Energy harvesting electro-optic displays

#This invention relates to electro-optic displays. More specifically, this invention relates to an energy harvesting electro-optic display, that is, a display that can gather energy for functioning by converting light energy into electrical energy.

#The term “electro-optic”, as applied to a material, a display or a device, is used herein in its conventional meaning in the imaging art to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material. Although the optical property is typically color perceptible to the human eye, it may be another optical property, such as optical transmission, reflectance, luminescence or, in the case of displays intended for machine reading, pseudo-color in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.

#Some electro-optic materials are solid in the sense that the materials have solid external surfaces, although the materials may, and often do, have internal liquid- or gas-filled spaces. Such displays using solid electro-optic materials may hereinafter for convenience be referred to as “solid electro-optic displays”. Thus, the term “solid electro-optic displays” includes rotating bichromal member displays, encapsulated electrophoretic displays, microcell electrophoretic displays and encapsulated liquid crystal displays.

#FIG. 1 is a detailed cross-sectional view of an embodiment of an energy harvesting electrophoretic display having a back photovoltaic layer.

#FIGS. 2A and 2B is a detailed cross-sectional view of the energy harvesting electrophoretic display of FIG. 1, showing the energy harvesting electrophoretic display operating in a closed and an open state respectively.

#FIG. 3 is a detailed transverse cross-sectional view of an embodiment of an energy harvesting electrophoretic display comprising an electrophoretic material layer comprising capsules and light-transmissive beads, and a back photovoltaic layer.

#To the extent possible, similar reference numerals are used to refer to like structures from Figure to Figure in the following description.

#The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All aspects that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims.

#A photovoltaic cell, also called a solar cell, is a device or a component of a device, which converts radiation energy directly into electrical energy by means of photovoltaic effect. Photovoltaic effect is the phenomenon that occurs when a semiconductor material absorbs light energy causing an electron excitation to a higher energy state and generating an electric potential.