Patent ID: 7475997
Filing Date: 2009-01-13
Classification: G02B,G02F

Abstract:
1. A reflective display device comprising: a retroreflective layer; and a modulation layer, which is provided closer to a viewer than the retroreflective layer is and which is switchable between first and second states with mutually different optical characteristics, wherein the retroreflective layer includes a two-dimensional arrangement of unit elements, which are arranged at a pitch of at most 250 μm, and wherein the retroreflective layer has a retro-reflectivity Rr of at least 45%, the retroreflectivity being defined as a ratio of the intensity of light, which has been reflected from the retroreflective layer and then received at a cone angle of 7.5 degrees by a retroreflectivity measuring system, to that of light, which has been reflected from a dielectric mirror and then received by the same retroreflectivity measuring system, and wherein the unit elements are square corner cubes.