Patent ID: 6250743
Filing Date: 2001-06-26
Classification: B41J,G03G

Abstract:
A tandem type direct printing apparatus comprising a plurality of printing stations for depositing printing particles on a print medium to form a layer of printing particles, the plurality of printing stations being positioned in a moving direction of the print medium, the printing station positioned downstream with respect to the moving direction of the print medium forming a layer of printing particles on a layer of printing particles formed by the printing station positioned upstream, the printing station comprising:a bearing member for bearing charged printing particles thereon;a backing electrode opposed to the bearing member;a power supply connected to the backing electrode for generating an electric field that attract the charged printing particles on the bearing member to propel the charged printing particles toward said backing electrode;a printing head disposed between the bearing member and the backing electrode, the printing head having a plurality of apertures through which the printing particles can propel and a plurality of electrodes disposed around the plurality of apertures; anda driver for applying the plurality of electrode with a voltage for allowing the printing particles to be propelled and a voltage for forbidding the printing particles to be propelled in response to an image signal;wherein at least any one of the printing stations is different in intention of the electric field from another in accordance with a charge quantity of printing particles or a number of the layer of printing particles in the one of the printing stations.