Abstract: An ink jet synchronization scheme, wherein the drop formation of respective streams in an ink jet array are synchronized acoustically by individual acoustic fiber inputs to each of the streams. The acoustic fibers are attached to grooves adjacent each of the nozzles, with acoustic isolation being provided between the fiber and the nozzle substrate to prevent direct excitation of the substrate. This prevents the occurrence of resonance within the nozzle plate. Alternatively, acoustic isolation is achieved by mounting the synchronization structure separate from the nozzle plate. For example, the acoustic fibers are attached to the charge electrode structure, or are attached to a support structure intermediate the nozzle plate and the charge electrode structure. The acoustic energy inputs to the fibers are independently controlled as is required for certain printing schemes or are made identical as is normally the case.

Abstract: Method and apparatus is described for controlling the formation and shape droplets in an ink jet stream. The continuous portion of the stream is illuminated with a radiant energy source such as a laser. The surface wave profile produced by illuminating the stream is sensed to provide the fundamental and harmonic frequency components thereof. A perturbation drive signal, the amplitude and relative phase of which is a function of the sensed frequency components, is provided for controlling the formation and shape of the droplets.

Abstract: A jet printer includes a nozzle plate having at least two rows of nozzles, with the nozzles in one row being laterally staggered with respect to the nozzles in another row. The jets emanating from the respective rows of nozzles are directed in non-parallel trajectories to form at least a portion of a single line of dots at a time on a printing medium, with the jets from a given row forming non-adjacent dots on the printing medium. In practice, the nozzle plate is comprised of a semiconductor substrate, for example silicon, with the exit aperture of each of the nozzles in at least one row being axially misaligned with respect to the longitudinal center axis of their respective entrance apertures, resulting in a non-normal jet trajectory with respect to the plane of the nozzle plate.