Abstract: In an ink-jet recording device in which a nozzle is so excited that ink droplets jetted from the nozzle are alternately separated into large-diameter ink droplets and small-diameter ink droplets, and recording ink droplets to be stuck onto the recording surface are made to fly straight while nonrecording ink droplets are charged and deflected to be retrieved by a gutter, there are provided a nonrecording ink droplet sense circuit and a correction signal generator circuit for generating correction charging voltage when an ink droplet to be controlled is generated provided that the preceding ink droplet is a nonrecording ink droplet and the ink droplet to be controlled is a recording ink droplet.

Abstract: An ink jet recorder in which ink droplets having different, large and small diameters are produced, only the small diameter ink droplets of the ink droplets are selectively charged and deflected to record dots on a recording medium. The property of the ink employed in the recorder is selected to meet the condition K.ltoreq.N.sup.n .times.T.sup.m (N represents the viscosity of the ink, T represents the surface tension thereof, and n, m and K are positive constants, respectively), thereby maintaining the diameter of the small diameter ink droplets at a substantially constant value in the operation temperature range of the recorder.

Abstract: Disclosed is an ink droplet expelling apparatus for expelling an ink droplet in response to an electric signal, compising a printing head provided with one or more ink chambers, electro-mechanical transducers disposed on the printing head corresponding to the ink chambers, and a driving signal generating circuit for producing electric signals for driving the electro-mechanical transducers. The elector-mechanical transducers are distorted by three different driving signals to reduce the volumes of the ink chambers to raise the pressure therein to thereby expel an ink droplet out of a nozzle formed at the front end of the head.

Abstract: An ink-jet printer including an ink jet nozzle for ejecting ink droplets onto the recording paper which is moved relative to the nozzle so that dots of ink are printed in the form of a pattern. The trajectory of flying ink droplets is deflected along the direction of the relative movement under control based on the measurement of the relative movement speed.

Abstract: While the excitation voltage of an ink jet nozzle is swept on the logarithmic scale, the generation state of ink droplets at a phase .theta..sub.k is examined. An excitation voltage value Vn generating an ink droplet of small diameter at the phase .theta..sub.k, an excitation voltage value Vn generating an ink droplet of large diameter at the phase .theta..sub.k, which is lower than vn, and an excitation voltage value Vn+1 generating an ink droplet of large diameter at the phase .theta..sub.k, which is higher than vn are stored. Difference values expressed asWn=vn-Vnwn=Vn-1-vnare derived on the logarithmic scale. Then the nozzle excitation voltage is set at such a value as to generate ink droplets and minimize the value of .vertline.Wn-wn.vertline..

Abstract: In an ink jet recording apparatus, an amplification-degree control circuit is associated with an amplifier circuit amplifying a detection signal indicative of the quantity of charge of charged ink droplets, so as to decrease the degree of signal amplification by the amplifier circuit when a charging signal is applied to a charging electrode charging the ink droplets, but to increase the degree of signal amplification by the amplifier circuit when the quantity of charge of the charged ink droplets is detected from the detection signal.

Abstract: An ink jet printing apparatus comprises a nozzle head including, orifices for ejecting ink particles, pressure chambers each having a piezoelectric element for applying a pressure wave to ink in the chamber and each communicating with corresponding one of the orifices and an ink chamber communicating with the pressure chambers, and electrical signal applying device for applying an electrical signal to selected one or ones of the piezoelectric elements to produce the pressure waves. The electrical signal applying device applies a main electrical signal pulse to the selected one or ones of the piezoelectric elements for inducing rises of the pressure waves and applies a sub-electrical signal pulse for suppressing the pulsations of the pressure waves a predetermined time interval after the main electrical signal.

Abstract: A liquid droplet projection apparatus is disclosed which comprises a nozzle arranged at a liquid droplet ejection head, a liquid droplet supply tank, and an electro-mechanical transducer section interposed on the head between the nozzle and the tank. The volume of the electro-mechanical converter means changes in volume in response to an electrical signal pulse applied thereto to cause the nozzle to eject liquid droplets in accordance with the electrical signal. When the pattern of the electrical signal applied to the electromechanical transducer section has an interruption period longer than a predetermined width and three or more successive electrical signals following the interruption period, the amplitude and/or width of the second one of the successive electrical signals is enlarged as compared with the amplitude and/or width of the other electrical signals, thus preventing the diameter of the second liquid droplet ejected following the interruption from being reduced.

Abstract: A drop jet apparatus has a nozzle head which defines a pressure chamber, a nozzle, and passages. Part of the pressure chamber is defined by a thin diaphragm which is made thick at the central and at a surrounding portion spaced from the central portion. A piezoelectric plate is adhered to the thick portions so as to bridge the thin portion between the projections.

Abstract: An ink-jet printing apparatus having a plurality of nozzles for projecting ink droplets which are selectively deposited on a printing medium in accordance with an information signal so as to form a printed pattern, such ink-jet printing apparatus comprising means for causing ink droplets used for printing to project from each nozzle in accordance with an information signal, a common power source for supplying a desired voltage to the ink-drop forming means provided at each nozzle thereby operating them, and switching means connected between the ink-drop forming means and the common power source and controlled by the information signal, the output of the power source being selectively supplied through the switching means to the ink-drop forming means, so that the driving system for driving the ink-drop forming means and the control system therefor can be separately provided, thus enabling a number of nozzles to be effectively controlled by a lowest control voltage.

Abstract: A nozzle head of an ink-jet printing apparatus according to the present invention comprises an ink reservoir for storing the ink supplied from an ink tank, a pump chamber provided between said ink reservoir and a nozzle for injecting ink particles, and a fluid diode provided between said ink reservoir and said pump chamber, which are all formed in a same substrate, wherein said pump chamber is caused to change its volume responsive to electric signals so that the ink stored therein is injected from said nozzle, and the ink is prevented from reversely flowing from said pump chamber to said ink reservoir when the volume of the pump chamber is changed, thereby to improve the frequency response of ink particles injected from the nozzle.

Abstract: A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.

Abstract: A bridge circuit with four arms including semiconductor strain gauge elements has input terminals for coupling a DC power supply with a pair of diagonally opposite junctions of the bridge circuit per se and output terminals coupled with a pair of remaining diagonally opposite junctions. Initial zero-point temperature compensators each are connected in series and in parallel to each of semiconductor strain gauge elements on adjacent two arms of the bridge circuit. Temperature compensators for zero-point shift adjustment are each provided between the adjacent arms closer to each output terminal. A temperature compensator for span adjustment is provided between one of the input terminals and the DC power source. A constant current control unit for feeding a constant current to the bridge circuit is provided between the other input terminal and the DC power supply.

Abstract: A semiconductor transducer comprising an improved strain-yielding body yielding a strain in response to the impartation of a force or displacement, and a semiconductor strain gauge bonded to the strain-yielding body. The improved strain-yielding body is made of an iron-nickel-cobalt alloy containing 28.2 to 31.0% by weight of nickel and 15.0 to 19.5% by weight of cobalt. This iron-nickel-cobalt alloy is initially heated up to a temperature above 600.degree. C. for the purpose of standard heat treatment for removing its internal strain. After the standard heat treatment, the iron-nickel-cobalt alloy is subjected to cold working at a working rate of more than and including 60%, and is then subjected to heat treatment at a temperature between 350.degree. C. and 600.degree. C. The heat-treated iron-nickel-cobalt alloy is shaped into the predetermined form of the strain-yielding body.

Abstract: A semiconductor transducer comprises a semiconductor strain gauge composed of a mono-crystalline semiconducting material and a strain sensing region formed in a first main surface of the mono-crystalline semiconducting material, and a strain measuring member coupled to the semiconductor strain gauge through an alloy material. An electrical insulating layer is attached to a second main surface of the mono-crystalline semiconducting material which is coupled to the strain measuring member through the alloy material. The insulating layer is extended to a side surface of the mono-crystalline semiconducting material thereby to cover the same side.

Abstract: A semiconductor pressure transducer comprises a circular diaphragm formed of a single crystal semiconductor material, at least a first strain gauge element having a piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in parallel with a predetermined axis which extends transversely of the surface of the diaphragm, at least a second strain gauge element having the piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in the direction perpendicular to the axis, and means for securing the diaphragm at the outer peripheral portion thereof. The distance between the second strain gauge element and the center of the diaphragm is differed from the distance between the center of the first strain gauge element and the latter.

Abstract: An apparatus for detecting misfire in a multicylinder internal combustion engine, comprising a sound pick-up transducer disposed in the exhaust passage of the engine or a chamber communicating with the exhaust passage for the purpose of detecting exhaust sound, an integrating circuit for integrating an electric output of the transducer in synchronism with the rotation of the engine and a comparison circuit for comparing the output of the integrating circuit with a reference signal, thereby misfire being detected on the basis of an output of the comparison circuit.