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: A method of manufacturing an inkjet recording head including drive electrodes arrayed at fixed pitches on the surface of an elastic plate, a common lead-out electrode lead from a common electrode formed on the surface of the elastic plate, the common lead-out electrode being arrayed extending in the direction of the arrays of the drive electrodes, while being spaced a fixed distance from the drive electrodes, the ends of the common lead-out electrode being connected to external, and piezoelectric vibration plates of which the reverse sides are in contact with the drive electrodes, and to the first ends are continuous, covering the common lead-out electrode. No disconnection is formed in the area of the piezoelectric vibration plates where the two groups of the piezoelectric vibration plates face, thereby ensuring a reliable bonding of the piezoelectric vibration plates and the elastic plate.

Abstract: A recess is formed in a surface confronting an actuator unit of an ink supply inlet forming substrate. When a flow path unit and the actuator unit are bonded together using a fusible film, thermally expanded air is released into the recess to thereby reduce pressure. Further, by arranging the recess at a position confronting a pressure generating chamber, an air layer formed by the recess is allowed to function as a vibration shielding member.

Abstract: An ink jet recording head including a vibrating plate made of ceramic, a pressure producing chamber forming member, made of ceramic, for forming a plurality of pressure producing chambers in rows, and drive electrodes formed on a surface of the vibrating plate so as to confront the pressure producing chambers. A width W2 of each drive electrode is smaller than a width W1 of each pressure producing chamber. A width W3 of a piezoelectric vibrating element is larger than the width W2 of each drive electrode and smaller than the width W1 of each pressure producing chamber, so that an operation region of the piezoelectric vibrating element is regulated by the width W2 of the drive electrode, and peripheral portions of the piezoelectric vibrating element are reliably bonded to peripheral portions of the drive electrode.

Abstract: An ink jet recording head includes drive electrodes arrayed at fixed pitches on the surface of an elastic plate, a common lead-out electrode led from a common electrode formed on the surface of the elastic plate, the common lead-out electrode being arrayed extending in the direction of the arrays of the drive electrodes, while being spaced a fixed distance from the drive electrodes, the ends of the common lead-out electrode being connected to external, and piezoelectric vibration plates of which the reverse sides are in contact with the drive electrodes, and the first ends are continuous covering the common lead-out electrode. No disconnection is formed in the area of the piezoelectric vibration plates where the two groups of the piezoelectric vibration plates face, thereby ensuring a reliable bonding of the piezoelectric vibration plates and the elastic plate.

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 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: To provide a magnetic transfer system capable of smoothly delivering a carrier between chambers by providing a independently-rotating carrier-feed driving shaft for each chamber without using a synchronous control mechanism and used for a semiconductor fabrication equipment or the like provided with a plurality of chambers. The magnetic transfer system is provided with a rotational driving member which is divided into two portions serving as a fixed driving shaft and a movable driving shaft in the axial direction and in which the fixed driving shaft is secured to a shaft core member and the movable driving shaft is set to the shaft core member so as to be limited in the rotational direction but so as to be freely movable in the axial direction at a certain width, and spiral magnetic coupling sections are formed on the surface of each driving shaft at the same pitch.

Abstract: An ink jet recording head including: a vibrating plate made of ceramic; a pressure producing chamber forming member, made of ceramic, for forming a plurality of pressure producing chambers in rows; and drive electrodes formed on a surface of the vibrating plate so as to confront the pressure producing chambers. A width of the drive electrode is smaller than a width of the pressure producing chamber. A width of a piezoelectric vibrating element is larger than the width W2 of the drive electrode and smaller than the width of the pressure producing chamber, so that the operation region of the piezoelectric vibrating element is regulated by the width of the drive electrode and the peripheral portions of the piezoelectric vibrating element are bonded to the peripheral portions of the drive electrode reliably.

Abstract: An ink jet recording apparatus provided with: an ink jet recording head having a pressurizing chamber communicated with a nozzle opening and a common ink chamber, and a piezoelectric vibrating plate which is formed at a surface of the pressurizing chamber and deflection-displaced, the head being caused to eject an ink drop by the deflection displacement of the piezoelectric vibrating plate; a charging circuit which supplies a current to the piezoelectric vibrating plate in response to a print signal, thereby producing the deflection displacement for ink ejection, and which outputs a signal for holding a charge final voltage during a fixed time period after an end of charge; and a discharging circuit which has a first discharge time constant suitable for sucking meniscus formed immediately after ink ejection toward the pressurizing chamber, thereby preventing the meniscus from being ejected from the nozzle opening, which stops discharge in a range which is (n+3/4) to (n+1) times (where n is 1, 2, 3, . . .

Abstract: In an ink jet type recording head, nozzles 190 to 197 for jetting droplets of ink are arranged in such a manner that these nozzles are located along two line segments L1 and L2 which are inclined mutually in opposite directions with respect to a main scanning direction, and the two line segments constitute a substantially V-shape, so that problems such as a printing quality deterioration phenomenon and ink chamber interference can be solved, and higher printing qualities can be realized at high printing density.

Abstract: In an ink jet recording head, after a plate-shaped piezoelectric element is positioned and fixed onto a fixing plate, the piezoelectric element is sliced into a large number of vibrators and the leading ends of the vibrators are embracingly held in positioning holes 33 respectively formed in a top surface of a holding frame and are thus positioned in the surface direction thereof. Further, a cavity unit is positioned and fixed on the top surface of the holding frame.

Abstract: An ink supply communication path is formed so that one end thereof is arranged outside a region confronting a pressure producing chamber at a region confronting a reservoir chamber; and an ink supply constricted port is arranged at a portion of the ink supply communication path, the portion being remotest from the pressure producing chamber. Since the pressure producing chamber is connected to the ink supply constricted port through the elongated ink supply communication path, a jet flow from the ink supply constricted port grows into a large flow along the ink supply communication path, which in turn allows air bubbles susceptible to stagnation in the vicinity of the ink supply constricted port to be discharged by such large flow.

Abstract: In an ink jet recording head, after a plate-shaped piezoelectric element is positioned and fixed onto a fixing plate, the piezoelectric element is sliced into a large number of vibrators and the leading ends of the vibrators are embracingly held in positioning holes 33 respectively formed in a top surface of a holding frame and are thus positioned in the surface direction thereof. Further, a cavity unit is positioned and fixed on the top surface of the holding frame.

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: An improved fuel injection control apparatus, in which a reference pressure is provided to a pressure regulator, for simplifying the fuel supply system by preventing the fuel quantity injected from injection valves into an engine from being influenced by variations in the air intake pressure. A pressure regulating device disposed in a fuel supply pipe between a fuel pump and the fuel injection valve regulates the pressure of fuel supplied from the fuel pump to the fuel injection valve so that the pressure is proportional to the predetermined pressure, without returning fuel from the injection valve to the fuel tank. An intake pressure detecting device detects the pressure in the intake pipe, and a fuel injection quantity correcting device corrects the fuel injection quantity according to deviations of the fuel pressure regulated by the pressure regulating device from a proper value due to the differential pressure between the pre-determined pressure of the pressure regulating means and the intake pressure.

Abstract: The apparatus includes a circuit 49 for generating a first voltage waveform for expanding piezoelectric vibrators at a rate suitable to form ink drops, a second voltage for holding an expansion or contraction state, and a third voltage waveform for contracting the piezoelectric vibrators at a rate suitable to suck ink into pressure generating chambers; a circuit 52 for detecting the time when the process of forming ink drops by the first voltage waveform is ended; a delay circuit 53 for delaying a signal from the circuit 52 by a time .DELTA.T until vibration of menisci caused by the ink drop formation process, switches to motion toward nozzle openings; a charge signal generating circuit 48 for generating the third voltage waveform on the basis of a signal from the delay circuit 53; and a discharge signal generating circuit 51 for generating the first voltage waveform on the basis of a print timing signal.

Abstract: In an ink jet recording head, after a plate-shaped piezoelectric element is positioned and fixed onto a fixing plate, the piezoelectric element is sliced into a large number of vibrators and the leading ends of the vibrators are embracingly held in positioning holes 33 respectively formed in a top surface of a holding frame and are thus positioned in the surface direction thereof. Further, a cavity unit is positioned and fixed on the top surface of the holding frame.

Abstract: A method of driving an ink jet recording head comprising the steps of: retreating a vibrating plate to a predetermined position from a nozzle opening at such a speed as to allow a meniscus at the nozzle opening to be jetted from the nozzle opening while applying a drive voltage to a piezoelectric vibrating element; holding the vibrating plate at the position; and advancing the vibrating plate toward the nozzle opening when the meniscus has returned to a position 1/3 or more of the farthest retreat position thereof. As a result, a pressure chamber contracted to thereby apply pressure to ink when inertial stream of the ink become stable and heads toward the nozzle opening, producing an ink droplet to be jetted at a predetermined speed irrespective of the position of the meniscus.

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.