Patent ID: 7706051

Claim:
A display medium comprising: a pair of substrates disposed in spaced-apart relation and substantially parallel to each other; an electrophoretic medium disposed between the pair of substrates and containing charged particles, whereby an electric field generated between the pair of substrates causes the charged particles contained in the electrophoretic medium to migrate for switching a display state; characterized in that the display medium further comprises a partitioning medium having fluidity and phase-separated from the electrophoretic medium at least at room temperature, the partitioning medium being in a phase-separated state phase-separated from the electrophoretic medium, wherein the partitioning medium is disposed between the pair of substrates as a partition to partition the electrophoretic medium; and a first surface treatment part having a greater affinity to the electrophoretic medium than the partitioning medium; and a second surface treatment part having a greater affinity to the partitioning medium than the electrophoretic medium; wherein the second surface treatment part is disposed on a surface of at least one of the pair of substrates in a position to which the partitioning medium contacts, in accordance with a shape of the partitioning medium, and the first surface treatment part is disposed on a surface of at least one of the pair of substrates in a position at which the electrophoretic medium is to be disposed.