Device for direct electrostatic printing (DEP) with "previous correction"

Abstract

A DEP device adapted for grey-scale printing comprising a back electrode (105), a printhead structure (106), an array of printing apertures (107) in the printhead structure (106) through which a particle flow can be electrically modulated by a control electrode (106a), a toner delivery means (101), at least one control means (111) for applying an electric field to the control electrodes, wherein: (i) the control means controls each single control electrode to enable the printing through each single printing aperture (107) of pixel dots (PD), each of the pixel dots intended to have a density D, and (ii) the control means controls the printing of the pixel dots through the each single printing aperture as a function of both the intended density (D.sub.intend) and the density (D.sub.prev) previously produced through the single printing aperture, i.e. the control means use "previous correction".

Dependencies are inferred from the claim text.