The invention provides an optical switching element and a device, an
optically addressed type display medium and a display each including such
an optical switching element. The optical switching element comprising an
optical switching layer including lower and upper charge generating
layers and a charge transporting layer sandwiched therebetween, wherein
the optical switching element has at least one of the following
characteristics. (1) In the charge transporting layer, a charge
transporting material to binder polymer ratio calculated according to the
formula: [charge transporting material/(charge transporting
material+binder polymer)].times.100 (% by weight) is 50% by weight or
more; (2) a polymer compound is used as the charge transporting material;
and (3) the charge generating layer on the light incident side (the lower
charge generating layer) has a lower light absorptance than that of the
other charge generating layer (the upper charge generating layer).