Abstract: A modular ink delivery system using ink jet heads effectively supplies ink to a multi-level array of ink jet heads, and ensures that the heads remain in position during printing even if there is vibration of the supporting structures. Delivery is provided by a number of ink containing chambers, at least one for each level and stacked one atop the other. A connection extends from each chamber to at least one ink jet, and ink is automatically supplied to all of the chambers for example by pumping ink to the upper of the chambers, the ink then cascading downwardly from each upper chamber to a lower chamber through standpipe connections between them. The heads are positively held in place by a first circular bar and a second non-circular bar, which bars are operatively engaged by a mounting block for each head for guided movement.

Abstract: A fluid (liquid or water) wash is used to clean the front surface of an ink jet printer cartridge. In addition, a nozzle plate that overlies the nozzle shields the nozzle array from the splatter of ink. In ink jet printers, ink droplets are propelled from an array of orifices in a nozzle plate in the printer head. During the ink droplet ejection, ink is sprayed or deposited around the orifices. The ink droplets are deposited on a paper web adjacent the nozzle and mist from the droplets drifts back to coat the face of the nozzle plate. Some ink seeps behind the nozzle plate onto the array of nozzle orifices. The ink coating attracts particles that tend to clog the nozzle orifices. The ink coating is washed away by fluid streams that flow over the nozzle surface and in some embodiments flow over the nozzle orifices themselves. The fluid may be water, ink or other liquid that is channelled across the nozzle surface, or the fluid may be an air stream that blows across the nozzle surface.

Abstract: Substantially optimum print quality is maintained for an ink jet printer which includes a nozzle plate having a number of orifice openings from which ink droplets for printing are sprayed. It is electronically determined when a particular orifice opening has been inactive for a predetermined period of time, and then an exercise print command is supplied to the orifice causing an ink droplet to dribble out of the orifice, rather than being sprayed out of the orifice, to keep the orifice clear for printing when a print command is supplied to it. The dribbling drops have a smaller size than the sprayed drops, and may be formed by supplying heater elements associated with the openings with pulses of shorter duration than normal. Dribbling ink droplets are automatically removed from the printer cartridge by one or more strands (e.g. continuous filament rayon thread) moving past the nozzle at a speed of between about 1-3 feet per hour while being positively guided.

Abstract: In a printer assembly having a rack of ink-jet print cartridges, a backup cartridge is moved into alignment with a cartridge to be cleaned and the backup cartridge substitutes for printing of the cartridge being cleaned until the cleaned cartridge is moved back to its printing position. The backup cartridge is then moved into alignment with another cartridge and prints for that cartridge which is then cleaned. Ink-jet print cartridges must be periodically cleaned to wipe excess ink and particles from the nozzle array on the front face of the cartridge. Cartridges are cleaned by moving them to a cleaning station that wipes clean the front face of the cartridge. To avoid interruption of printing while cartridges are being cleaned, a backup cartridge is moved into alignment and substitute prints for a cartridge to be cleaned.