Abstract: High frequency of droplet ejection with minimized crosstalk and a uniform large ink droplet weight are realized in an inkjet printer printhead which employs two ink feed channels to couple an ink firing chamber to the source of ink. A first one of the ink feed channels has a lower fluid resistance to ink flowing in the channel than a second one of the ink feed channels. The first ink feed channel and the second ink feed channel each have an inlet to the ink source and are arranged such that the inlet of the first ink feed channel is closer to the ink firing chamber than the inlet of the second ink feed channel. Furthermore, adjacent ink firing chambers are arranged such that a lower fluid resistance ink channel of one ink firing chamber is next to a higher fluid resistance ink channel of a neighboring ink firing chamber. Nozzle diameter, heater resistor, and firing chamber dimensions are also optimized for the printhead.

Abstract: An improved ink jet head is provided. This improved ink jet head comprises a diaphragm, which is part of an ink chamber. The diaphragm includes a segment which contacts an opposing wall by a drive voltage lower than that for the rest of the diaphragm. The ink jet head also comprises an opposing wall opposite to the diaphragm. When the pressure for ink droplet ejection is generated, the segment of the diaphragm contacts the opposing wall, creating an extremely low compliance state. After ink droplet ejection, the segment of the diaphragm separates from the opposing wall, producing a high compliance state that absorbs the pressure created in the ink chamber by oscillation in the ink channel. Thus, pressure in the ink chamber resulting from ink vibration in the ink path including the ink chamber is buffered to prevent satellite emissions.

Abstract: Variation of ink droplet velocity and droplet mass in thermal ink-jet print heads having at least one primary heater element is achieved by means of a circuit for generating time-shifted heating pulses. The heater element structure is such that there is at least one secondary heater element in addition to and physically separated from each primary heater element. The circuit for generating time-shifted heating pulses for the primary and secondary heater elements applies those pulses in such a way that a vapor bubble has already formed in the printing fluid on the secondary heater element at the point at which a vapor bubble starts to form in the printing fluid on the primary heater element.

Abstract: An ink jet printhead includes a chip layer having a via for receiving ink, and having at least one actuator. A barrier layer is disposed adjacent the chip layer, and forms at least one throat which has a width and a cross-sectional area. The barrier layer also forms at least one bubble chamber, with each throat adapted to receive ink from the via and provide it to the respective bubble chamber. A nozzle layer is disposed adjacent the barrier layer, opposite the chip layer, and forms at least one nozzle for ejecting ink from the respective bubble chamber when the ink is energized by the associated actuator. At least one post is disposed proximate the throat, and extends part way between the chip layer and the nozzle layer. The post forms one or more gates through which the ink must pass from the via to the at least one throat.

Abstract: An inkjet printhead includes multiple printing elements grouped in sets about an ink refill channel. Each printing element includes a firing chamber and resistive element in communication with the refill channel via an ink feed channel. The feed channels are of differing length resulting in resistive elements being at staggered distances from the refill channel. To balance fluidic dynamics among printing elements a first constriction and second constriction occur along the length of the feed channels. The first constriction is adjacent the firing chamber and acts as a diffuser during firing. The second constriction is adjacent the refill channel and slows the refill process for feed channels of shorter length. For longer feed channels the second constriction is wider. For shorter feed channels the second constriction is narrower. Differing widths of the second constriction slow down refill by differing amounts to balance fluid dynamics among the printing elements.

Abstract: An ink jet print head (10) has a supply channel (14, 24, 52) connecting an ink source with an upper manifold (60U) and a lower manifold (60L). Each manifold has a tapered structure. From each manifold multiple inlet channels (36, 34, 44, 54) each lead to a respective pressure chamber (28) from which an outlet channel (40, 38, 46, 56, 62, 76, 82) leads to nozzles (88) from which droplets of liquid ink are expelled as a result of the action of a pressure transducer on the pressure chamber. Each manifold is separated from the supply channel by a baffle structure (92) that includes three baffles (94) formed by alternating plates (64, 78) having an open manifold with plates (58, 72) having a blocked manifold. The baffle structure reduces jetting nonuniformity by damping pressure displacement waves in the ink caused by the expulsion of ink droplets. The baffle structure also promotes effective heat transfer from the print head to ink being drawn in to the print head from the ink source.

Abstract: An ink jet print head includes ink ejection outlets for ejecting ink, passages communicating with the ejection outlets; a common chamber for supplying the ink to the passages; ejection energy generating elements for producing energy for ejecting the ink; an ink supply passage for supplying the ink to the common chamber; a buffering chamber disposed at a position through which a pressure wave resulting from driving of the ejection energy generating elements propagate, the buffering chamber containing a gas for attenuating the pressure wave, wherein a part of a wall constituting the buffering chamber has a gas transmitting property permitting introduction of gas external of the print head into the buffering chamber and preventing passage of ink from the common chamber through the gas transmitting member.

Abstract: An ink jet printing system having an ink accumulator holding a supply of ink for delivery under pressure to printheads of the system, the volume of the supply decreasing as ink is delivered to the printheads, and a pump operable intermittently to pump ink from a supply to the accumulator when the volume in the accumulator decreases to a lower limit, operation of the pump being terminated when the volume in the accumulator increases to an upper limit.

Abstract: An ink jet head includes an orifice plate having a plurality of orifices disposed transversely at prescribed intervals, a vibrating plate disposed parallel to orifice plate and deformed by applying a potential difference perpendicularly to the direction of polarization, and a plurality of partitions disposed between orifice plate and vibrating plate in the space between adjacent orifices, and the space surrounded by orifice, vibrating plate and partition defines a pressure chamber to be filled with ink. Vibrating plate is provided with a groove having a rectangular cross section in a region having relatively low field intensity when signal voltage is applied. In this structure, the electric capacitance of vibrating plate is reduced without adversely affecting the electric field intensity, and the efficiency of deformation of vibrating plate is increased.

Abstract: A thermal ink-jet ejector having a fluid flow channel extending between an ink inlet and a nozzle for the ejection of liquid ink therefrom, includes a rear channel diffuser disposed between the heating element and the inlet, and/or a front channel diffuser disposed between the heating element and the nozzle. Each diffuser includes an arrangement of tapers which decrease the flow impedance of liquid ink flowing toward the nozzle, and increase the flow impedance of liquid ink flowing toward the inlet. The arrangement increases the kinetic energy of droplets being ejected, and also increases the speed of re-fill of the channel with liquid ink following ejection.

Abstract: An ink jet head has plural liquid ink paths, each having a discharge opening for discharging ink when energy is applied to ink in a corresponding ink path, and a common ink chamber communicating with an end of each ink path for supplying ink to the discharge openings. The discharge openings are disposed in plural groups, which are consecutively driven by simultaneously applying energy to ink paths corresponding to selected discharge openings in a given group. The ends of the ink paths are disposed in the common ink chamber in groups consecutively arranged in accordance with the driving order of the discharge opening groups, and each ink path includes a portion proximate to that end which is directed away from the next consecutively arranged ink path group. This arrangement suppresses pressure interference between the consecutively driven discharge opening groups and enables high-quality, high-speed recording in a compact recording head.

Abstract: An ink-jet apparatus (10) and method provides high-resolution, high-speed printing by providing a transducer drive waveform (160) having a spectral energy distribution (170) that concentrates energy (172) around a frequency associated with a dominant (Helmholtz) ink drop ejection mode and that suppresses energy (174) at resonant frequencies associated with ink inlet (18) and ink outlet structures (24, 26, 28, 14) of the ink-jet head. Spectral energy distribution principles used to shape the transducer drive waveform can be used to enhance the jetting performance of many conventional ink-jet heads.

Abstract: An improved ink delivery system for an ink jet printer having a print carriage that traverses across a print medium comprising an ink source, a print head, and a coupler for coupling the ink source to the print head, the coupler including a pair of flexible tubes for carrying the ink and a Y-coupler for coupling to the pair of flexible tubes and the ink source, the Y-coupler causing the pair of flexible tubes to initially diverge. A check valve is provided to prevent back siphoning.

Abstract: A liquid droplet ejecting recording head includes a wall defining a chamber for being filled with recording liquid, said wall having a portion for defining an orifice communicated with the chamber; and a thin-film resistor provided on a surface of the wall facing the chamber so as to be located in the chamber, the thin-film resistor having one surface facing the chamber with which the thin-film resistor may be exposed to the recording liquid contained in the chamber, the thin-film resistor being energized with pulsed electric current for generating pulsed heat to directly heat the recording liquid, to thereby allow the recording liquid to be ejected outside through the orifice from the chamber in the form of a droplet and to be attached onto a surface of image recording medium positioned in confrontation with the orifice.

Abstract: A thermal ink-jet head of the present invention is so designed as to improve operating frequency by surely trapping foreign substances and reducing the influence of a cross stroke. In the thermal ink-jet head of the present invention, a channel wafer is provided with a nozzle channel, a coupling flow channel, and an ink reservoir. A protective layer and a polyamide layer are formed on a heater wafer. The polyamide layer is provided with pits extending from a heating element up to the coupling flow channel and a bypass pit for coupling the ink reservoir and the coupling flow channel. Foreign substances are trapped at the entry port of the bypass pit and the entry port of the coupling flow channel. The pit controls the growth of the bubble by eating away the front end of the heating element and reducing its rear end.

Abstract: A head for an ink jet printer has a substrate with a longitudinal dimension extending across the width of the paper to be printed upon. A cavity is formed longitudinally in the substrate and a conduit is provided to supply ink to the cavity. A series of orifices are spaced along a longitudinal surface of the substrate and extend between the surface and the cavity. A plurality of electrodes are provided to generate an arc within each orifice to expel ink there from. A pair of electrodes are associated with each orifice and the electrodes connect to electrical buses that supply bias voltage to the electrodes. The bus connection multiplexes the electrodes enabling relatively few switches to selectively control the expulsion of ink from each orifice. A diaphragm lies against the substrate forming a wall of the cavity and of the orifices. The diaphragm is formed of a resilient material that dampens pressure waves produced within an orifice and the cavity when an arc occurs between electrodes for that orifice.

Abstract: An ink jet head comprises a plurality of ink liquid paths in which energy generating elements are formed, a common liquid chamber communicated with the plurality of ink liquid paths, and an air chamber which is communicated with the common liquid chamber via a communication section formed at substantially a central portion of the air chamber and which ls formed along the longitudinal direction of the common liquid chamber. This arrangement of the ink jet head enables air in the air chamber to act on refilling behavior of ink in each of the ink liquid paths so that refilling in each of the ink liquid paths is not delayed.

Abstract: A piezoelectric ceramic plate has a plurality of grooves and partition walls formed in it. A cover plate is attached to the piezoelectric ceramic plate to cover the grooves to form interleaved ink channels and air channels. A flexible print board is adhesively attached to one end surface each of the piezoelectric ceramic plate and the cover plate. The ink supply ports formed in the flexible print board connect to the ink channels. A cover portion formed on the flexible print board covers the inlet ports of the air channels so that no ink enters the air channels. A first contact electrode formed on the flexible print board is electrically connected to metal electrodes in the ink channels. A second contact electrode is electrically connected to metal electrodes in the air channels.

Abstract: A compact ink jet print head has cross-sectionally tapered ink manifolds (16) for supplying ink to ink supply channels (18) leading to the acoustically driven ink pressure chambers (22). An array of closely spaced nozzles (14) which are supplied with ink from the densely packed ink pressure chambers by way of offset channels (71). The tapered manifolds, ink supply channels, pressure chambers, and offset channels are designed to provide uniform operating characteristics among the ink jet nozzles of the array. To enhance the packing density of the pressure chambers, the ink supply channels leading to the pressure chambers and offset channels are positioned in planes between the pressure chambers and nozzles. The tapered ink supply manifolds enhance purging of contaminants or bubbles from the print head by providing uniform ink flow rates (97, 97') along the entire length of the manifolds.

Abstract: An inkjet printer printhead is coupled to an ink source and has a plurality of ink firing chambers dimensionally defined by a barrier layer disposed between a substrate and an orifice plate. Two ink feed channels are coupled to one ink firing chamber and are dimensionally defined, in part, by the barrier layer. One of these ink feed channels has a smoothly converging wide dimension inlet at the ink source and a narrow dimension outlet at the ink firing chamber. The other ink feed channel also has a converging wide dimension inlet at the ink source and a narrow dimension outlet at the ink firing chamber but has an "S" shaped wall contour to make it asymmetrical to the first ink feed channel. An island of the barrier layer separates one ink feed channel from the other ink feed channel serving the ink firing chamber. This island has an essentially flat wall surface disposed toward the ink firing chamber.

Abstract: An ink-jet printing system having a pressurized ink reservoir. Ink at elevated pressure is supplied to a back pressure regulator which reduces the pressure down for use by conventional ink-jet printhead. The ink reservoir can be either stationary and off-axis or movable and onboard with the printhead.

Abstract: An ink ejecting apparatus is composed of a piezoelectric ceramics plate, a cover plate, and a nozzle plate. The piezoelectric ceramics plate is provided with a plurality of grooves. The cover plate is composed of a front plate and a rear plate. The rear plate is provided with a plurality of ink inlet holes and a manifold. The cover plate is bonded to the piezoelectric ceramics plate to define a plurality of ink chambers communicating with the manifold through the ink inlet holes and a plurality of air chambers that do not communicate with the manifold.

Abstract: An ink-supplied wire dot matrix printer head for actuating wires with ink attached to tip ends thereof into contact with a sheet of print paper to transfer ink to the sheet, thereby forming ink dots thereon. The ink-supplied wire dot matrix printer head includes a wire guide member having a wire guide hole for guiding the tip end of the wire, and an ink tank containing an ink absorbing body therein and having an ink supply port in which a portion of the wire guide member is inserted. The wire guide member has a capillary ink path communicating with a side of the wire and supplied with ink from the ink absorbing body.

Abstract: A drop-on-demand ink-jet printing head provided with an array of a plurality of piezoelectric elements arranged at regular intervals and fixed at their one ends to a base, the other ends of the respective piezoelectric elements being free ends which are disposed in opposition to nozzle respective apertures, the piezoelectric elements being formed by cutting, at predetermined width, a piezoelectric plate obtained by firing a lamination of paste-like piezoelectric material and conductive material stacked alternately in layers. Since each piezoelectric element is composed of a thin piezoelectric plate interposed between electrodes, if a voltage of only about 30 V, which is sufficient to drive the thin piezoelectric plate, is applied across the electrodes, it is possible to largely flex the whole of the piezoelectric element. By this transformation, ink between the top end of the piezoelectric element and the nozzle aperture is discharged to the outside as an ink drop.

Abstract: A driving method for an ink jet head and an ink jet apparatus using such ink jet head, features charging ink as a droplet from a discharge opening communicated with an ink path to carry out the recording by the pressure generated in the ink by means of an electric-mechanical converting element provided along the ink path. A driving pulse applied to the converting element begins to fall a predetermined time after its application.

Abstract: A nozzle arrangement structure in an ink jet print head. A plurality of pressure chambers are arranged in circular form, and a plurality of nozzles receive an ink supply from the corresponding pressure chambers and are arranged in an zig zag arrangement to obtain a small interval between the dots. Two straight lines concerning the zig zag arrangement are inclined against a printing direction and a direction perpendicular to the printing direction. When an ink discharge from the nozzles is controlled, preprocessing of serial data is carried out by hardware.

Abstract: An electrothermal ink jet print head is constructed in layer structure, wherein the expansion direction of the ink vapor bubble is directed opposite to the ink-ejection direction. Each ink channel (16) of the ink jet print head is supplied with ink by flow throttles for a highest degree of effectiveness. For this purpose, a cover plate (1) is furnished with openings (2). The openings (2) join into an ink storage container. The openings (2) are connected with recess openings (25) to the ink channel (16) in the chip (11). Selectively, the recess openings (25) can be furnished in the chip (11) or in the cover plate (1). A method is provided for producing the recess openings (25).

Abstract: In a piezoelectric type ink jet head, a plurality of pressure chambers are separated into n groups each having dummy pressure chambers at opposite ends. An increased spacing between ejection nozzles resulting from the dummy pressure chambers is compensated for by inclining the nozzle openings within each of the groups. The ink jet head is driven in a time sharing manner.

Abstract: The invention relates to a method of compensating for crosstalk between adjacent charging electrodes (14) in an ink jet printer having multiple printing jets (12) or channels, each with one charging electrode (14). In order to provide a desired drop charge in a specific channel X, there is applied, to the corresponding charging electrode (14.sub.X), a charge potential V.sub.X which is compensated for in response to (i) any charge potentials V.sub.X-1 and V.sub.X+1 applied to charging electrodes (14.sub.X-1, 14.sub.X+1) of the nearest channel X-1 and X+1, respectively, on each side of the specific channel X, and (ii) in response also to at least charge potentials V.sub.X-2 and V.sub.X+2 applied to charging electrodes (14.sub.X-2, 14.sub.X+2) of the next nearest channel X-2 and X+2, respectively, on each side of the specific channel X. The compensation is achieved by selecting V.sub.

Abstract: A liquid storing container storing liquid, therein and having a supply port for supplying the liquid to the outside has flow rate control means having a slit adapted to be closed in a steady state and to be opened for predetermined differential pressure or greater and controlling the flow rate of the liquid supplied from the supply port to the outside, and pressure regulating means disposed more adjacent to the supply port than to the flow rate control means for regulating the pressure of the liquid more adjacent to the supply port than to the flow rate control means.

Abstract: The present invention is directed to drop-on-demand ink jet heads. An exemplary form of an ink jet head of the present invention includes a plurality of elongated members formed of piezoelectric material, the elongated members being spaced apart from one another so as to define therebetween a plurality of elongated channels, alternating ones of which are adapted to be filled with ink so as to define ink channels. Electrodes are formed in the channels on opposing sides of the elongated members. A channel closing member is mounted to the elongated members to cover portions of the channels, the channel closing member having nozzle holes formed therein in alignment with at least some of the channels. The elongated members are polarized in at least one direction.

Abstract: An improved electrothermal ink print head has a sandwich-type construction in which the propagating direction of the electrothermally-produced steam bubble is opposite to the direction of ink discharge onto a print medium or substrate. To improve efficiency and reduce the reciprocal influence of adjacent ink ducts, the side of the chip 11 facing the ink supply vessel 12 is provided with a cover plate 1. At the points of intersection of the ink ducts 16 and supply conduits 15, the cover plate 1 includes openings 2 whose cross-sectional extents or areas are predeterminately related to the intersecting ducts and conduits. In a first variation, the cover plate 1 is formed of glass or ceramic and is anodically bonded on the chip. In a second variation, the cover plate 1 is fabricated of a plastic foil that is laminated on the chip 11 and is adhesive on both its opposite surfaces. In a third variation, the cover plate 1 is formed of a metal foil that is anodically bonded to the chip 11.

Abstract: A method of operating a pulsed droplet deposition apparatus, e.g. a drop-on-demand ink jet printer, having a droplet liquid chamber (16) with which a nozzle (18) communicates for expulsion of droplets (12) from the chamber, droplet liquid replenishment means (20) connected to the chamber and energy pulse applying means for imparting pulses of energy to the droplet liquid in the chamber, employs, to increase the volume of droplets expelled by respective energy pulses, a droplet liquid having high viscosity at low shear rate and low viscosity at high shear rate, the liquid relaxation time constant being of the same order or greater than the period of pulses applied to the liquid and the characteristic time of the liquid in the nozzle being of the same order or less than the period of the pulses.

Abstract: A drop-on-demand ink-jet printing head provided with an array of a plurality of piezoelectric elements arranged at regular intervals and fixed at their one ends to a base, the other ends of the respective piezoelectric elements being free ends which are disposed in opposition to nozzle respective apertures, the piezoelectric elements being formed by cutting, at predetermined width, a piezoelectric plate obtained by firing a lamination of paste-like piezoelectric material conductive material stacked alternately in layers. Since each piezoelectric element is composed of a thin piezoelectric plate interposed between electrodes, if a voltage of only about 30 V, which is sufficient to drive the thin piezoelectric plate, is applied across the electrodes, it is possible to largely flex the whole of the piezoelectric element. By this transformation, ink between the top end of the piezoelectric element and the nozzle aperture is discharged to the outside as an ink drop.

Abstract: Multi-channel droplet deposition apparatus of the kind having an array of parallel channels (1-11) with which respective nozzles and common ink supply communicate and in which electrically actuable devices (21-31) are located in relation to said channels to impart energy pulses to selected channels for effecting droplet ejection therefrom is operated by applying energy pulses to selected channels of the array and channels in the vicinity of the selected channels the amplitudes of which depend on the value of the compliance ratio of the channel walls to the droplet liquid and which together produce a pressure distribution in the channels to which they are applied which both effects droplet ejection from only said selected channels and is substantially free from pressure crosstalk between said selected channels or between said selected channels and other channels of the array.

Abstract: In a shear mode type ink jet head, nozzle holes are disposed at substantially central portions of channels formed between barriers of piezoelectric material, and common ink reservoirs are provided at both ends of the channels. In one embodiment, two kinds of channels having different depths are formed in alternating succession on a board made of piezoelectric material. Channels of one depth are used as dummy channels and are kept empty, and channels of the other depth are filled with ink and the ink can be ejected from the channels through nozzle holes.

Abstract: An ink jet cartridge is composed integrally of a recording head and an ink tank, which are constructed in mutually separable manner, in order to enable repeated use of the recording head by replacement of the ink tank. In an ink supply part in the ink tank, an elastic partition wall is provided with a slit which is normally closed but is opened under a predetermined pressure difference. The slit is so designed as to generate an appropriate negative pressure on the recording head, thereby preventing ink leakage. Also a slit shielding valve member is provided to shield the slit at the abrupt inhaling action of the ink tank at the detaching of the ink tank, in order to prevent air intrusion into the ink tank.

Abstract: An ink jet printing head driving method includes steps of: applying a voltage falling edge of a first pulse signal to cause a piezoelectric element to contract so that a capacity of a liquid passage is increased so as to supply ink to the liquid passage; applying a voltage rising edge of the first pulse signal to cause the piezoelectric element to expand so that the capacity of the liquid passage is decreased, for discharging an ink droplet through a discharge port, the first pulse signal having a first pulse width and a first peak voltage amplitude; and applying a voltage rising edge of a second pulse signal to the piezoelectric element after a predetermined delay time has elapsed since application of the first pulse signal for discharging the ink droplet, a pulse width of the second pulse signal being smaller than the first pulse width, and a peak voltage amplitude of the second pulse signal being equal to the first peak voltage amplitude.

Abstract: An ink jet head is disclosed for use with a drop-on demand type printer, and includes an insulating base, a plurality of elongated barriers projecting upwardly from the base so as to form a plurality of slots between the barriers, a plurality of nozzle holes communicating with the slots, and electrodes formed on the side walls of the elongated barriers. Voltage can be applied to the various barriers through the electrodes in order to cause deflection of the barriers and a corresponding reduction in the cross-sectional area of selected slots, so as to force ink contained in the slots to be jetted through the nozzle holes. In order to provide a uniform ink jet intensity from the outermost slots relative to the inner slots, dummy slots can be formed outwardly of the outermost active slots by providing dummy barriers outwardly of the outermost active barriers. In addition, the nozzle holes are formed in a nozzle plate. The nozzle plate can either be mounted against the ends of the slots, or atop the base.

Abstract: A sloped surface is provided inside an ink tank of an exchangeable ink jet head cartridge arranged in a scan-type ink jet apparatus. An acceleration of the ink jet head cartridge scanned for recording and an inertia of ink are utilized to allow the ink to climb the slope, whereby the ink can be favorably supplied to a recording head.

Abstract: An .Iadd.acoustically soft .Iaddend.ink jet nozzle .?.assembly is produced from materials, such as.!. .Iadd.for continuous jets. The nozzle is a tubular member formed from .Iaddend.polyphenylene sulfide.?.. The resulting assembly is acoustically soft so that undesirable fluid and mechanical resonances are.!. (.Iadd.RYTON) which has a .Iaddend.substantially .?.attenuated.!. .Iadd.constant response over a transducer range of 10-100 KHz.Iaddend..