Abstract: An ink jet printhead includes a drop generator having an attached orifice structure forming a jet array adapted to use ink jet fluids with a charge device disposed opposite the jet array forming a gap. The charge device includes a dimensionally stable, non-porous substrate layer having a high load to deflection ratio, one or more electrically conducting leads bonded to the substrate layer, an insulating protective layer disposed over the electrically conducting lead, and a non-wetting polymer coating compatible with the ink jet fluids disposed on the insulating protective layer.

Abstract: An ink jet printing system includes a printhead generating a plurality of continuous ink jets that are in a row and directed toward a print receiving medium. The printhead contains a drop generator and an orifice plate that includes a plurality of nozzles to form the continuous ink jets. The orifice plate includes a stimulating device to produce first and second synchronous drop breakoffs in a phased relationship and each ink jet in the drop breakoffs alternate producing plurality of drops in a phased relationship. A charge plate is placed opposite the drop generator and includes a plurality of drop charging electrodes adjacent the continuous ink jets. A controller is in communication with each drop charging electrode and supplies a plurality of synchronized controlled drop selection pulses to the drop charging electrodes.

Abstract: A continuous liquid drop emission apparatus is disclosed comprising a liquid drop emitter containing a positively pressurized liquid in flow communication with a plurality of nozzles formed in a common nozzle member for emitting a plurality of continuous streams of liquid. A jet stimulation apparatus is provided comprising a plurality of transducers corresponding to the plurality of nozzles and adapted to transfer energy to the liquid in corresponding flow communication with the plurality of nozzles sufficient to cause the break-off of the plurality of continuous streams of liquid at a plurality of predetermined break-off times into a plurality of streams of drops of predetermined volumes.

Abstract: An ink jet printhead includes a drop generator having an attached orifice structure forming a jet array adapted to use ink jet fluids with a charge device disposed opposite the jet array forming a gap. The charge device includes a dimensionally stable, non-porous substrate layer having a high load to deflection ratio, one or more electrically conducting leads bonded to the substrate layer, an insulating protective layer disposed over the electrically conducting lead, and a non-wetting polymer coating compatible with the ink jet fluids disposed on the insulating protective layer. The coating reduces the capillary forces that hold liquid in the gap between the orifice structure and the charge device.

Abstract: An ink jet printhead includes a drop generator having an attached orifice structure forming a jet array adapted to use ink jet fluids with a charge device disposed opposite the jet array forming a gap. The charge device includes a dimensionally stable, non-porous substrate layer having a high load to deflection ratio, one or more electrically conducting leads bonded to the substrate layer, an insulating protective layer disposed over the electrically conducting lead, and a non-wetting polymer coating compatible with the ink jet fluids disposed on the insulating protective layer.

Abstract: A differential circuit is used to compare the current to the drive transducers to a matched reference circuit. With the capacitive current from the piezoelectric transducer canceled out in this manner, the resulting output current provides a direct measure of the vibration amplitude of the drop generator. By adding an appropriate inductor in parallel to the capacitive piezoelectric drive transducers, the loading of the drive electronics, or oscillator, is significantly reduced.

Abstract: A system for flushing ink residue from a fluid system is provided for use with a continuous ink jet print station. Ink is rapidly drained from the fluid system, and the fluid system is refilled with a flush fluid. The flow of flush fluid is directed through all fluid system components which normally contain ink. Subsequently, the flow of flush fluid can be diverted to a waste tank rather than re-circulated into the ink tank.

Abstract: A system and method are provided for protecting the vacuum pump of an ink jet printer system from the harmful effects of condensation in the vacuum lines, and from the harmful effects of moisture and water in the vacuum lines. This is accomplished by suppressing the condensation and drying the vacuum line walls.

Abstract: A print pulse phase control system for a continuous ink jet printer determines whether to charge ink droplets for recirculating, or not to charge ink drops for printing. The system includes a drop generator which receives a drive signal and generates a feedback signal. Print pulses are then produced at a fixed phase relative to the feedback signal for controlling drop charging.

Abstract: An apparatus and method allow for assembly of a print head apparatus for an ink jet printer. The apparatus comprises control capability for controlling the flow of fluid to the droplet generator and for controlling transfer of data to the droplet charging and collecting element. The control capability for controlling transfer of data to the droplet charging and collecting element is a motherboard containing various elements. The motherboard includes a microcontroller and fiber optics for receiving data and control signals and providing the signals to an input buffer. A RAM provides data memory, and a latch and shift register latch and shift the data from the RAM. A high voltage driver receive data from the latch and shift register. A control state machine communicates with the microcontroller, for handling generation of all control signals for the input buffer, the RAM, and the latch and shift register.

Abstract: An ink jet printing device has a drop generator for producing continuous streams of ink drops from at least one orifice and further has stimulation control electronics for maintaining desired stimulation conditions in response to a feedback from the drop generator. First and second feedback transducers measure the stimulation amplitude in the drop generator and generate feedback output signals in response to the stimulation. The feedback output signals are approximately equal in magnitude and opposite in sign to each other when the stimulation amplitude in the drop generator is a desired stimulation mode. An amplifier, whose inputs are the feedback output signals, provides an amplifier output signal to the stimulation control electronics which is the difference between the two feedback output signals.

Abstract: A drop ejection device for continuous ink jet printing includes a rectangular solid divided by parallel, elongated through-slots between its major surfaces, into a plurality of approximately identical dilatational regions. Each such region has a longitudinal mechanical resonance mode approximately the same as the desired drop ejection frequency. The body has an ink supply manifold adjacent a drop ejection face, which is normal to the longitudinal axis of the through-slots. An orifice plate having a linear orifice array, substantially longer than the through-slots, is attached to the ejection face. A plurality of elongated piezoelectric strips pairs are attached in opposing positions on major surfaces of each dilatational region. Upon actuation, said strips expand and contract to effect synchronous stimulation at the desired drop frequency.

Abstract: A system for selectively shifting the phase of drop charging along the array of ink jets of a continuous ink jet printer by producing a replicate signal of the drop stimulation signal; selectively shifting the phase of the replicate signal to provide a phase control signal; synchronizing a media feed tachometer signal to the phase control signal to produce a print enable signal; and controlling address of the charge electrodes with the print enable signal. The system further includes a selection mode wherein drop charge phase can be made random by selecting synchronization with the media feed tachometer signal.

Abstract: A method for avoiding drop charge switching errors in continuous ink jet printing of the kind using stimulation to regulate ink drop break-off of a linear array of ink streams. The method includes the steps of: controlling ink drop stimulation so that the phase distribution of drop break-off along the length of the ink stream array remains stable in time and charging stimulated drop streams in at least two different groups during at least two different address periods which are offset in phase so that all drop streams are addressed during a drop break-off condition.

Abstract: An improved print head construction for continuous ink jet printing of the kind which directs a plurality of ink streams through a drop charge region toward a print zone. The print head includes: (i) charge electrodes located adjacent the drop charge region for selectively applying an information voltage to droplets; (ii) a deflection electrode(s) closely spaced to, and downstream from, the charge electrodes, for applying a deflection field to the droplets; and (iii) a dielectric matrix for integrally embedding the charge and deflection electrodes in closely spaced relation. Methods for fabricating such print heads are also disclosed.

Abstract: An improved printing method using a print head having a linear array of print elements adapted to be indexed in a direction parallel to the line of the array direction to address successive groups of rows of print media pixels moved therepast in a direction generally perpendicular to the array direction. The method includes the steps of (i) selecting such print head to comprise an even number (A) of print elements located in a linear array and having with a uniform 2 pixel spacing; (ii) alternately indexing the print head, in a direction parallel to the array direction by the amounts of A-1 and A+1 pixels; and (iii) in correspondence with such alternate indexings respectively printing on even or odd rows of the print medium in accord with image information.

Abstract: A method of adjusting stimulation amplitude in continuous ink jet printers to provide satellite-free printing includes the steps varying the stimulation amplitude between the underdrive and overdrive stimulation conditions, charging the resulting ink jet filaments at their break off points with sawtooth voltage of period equal to the stimulation period, detecting and storing the resultant drop charging events and setting the operating stimulation amplitude based on the inception point inflection in the resulting stimulation amplitude versus detected charge relation.

Abstract: Method and apparatus for detecting and correcting misregistration of color separation planes in a multicolor printing process include the functions of: (i) printing on a test sheet, with a first color printing subsystem, a first array of M parallel lines which are uniformly spaced N adjustment steps apart and (ii) printing on the same test sheet with a second color printing subsystem, a second array of M parallel lines, which are uniformly spaced N+1 adjustment steps apart and which are predeterminedly juxtaposed, with respect to the lines of the first line array, so that when registration is correct, base registration lines of the first and second arrays are aligned.Upon visually inspecting the alignment of marks on said first and second line series, the operator can effect automated position shifting of the second subsystems printout color plane in an amount and direction based on which juxtaposed mark pair of said two arrays are in best alignment.

Abstract: A system for adjusting the stimulation amplitude of a continuous ink jet printer to operate in a satellite-free, drop break off region includes a test charge electrode located downstream from the nominal information charging zone, an electrometer for detecting drop charge imported by the test charge electrode and a control circuit for gradually varying stimulation between the underdrive to overdrive regions. An information storage and processing system stores and computes the stimulation amplitude corresponding to the overdrive inception point during such stimulation ramping and a nominal operating stimulation amplitude is selected based on the computed inception point stimulation.

Abstract: An improved damping system for continuous ink jet printers of the kind having: (i) a print head, including an ink cavity and an orifice plate coupled to the cavity, and (ii) an ink circulation system having an ink supply conduit to the print head cavity inlet and an ink return conduit coupled to the cavity outlet. The damping system reduces ink pressure transients within said print head means and includes: (i) a damping chamber for enclosing a gas-over-ink region that is coupled to the ink return conduit at a location proximate the print head and (ii) a printer subsystem for periodically introducing gas into said ink return conduit upstream of the damper chamber.