Abstract: There is provided a condition; n.times.T.ltoreq.P.ltoreq.(n+0.4).times.T between a pulse width P of the driving voltage that is to be applied to said piezoelectric element 7 of a piezoelectric plate 6 and a time T needed for that a pressure wave of ink, which generates when the ink chamber 2 is pressurized through the piezoelectric element 7, travels through the ink chamber by a length thereof. Under the condition, each of the piezoelectric elements 7 is driven. Here, the "n" is an integral odd number (preferably, 1 or 3).

Abstract: In the ink jet recording apparatus for recording an image by supplying ink obtained by dispersing color material components in a solvent to a head substrate and by jetting ink drops containing at least the color material components to a recording medium on the basis of electrostatic force applied to the color material components, the recording apparatus comprises a driving circuit (107) for applying voltages to electrodes of an electrode array (102) arranged on a head substrate (101), in such a way that a first potential difference whose potential level relationship is reversed at a predetermined period between the two adjacent electrodes can be applied when the color material components are cohered and/or stirred on the head substrate, and a second potential difference different from the first potential difference between the two adjacent electrodes can be applied when the ink drops are jetted toward a recording medium.

Abstract: The selected ink channels of a drop-on-demand ink jet printer are caused to expand and then contract, ejecting ink droplets by the application of unipolar voltages first to selected channels and then to non-selected channels. Further unipolar voltages, delayed in time by 2L/c and scaled by a pressure wave reflection coefficient r of the nozzle, effect prompt cancellation of residual pressure waves so that adjacent channels are ready for actuation with minimum delay.

Abstract: An ink jet recording apparatus capable of ejecting ink droplets in which the volume is precisely and easily controlled. The gradient of the pixel to be printed, based on a digital gradient input signal, is provided for printing high resolution gradient images using a low drive voltage in this ink jet head. More specifically, the ink jet recording apparatus of the present invention will include a diaphragm formed at one part of a wall of each independent ejection chamber, with electrodes formed opposite each diaphragm and spaced therefrom at a predetermined gap distance. Ink droplets are selectively ejected from nozzle openings in the ejection chamber by applying a voltage to generate an electrostatic force which momentarily deforms the diaphragm. Moreover, plurality of independent electrodes oppose each diaphragm and a pulse voltage is applied to a predetermined number of electrodes according to a gradient signal to eject ink droplets of a volume determined by the gradient signal.

Abstract: An ink jet recording apparatus includes a recording head for ejecting ink from an ejection unit to cause a change in temperature in a recording period, a temperature keeping unit for maintaining a temperature of the recording head at a predetermined keeping temperature higher than an upper limit of a surrounding temperature range in which recording is possible, a temperature prediction unit for predicting an ink temperature in the ejection unit in the recording period prior to recording, and an ejection stabilization unit for stabilizing ink ejection from the ejection unit according to the ink temperature in the ejection unit predicted by the temperature prediction unit.

Abstract: A head driving device has first MOS field effect transistors connected between a VDD power supply terminal and electrodes, and second MOS field effect transistors connected between a VSS power supply terminal and the electrodes. In the driving device, ink is ejected from each ink chamber due to the variation in pressure which is caused by charging and discharging of corresponding capacitances each across an electrode of the predetermined ink chamber and electrodes of ink chambers adjacent to the predetermined ink chambers. Both of the first MOS field effect transistors and second MOS field effect transistors are formed on one semiconductor substrate. T the potential of the semiconductor substrate is set to be out of a range between the potentials of the VDD and VSS power supply terminals.

Abstract: To prevent fluctuations in the quantity of ink of an ink droplet that are brought about by drive frequency due to the natural vibration of common ink chambers, a relationship between the maximum drive frequency F of a laminated ink jet recording head and the natural vibration cycle T of common ink chambers that supply ink to a pressure producing chamber is set so that F/n<15/16.times.T, or 17/16.times.T<F/n, where n=1, 2, 3, . . . , 8. Ink droplets jetted out thus avoid a period in which the ink in the common ink chambers is flowing toward an ink introducing port with a high rate of flow.

Abstract: An ink Jet head includes first base second base which are made of a piezoelectric material. The first and second bases are formed with a plurality of first and second grooves in their surfaces, respectively, and are formed with first and second electrodes on their surfaces between the first grooves, respectively. The first and second bases also includes side surfaces intersecting the surfaces of the first and second bases, respectively. The electrodes are spaced apart from the side surfaces. The second base is placed on the first base so that the grooves in the first base and the grooves in the second base communicate with each other to define ink pressure chambers. An insulating layer is formed on the inner walls of the ink pressure chambers. An orifice plate having orifices is bonded to the side surfaces so that the ink chambers communicate with atmosphere through the orifices.

Abstract: A laminated, multi-substrate ink jet head and methods creating the same, wherein the ink jet head includes nozzle holes, emitting chambers respectively led to the nozzle holes, diaphragms formed on a wall of the emitting chambers, a common ink cavity for supplying ink to the emitting chambers through orifices and electrodes placed so as to face to the diaphragms so as to drive the diaphragms by static electricity. The lower substrate which forms the electrodes may include a plurality of indentations for mounting the electrode therein to serve as a gap spacing element for respective diaphragm/electrode pairs when the head is assembled. Alternatively, areas immediately beneath the diaphragm may be etched away to expand the vibrating chamber to a predetermined gap distance, or a membrane of a predetermined thickness may interpose the respective diaphragm and electrode substrates.

Abstract: A Direct Electrostatic Printing (DEP) device is provided that includes a back electrode (105), a printhead structure having an insulating substrate (102), a control electrode (102a) and a slit aperture (103) through which a particle flow can be electrically modulated by the control electrode (102a), and a toner delivery means (101), in which control electrodes (102a) are present only on one side of the slit aperture. In a preferred embodiment the printhead structure is realized by a slit having two sides, side A (SA) and side B (SB), defined by two edges (A and B), which are formed by at least one sheet of insulating material. The insulating material has an elasticity modulus (Young's Modulus, YM) fulfilling the equation 0.1 GPa.ltoreq.YM.ltoreq.10 GPa and the edges A and B are placed with respect to each other at an angle .alpha. fulfilling the equation 0.degree..ltoreq..alpha.<45.degree..

Abstract: An ink jet printing head includes a nozzle plate having an outside surface and a plurality of nozzles for discharging ink from the outside surface, each nozzle having a first diameter at a peripheral edge of the nozzle plate. A surface treatment layer is provided on the outside surface of the nozzle plate, the surface treatment layer having a plurality of openings overlapping the plurality of nozzles, each opening having a second diameter at a peripheral edge of the surface treatment layer, the second diameter being smaller than the first diameter.

Abstract: A piezoelectric actuator is deformed from an initial condition for a time (T1) in a direction, in which an inner volume of an ink chamber is increased, to supply ink to the ink chamber. Subsequently, the piezoelectric actuator is deformed for a time (T2) at a considerably slow speed as compared with the time (T1) for the preceding supply of ink to gradually increase the inner volume of the ink chamber to supply ink to the ink chamber. During the time (T2), free oscillation having generated in ink in the piezoelectric actuator and the ink chamber attenuates. Subsequently, the piezoelectric actuator is rapidly deformed to compress the ink chamber, thereby jetting ink in the ink chamber via nozzle holes.

Abstract: A piezoelectric element is driven by a predetermined pulse width in the range of 60 to 100% of the Helmholtz resonance vibration period of an ink vibration system comprising an orifice, a pressurizing chamber, a restrictor, the piezoelectric element, and an elastic material.

Abstract: An ink-jet head and its manufacturing method and an ink-jet recording device, which condense a color component in an ink with the color dissipated in a solvent, and record with the ink flown toward a record medium. A protruded-type electrode and its leading electrode are formed on a supporting substrate. An ink-guide-groove which is formed from the bottom section to the pointed end portion on the wall surface, is provided at the protruded-type electrode. A connected portion by the protruded-type electrode of the leading electrode and an end portion of an opposite portion are exposed outward. A plurality of protruded-type electrodes are provided on the supporting substrate along main scanning direction X. The shape of the protruded-type electrode is pyramid, and its pointed end portion is sharpened. Ink guide grooves are formed on each wall surface of the pyramid of the protruded-type electrode.

Abstract: An ink-jet recording head comprising: an elastic sheet providing pressure generating chambers; nozzle orifices, each communicating with the pressure generating chamber; piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators having, a lower electrode formed on the elastic sheet, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the piezoelectric layer such that the upper electrode faces the respective pressure generating chamber, wherein the upper electrodes of the piezoelectric vibrators are positioned independently of each other; an electrical insulator layer having windows, wherein the electrical insulator layer covers the upper electrodes; and a conductor pattern connecting with the upper electrodes via the windows of the electrical insulator layer.

Abstract: An ink jet recording apparatus which jets out a plurality of ink droplets at a predetermined cycle within a single drive period and such that the ink droplets are combined in the air to form a single ink droplet which is supplied to a recording sheet. A charge pulse generating circuit and a discharge pulse generating circuit which divide a drive period into a plurality of segments and output a pulse signal, having cycle Tp which is larger than the Helmholtz cycle Tc, in synchronism with an auxiliary print signal. A time constant adjusting circuit changes an output waveform of a constant current circuit with the pulse signal to increase the velocity of an ink droplet last jet out so that the velocity of the ink droplet allows the ink droplet to be combined, in the air, with an ink droplet previously jet out.

Abstract: An ink jet print head can be formed by an anodic bonding process. In order to bond a vibrating plate to a head base, a glass surface is bonded to a conductive surface of an electrically conductive material through anodic bonding. One of the vibrating plate or the head base can be formed of glass and the other of an electrically conductive material in order to form the bond. Alternatively, a glass layer an electrically conductive layer can be formed on each of the pieces, which can then be bonded. Thus, by using appropriate layers, the head base and vibrating plate can be formed of plastic, glass or an electrically conductive material.

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: A piezoelectric member includes a flat part and a plurality of convex parts on the flat part, and at least a part of each convex part is a piezoelectric element. A non-piezoelectric member is made of non-piezoelectric materials, and includes a plurality of concave parts corresponding to the piezoelectric elements and a convex part formed between adjacent concave parts. The piezoelectric member and the non-piezoelectric member are engaged with each other by inserting each non-piezoelectric convex part between adjacent piezoelectric elements and an ink cavity is formed between a bottom surface of each concave part and a top surface of each piezoelectric element. Also between a side of the piezoelectric convex part and a side of the non-piezoelectric concave part is provided a space, and the space is filled with a filler.

Abstract: Transducer arrays for use in multi-jet, drop-on-demand ink jet printers are formed of one or more thin plate-shaped layers of piezoelectric material. Electrodes are electrically coupled to the opposite facing flat plate surfaces of each layer, so as to provide an electric field in the direction orthogonal to the flat plate surfaces. The electric field causes the layer(s) of piezoelectric material to selectively contract or expand in the direction of the electric field. The selective expansion and contraction of the transducer is communicated, through a foot, to selectively contract and expand the volume of an ink-jet chamber. Contraction of the ink-jet chamber causes ink to be expelled through an orifice provided in communication with the ink-jet chamber. A plurality of transducers are arranged in a linear array corresponding to a linear array of ink-jet chambers and orifices.