A multi-color display device has front and rear electrodes on opposed sides of an electrophoretic medium. The device has a voltage controller configured to apply a first and a smaller second potential difference, of either polarity, between the electrodes. The electrophoretic medium has first, second, and third species of particles of differing colors and charge polarities. The first and second particles move independently of one another in response to the first potential difference, but upon application of the second potential difference form charged aggregates, moving as a unit, having an aggregate color different from the first and second colors.

The present invention provides a color display device in which each pixel or sub-pixel can display four high quality color states, More specifically, an electrophoretic fluid is provided which comprises four types of particles, dispersed in a solvent or solvent mixture. The fluid may further comprise substantially uncharged neutral buoyancy particles.

The present invention relates to a drive method for an electrophoretic cell and a device adapted to implement the method. The cell comprises a first storage electrode (24), a second storage electrode (22), a first target area electrode (28), a second target area electrode (30), a first type of particle (32) and a second type of particles (33), said second type of particles being of opposite polarity to the first type of particles. An area (31) extending between the target area electrodes (28, 30) is a target area. The method comprises a reset phase (110), wherein said first and second type of particle are reset to determined reset positions, a first write phase (120), wherein the first type of particles are moved to and/or from the storage electrodes and change in amount in said target area (31), a second write phase (140) similar to the first write phase but for the second type of particles, and a spread phase (150) so that the particles in said target area (31) distribute and mix. The method allows for short distance movements and two particle type in the same cell can be written comparatively fast.

A light-modulating element comprises: first and second transparent substrates arranged in opposition to one another; a first transparent electrode arranged on the opposition surface of the first transparent substrate; a plurality of light transmissive regions arranged between the first transparent electrode and the second transparent substrate so as to be separated from one another; a plurality of second transparent electrodes arranged at respective positions on the second transparent substrate opposing the respective light transmissive regions, and that are arranged so as to be separated by a given distance from the respective light transmissive regions; a plurality of third transparent electrodes arranged individually between the second transparent electrodes at a predetermined distance therefrom on the second transparent substrate side; and an electrophoretic member arranged within a gap formed between the first transparent substrate and the second transparent substrate, and that includes light-shielding electrophoretic particles.

A multi-color display device has front and rear electrodes on opposed sides of an electrophoretic medium. The device has a voltage controller configured to apply a first and a smaller second potential difference, of either polarity, between the electrodes. The electrophoretic medium has first, second, and third species of particles of differing colors and charge polarities. The first and second particles move independently of one another in response to the first potential difference, but upon application of the second potential difference form charged aggregates, moving as a unit, having an aggregate color different from the first and second colors.

A multi-color display device has front and rear electrodes on opposed sides of an electrophoretic medium. The device has a voltage controller configured to apply a first and a smaller second potential difference, of either polarity, between the electrodes. The electrophoretic medium has first and second species of particles of differing colors and charge polarities. The first and second particles move independently of one another in response to the first potential difference, but upon application of the second potential difference form charged aggregates, moving as a unit, having an aggregate color different from the first and second colors.

A laminate which can serve as either a smart window or a smart mirror is formed using first and second substrates coated with transparent first and second electrodes which are separated by foraminous layer and a third grid-like linear electrode insulated from the first and second electrodes. The foraminous layer includes spacers defining a cell space which is filled with a colloidal ink having first and second particles. The first particles have a positive charge and a first color and second particles having a negative charge and a second color different from the first color. By altering the voltages of the first, second and third electrodes, one can achieve different light transmission characteristics which, for example, can alter the color temperature of the light transmitted through the laminate or enhance reflective colors.

A laminate which can serve as either a smart window or a smart mirror is formed using first and second substrates coated with transparent first and second electrodes which are separated by foraminous layer and a third grid-like linear electrode insulated from the first and second electrodes. The foraminous layer includes spacers defining a cell space which is filled with a colloidal ink having first and second particles. The first particles have a positive charge and a first color and second particles having a negative charge and a second color different from the first color. By altering the voltages of the first, second and third electrodes, one can achieve different light transmission characteristics which, for example, can alter the color temperature of the light transmitted through the laminate or enhance reflective colors.

An electrophoretic display device includes a pixel structure and a color filter array. In the pixel structure, an area of a blue pixel electrode is less than an area of a red pixel electrode, and the area of the blue pixel electrode is less than an area of a green pixel electrode. In the color filter array, areas of red, green, and blue filter units are all substantially the same and the red, green, and blue filter units are overlapped with the red, green, and blue pixel electrodes respectively. A ratio of the area of the red filter unit to the area of the red pixel electrode is RFF; a ratio of the area of the green filter unit to the area of the green pixel electrode is GFF; a ratio of the area of the blue filter unit to the area of the blue pixel electrode is BFF, and BFF>RFFGFF.

An electrophoretic display device includes a pixel structure and a color filter array. In the pixel structure, an area of a blue pixel electrode is less than an area of a red pixel electrode, and the area of the blue pixel electrode is less than an area of a green pixel electrode. In the color filter array, areas of red, green, and blue filter units are all substantially the same and the red, green, and blue filter units are overlapped with the red, green, and blue pixel electrodes respectively. A ratio of the area of the red filter unit to the area of the red pixel electrode is RFF; a ratio of the area of the green filter unit to the area of the green pixel electrode is GFF; a ratio of the area of the blue filter unit to the area of the blue pixel electrode is BFF, and BFF>RFFGFF.