Abstract: An apparatus is provided for locking an ink jet resonator assembly into a printhead of a continuous ink jet printer. The locking apparatus comprises a resonator holder for holding the resonator prior to alignment of the resonator assembly; a frame for supporting the resonator holder and the resonator assembly after alignment; and a methyl-cyanoacrylate adhesive applied between the resonator holder and the frame to lock into position the properly aligned resonator assembly.

Abstract: A continuous linear array ink jet apparatus deposits a predetermined amount of printing fluid of at least one color onto a linear array of pixels at high resolution. The continuous ink jet system includes a linear array of orifices fluidically connected to a fluid supply, for producing a linear array of jets. The jets are stimulated for regular break-up of each jet into a plurality of uniform streams of drops. A linear array of planar conducting elements, disposed along a path of motion of the array of jets, deflects the print drops into at least two print positions. The linear array of planar conducting elements is situated at a predefined angle with the motion of the print medium so that the resolution of the print system is substantially higher than the number of jets per inch along the array.

Abstract: A mounting apparatus holds in position a droplet generator assembly to be mounted in a continuous ink jet printing system. The droplet generator assembly comprises a pair of conical slots and a pair of conical apertures, located on opposing sides of the droplet generator. A resonator clamping plate includes a plurality of mating protrusions. A resonator support includes a plurality of spherical protrusions. A holding force, such as a screw, securely holds the assembled structure. The clamp and support interact with the conical slots and apertures to locate and exactly constrain the droplet generator. With the mounting structure of the present invention, the six degrees of freedom of adjustment are controlled.

Abstract: A fluid flow detection method is used in a continuous ink jet printer which generates a row of parallel selectively charged drop streams from a fluid system. In the fluid flow detection method, a low airflow catcher device is provided for establishing bubble flow in an associated catcher vacuum port and catcher return line. The catcher return line contains catcher return fluid. Pressure fluctuations are monitored in the catcher return fluid to the ink tank, the ink tank having a tank vacuum. The tank vacuum is automatically lowered to a preset value, which preset value is greater than bubble flow transition. The tank vacuum is then incrementally lowered as pressure fluctuations are monitored. The tank vacuum is maintained at a constant level when the pressure fluctuations decrease below a predetermined level due to the establishment of bubble flow.

Abstract: An ink jet ink composition comprises a liquid vehicle, a dye, a hydroxyalkylated polyethyleneimine, and an ammonium salt for enhancement of waterfastness. The ammonium salt preferably comprises less than 1% by weight of the ink composition, and is added to a combination of the dye and ethoxylated polyethyleneimine. The ink jet ink composition increases the waterfastness of the ink to a level greater than 85%.

Abstract: A platen assembly is provided for use with a printing system which uses ink jet technology to produce images on a substrate. A platen and the substrate move together as a unit. One or more print rollers deflect the substrate under tension to maintain a stable substrate, critical for maintaining print quality. A pivot point is provided from which the rollers can be cantilevered away. A lifting mechanism is then used to raise and lower the platen and the substrate to and away from a print position.

Abstract: An ink jet ink composition comprises a liquid vehicle, a pigment, a pH adjusting component, and a chemical with a plurality of electron donating groups. The chemical with a plurality of electron donating groups comprises a chemical with at least three electron donating groups, wherein the at least three electron donating groups are situated in close proximity to provide high dried film resistivity. With the present invention, significant improvement in dried film resistivity of carbon pigment ink jet inks is achieved, sufficient to eliminate charge lead to charge lead shorts and improve machine runnability and can, therefore, be used in ink jet printers.

Abstract: An ink jet ink composition comprises a water soluble polymer, a cosolvent, a water soluble dye, a surfactant, and water as a primary vehicle. The water soluble polymer, the cosolvent, and the surfactant are all present in extremely low amounts. The water soluble polymer is present in a range of from about 0.05 to 0.10%; the cosolvent, or glycol ether blend, is present in a range of from about 0.10 to 2.00%; and the surfactant is present in a range of from about 0.01 to 0.10%.

Abstract: An ink jet ink composition comprises a liquid vehicle, a single dye component, a surfactant and a glycol. The dye is water soluble and selected from the group consisting of Direct Dyes, Acid Dyes and Food Dyes, and preferably from the group consisting of Direct Yellow 86, Acid Red 249, Acid Red 92 and Direct Blue 199. Concentration of the dye is preferably in the range of 1% to 2% by weight. Using the ink composition of the present invention, images are generated by a continuous stream digital color press ink jet printing apparatus. In a preferred embodiment, to optimize runnability and jet straightness, the digital color press employs a gold orifice plate having an orifice diameter in the range of 0.7 to 0.8 mil.

Abstract: A continuous ink jet printer employing conductive ink and having a main ink supply, a supplemental ink supply, and a replenishment carrier fluid supply includes a fluid system that replenishes ink or carrier fluid based on the resistivity of ink in the main ink supply.

Abstract: A charge plate fabrication process provides a charge plate assembly having minimal distortion caused by shifts in temperature and humidity. The fabrication process includes the steps of forming a charge plate coupon having a plurality of charging electrodes and electrical connections on an etchable substrate and providing a ceramic charge plate substrate. An adhesive layer is then applied between the charge plate coupon and the charge plate substrate before assembling the charge plate coupon and the charge plate substrate in a fixture. Finally, the assembly is cured in the fixture.

Abstract: An ink jet ink composition comprises a liquid vehicle, a pigment, and a base for raising the pH of the system. The problem to be addressed for pigmented inks is how to achieve excellent ink redispersibility within a short time period, usually within 1-2 minutes, without any mechanical agitation. With the present invention, dried ink redispersibility/charge plate deposit redispersibility of aqueous pigmented ink is improved by raising the pH of the ink, for example, between 9 and 12. The time required for dried ink redispersibility is then reduced from greater than 10 minutes to an acceptable 1-2 minutes. The present invention results in significant improvement in machine runnability and can, therefore, be used in ink jet printers.

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 ink jet ink composition comprises a security component, a liquid vehicle, a dye, and an N-hydroxyalkyl imine substituted at about 80% of the available nitrogens. The security component in this ink jet composition causes the ink to maintain color when subjected to bleach to prevent alteration of a printed document, and can be used in ink jet printers.

Abstract: A vacuum system solves the heretofore unknown problem of mist generation from an ink reservoir under vacuum. The vacuum system includes an ink reservoir and a vacuum pump for supplying vacuum to the ink reservoir. A mist filter is housed in a housing associated with the vacuum system for capturing ink mist from the ink reservoir.

Abstract: An apparatus and method allows for mounting and aligning of the charge plate/catcher assembly and the droplet generator within the structure that holds these two parts. Three degrees of freedom of adjustment are incorporated into the frame and are self-locking. Two of the degrees of freedom are the positioning distance of a jet array to charge leads and the parallelism of the jet array to the charge leads. The third degree of freedom is the ability to adjust the jet array so as to align and center the jets in front of the charge leads.

Abstract: An apparatus and method allows for mounting and aligning of the charge plate/catcher assembly and the droplet generator and has six degrees of freedom of adjustment, including three degrees of freedom of translation and three degrees of freedom of rotation. A first degree of freedom of translation comprises a height adjustment of the resonator relative to the charge plate; a second degree of freedom of translation comprises an alignment adjustment for aligning the plurality of jets with respect to the plurality of charge leads; and a third degree of freedom of translation comprises a reciprocal adjustment for moving the plurality of jets relative to the charge plate.

Abstract: An ink jet printer includes an ink jet printhead having a drop generator and an ink drop charging and catching assembly. An elastomeric seal mounted on a lever arm about a pivot remote from the charging and catching assembly seals the ink drop generator and charging and catching assembly when the ink jet printer is not in use.

Abstract: A charge plate fabrication process provides a catcher/charge plate assembly having improved manufacturability. The fabrication process includes the steps of providing a catcher, including a catch pan, and providing a ceramic charge plate, the charge plate having an electrode face. The charge plate electrode face is prelapped to a uniform negative angle before assembling the charge plate and the catcher in a fixture. The assembled catcher and charge plate are then bonded in the fixture.

Abstract: Ink concentration in a system is maintained regardless of the duty cycle under which the system is operating. In an ink jet system, a print head receives ink from the main ink supply and forms continuous drops. The drops needed for printing to form the desired image are selected from the continuously formed drops. Based on the selection, a count signal is produced indicative of the number of drops printed. An ink level sensor in the main ink reservoir generates a low ink level signal when ink in the reservoir reaches a predetermined low level, the difference between a normal level and the low level corresponding to a predetermined cycle volume. A fluid connection selectively allows flow into the main ink reservoir from either the external supply of ink or the external supply of ink replenisher.