Electrophoretic media comprising combination of electrophoretic particles and charge control agents

An electrophoretic medium is disclosed that includes four types of particles. The particles of the first type have a first charge polarity. The particles of the second and third types have a second charge polarity opposite the first charge polarity. The electrophoretic medium further includes a first charge control agent and a second charge control agent, the molecular structure of the first charge control agent including a quaternary ammonium group and a non-polar tail, and the molecular structure of the second charge control agent including two or more polar groups and a non-polar tail. 公开了一种电泳介质，该电泳介质包括四种类型的粒子。第一类型的粒子具有第一电荷极性。第二类型和第三类型的粒子具有与第一电荷极性相反的第二电荷极性。该电泳介质还包括第一电荷控制剂和第二电荷控制剂，第一电荷控制剂的分子结构包括季铵基和非极性尾部，并且第二电荷控制剂的分子结构包括两个或者更多个极性基、以及非极性尾部。