Abstract: An electronic device may have a liquid crystal display having a backlight and color mixing prevention structures. The color mixing prevention structures may, in part, be formed from one or more arrays of color filter elements. The liquid crystal display may include first and second transparent substrate layers on opposing sides of a liquid crystal layer. The display may include a first array of color filter elements on the first transparent substrate layer and a second array of color filter elements on the second transparent substrate layer. One or more of the arrays of color filter elements may include a black matrix formed over portions of the color filter elements. The color filter elements may fill or partially fill openings in the black matrix. The display may include a collimating layer on the second transparent substrate layer. The color filter elements may include cholesteric color filter elements.

Abstract: Systems, methods, and devices for adjusting a white point of a liquid crystal display (LCD) using column inversion are provided. In one example, a method includes measuring white points of an electronic display that occur when the display employs different column inversion schemes. The display may be programmed to perform the column inversion scheme that produces a white point closest to a desired white point.

Abstract: A display may have an array of pixels. The display may be controlled using display driver circuitry. The display driver circuitry may analyze image data to be displayed on the array. When static content is detected, the rate at which the pixels are refreshed may be adjusted to conserve power. If a static image is detected, the gate lines may be asserted at a lower refresh rate than if moving content is detected. To avoid visible artifacts, the display driver circuitry may use temporal and spatial refresh rate buffers. Temporal buffers ensure that refresh rates are changed gradually as a function of time, thereby minimizing flicker. Spatial refresh rate buffers are used to provide a smooth transition between low refresh rate and high refresh rate regions in a display as a function of position.

Abstract: System and method for improving displayed image quality of an electronic display that displays a first image frame by applying a first voltage to a display pixel and a second image frame directly before the first image frame by applying a second voltage to the display pixel. A display pipeline is communicatively coupled to the electronic display and receives first image data corresponding with the first image frame, where the image data includes a first grayscale value corresponding with the display pixel. Additionally the display pipeline determines an inversion balancing grayscale offset based at least in part on the first grayscale value when polarity of the first voltage and polarity of the second voltage are the same and determines magnitude of the first voltage by applying the inversion balancing grayscale offset to the first grayscale value to reduce likelihood of a perceivable luminance spike when displaying the first image frame.

Abstract: A display polarizer may have a polymer layer such as a polyvinyl alcohol layer coated with a dichroic dye such as iodine. A polymer layer such as a tri-acetyl cellulose layer may be formed on the polyvinyl alcohol layer so that the iodine is interposed between the polyvinyl alcohol layer and the tri-acetyl cellulose layer. To provide protection for the iodine layer, an additional polymer layer such as an additional tri-acetyl cellulose layer and a layer of adhesive may be formed on top of the polymer layer. A functional layer such as an antireflection layer may form an outermost layer in the polarizer. Compensation films may be formed beneath the polyvinyl alcohol layer. Additional display layers such as a lower polarizer layer and interposed layers such as a thin-film transistor layer, liquid crystal layer, and color filter layer may be formed below the compensation films.

Abstract: A display may have a thin-film transistor layer formed from a layer of thin-film transistor circuitry on a substrate, a color filter layer, and a layer of liquid crystal material interposed between the thin-film transistor layer and the color filter layer. The thin-film transistor layer, the liquid crystal layer, and the color filter layer may be sandwiched between upper and lower polarizers. A backlight unit may supply backlight illumination for pixels in the display. The color filter layer may have a black matrix with an array of openings. Color filter elements of different colors may be formed in the openings. The black matrix may have sidewalls that are steep or that are undercut. The profile of the black matrix helps block improperly colored off-axis light and thereby reduces undesired color mixing in the display.

Abstract: Systems, methods, and devices for reducing the loss of transmittance caused by column inversion. To provide one example, an electronic display may include a display panel with columns of pixels and driver circuitry to drive the pixels using column inversion. Adjacent columns that are driven at like polarity are spaced more closely than adjacent columns driven at opposite polarities.

Abstract: A display may have a layer of liquid crystal material between a color filter layer and a thin-film transistor layer. Column spacer structures may be formed between the color filter layer and the thin-film transistor layer to maintain a desired separation between the color filter and thin-film transistor layers. The column spacer structures may be formed from polymer structures such as photoresist pillars and may include metal pads. The metal pads may be formed on the upper surface of the thin-film transistor layer or the lower surface of the color filter layer. The photoresist pillars may be formed on a surface in the display such as the lower surface of the color filter layer. Column spacer structures may include main spacer structures, subspacer structures, and intermediate thickness spacer structures to enhance pooling mura and light leakage performance.

Abstract: A display may have a color filter layer and a thin-film transistor layer. A layer of liquid crystal material may be located between the color filter layer and the thin-film transistor layer. Column spacers may be formed on the color filter layer to maintain a desired gap between the color filter and thin-film transistor layers. Support pads may be used to support the column spacers. The column spacers and support pads may have comparable thicknesses. Different column spacers may be located at different portions of the support pads to allow the support pad size to be reduced while ensuring adequate support.

Abstract: A liquid crystal display may have a layer of liquid crystal material. The display may have an array of display pixel circuits. The display pixel circuits may each include a display pixel electrode that applies electric fields to a corresponding portion of the liquid crystal material. Thin-film transistor circuitry and other structures in the display pixels may control operation of the display pixels circuits. The thin-film transistor circuitry may be configured to handle operation of the display at multiple refresh rates. To accommodate multiple refresh rates, each pixel circuit may include a pair of transistors. A first transistor is used to apply data signals from a data line to the display pixel electrode. A storage capacitor is used to maintain the data signal on the electrode. The second transistor may be used to adjust the capacitance of the storage capacitor depending on the refresh rate of the display.

Abstract: Common electrodes (Vcom) of integrated touch screens can be segmented into electrically isolated Vcom portions that can be operated as drive lines and/or sense lines of a touch sensing system. The touch screen can include high-resistivity connections between Vcom portions. The resistivity of the high-resistivity connections can be high enough so that touch sensing and image display can be performed by the touch screen, and the high-resistivity connections can provide an added functionality by allowing a charge build up on one of the Vcom portions to be spread to other Vcom portions and/or discharged from system by allowing charge to leak through the high-resistivity connections. In this way, for example, visual artifacts that result from charge build up on a Vcom portion can be reduced or eliminated.

Abstract: A liquid crystal display may have a layer of liquid crystal material. The display may have an array of display pixel circuits. The display pixel circuits may each include a display pixel electrode that applies electric fields to a corresponding portion of the liquid crystal material. Thin-film transistor circuitry and other structures in the display pixels may control operation of the display pixels circuits. The thin-film transistor circuitry may be configured to handle operation of the display at multiple refresh rates. To accommodate multiple refresh rates, each pixel circuit may include a pair of transistors. A first transistor is used to apply data signals from a data line to the display pixel electrode. A storage capacitor is used to maintain the data signal on the electrode. The second transistor may be used to adjust the capacitance of the storage capacitor depending on the refresh rate of the display.

Abstract: An electronic device may be provided with a display mounted in a housing. The display may include a liquid crystal display module and a reflective polarizer having an in-plane optical axis. The display may also include a backlight unit that includes a light source, a light guide element, and a reflector film coupled to a backside of the light guide element. The display may also include a light retardation layer such as a quarter wave film. The quarter wave film may be arranged between the reflective polarizer and the reflector film of the backlight unit. Partially polarized light that is output from a front side of the light guide element may have a first component parallel to the in-plane optical axis and a second component perpendicular to the in-plane optical axis of the reflective polarizer. The second component may be reflected from the reflective polarizer.

Abstract: An electronic device may have a liquid crystal display having a backlight and color mixing prevention structures. The color mixing prevention structures may, in part, be formed from one or more arrays of color filter elements. The liquid crystal display may include first and second transparent substrate layers on opposing sides of a liquid crystal layer. The display may include a first array of color filter elements on the first transparent substrate layer and a second array of color filter elements on the second transparent substrate layer. One or more of the arrays of color filter elements may include a black matrix formed over portions of the color filter elements. The color filter elements may fill or partially fill openings in the black matrix. The display may include a collimating layer on the second transparent substrate layer. The color filter elements may include cholesteric color filter elements.

Abstract: A display may have a layer of liquid crystal material between a color filter layer and a thin-film transistor layer. Column spacer structures may be formed between the color filter layer and the thin-film transistor layer to maintain a desired separation between the color filter and thin-film transistor layers. Column spacers may be deposited in column spacer regions of the color filter layer. The color filter layer may include rows of red, green, and blue color filter elements. Blue color filter material that forms blue color filter elements in the color filter layer may also be used to form a planar surface over red and green color filter elements in the column spacer regions. Using the blue color filter material to planarize the surface on which column spacers are formed ensures that the column spacers provide sufficient support for the display without requiring an additional planarization layer.

Abstract: A display polarizer may have a polymer layer such as a polyvinyl alcohol layer coated with a dichroic dye such as iodine. A polymer layer such as a tri-acetyl cellulose layer may be formed on the polyvinyl alcohol layer so that the iodine is interposed between the polyvinyl alcohol layer and the tri-acetyl cellulose layer. To provide protection for the iodine layer, an additional polymer layer such as an additional tri-acetyl cellulose layer and a layer of adhesive may be formed on top of the polymer layer. A functional layer such as an antireflection layer may form an outermost layer in the polarizer. Compensation films may be formed beneath the polyvinyl alcohol layer. Additional display layers such as a lower polarizer layer and interposed layers such as a thin-film transistor layer, liquid crystal layer, and color filter layer may be formed below the compensation films.

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: Systems, methods, and devices for performing column inversion using reordered image data are provided. In one example, an electronic display may include a display panel with columns of pixels and driver circuitry to drive the pixels using column inversion. The driver circuitry may drive pixels of a first superpixel in a first color order and drive pixels of an adjacent second superpixel in a second color order, such that more pixels are driven sequentially at a common polarity than would have been driven sequentially at the common polarity were the pixels of the first superpixel driven at the same color order as the pixels of the second superpixel.

Abstract: Systems, methods, and devices for performing column inversion using 2-column demultiplexers are provided. In one example, an electronic display may include a display panel with columns of pixels configured to be programmed with frames of image data and display driver circuitry. The display driver circuitry may include three demultiplexers, each respectively coupled to one pixel column of a first superpixel and one pixel column of a second superpixel. Each of the three demultiplexers may receive amplified image data of a single polarity per frame.

Abstract: An electronic device may have a liquid crystal display having a backlight and color mixing prevention structures. The color mixing prevention structures may, in part, be formed from one or more arrays of color filter elements. The liquid crystal display may include first and second transparent substrate layers on opposing sides of a liquid crystal layer. The display may include a first array of color filter elements on the first transparent substrate layer and a second array of color filter elements on the second transparent substrate layer. One or more of the arrays of color filter elements may include a black matrix formed over portions of the color filter elements. The color filter elements may fill or partially fill openings in the black matrix. The display may include a collimating layer on the second transparent substrate layer. The color filter elements may include cholesteric color filter elements.