Printhead control

US9352556B2 · kind B2 · utility

Assignee

• Tonejet Limited · GB

Inventors

• Andrew John Clippingdale · Royston, GB
• Robin Timothy Bacon · Cambridge, GB

Key dates

• Filing date: Jun 27, 2013
• Grant date: May 31, 2016
• Expiry date: Jun 27, 2033

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B41J2202/20
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A method of printing a two-dimensional bit-mapped image having a number of pixels per row for printing is disclosed. The method and apparatus use either a plurality of overlapping printheads (300) or a printhead or plurality of printheads indexed through overlapping positions. The or each printhead has a row of ejection channels (301), each of which has associated ejection electrodes to which a voltage is applied to cause particulate concentrations to be formed from within a body of printing fluid. In order to cause volumes of charged particulate concentrations of one of a number of predetermined volume sizes to be ejected as printed droplets from selected ejection channels of the overlapping printheads, voltage pulses (VE) of respective predetermined amplitude and duration, as determined by respective image pixel bit values, are applied to the electrodes of the selected ejection channels. For each row of the image, the values of the voltage pulses to be applied to the overlapping printheads to form pixels printed by overlapped ejection channels are adjusted in dependence on the position of the pixel within an overlapped region of the printheads and in dependence on the predetermin…