Abstract: There are provided display controllers and driving methods related to those described in US Published Patent Application No. 2013/0194250.

Abstract: A system for rendering color images on an electro-optic display when the electro-optic display has a color gamut with a limited palette of primary colors, and/or the gamut is poorly structured (i.e., not a spheroid or obloid). The system uses an iterative process to identify the best color for a given pixel from a palette that is modified to diffuse the color error over the entire electro-optic display. The system additionally accounts for variations in color that are caused by cross-talk between nearby pixels.

Abstract: An electrophoretic display having a plurality of display pixels, each of the plurality of display pixels may include a pixel electrode for driving the display pixel, a single thin film transistor (TFT) coupled to the pixel electrode for transmitting waveforms to the pixel electrode, a front plane laminate (FPL) coupled to the single thin film transistor, and a storage capacitor coupled to the pixel electrode and placed in parallel with the FPL, where the storage capacitor is configured to be sufficiently ohmically conductive to allow the discharge of remnant voltages from the FPL through the storage capacitor.

Abstract: An electro-optic display is provided that may include a layer of light-transmissive conductive material, a substrate, a layer of an electro-optic medium disposed between the layer of conductive material and the substrate, a color filter array, and a light emitting layer. The electro-optic medium may include a photo-luminescent material that functions as either a down-converter or an up-converter that may be excited by the light received from the light emitting layer. The photo-luminescent material may be excited by radiation having a first wavelength transmitted by a filter within the color filter array and emit radiation having a second wavelength transmitted by the filter. The photo-luminescent material may also be excited by radiation at a wavelength within a first and second range of wavelengths transmitted by two filters within the color filter array and emit radiation at a wavelength within one of the first and second ranges.

Abstract: A variety of methods for driving electro-optic displays so as to reduce visible artifacts are described. Such methods include (a) applying a first drive scheme to a non-zero minor proportion of the pixels of the display and a second drive scheme to the remaining pixels, the pixels using the first drive scheme being changed at each transition; (b) using two different drive schemes on different groups of pixels so that pixels in differing groups undergoing the same transition will not experience the same waveform; (c) applying either a balanced pulse pair or a top-off pulse to a pixel undergoing a white-to-white transition and lying adjacent a pixel undergoing a visible transition; (d) driving extra pixels where the boundary between a driven and undriven area would otherwise fall along a straight line; and (e) driving a display with both DC balanced and DC imbalanced drive schemes, maintaining an impulse bank value for the DC imbalance and modifying transitions to reduce the impulse bank value.

Abstract: An electro-optic display having a plurality of pixels is driven from a first image to a second image using a first drive scheme, and then from the second image to a third image using a second drive scheme different from the first drive scheme and having at least one impulse differential gray level having an impulse potential different from the corresponding gray level in the first drive scheme. Each pixel which is in an impulse differential gray level in the second image is driven from the second image to the third image using a modified version of the second drive scheme which reduces its impulse differential The subsequent transition from the third image to a fourth image is also conducted using the modified second drive scheme but after a limited number of transitions using the modified second drive scheme, all subsequent transitions are conducted using the unmodified second drive scheme.

Abstract: A method for driving an electro-optic display having a front electrode, a backplane, and a display medium including at least three differently-colored particles, wherein the medium is positioned between the front electrode and the backplane. The method includes applying a DC balance reset phase to first and second pixel electrodes such that the sum of all impulses results in an offset that maintains a DC-balance across the display medium. The invention additionally includes controllers for executing the method.

Abstract: An electro-optic display having a plurality of display pixels, each of the plurality of display pixels comprising: a pixel electrode for driving the display pixel; a thin film transistor (TFT) coupled to the pixel electrode for transmitting waveforms to the pixel electrode; a resistor coupled to the pixel electrode for discharging remnant charges from the display subsequent to the TFT being de-activated; and a storage capacitor coupled to the pixel electrode and placed in parallel with the resistor. A time constant of a circuit comprising the pixel electrode, the resistor, and the storage capacitor is larger than a driving frame time of the electro-optic display.

Abstract: A system for rendering color images on an electro-optic display when the electro-optic display has a color gamut with a limited palette of primary colors, and/or the gamut is poorly structured (i.e., not a spheroid or obloid). The system uses an iterative process to identify the best color for a given pixel from a palette that is modified to diffuse the color error over the entire electro-optic display. The system additionally accounts for variations in color that are caused by cross-talk between nearby pixels.

Abstract: A display device is operated by using several iterations of a scan phase followed by a global drive phase. In the scan phase, the state of each pixel in the display device is set to either “enabled” or “disabled”, during which time a global drive generator is inactive. Then, in the global drive phase, a global drive signal is sent to the display device. Only the subset of enabled pixels is affected by the global drive signal, which causes the enabled pixels to perform a transition to a desired display state. The sequence of the scan phase followed by the global drive phase is then repeated up to the number of unique transitions required to update the display device.

Abstract: An electrophoretic display comprising a fluid including a first species of particles and a charge control agent disposed between first and second electrodes. When a first addressing impulse have an electrical polarity is applied to the medium, the first species of particles move in one direction relative to the electric field, but when a second addressing impulse, larger than the first addressing impulse but having the same electrical polarity, is applied to the medium, the first species of particles move in the opposed direction relative to the electric field.

Abstract: A method for driving an electro-optic display having a front electrode, a backplane, and a display medium including at least three differently-colored particles, wherein the medium is positioned between the front electrode and the backplane. The method includes applying a reset phase and a color transition phase to the display such that the sum of all impulses results in an offset that maintains a DC-balance across the display medium. The invention additionally includes controllers for executing the method.

Abstract: Techniques for operating an electro-optic display to reduce the appearance of light edge artifacts in displayed images are described. A method for operating the electro-optic display includes detecting a null state transition of a first pixel when transitioning from a first image to a second image. The method further includes determining whether a threshold number of cardinal neighbors of the first pixel transition from a black state to a white state when transitioning from the first image to the second image. In response to a subsequent transition to a third image, the method further includes applying a voltage signal to the first pixel, wherein the voltage signal has a waveform configured to generate an optical black state for the first pixel.

Abstract: A display device is operated by using several iterations of a scan phase followed by a global drive phase. In the scan phase, the state of each pixel in the display device is set to either “enabled” or “disabled”, during which time a global drive generator is inactive. Then, in the global drive phase, a global drive signal is sent to the display device. Only the subset of enabled pixels is affected by the global drive signal, which causes the enabled pixels to perform a transition to a desired display state. The sequence of the scan phase followed by the global drive phase is then repeated up to the number of unique transitions required to update the display device.

Abstract: A driving method is provided for an electric-optic display having a plurality of display pixels, the method including dividing the plurality of display pixels into multiple groups of pixels, applying at least one waveform structure to the multiple groups of pixels, the at least one waveform structure having a driving section for updating the multiple groups of pixels, and updating the multiple groups of pixels in a contiguous fashion such that only one group of display pixels completes the driving section at any given time.

Abstract: An electro-optic display having a plurality of display pixels, each of the plurality of display pixels comprising: a pixel electrode for driving the display pixel; a thin film transistor (TFT) coupled to the pixel electrode for transmitting waveforms to the pixel electrode; a resistor coupled to the pixel electrode for discharging remnant charges from the display subsequent to the TFT being de-activated; and a storage capacitor coupled to the pixel electrode and placed in parallel with the resistor. A time constant of a circuit comprising the pixel electrode, the resistor, and the storage capacitor is larger than a driving frame time of the electro-optic display.

Abstract: An image is rendered on a display having a limited number of primary colors by (104) combining input data representing the color of a pixel to be rendered with error data to form modified input data, determining in a color space the simplex (208—typically a tetrahedron) enclosing the modified input data and the primary colors associated with the simplex, converting (210) the modified image data to barycentric coordinates based upon the primary colors associated with the simplex and (212) setting output data to the primary having the largest barycentric coordinate. calculating (214) the difference between the modified input data and the output data for the pixel, thus generating error data, applying (106) this error data to at least one later-rendered pixel, and applying the output data to the display and thus rendering the image on the display. Apparatus and computer-storage media for carrying out this process are also provided.

Abstract: An apparatus for driving an electro-optic display may comprise a first switch designed to supply a voltage to the electro-optic display during a first driving phase, a second switch designed to control the voltage during a second driving phase and a resistor coupled to the first and second switches for controlling the rate of decay of the voltage during the second driving phase.

Abstract: This invention provides methods of and related apparatus for driving an electro-optic display having a plurality of pixels. The method includes dividing the plurality of pixels into n groups, where n is an integer larger than 1, applying a full clearing waveform to at least one group of the n groups of pixels, and applying a top off waveform to cardinal pixels of the at least one group of pixels.

Abstract: An electrophoretic medium includes a fluid, a plurality of light scattering charged particles having a first polarity, and a first, second, and third set of particles, each set having a color different from each other set. The first and second particles may have a second polarity opposite to the first polarity, and the mobility of the third set of particles is less than half of the mobility of the light scattering particles, the first set of charged particles, and the second set of charged particles.