Photoluminescent sign with electrophoretic display component

A method of operating a sign having a viewing side receiving incident light, the sign comprising a photoluminescent layer and an electrophoretic display component superposed on the photoluminescent layer, the electrophoretic display component comprising (a) a first light-transmissive electrode layer at the viewing side;

• (b) a second light-transmissive electrode layer;
• and (c) an electrophoretic material layer disposed between the first light-transmissive electrode layer and the second light-transmissive electrode layer, the electrophoretic material layer comprising an electrophoretic medium compartmentalized in microcells, the microcells comprising compartments separated by light-transmissive walls, wherein the electrophoretic medium comprises electrophoretic particles in a non-polar electrophoretic liquid disposed in the compartments, the method comprising:
• applying an electric field between the first light-transmissive electrode layer and the second light-transmissive electrode layer configured to drive the electrophoretic particles in the electrophoretic medium to form a selected particle arrangement in each compartment between the light-transmissive walls defining one of a plurality of optical states of the electrophoretic display, wherein the photoluminescent layer continuously receives a portion of the incident light via the light-transmissive walls separating the compartments in all optical states of the electrophoretic display, and wherein the photoluminescent layer outputs visible light from the received incident light.