Abstract: An electrophoretic display panel and a method for driving an electrophoretic display panel in which the drive pulse, i.e. the grey scale pulse, to bring an element from a preceding optical state to an optical state is split in more than one sub-pulses. A more gradual introduction of the grey scale is thereby achieved reducing the suddenness of the transition form one image to another. Preferably application of the grey scale potential differences is preceded by application of reset pulses in which case the preceding optical state is an extreme optical state.

Abstract: In a first display mode, only the information in a first sub-area (W1) of the display screen of a bi-stable matrix display (100) has to be updated. In a second display mode, the information in a second sub-area (W2) of the display screen has to be updated. The information in the first sub-area (W1) is displayed using optical states which require first drive voltage waveforms (DV1) having a maximum duration equal to a first image update period (IUP1). The information in the second area (W2) is displayed using optical states which require second drive voltage waveforms (DV2) having a maximum duration equal to a second image update period (IUP2). The optical states allowed to be used during the first mode are selected to obtain a first image update period (IUP1) which is shorter than the second image update period (IUP2). In this manner, the refresh rate of the information in the first area (W1) is higher than the refresh rate in the second area (W2).

Abstract: The electrophoretic display panel has an electrophoretic medium having charged particles, a plurality of picture elements, electrodes associated with each picture element for receiving a potential difference, and drive means. The drive means are arranged for controlling the potential difference of each of the plurality of picture elements to be a potential difference for enabling the particles to occupy the position corresponding to image information. For the display panel to be able to provide a smoother change-over from one image to another, the drive means are arranged for providing, during a portion of the image transition period, different starting times for application of the potential differences within the duration of the portion of the transition period for potential differences having a duration less than the maximum duration of the portion of the image transition period.

Abstract: A display device (1) comprises electrophoretic particles (8,9) and an image screen comprising an array of display elements comprising a pixel electrode and a second electrode. The display device comprises control means (15) for supplying drive signals to the electrodes. In operation the image is displayed in subsequent frames. The control means comprise a row driver (16) and a column driver (10). Preset signals (53) are in operation supplied to the display elements whereby the preset signals applied to display elements alter between subsequent frames. The control means are arranged to change preset-signals between frames in a column-to-column scheme. The means for supplying preset signals are arranged such that for the preset signals to at least a part of the image screen comprising a group of columns and rows only one set of data is transferred for the preset signals for said group.

Abstract: An electrophoretic display, in which a driving method is employed whereby a sequence of discrete picture potential differences in the form of a driving waveform is supplied for enabling the charged particles (6) of the display to occupy a position for displaying an image, the position being one of a number of positions between the electrodes (3, 4). The driving waveform consists of a sequence of image update signals including a picture potential difference, the image update signals being separated by dwell times, and the method includes the step of generating one or more shaking pulses during the dwell times. Such shaking pulses may be generated immediately after each image update signal or they may comprise regular shaking pulses generated at predetermined intervals along the waveform.

Abstract: An electrophoretic display (10) and a system (12) implement a method of activating a portion of the electrophoretic display (10). The method involves a reception of drawing information (14), a determination of at least one drawing-mode waveform (68) based on the drawing information (14), and an addressing of the electrophoretic display (10) based on the received drawing information (14) and the drawing-mode waveform (68).

Abstract: A cyclic rail-stabilized method of driving an electrophoretic display device (1), wherein a substantially dc-balanced driving waveform is used to effect the various required optical transitions. The driving waveform consists of a plurality of picture potential differences (20), which cause the charged particles (6) of the electrophoretic device (1) to cyclically between extreme optical positions in a single optical path, irrespective of the image sequence required to be displayed, i.e. in order to display each grey scale, it is necessary for the particles (6) to first pass through one of the extreme optical states. In order to minimise the effects of dwell time on the image quality and minimise, or even eliminate, the need to consider image history, shaking pulses (10) are generated immediately prior to each picture potential difference (20).

Abstract: Electrophoretic display units (1) can get a shorter total image update time by generating and supplying at least some of the data independent signals (Sh1, Sh2, S4, Sh5) during the processing of image information (Del). The processing is done to calculate the data-dependent signals (R,Dr). Data-independent signals (Sh1, Sh2, Sh3, Sh4, Sh5) do not depend on this processing, so these signals may be supplied during the processing. The total image update time is formed by the sum of the time required for image processing (Del) and of the subsequent time required to supply the data-dependent signals (R,Dr) to the pixels (11).

Abstract: A method and system for controlling electrophoretic and other bi-stable displays (310). Coded data (605, 610, 615) for driving the display is stored in memory (320) for different pixel transitions and different temperatures. The coded data includes voltage level and timing information for the different pixel transitions. A portion (705, 710, 715, 720, 725, 730) of the coded data is retrieved by a controller (100) such as an ASIC based on a selected pixel transition, temperature, and update mode. The portion of the coded data, which may include fixed length frame instructions, is decoded to provide decoded data. The decoded data is used to provide voltage waveforms for driving the display.

Abstract: Image quality is improved when updating a display image (310) in a bi-stable electronic reading device (300, 400) such as one using an electrophoretic display by applying rest pulses (R1, R2) adjacent to and following hardware driving pulses (S1, S2). The voltage of the rest pulses (R1, R2) is zero or otherwise below a threshold for moving particles that form the bi-stable display.

Abstract: An accurate greyscale is obtained with more natural image updates when updating a display (310) in a bi-stable electronic reading device (300,400), such as one using an electrophoretic display, by applying a first shaking pulse (S1) to the display, applying a first portion (R1) of a reset pulse to the display following the first shaking pulse (S1), applying a second shaking pulse (S2) to the display following the first portion (R1), and applying a second portion (R2) of the reset pulse to the display following the second shaking pulse (S2). The first portion may have a standard reset duration, while the second portion has an over-reset duration. A visual shock effect is avoided which would otherwise as applied after the entire reset pulse.

Abstract: Image quality is improved when updating a display image (310) in a bi-stable electronic reading device (300, 400) such as one using an electrophoretic display, by providing both monochrome and greyscale images. When an update mode of a pixel (2) of the display changes from a monochrome to greyscale, a compensating pulse (805, 825, 845, 865) is applied. The compensating pulse represents an energy based on the energy difference between: (a) an over-reset pulse (815, 835, 855, 875) used during the greyscale update mode and (b) a standard reset pulse (610, 660) used during the monochrome update mode. Also, a monochrome update waveform (600, 650) includes a standard reset pulse (610, 660) whose duration is substantially less than a duration of an over-reset pulse (815, 835, 855, 875) used in a greyscale update waveform (800, 820, 840 and 860). The monochrome update mode is used in combination with the greyscale update mode when possible.

Abstract: An image is updated on a bi-stable display (310) such as an electrophoretic display by applying a drive waveform (900,920,940, 960; 1000, 1020,1040, 1060; 1100, 1120, 1140, 1160; 1220, 1240, 1260) with a compensating impulse (C) to at least one pixel (2) in the display. An energy of the compensating impulse depends on the image holding time, and is sufficient to restore the display to an original, pre-drift, brightness level. In one approach, the energy of the compensating impulse is determined as a predetermined function of the image holding time. In another approach, data defining different waveforms for respective different image holding times is provided in respective different look-up tables, and the data from one of the tables is selected according to the image holding time for driving the display. The compensating impulse may be provided in different portions of the drive waveform.

Abstract: An electrophoretic display panel and a method for driving an electrophoretic display panel in which the drive pulse, i.e. the grey scale pulse, to bring an element from a preceding optical state to an optical state is split in more than one sub-pulses. A more gradual introduction of the grey scale is thereby achieved reducing the suddenness of the transition form one image to another. Preferably application of the grey scale potential differences is preceded by application of reset pulses in which case the preceding optical state is an extreme optical state.

Abstract: Electrophoretic display units (1) are driven with a reduced amount of power by efficiently clocking a data signal into the data driving circuitry (30) only once and then supplying this data signal subsequently to two or more pixels (11) in two or more different lines. This can be done in case the pixels (11) in a same column require the same data pulse, like a shaking data pulse (Sh1, Sh2) or a reset data pulse (R). As a result, time is saved, which allows frame periods to be shorter. Even more time can be saved and even shorter frame periods are possible when combining the efficient clocking with the parallel driving of groups of lines (70-72).

Abstract: A display device (1) comprises two or more groups of display elements having electrophoretic particles (8,9), a pixel electrode (5) and a counter electrode (6). Drive signals (50, (V,t)drive, (V,t)reset) are supplied to the electrodes to bring the display elements in a predetermined optical state. The drive signals are preceded by preset signals (53, (V,t)preset) to release the electrophoretic particles but too low in intensity to enable the particles to change the optical state significantly. The preset signals supplied to the groups show differences in phase. This reduces flicker. The preset and drive signals are, in operation, so supplied that the phase of the preset pulse preceding the drive pulse is, in respect of the drive pulse, substantially the same for all groups. The combination of a drive and preceding preset pulse is then for the groups substantially the same, reducing grey level variations.

Abstract: A driving circuit for an electrophoretic display has a plurality of pixels (18) of an electrophoretic material which comprises charged particles (8, 9). The pixels (18) are associated with a respective first electrode (6) and second electrode (5, 5?) which present a drive voltage (VD) to the pixels (18) to at least enable the charged particles (8, 9) to occupy one of two limit positions between the first electrode (6) and the second electrode (5, 5?). The driving circuit comprises an addressing circuit (16, 10) which generates the drive voltage (VD) by applying between the first electrode (6) and the second electrode (5, 5?): (i) an reset pulse (RE) which has an energy content sufficient or larger than required for the charged particles (8, 9) to reach one of the limit positions, and (ii) a shaking pulse (SP1) which at least partially overlaps the reset pulse (RE). The shaking pulse SP1 has, during the reset pulse (RE), at least partially a level with an opposite polarity than a level of the reset pulse (RE).

Abstract: An electrophoretic display panel (1) comprises: an electrophoretic medium (5) comprising charged particles (6); a plurality of picture elements (2); electrodes (3,4) associated with each picture element (2) for receiving a potential difference; and drive means (100). The drive means (100) are arranged for application of a grey scale potential difference to enable the particles (6) to occupy the position corresponding to the image information. The drive means are further arranged for application of grey scale potential differences during an update period to only a sub-assembly of the picture elements of the display, without addressing the remainder of the picture elements of the display during said update period. More grey scales are obtained.

Abstract: A display device comprising electrophoretic particles, a display element comprising a pixel electrode and a counter electrode between which a portion of the electrophoretic particles are present, and control means for supplying a drive signal to the electrodes to bring the display element in a predetermined optical state corresponding to the image information to be displayed, characterized in that control means are further arranged for supplying a preset signal preceding the drive signal comprising a preset pulse having an energy sufficient to release the electrophoretic particles at a first position near one of the two electrodes corresponding to a first optical state, but too low to enable the particles to reach a second position near the other electrode corresponding to a second optical state, and in that the control means are further arranged for supplying the preset signal, in anticipation of or upon receipt of a power-up or image change operation.

Abstract: Electophoretic display units (1) are driven with a relatively low amount of power and more efficiently by addressing the pixels (11) only once during a sequence of frame periods. Compared to addressing a pixel (11) each frame period, for signals having a duration of more than one frame period, a large amount of power is saved. During a sequence of frame periods formed by a time-interval (T1-T8), one or more reset pulses (R) or one or more driving pulses (Dr) are provided. The addressing of a line of pixels (11) can be skipped during a sequence of frame periods if all pixels (11) of the line of pixels (11) have to remain unchanged. Signals having a duration of two or more frame periods do not need to be supplied to the pixels (11) each frame period, but need to be supplied only once by addressing the pixels (11) only once during a sequence of frame periods.