Abstract: An apparatus for controlling ink pressure in a printhead, the apparatus comprising: an integrally formed structure having: at least one control reservoir separated into first and second chambers by a weir; at least one inlet passageway, extending from the first chamber to an inlet port on an edge of the structure, for supplying ink from a remote source into the first chamber of the reservoir; at least one fluid outlet passageway, extending from the second chamber to an outlet port on an edge of the structure, for recirculating fluid from the reservoir to the remote source of ink; and at least one ink supply port, in communication with the first chamber, for supplying ink to, or receiving ink from, a printhead.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: A method of cleaning an electrostatic printhead which has one or more ejection tips from which, in use, ink is ejected, the method comprising: stopping a prior flow of ink to a region around the ejection tip(s) for, in use, printing; causing a pressure differential to occur at the tip region thereby causing the ink meniscus to retreat from the tip; and passing a rinse into the tip region to clean the tip.

Abstract: The invention relates to a method of printing a two-dimensional bit-mapped image having a number of pixels per row, the printhead having a row of ejection channels and each ejection channel having associated ejection electrodes to which voltages are applied in use. During printing, in order to cause volumes of fluid to be ejected from selected ejection channels of the printhead for printing, voltage pulses having values of predetermined amplitude and duration as determined by respective image pixel bit values generated by a raster image processor are applied, at a given pulse period, to the electrodes of the selected ejection channels.

Abstract: An apparatus for controlling ink pressure in a printhead, the apparatus comprising: an integrally formed structure having: at least one control reservoir separated into first and second chambers by a weir; at least one inlet passageway, extending from the first chamber to an inlet port on an edge of the structure, for supplying ink from a remote source into the first chamber of the reservoir; at least one fluid outlet passageway, extending from the second chamber to an outlet port on an edge of the structure, for recirculating fluid from the reservoir to the remote source of ink; and at least one ink supply port, in communication with the first chamber, for supplying ink to, or receiving ink from, a printhead.

Abstract: A method of reducing and/or preventing the accumulation of concentrated ink at an ejection point of a printhead of an electrostatic inkjet printer when ink is not being ejected at the ejection point, the method comprising reversing the electric field at the ejection point of the printhead during a non-printing phase of operation to reduce the concentration of ink at the ejection point.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: A method of calibrating a printhead, for printing two-dimensional bit-mapped images having a number of pixels per row, is disclosed for printheads (1) having a row of printing channels (5). During printing, in order to cause volumes of charged particulate concentrations of one of a number of predetermined volume sizes to be ejected from selected ejection channels of the printhead to form printed pixels, control pulse values of respective predetermined amplitude and duration, as determined by respective image pixel bit values, are applied to the selected printing channels. The calibration method comprises providing an image (50) that causes each channel of the printhead to be driven with the same pulse value, and printing one or more test prints of the image.

Abstract: A method of cleaning an electrostatic printhead which has one or more ejection tips from which, in use, ink is ejected, the method comprising: stopping a prior flow of ink to a region around the ejection tip(s) for, in use, printing; causing a pressure differential to occur at the tip region thereby causing the ink meniscus to retreat from the tip; and passing a rinse into the tip region to clean the tip.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: A method of reducing and/or preventing the accumulation of concentrated ink at an ejection point of a printhead of an electrostatic inkjet printer when ink is not being ejected at the ejection point, the method comprising reversing the electric field at the ejection point of the printhead during a non-printing phase of operation to reduce the concentration of ink at the ejection point.

Abstract: The invention relates to a method of printing a two-dimensional bit-mapped image having a number of pixels per row, the printhead having a row of ejection channels and each ejection channel having associated ejection electrodes to which voltages are applied in use. During printing, in order to cause volumes of fluid to be ejected from selected ejection channels of the printhead for printing, voltage pulses having values of predetermined amplitude and duration as determined by respective image pixel bit values generated by a raster image processor are applied, at a given pulse period, to the electrodes of the selected ejection channels.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: A method of calibrating a printhead, for printing two-dimensional bit-mapped images having a number of pixels per row, is disclosed for printheads (1) having a row of printing channels (5). During printing, in order to cause volumes of charged particulate concentrations of one of a number of predetermined volume sizes to be ejected from selected ejection channels of the printhead to form printed pixels, control pulse values of respective predetermined amplitude and duration, as determined by respective image pixel bit values, are applied to the selected printing channels. The calibration method comprises providing an image (50) that causes each channel of the printhead to be driven with the same pulse value, and printing one or more test prints of the image.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.

Abstract: A method of driving an electromechanical converter of a print head of a continuous inkjet printer, wherein the electromechanical converter is arranged to break up a continuous stream of ink into a plurality of drops. The method includes determining a modulation voltage to drive the electromechanical converter, at least a property of the modulation voltage being controlled to take into account movement of a break up point of the continuous stream of ink, and to ensure that in a characteristic of modulation voltage versus a property at least indicative of a break up point of the continuous stream of ink, the characteristic has a predetermined gradient, or a gradient related to this predetermined gradient; and driving the electromechanical converter at the determined modulation voltage.

Abstract: An ink supply system for an ink jet printer, particularly a continuous ink jet printer, has a manifold assembly of two parts that are brought together at interfacing surfaces. At least one of the surfaces has a plurality of ink flow channels for conveying ink around an ink circuit between components. The other of the interfacing surfaces is configured to close and seal the channels. A plurality of ports is provided in fluid communication with the channels, the circuit components being connectable to the ports. The manifold assembly provides for a compact and neat arrangement free of many tubes and pipes. The lower number of connections significantly reduces the risk of leakage.