Parameters influencing toner charging characteristics in electrophotographic printing

The charge-to-mass ratio, q/m, of a two-component developer is the importan t factor in an electrophotographic system, since the toner charge controls the developed tone mass and the print quality. This article investigates th e charging properties of differently shaped toners (spherical and irregular ), and carrier particles that differ in their composition and surface oxide layer thickness by adjusting the applied current. The parameters for toner charging involving the mixing force, the toner concentration, the shape of the toner, the carrier type, and the current of the carrier surface are st udied. The print quality is evaluated by focusing on the solid density, 60 and 40% halftone densities, background density, and edge sharpness of the c haracters. An explanation of the force between the toner and carrier partic les is proposed.