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.
Abstract:
An electronic device may include a display having an array of display pixels and having display control circuitry that controls the operation of the display. The display control circuitry may adaptively adjust the spectral characteristics of display light emitted from the display to achieve a desired effect on the human circadian system. For example, the display control circuitry may adjust the spectral characteristics of blue light emitted from the display based on the time of day such that a user' s exposure to the display light may result in a circadian response similar to that which would be experienced in natural light. The spectral characteristics of blue light emitted from the display may be adjusted by adjusting the relative maximum power levels provided to blue pixels in the display or by shifting the peak wavelength associated with blue light emitted from the display.
Abstract:
Touch sensor panel configurations for reducing wobble error for a stylus translating on a surface over and between electrodes of the touch sensor panel are disclosed. In some examples, electrodes with more linear signal profiles are correlated with lower wobble error. In some examples, diffusing elements formed of floating segments of conductive materials can diffuse signal from a stylus to a plurality of electrodes, thus, making the signal profiles associated with the electrodes more linear. In addition, diffusing elements can be configured to improve the optical uniformity of the touch sensor panel. In some examples, the diffusing elements can be formed on the same layer as floating dummy pixels and resemble a plurality of merged floating dummy pixels.
Abstract:
Devices and methods related to high-contrast liquid crystal displays (LCDs) are provided. For example, such an electronic device may include an LCD with two liquid crystal alignment layers not symmetric to one another and upper and lower polarizing layers respectively above and below the alignment layers. Light transmittance through the plurality of pixels may increase monotonically with gray scale voltage. The display 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 of the two alignment layers 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 or a second polarizing axis of the lower polarizing layer, or both, may be neither parallel nor perpendicular to one of the liquid crystal molecular alignment axes.
Abstract:
Disclosed herein are liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry. The integration may take a variety of forms. Touch sensing elements can be completely implemented within the LCD stackup but outside the not between the color filter plate and the array plate. Alternatively, some touch sensing elements can be between the color filter and array plates with other touch sensing elements not between the plates. In another alternative, all touch sensing elements can be between the color filter and array plates. The latter alternative can include both conventional and in-plane-switching (IPS) LCDs. In some forms, one or more display structures can also have a touch sensing function. Techniques for manufacturing and operating such displays, as well as various devices embodying such displays are also disclosed.
Abstract:
A display may have an array of pixels. Display driver circuitry may supply data and control signals to the pixels. Each pixel may have seven transistors, a capacitor, and a light-emitting diode such as an organic light-emitting diode. The seven transistors may receive control signals using horizontal control lines. Each pixel may have first and second emission enable transistors that are coupled in series with a drive transistor and the light-emitting diode of that pixel. The first and second emission enable transistors may be coupled to a common control line or may be separately controlled so that on-bias stress can be effectively applied to the drive transistor. The display driver circuitry may have gate driver circuits that provide different gate line signals to different rows of pixels within the display. Different rows may also have different gate driver strengths and different supplemental gate line loading structures.
Abstract:
Methods for chemically strengthening the edges of glass sheets are provided. Voids can be formed in a mother sheet. The edges of these voids may correspond to a portion of the new edges that would normally be created during separation and free shaping of the mother sheet. The mother sheet can then be immersed in a chemical strengthener. The edges of the voids can be chemically strengthened in addition to the front and back sides of the mother sheet. After thin film processing and separation, each of the resulting individual sheets has been chemically strengthened on both sides and on a portion of its edges.
Abstract:
An edge-lit backlight unit for a display is provided. In one embodiment, the backlight unit may include a light guide configured to receive light from a source and emit such light in a broad distribution to a turning film disposed over the light guide. The turning film may be configured to redirect light received from the light guide toward a normal of the turning film. In one embodiment, the light guide may be configured such that peak light distribution therefrom occurs at an incident angle of approximately sixty degrees, with broad light distribution substantially occurring over an angular range between incident angles of thirty-five and eighty-five degrees. Additionally, in one embodiment, the turning film may include multiple prisms that receive and redirect the light emitted from the light guide, and that include apex angles of less than or about sixty degrees. Additional edge-lit backlight units and methods are also disclosed.
Abstract:
An electronic device may be provided with an organic light-emitting diode display with minimized border regions. The display includes a first polymer layer 48, a layer of organic emissive material 46 on the first polymer layer, an encapsulation layer 50 formed over the layer of organic emissive material and a second polymer layer 52 attached to the first polymer layer. The border regions may be minimized by providing conductive structures (microvias 73) that pass through polymer layers 48, 52 of the display and couple conductive traces 51 on the display to conductive traces 59 on additional circuitry 62 that is mounted behind the display.
Abstract:
Methods for chemically strengthening the edges of glass sheets are provided. Voids can be formed in a mother sheet. The edges of these voids may correspond to a portion of the new edges that would normally be created during separation and free shaping of the mother sheet. The mother sheet can then be immersed in a chemical strengthener. The edges of the voids can be chemically strengthened in addition to the front and back sides of the mother sheet. After thin film processing and separation, each of the resulting individual sheets has been chemically strengthened on both sides and on a portion of its edges.