Abstract:
An organic light-emitting diode (OLED) display may have an array of organic light-emitting diode pixels that each have OLED layers interposed between a cathode and an anode. Voltage may be applied to the anode of each pixel to control the magnitude of emitted light. The conductivity of the OLED layers may allow leakage current to pass between neighboring anodes in the display. To reduce leakage current and the accompanying cross¬ talk in a display, the pixel definition layer may disrupt continuity of the OLED layers. The pixel definition layer may have a steep sidewall, a sidewall with an undercut, or a sidewall surface with a plurality of curves to disrupt continuity of the OLED layers. A control gate that is coupled to a bias voltage and covered by gate dielectric may be used to form an organic thin-film transistor that shuts the leakage current channel between adjacent anodes on the display.
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:
Systems and methods for operating a display by dynamically determining a refresh rate for the display. In certain implementations, a processor determines a number of pixels having medium grayscale levels from a histogram for the image. If the number does not exceed a threshold, the processor sets a refresh rate for the display to a first refresh rate. In certain implementations, if the number exceeds a threshold, the processor may set the refresh rate for the display to a second refresh rate. Moreover, the first refresh rate may be lower than the second threshold. In some implementations, the image may be analyzed by subdividing the image into blocks and determining a refresh rate based on grayscale levels or distributions in the blocks. Based on the analysis of the blocks, a corresponding refresh rate may be selected.
Abstract:
An electronic device is provided with a display such as a liquid crystal display. The display includes a liquid crystal display module an array of display pixels. A backlight unit is used to provide backlight illumination to the display module. A shutter module having local dimming elements is used to locally control the amount of light that is transmitted through the display. The local dimming elements can be formed from liquid crystal display structures, polymer-dispersed liquid crystal display structures, photovoltaic material, electrowetting display structures, and/or other suitable light controlling elements. Each local dimming element controls the amount of light that is transmitted through an overlapping region of the array of display pixels. The local dimming elements may be arranged in a uniform array having rows and columns or may be shaped and sized differently and located in specific regions of the display.
Abstract:
An electronic device may have a display such as a liquid crystal display. A color filter layer may be formed on a display layer such as a transparent substrate layer of the display. The color filter layer may include an array of color filter elements on an inner surface of the transparent substrate layer. The color filter layer may include opaque masking material. In an inactive portion of the display, the opaque masking material may be formed over the color filter elements and interposed between the color filter elements. In the inactive portion of the display, the opaque masking material and the color filter elements may form a ring that serves as a border region surrounding an active portion of the display. In the active portion of the display, the opaque masking layer may be patterned to from an opaque matrix that separates the color filter elements.
Abstract:
Systems, methods, and devices for column inversion are provided. In one example, an electronic display may include a display panel having columns of pixels and display driver circuitry. The display driver circuitry may include source amplifiers and demultiplexers. Each demultiplexer may channel data output by at least one source amplifier to one of three columns of pixels. The display driver circuitry may drive the display panel according to a 3-column inversion scheme using one source amplifier per demultiplexer per frame of image data.
Abstract:
One embodiment may take the form of a UV mask for use while curing sealant on LCD displays. The UV mask includes a mother glass and a UV mask layer on the mother glass. A UV absorption film is located adjacent the UV mask layer and an anti-reflection (AR) film is located adjacent the UV absorption film.
Abstract:
An electronic display (102) configured to provide a visual output, such as a liquid crystal display. The electronic display includes an optical shutter and a first polarizer (214) operably connected to the optical shutter. The first polarizer includes an optical filter layer (136; 336), a protective layer (134, 138; 334, 338), and a moisture barrier (210; 310) positioned on a first surface of either the optical filter or the protective layer. The moisture barrier substantially prevents water molecules from being transmitted therethrough.
Abstract:
Devices and methods related to high-contrast liquid crystal displays (LCDs) are provided. For example, such an electronic device 10 may include an LCD 18 with two liquid crystal alignment layers 76, 82 not symmetric to one another and upper and lower polarizing layers 66, 68 respectively above and below the alignment layers 76, 82. Light transmittance through the plurality of pixels 42 may increase monotonically with gray scale voltage. The display 18 may operate using a gray scale level 0 voltage higher than a minimum gray scale level 0 voltage capability of the display. Additionally or alternatively, liquid crystal molecular alignment axes 110 of the two alignment layers 76, 82 may be offset from one another by an angle other than a multiple of 180 degrees. Additionally or alternatively, a first polarizing axis of the upper polarizing layer 66 or a second polarizing axis of the lower polarizing layer 68, or both, may be neither parallel nor perpendicular to one of the liquid crystal molecular alignment axes 110.
Abstract:
Systems, methods, and devices are provided for maintaining a target white point on a light emitting diode based backlight In one embodiment, the backlight may include two or more strings of light emitting diodes, each driven at a respective driving strength. Each string may include light emitting diodes from a different color bin, and the respective driving strengths may be adjusted, for example, through pulse width modulation or amplitude modulation, to maintain the target white point. In certain embodiments, the driving strengths may be adjusted to compensate for shifts in the white point that may occur due to temperature or aging. A controller 70 may adjust the driving strengths based on feedback from a temperature sensor, from an optical sensor 76, from a user input, or from calibration data included within the backlight or system.