An electrophoretic display able to operate on a reduced power supply includes a display panel and a driving circuit electrically connected to the display panel. The display panel includes a plurality of first electrophoretic particles and a plurality of second electrophoretic particles. The driving circuit is configured to provide a balance signal to the display panel during a balance period, provide a mixed signal to the display panel during a mixing period, and provide a driving signal to the display panel during a coloring period. The balance period, the mixing period, and the coloring period are sequential in time, and a preset time interval is between each of the periods.

An electrophoretic medium comprises a fluid and first, second, third and fourth types of particles (W, Y, R, B) having four different colors. The first and third particles have charges of one polarity and the second and fourth particles charges of the opposite polarity; the first particles have a greater zeta potential or electrophoretic mobility than the third particles, and the second particles a greater zeta potential or electrophoretic mobility than the fourth particles. One particle is white (W), one non-white particle (B) is partially light-transmissive, and the remaining two non-white particles (R, Y) are light-reflective. A third light-reflective particle (G) may be added to create a five particle medium.

Methods for driving an electrophoretic medium including two pairs of oppositely charged particles. The first pair including a first type of positive particles and a first type of negative particles and the second pair consists of a second type of positive particles and a second type of negative particles, wherein the first pair of particles and the second pair of particles have different charge magnitudes (identifiable as zeta potentials). In particular, the driving methods produce cleaner optical stakes of the lesser-charged particles with less contamination from the other particles and more consistent electro-optical performance when the intermediate driving voltages are modified.

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.

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.

The present disclosure is in the field of an electrophoretic device for switching between a transparent and non-transparent mode, comprising a fluid and particles, electrodes for moving said particles, and comprising various further elements, as well as uses thereof, in particular as a window blind.

A display device including a pair of substrates, a display medium formed between the pair of substrates and including charged particles encapsulated therebetween such that an image is displayed by moving the charged particles electrophoretically, a drive unit that applies a voltage to the display medium, and a display control unit that controls a display of the display medium. After data communication for rewriting a display of a display device commences and before the data communication ends, the display control unit commences rewriting using a first waveform, and after completion of the data communication and after the rewriting using the first waveform, the display control unit executes rewriting using a second waveform.

A display device includes a substrate, first electrodes, lines, pixel electrodes, a display functional layer, a common electrode, second electrodes, and a controller. The first electrodes are opposed to the second electrodes with a space therebetween, and an insulating layer is provided between the common electrode and the first and second electrodes. During the display periods, in response to a control signal from the controller, the pixel electrodes are supplied with a pixel signal through the lines, and the common electrode is supplied with a common signal. During the sensing period, in response to the control signal from the controller, the lines are supplied with a first drive signal to generate a magnetic field. The first electrodes are supplied with a second drive signal to generate electrostatic capacitance between themselves and the second electrodes in response to the control signal from the controller, synchronously or asynchronously with the display periods.

A control method of an electronic ink screen includes: outputting a first color driving signal to pixel(s) expected to display a first color in the electronic ink screen. The first color driving signal includes a first dither signal and a first color first pull-up signal in adjacent periods. The first dither signal includes a first rectangular wave signal, a first electric field cancellation signal and a first constant voltage signal. The first constant voltage signal is configured to drive first color charged particles in the pixel(s) expected to display the first color to move toward a side proximate to a display surface of the electronic ink screen, and the first color first pull-up signal is configured to drive the first color charged particles in the pixel(s) expected to display the first color to move toward the side proximate to the display surface of the electronic ink screen.

The present invention provides improved driving methods for four particle electrophoretic displays that improves the performance of such displays when they are deployed in low temperature environments and the displays are required to be updated when positioned vertically (i.e., the driving electric fields are substantially perpendicular to the direction of Earth's gravity). Methods are provided for displaying each of the colors at each pixel, as desired, with minimal interference (contamination) from the other particles.