Abstract: Described is a piezoelectric drive element assembly for use in ink jet printer devices. The assembly comprises a piezoelectric drive element, which is characterized by a pair of electrodes spaced apart and thereby electrically isolated from one another on an external lateral face of the drive element. The assembly further includes a printed circuit board having holes through which the drive element is fitted, with the electrodes of the drive element being soldered to opposite sides of the printed circuit board.

Abstract: An ink jet printer includes a print head having a plurality of piezoelectric driving elements selectively energizable to cause ejection of droplets of ink through nozzles in a nozzle plate. Ink is supplied to the print head from an ink reservoir which is connected to a bellows device. The ink reservoir and the bellows device together form an air-tight container. The bellows device has a resilient form of construction so as to tend to increase the volume of the container. As a result, an appropriate underpressure is maintained in respect of the ink in the nozzles, such underpressure being necessary to prevent ink escaping from the nozzles under quiescent conditions. In operation, the bellows device progressively collapses so as to reduce the rate at which the underpressure increases as ink is ejected, thereby prolonging the period for which the underpressure is maintained within a desired operating range.

Abstract: An ink jet print head has a plurality of nozzles arranged in a vertical line at the printing end and connected by respective ink channels to pressure cavities in a circular arrangement at the ink supply end. The pressure cavities are supplied from an intermediate chamber contained in the print head and formed in a thin elongated shape and positioned generally in a plane parallel with the line of the nozzles. The construction of the print head compensates for acceleration and deceleration forces which are induced in the ink due to movement of the print head in the horizontal direction or perpendicular to the plane of the nozzles.

Abstract: The nozzle plate of an ink jet print head is made of glass to provide a desirable wetting property for a stable meniscus of the ink column and the front surface of the plate is coated with a non-wetting material such as metal or plastic to prevent ink deposits at the front surface around the orifice. Any ink deposits at such front surface would adversely affect the ejection of ink droplets.

Abstract: A mold having a desired print head shape includes a cover in which a plurality of rods or ductile fibers are attached, the cover being positioned with the rods extending into the mold and to the side opposite the cover. A hardenable synthetic material is introduced through a hole in the cover and after hardening of the material to form the print head, the rods are withdrawn from the mold to leave bores or apertures in the print head which serve as passageways for the droplets of ink.

Abstract: Means for supplying ink to a plurality of individually-spaced movable print heads is caused to be moved in a direction therewith but which ink supply means is positioned and directed in a manner perpendicular to the direction of movement of the print heads. An ink container is fixed at a distance from the print heads and a separate flexible ink supply tube, extending substantially in a vertical direction, connects the container with each individual print head. The ink supply tubes are movably swung or pivoted as the print heads are caused to be laterally moved and the swinging or pivoting movement of the supply tubes prevents interruption of the flow of ink to the print heads upon reversal of travel thereof at the ends of the printing lines.

Abstract: A printing device is provided which includes a feeler pivotally mounted on a printer frame and urged into engagement with record media positioned on a platen for printing. A magnetic element on the feeler coacts with a Hall generator on the frame to provide a control voltage which is effective to control a motor for positioning of the frame so that a print head mounted on said frame is located at a proper distance from the record media for printing thereon.