1. Technical Field
The present invention relates to a technical field regarding an electrophoretic display and an electronics device.
2. Related Art
Known examples of this kind of an electrophoretic display (EPD) includes an electrophoretic display provided therein with electrophoretic dispersion liquid which is obtained by dispersing electrophoretic particles in a dispersion medium, and which is sealed between a pair of substrates (for example, refer to JP-A-2010-91908, JP-A-2003-5226 and JP-A-2003-5225). For example, an electrophoretic display, which is disclosed in JP-A-2010-91908, includes white-color electrophoretic particles and black-color electrophoretic particles (hereinafter, which will be arbitrarily called “white particles” and “black particles”, respectively) dispersed in a dispersion medium, these two kinds of electrophoretic particles being electrically charged and having mutually different polarities, and causes voltages to be supplied between pixel electrodes provided on one substrate and opposing electrodes provided on the other substrate. This electrophoretic display causes the white particles and the black particles to move to mutually different substrate sides by supplying an appropriate voltage between each pair of the pixel electrode and the opposing electrode; thereby enabling realization of displaying images on a display surface thereof. Moreover, for example, an electrophoretic display, which is disclosed in JP-A-2003-5226 and JP-A-2003-5225, includes black particles dispersed in a dispersion medium; a first display electrode provided so as to be along a lower surface of a stair portion which is formed for each of pixels on one substrate; a second display electrode so as to along an upper surface of the stair portion; an area which includes the first display electrode formed therein, and which is colored in black color; and an area which includes the second display area, and which is colored in white color. This electrophoretic display causes the black particles to move so as to cover the first display electrode or the second electrode by supplying an appropriate voltage between each pair of the first display electrode and the second display electrode; thereby enabling realization of displaying black color of white color for each pixel. Moreover, this electrophoretic display further includes a partition wall member which is disposed so as to enclose the peripheries of individual pixels, and which prevents movement of electrophoretic particles across borders between mutually adjacent pixels.
Among the above-described electrophoretic displays, for example, for the electrophoretic display disclosed in JP-A-2010-91908, for example, a smaller thickness of a white-particle layer formed of a plurality of white particles, which have moved to the opposing electrode side when required to display white color on a display surface, leads to more difficulty in allowing the white-particle layer to sufficiently cover the black particles, and thus, is likely to result in making it difficult to display the white color. Therefore, in order to realize high-quality display, it is necessary to, when required to display white color on the display surface, increase the thickness of the white-particle layer to a degree sufficient to cover the black particles having moved to the pixel electrode side. For this reason, there is a technical problem in that it is difficult to shorten a distance between the opposing electrode and the pixel electrode (in other words, a distance between the pair of substrates), and thus, in order to allow the white particles and the black particles to move sufficiently, there is no choice other than making the level of a voltage to be supplied between the opposing electrode and the pixel electrode be relatively high. Moreover, there is also a technical problem in that, increasing the number of the white particles in order to increase the thickness of the white-particle layer for displaying white color on a display surface leads to a larger particle concentration of particles dispersed in the electrophoretic dispersion liquid, and thus, is likely to result in lowering moving speeds with which the electrophoretic particles move in the dispersion liquid upon supply of an appropriate voltage between the opposing electrode and the pixel electrode.
Further, among the above-described electrophoretic displays, for example, for the electrophoretic display disclosed in JP-A-2003-5226 and JP-A-2003-5225, there is a technical problem in that the partition wall member, which is disposed so as to enclose the peripheries of individual pixels, leads to reduction of an effective display area, in which displaying can be effectively performed, by an area of a portion in which the partition wall member is disposed, and thus, is likely to result in a difficulty in realization of high-quality display.