20) that measures the color of ambient light and control circuitry (30) that adjusts the color of light emitted from the backlight based on the color of ambient light. The light sources may include at least first and second light-emitting diodes that emit light having different color temperatures. The control circuitry may adjust the intensity of light emitted from the first light-emitting diode relative to the intensity of light emitted from the second light-emitting diode to produce a backlight color that more closely matches the color of ambient light. The first and second light-emitting diodes may include an ultraviolet light-emitting diode die and a blue light-emitting diode die coated with red and green phosphors and mounted in a common semiconductor package.
Abstract:
An electronic device may be provided with a display. Backlight structures may be used to provide backlight for the display. The backlight structures may include a light guide plate. A rectangular ring-shaped chassis may have a rectangular opening that receives the light guide plate. One or more edges of the chassis may be provided with an array of notches that receive light-emitting diodes or other light sources. The light sources may launch light into edge portions of the light guide plate. The chassis may include a first plastic structure such as a light reflecting structure formed from a material such as white plastic. The first plastic structure may surround two or more peripheral edges of the light guide plate. The chassis may also include a second plastic structure such as a light blocking structure formed from a material such as black plastic that helps prevent light leakage.
Abstract:
Displays such as liquid crystal displays may be provided with structures that minimize curtain mura. A display may have upper (22) and lower (24) polarizers. A color filter layer (12) and a thin film transistor layer (14) may be located between the upper and lower polarizers. A liquid crystal layer (16) may be interposed between the color filter layer and the thin film transistor layer. A first optical film layer (18) that includes a birefringent compensating layer (62) may be located between the upper polarizer and the color filter layer. A second optical film layer (20) that is devoid of birefringent compensating layers may be located between the thin film transistor layer and the lower polarizer. A grid of metal signal lines (66) may be used to distribute signals to thin film transistors on the thin film transistor layer. A black mask (68) may be interposed between the grid of signal lines and the thin film transistor layer.
Abstract:
A liquid crystal display may have upper and lower polarizers (22, 24). A color filter layer (12) and a thin film transistor layer (14) may be located between the upper and lower polarizers. A liquid crystal layer (16) may be interposed between the color filter layer and the thin film transistor layer. A first optical film layer (18) that includes a birefringent compensating layer (62) may be located between the upper polarizer and the color filter layer. A second optical film layer (20) that may be devoid of birefringent compensating layers may be located between the thin film transistor layer and the lower polarizer. A grid of metal signal lines (66) may be used to distribute signals to thin film transistors on the thin film transistor layer. A black mask (68) may be interposed between the grid of signal lines and the thin film transistor layer.