Toner carrier tube for electrophotographic copiers - consists of ferromagnetic material homogenising field of pole pieces on magnetic roller

摘要

Toner carrier tube for electrophotographic copiers, which surrounds a magnetic roller having pole pieces of a permanently magnetic material over its periphery and length, covered with material of high magnetic permeability, consists of a ferromagnetic material of such thickness or magnetic character that the magnetic field is homogenised but only partly closed. The use of this carrier tube instead of one of diamagnetic material eliminates the need to fix additional strips of material to the pole pieces.