Abstract: A drop-on-demand piezo-electric printhead has channel walls defined by piezo-electric material (10) with electrodes (26) along the length thereof. In portions of the channels which are open to an ink supply conduit, the piezo material is locally disabled, e.g. by reducing the width of the electrode or by interposing a material (40) of lower dielectric constant between the electrode and the piezo material. A lower capacitive load results.

Abstract: A ceramic piezoelectric ink jet print head having at least one channel with walls coated with a multi-layer coating including an electronic barrier layer and an electrically conducting layer where the electric barrier layer is disposed between the channel well and the electrically conducting layer.

Abstract: A process for the selective passivation of the channel walls of a channelled ink-jet printhead component by the chemical vapor deposition of a passivant coating, the process comprising mounting the component in a support in registration with a datum location therein, the support having masking means for masking selected areas of the component, and depositing the passivant coating on unmasked portions of the channel walls.

Abstract: A drop-on-demand piezo-electric printhead has channel walls defined by piezo-electric material (10) with electrodes (26) along the length thereof. In portions of the channels which are open to an ink supply conduit, the piezo material is locally disabled, e.g. by reducing the width of the electrode or by interposing a material (40) of lower dielectric constant between the electrode and the piezo material. A lower capacitive load results.

Abstract: A drop-on-demand piezo-electric printhead has channel walls defined by piezo-electric material (10) with electrodes (26) along the length thereof. In portions of the channels which are open to an ink supply conduit, the piezo material is locally disabled, e.g. by reducing the width of the electrode or by interposing a material (40) of lower dielectric constant between the electrode and the piezo material. A lower capacitive load results.

Abstract: A process for the selective passivation of the channel walls of a channelled ink-jet printhead component by the chemical vapor deposition of a passivant coating, the process comprising mounting the component in a support in registration with a datum location therein, the support having masking means for masking selected areas of the component, and depositing the passivant coating on unmasked portions of the channel walls.

Abstract: A process for the selective passivation of the channel walls of a channelled ink-jet printhead component by the chemical vapor deposition of a passivant coating, the process comprising mounting the component in a support in registration with a datum location therein, the support having masking means for masking selected areas of the component, and depositing the passivant coating on unmasked portions of the channel walls.

Abstract: This invention relates to improvements in or relating to ceramic piezoelectric ink jet print heads of the kind having an ink channel for connection to an ink ejection nozzle and to a reservoir for the ink, and a piezoelectric wall actuator which forms part of the channel and is displaceable in response to a voltage pulse thereby generating a pulse in liquid ink in the channel due to a change of pressure therein which causes ejection of a liquid droplet from the channel. Such print heads are referred to hereafter as piezoelectric ceramic ink jet print heads.