Abstract:
A display may have an array of pixels that display images for a user. The backlight unit may have a light-guide layer. An array of light-emitting diodes may emit light into an edge of the light-guide layer. The light guide layer may overlap a backlight reflector. The backlight reflector may include a backlight reflector panel formed from a stack of dielectric layers on a rectangular substrate. The backlight reflector may also include a strip of backlight reflector tape having an edge that is overlapped by an edge portion of the backlight reflector panel. Color compensating features such as printed colored ink patterns may be formed on the backlight reflector to adjust the color of backlight illumination in portions of the backlight unit adjacent to the light-emitting diodes.
Abstract:
A display has an array of display pixels formed from display layers such as one or more polarizer layers, a substrate on which an array of display pixel elements such as color filter elements and downconverter elements are formed, a liquid crystal layer, and a thin-film transistor layer that includes display pixel electrodes and display pixel thin-film transistors for driving control signals onto the display pixel electrodes to modulate light passing through the display pixels. A light source such as one or more laser diodes or light-emitting diodes may be used to generate light for the display. The light may be launched into the edge of a polymer layer or other light guide plate structure. A light guide plate may include phase-matched structures such as holographically recorded gratings or photonic lattices that direct the light upwards through the array of display pixels.
Abstract:
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes on a printed circuit board. The backlight unit may include first, second, and third light spreading layers formed over the array of light-emitting diodes. A color conversion layer may be formed over the first, second, and third light spreading layers. First and second brightness enhancement films may be formed over the color conversion layer.
Abstract:
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a backlight unit. The backlight unit may include a printed circuit board, a plurality of light-emitting diodes mounted on the printed circuit board, at least one light spreading layer formed over the printed circuit board that spreads light received from the plurality of light-emitting diodes, a partially reflective layer formed over the at least one light spreading layer, a color conversion layer formed over the partially reflective layer, a collimating layer formed over the color conversion layer, a brightness enhancement film formed over the collimating layer, and a diffuser formed over the brightness enhancement film. The at least one light spreading layer may include two light spreading layers with elongated protrusions that are rotated relative to each other.
Abstract:
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a backlight unit. The backlight unit may include a printed circuit board, a plurality of light-emitting diodes mounted on the printed circuit board, at least one light spreading layer formed over the printed circuit board that spreads light received from the plurality of light-emitting diodes, a partially reflective layer formed over the at least one light spreading layer, a color conversion layer formed over the partially reflective layer, a collimating layer formed over the color conversion layer, a brightness enhancement film formed over the collimating layer, and a diffuser formed over the brightness enhancement film. The at least one light spreading layer may include two light spreading layers with elongated protrusions that are rotated relative to each other.
Abstract:
An electronic device may have a display such as a liquid crystal display. The display may have an array of pixels that display images to a user. Backlight structures may provide the array of pixels with backlight illumination at a backlight illumination level. The backlight structures may have a light source with an array of light-emitting diodes and photoluminescent material that is pumped by pump light from the light-emitting diodes. The backlight illumination may experience color variations as a function of the backlight illumination level. Circuitry in the electronic device may be used to implement a backlight level color compensator. The backlight level color compensator may apply color correction factors to the image data of the displayed images to compensate for variations in color of the image data due to variations in backlight illumination level and operating temperature.
Abstract:
A display device is provided. The display device includes a light source emitting a blue light and a light emitting layer including a first group of red quantum dots and a second group of green quantum dots. The light emitting layer is configured to absorb a first portion of the blue light from the light source to emit red light and green light and to transmit a second portion of the blue light. The display device also includes dichroic filter layers to improve light recycling and backlight efficiency.
Abstract:
A display device is provided. The display device includes a light source emitting a blue light and a light emitting layer including a first group of red quantum dots and a second group of green quantum dots. The light emitting layer is configured to absorb a first portion of the blue light from the light source to emit red light and green light and to transmit a second portion of the blue light. The display device also includes a dichroic filter layer configured to reflect a portion of the transmitted second portion of the blue light such that the reflected portion of the blue light is recycled in the light emitting layer and to transmit a remaining portion of the transmitted second portion of the blue light to output a white light.
Abstract:
A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a backlight unit. The backlight unit may include a printed circuit board, a plurality of light-emitting diodes mounted on the printed circuit board, at least one light spreading layer formed over the printed circuit board that spreads light received from the plurality of light-emitting diodes, a partially reflective layer formed over the at least one light spreading layer, a color conversion layer formed over the partially reflective layer, a collimating layer formed over the color conversion layer, a brightness enhancement film formed over the collimating layer, and a diffuser formed over the brightness enhancement film. The at least one light spreading layer may include two light spreading layers with elongated protrusions that are rotated relative to each other.
Abstract:
An electronic device may include display layers such as liquid crystal display layers and a backlight unit that provides illumination for the display layers. The backlight unit may include light-emitting diodes that emit light into the edge of a light guide film. To minimize the inactive area of the display, the light-emitting diodes may be tightly spaced to approximate a line light source instead of point light sources. Color and/or luminance compensation layers may be incorporated at various locations within the backlight structures to ensure that the backlight provided to the display layers is homogenous. A thin-film transistor layer of the display may be coupled to a printed circuit board by a flexible printed circuit. The flexible printed circuit may have additional solder mask layers to improve robustness, may include encapsulation, and may have traces with a varying pitch.