Patent ID: 8579415
Filing Date: 2013-11-12
Classification: B41J,H05K

Abstract:
1. A method of depositing ink on a substrate, the method including: preparing an ink comprising a liquid vehicle and pigment particles dispersed in the vehicle, at least the pigment particles being electrically charged; applying a first potential to an outlet nozzle for the ink; applying at least a second potential to one or more auxiliary electrodes located adjacent the outlet nozzle; and expelling droplets of ink from the outlet nozzle towards a target zone on a substrate, wherein said one or more auxiliary electrodes are arranged to apply an electric field to a droplet of ink that has exited the nozzle, the configuration of the outlet nozzle and said one or more auxiliary electrodes, and the values of the first and second potentials, being selected to cause pigment particles to be concentrated electrophoretically toward the centre of said droplet of ink that has exited the nozzle as it falls, thereby to deposit a quantity of the pigment particles in the target zone having a higher concentration than the concentration of the pigment particles in the ink.