Abstract: Embodiments of the present invention relate to a pressure damping ink filter for use with an ink jet printer. The pressure damping ink filter includes at least one flow control member and a filter. The flow control member, in combination with any pressure damping provided by the thickness of the filter medium and the ink volume capacity of the filter housing, may substantially reduce, if not eliminate, pressure fluctuations in the ink stream that are generated by a high frequency electric pump. The flow control member may be a fixed or variable input restrictor and a fixed or variable output restrictor. The input restrictor and/or output restrictor may also be located inside or outside of the filter housing. Further, the input and output restrictors may be molded as part of the filter housing or the filter itself.

Abstract: Embodiments of the present invention relate to a pressure damping ink filter for use with an ink jet printer. The pressure damping ink filter includes at least one flow control member and a filter. The flow control member, in combination with any pressure damping provided by the thickness of the filter medium and the ink volume capacity of the filter housing, may substantially reduce, if not eliminate, pressure fluctuations in the ink stream that are generated by a high frequency electric pump. The flow control member may be a fixed or variable input restrictor and a fixed or variable output restrictor. The input restrictor and/or output restrictor may also be located inside or outside of the filter housing. Further, the input and output restrictors may be molded as part of the filter housing or the filter itself.

Abstract: According to certain aspects of an embodiment of the present invention, a deflection electrode assembly is provided for use in a continuous ink jet printer of the type which projects a stream of ink drops toward a substrate and controls placement of the ink drops on the substrate by selectively charging the individual ink drops and passing the charged ink drops through an electric (deflection) field created by the deflection electrode assembly. The deflection electrode assembly includes a high voltage deflection electrode and a low voltage deflection electrode positioned on opposite sides of the ink drop stream. A dielectric insulating member is mounted on at least one of the deflection electrodes. The insulating member include a longitudinal opening which exposes the deflection electrode along the path of the ink jet stream, thereby virtually eliminating the tendency for accumulated ink to decrease the strength of the deflection field.

Abstract: According to certain aspects of an embodiment of the present invention, a deflection electrode assembly is provided for use in a continuous ink jet printer of the type which projects a stream of ink drops toward a substrate and controls placement of the ink drops on the substrate by selectively charging the individual ink drops and passing the charged ink drops through an electric (deflection) field created by the deflection electrode assembly. The deflection electrode assembly includes a high voltage deflection electrode and a low voltage deflection electrode positioned on opposite sides of the ink drop stream. A dielectric insulating member is mounted on at least one of the deflection electrodes. The insulating member include a longitudinal opening which exposes the deflection electrode along the path of the ink jet stream, thereby virtually eliminating the tendency for accumulated ink to decrease the strength of the deflection field.

Abstract: A self-cleaning print head for an ink jet printer directs ink to a substrate to be marked. The print head has a drop generator with a body that has a front face, an ink supply conduit and at least one orifice extending through the front face. The orifice also defines a nozzle for ejecting ink droplets. A solvent supply conduit is provided for supplying solvent to the front face of the drop generator, and a drain conduit is provided for suctioning the solvent from the front face and into the drain conduit. The supply conduit and the drain conduit have openings on the front face disposed relative to each other and the orifice(s) so that the solvent released from the supply conduit moves along the front face, adjacent the orifice(s) and into the drain conduit regardless of the spatial orientation of the print head. This allows the solvent to move residue from the front face and into the drain conduit no matter the orientation of the print head.

Abstract: A clean-in-place system for use in an ink jet printhead has a compartment and an end plate with a slot therein to permit ink drops to be projected from the compartment onto a substrate to be marked. For cleaning purposes, a shutter is disposed adjacent the slot to seal it. Thereafter, the pump floods the compartment with ink solvent from a solvent reservoir. The solvent may be agitated by air or a mechanical device. Thereafter, a drain line is used to remove the solvent from the compartment. The pneumatic shutter is reopened after the solvent is withdrawn to enhance the drying of the components. The shutter may consist of an inflatable member and a pump for supplying compressed air to the inflatable member to inflate and deflate it.

Abstract: A priming system for ink jet printers includes an ink tank, an ink supply line, an ink bypass line and a valving arrangement which alternately permits either pressurized ink to be supplied to a remote printhead for printing purposes or unpressurized ink to be drawn to the printhead by use of a vacuum source applied to the bypass line.

Abstract: An ink and solvent supply consists of a dual-chambered container. The lower chamber is provided with make-up solvent, while the upper chamber is provided with ink concentrate. When solvent is required, it is removed directly from the lower chamber. When fresh ink is required, vacuum is applied to the upper chamber causing solvent to pass from the lower chamber to the upper chamber via a conduit, to dilute the ink concentrate to form fresh ink which is then provided to the printing system.

Abstract: A variable orientation ink catcher for use with ink jet printing equipment receives unused ink drops. The drops are returned to the printing system for reuse. The catcher includes an arcuate receiving portion offset from an outlet port. Caught ink flows by gravity from the receiving portion via a reservoir to the outlet port through a wide range of angular orientations.

Abstract: The invention is an ink drop catcher for use in a drop marking device such as an ink jet printer. The catcher receives drops which are not to be deposited on the recording medium. The catcher includes a convoluted passage through which the drops pass to return to the ink supply. An electrode disposed along the convoluted passage senses the current flow created by the accumulation of the charges from a series of test drops. This current flow is used by phasing circuitry to insure that the drops are correctly charged at the time they are formed.

Abstract: A valve is disclosed suitable for use in ink marking systems. The valve has an output port, a supply port, and a control port. The control port communicates with a chamber disposed above a flexible diaphragm while the output port communicates with a reservoir to be periodically supplied with fluid. The diaphragm flexes between an open position permitting the supply port to communicate with the output port and a closed position blocking such communication as a function of the pressure differential across the diaphragm created by pressure changes at the central port.

Abstract: A method and apparatus are disclosed for providing feedback control of the ink drop velocity in a drop marking system. The control system maintains essentially constant velocity of the ink drops as they pass through a deflection field which causes certain of the electrically conductive drops to be directed onto a substrate to be marked. The ink flow between two selected points is monitored by a control device to generate ink flow rate data and compared against a reference value. In the event that a flow rate deviation is sensed, appropriate action is taken to change the flow rate. Such action includes altering ink viscosity and/or ink pressure.

Abstract: A fast acting ink valve adapted to be used in conjunction with the nozzle of an ink jet printing system is disclosed. A flexible diaphragm modulates flow through a valve chamber. A spring biases the diaphragm to a sealed position to prevent flow. Ink pressure in the marking system unseals the diaphragm permitting flow. Unlike check valves, the invention has minimal pressure drop due to the location of the bias spring outside the ink flow path.

Abstract: An ink return system for an ink jet printer which directs a portion of the ink projected from a nozzle to a print surface and the remainder to a catcher, the catcher having a receptacle entrance for intercepting the ink stream including a tube with an entrance to catch the ink stream and then convey the ink liquid along a flow path away from the catcher and a cowling adjacent the receptacle connected to a vacuum source to create a scavenging air flow at the tube entrance for ingesting ink mist without exposing the intercepted liquid ink to the relatively high rate of air flow necessary to sweep away the ink mist.

Abstract: A vacuum return ink system for an ink jet printing apparatus includes an ink/air separator comprising a housing having a chamber formed therein. A first inlet port of relatively large diameter connects the chamber via a short tube of similar diameter to the ink catcher of the printing apparatus used for accumulating unused ink. A second port of relatively large diameter is provided to connect the chamber via a tube of a similar diameter to a vacuum source. A third port of relatively small diameter is provided to connect the chamber via a tube of similar diameter to an evacuated ink return tank. A tubular section defining the third port is inserted into the housing with the end thereof extending to the floor of the chamber. Ink and air are drawn from the catcher into the chamber via the first port at a high rate of flow, thereby minimizing a buildup of ink at the catcher mouth.