Patent ID: 8482515

Claim:
A display apparatus, comprising: a first substrate provided with a plurality of closed containers, a fluid filled in the closed containers, a plurality of positively charged particles which have a relative dielectric constant different from the fluid and are dispersed and held in the fluid, a plurality of negatively charged particles which have a relative dielectric constant different from the fluid and are dispersed and held in the fluid, and a pair of electrodes, having a first electrode and a second electrode, for generating an electric field in the closed containers, wherein the pair of electrodes generate an electric field having a non-uniform electric field strength in each of the closed containers, wherein a first DC voltage is applied between the pair of electrodes to distribute the positively charged particles at the first electrode and to distribute the negatively charged particles at the second electrode, wherein a second DC voltage having a polarity opposite to that of the first DC voltage is applied between the pair of electrodes to distribute the negatively charged particles at the first electrode and to distribute the positively charged particles at the second electrode, and wherein an AC voltage is applied between the pair of electrodes to distribute the positively charged particles and negatively charged particles at a maximum electric field strength position or at a minimum electric field strength position, depending on a difference in relative dielectric constant between the positively charged particles and the fluid and between the negatively charged particles and the fluid, wherein the first electrode is provided proximate to the first substrate, and the second electrode is provided proximate to a second substrate disposed opposite to the first substrate, and at least one of the first and second electrodes has a projected portion at a center of the closed container.