Patent ID: 7206115

Claim:
An optically addressed type display medium comprising: a pair of electrodes, at least one of which has optical transparency; and an optical switching element and a display element, which includes a display layer with a memory function, the optical switching element and the display element being stacked between the pair of electrodes; wherein the optical switching element comprising an optical switching layer that includes a pair of charge generating layers and a charge transporting layer sandwiched therebetween, wherein the optical switching element has at least one of the following characteristics: (1) the charge transporting layer includes a charge transporting material and a binder polymer, wherein a charge transporting material to binder polymer ratio calculated according to the formula: {charge transporting material/(charge transporting material+binder polymer)}×100 is at least 50% by weight; or (2) the charge transporting layer includes a charge transporting material selected from charge transporting macromolecular materials; or (3) the pair of the charge generating layers include a first charge generating layer on an incident light side of the optical switching layer and a second charge generating layer on the other side of the optical switching layer, wherein the first charge generating layer has a lower light absorptance than that of the second charge generating layer.