In-plane switching electrophoretic colour display

Abstract

The invention relates to an in-plane switching electrophoretic color display. The electrophoretic layer comprises cavity (18ab) comprising a suspension and limiting pixels (10, 12). Two control electrodes (20a, 20b) adjacent to each cavity are arranged outside the visual field (26) of the pixel to start the in-plane movement. Two particle types (24a, 24b) are arranged in the suspension of the pixel unit and are different in the color aspect (yellow, cyan), and can be selected for differences in the following aspects: (i) threshold value electric field or particle migration rate for starting the movemnet and posiblely charge polarity, or (ii) additional control electrodes arranged outside of the visual field. the arrangement enables the controlable mode to obtain a composite color plan for each pixel. The control electrodes can be arranged on the boundary ends of the cavity, namely vertical to the plane, or arranged in the layer plane of the edge of the cavity. Because of being covered by a light shielding body layer, the electrodes and particles assembled thereon can not affact the visual field of the pixel. Two units (18ab, 18cd) can be stacked with each other thereon. In addition, only one small part of the cavity area can be covered by the electrode materials, thereby optimizing the full transmission of pixels. Two units (18ab, 18cd) can be stacked with each other thereon. The colors (yellow, cyan) of the particles in the second unit are different from the colors (carmine, black) of the particles in the first unit, but the other properties of the particles can be arranged according to the (i). One unit determines the lightness of the display, the other unit mainly determines the color, a white reflector can implement the reflection type CMY or CMYK color reduction display. A transmission deformation with backlight is also disclosed.

Description

technical field [0001] The present invention relates to an electrophoretic color display panel for displaying images. Background technique [0002] An example of an electrophoretic color display panel is disclosed in US6680726. More precisely, US 6680726 relates to a transmissive color electrophoretic display incorporating a backlight. The display has a plurality of laterally adjacent pixels. Each pixel consists of two or more cells stacked vertically, one cell directly above the other on the horizontal surface of the panel at the back or bottom of the stack. Each cell in the stack also has laterally adjacent similar cells that together form a layer of cells in the display. There are light transmissive windows between each unit. The cells contain a light transmissive fluid and charged particles that absorb a portion of the visible spectrum, each cell in the stack containing particles of a different color than particles in other cells in the stack. The color of a pixel i...

AI Technical Summary

Problems solved by technology

[0004] However, a problem with the display disclosed in US 6680726 is that the counter electrode is arranged substantially at the center of the cell, the electrical connection being through the appropriate lower, stacked cell

This complicates the manufacture of the unit and therefore increases the production cost of the display panel

Also, using one layer per color results in CMY displays using at least three layers, which can cause alignment issues when producing display panels

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