Abstract: Ink ejection device including a polarized piezoelectric element having a natural shape and forming at least a portion of a wall of an ink chamber, the ink chamber having a length and a natural volume and being connected with the nozzle and filled with ink; an electrode formed on the piezoelectric element; and an LSI chip applying voltage to the electrode to deform the piezoelectric element so that volume of the ink chamber increases, whereupon a pressure wave that propagates through the ink at a velocity of one length of the ink chamber in a time interval is generated in the ink, and, upon completion of a predetermined duration of time defined as approximately the time interval multiplied by an odd number equal to or greater than three, stopping application of voltage to the electrode to return piezoelectric element to the natural shape.

Abstract: A piezoelectric-type liquid droplet ejecting device including a piezoelectric element. A predetermined voltage pulse is applied to the piezoelectric element, whereupon residual pressure fluctuations are generated in the pressure chamber of the liquid droplet ejecting device. The piezoelectric element or a separate piezoelectric element generates an electric signal corresponding to the residual pressure fluctuations. A detection circuit receives the electric signal and supplies a detection signal corresponding to the electric signal to a calculation circuit for calculating a voltage pulse. The calculation circuit supplies the voltage pulse to a drive circuit, which applies it to the piezoelectric element. The voltage pulse deforms the piezoelectric element upon application thereto in a manner sufficient to compensate for residual pressure fluctuation in the pressure chamber.

Abstract: In an ink jet head having: a nozzle plate in which a plurality of nozzle openings are formed; a flow path substrate comprising a reservoir to which ink is externally supplied, and a plurality of pressure chambers which are connected to the reservoir via an ink supply port and which respectively communicate with the nozzle openings; an elastic film which pressurizes ink in the pressure chambers; and driving means located at a position opposing the respective pressure chambers for causing the elastic film to conduct flexural deformation, the pressure chambers are arranged in a single-crystal silicon substrate of a (110) lattice plane and along a <112> lattice orientation.

Abstract: In a print head for a powder jet image forming apparatus according to the present invention, a grid electrode is provided between first electrodes and a developer supply roller in parallel with major surfaces of an insulating layer, and therefore, a distance between any of the first electrodes and the grid electrode is kept fixed. Thus, applying a given level of voltage to the grid electrode allows an electric field for supplying developer to the first electrodes to arise uniformly. This is effective in avoiding uneven density in the resultant image.

Abstract: According to an image forming apparatus, wiring portions of control electrodes of an aperture electrode unit are disposed at a farther position away from a toner carry roller than operating portions of the control electrodes. So, toner on the toner carry roller can be prevented from repetitively attaching to and detaching from an insulating sheet of the aperture electrode unit. Therefore, stable toner flow can be produced. Thus, a delicate image can be output from the image forming apparatus.

Abstract: An ink jet printhead body has an ink filter structure integrally incorporated therein and operative to filter ink flowing into its internal ink receiving channels disposed between piezoelectrically deflectable interior wall portions of the body. In various illustrated embodiments of the printhead, the filter structure is defined by a series of photoetched micro filter passageways formed integrally in an outer side portion of the printhead body, a filter cavity formed in the outer side portion and receiving a separate photoetchable filter member in which photoetched micro filter passageways are formed, and a filter cavity formed in the outer side portion and receiving a separate mesh-type micro filter member.

Abstract: An ink jet printing head includes a nozzle plate including nozzles, a plurality of ink cavities each containing ink, a plurality of actuators each made of a phase transition material, an oscillating plate having a top surface with which the ink in each ink cavity is brought into contact, and having a bottom surface bonded to each actuator, the oscillating plate pressing the ink in each ink cavity in association with the actuators to discharge ink drops from the nozzles at a sheet of paper so that an image is printed on the paper.

Abstract: Control electrodes of an aperture electrode member have no portions arranged upstream of apertures in the direction of transportation of the toner particles. Consequently, when a voltage is applied to the control electrodes, toner particles do not adhere upstream of the control electrodes. As no adhering toner particles appear upstream of the apertures in the toner transportation direction, even if the application of the voltage to the control electrodes is interrupted, the problem of excessive toner particles being jetted from openings of the apertures does not occur. Consequently, the production of a shadow or abnormal dots on an image recording medium is prevented.

Abstract: An ink jet recording head formed by laminating and fixing: a flow path forming plate having through holes for defining pressure producing chambers, ink supply inlets, and a common ink chamber, a nozzle plate having nozzle openings communicating with the pressure producing chambers, and a vibration plate having diaphragm portions that are resiliently deformed in response to displacement of piezoelectric vibration elements one upon another with an adhesive so as to be watertight. The vibration plate has frame-like thick wall portions that extend as far as to the ink supply inlet side of the pressure producing chamber as well as to the inner side of the nozzle opening, and portions closer to a piezoelectric vibration element than to both ends of the pressure producing chamber are made to be supported by a base. As a result of this construction, a nonsupported region of the pressure producing chamber can be shortened, which in turn improves the rigidity of a substrate unit as a whole.

Abstract: Disclosed herein is an ink jet printer head including a substrate which includes a piezoelectric member polarized across a thickness thereof and a plate-like low-rigid member bonded to an upper surface of the piezoelectric member. The low-rigid member has a low permittivity and a rigidity lower than that of the piezoelectric member. The substrate has a plurality of grooves cut from an upper surface of the low-rigid member to a depth beyond a bonded surface between the low-rigid member and the piezoelectric member. A top plate is bonded to the upper surface of the low-rigid member so as to cover upper openings of the grooves, thereby defining a plurality of pressure chambers between the grooves and the top plate. A plurality of ink jet nozzles are provided so as to respectively communicate with the pressure chambers. A plurality of electrodes are formed on inner surfaces of the pressure chambers.

Abstract: In the particular embodiments described in the specification, a thin-film PZT piezoelectric transducer ink jet head includes a dielectric layer with electrodes and a thin film piezoelectric layer having a thickness in the range of 1-25 microns including one or more layers of perovskite-seeded PZT material and a further pattern of electrodes on the surface of the PZT layer along with a silicon substrate containing openings to provide ink chambers in the region of the electrodes. An orifice plate affixed to the substrate encloses the ink.

Abstract: An ink jet of the present invention includes a nozzle plate having a nozzle orifice, a substrate having an opening communicating with the nozzle orifice, an ink discharge plate having a center portion positioned in the nozzle orifice of the nozzle plate and the opening, and both ends supported by being sandwiched between the nozzle plate and the substrate, the center portion being closer to the nozzle plate than the both ends, and a compressive member for applying a compressive force in the axis direction of the ink jet plate so that the center portion of the ink discharge plate is deformed towards the nozzle orifice by buckling. Because of this structure, the ink discharge plate is always buckled towards the nozzle orifice, and forms an ink droplet without erroneous operation.

Abstract: A piezoelectric vibration element is abutted against a vibration plate such that a central point C1 of the piezoelectric vibration element by is displaced by a distance .DELTA.d toward a nozzle opening from a central point C2 of a length L of an effective displacement region on vibration plate, whereby the displacement of the piezoelectric vibration during operation of the element is particularly efficiently transmitted to ink in the vicinity of the nozzle opening.

Abstract: To provide an ink ejecting device with high quality and excellent stability, three-layered laminated protective film is formed to cover an electrode which is formed on a ceramic element. The protective film is composed of an organic continuous film formed on the electrode as a first layer for covering surface unevenness. On the resultant smooth surface, a continuous inorganic film is formed as a second layer. Further, an organic layer is formed as a final layer.

Abstract: An ink droplet jet device having a piezoelectric ceramic plate is provided with ink chambers having partitions. The front half of each partition is opposite to the rear half in the direction of polarization. When a voltage is applied to the electrodes of a given partition, the front and the rear half thereof deform in the opposite directions because of their inverse directions of polarization. This prevents the introduction of air through the nozzles into the ink chambers adjacent to the activated ink chamber and the speed of printing is increased.

Abstract: In an image forming apparatus, plural apertures are formed in a base member of an aperture electrode unit with a control electrode surrounding each aperture. Middle holes are formed between neighboring control electrodes. Each middle hole is controlled by the two neighboring control electrodes. An ON electric field is formed in the middle hole when both of the neighboring control electrodes adjacent to the middle hole are switched on. At this time, toner which is fed to a space between the apertures is passed through the middle hole. Therefore, continuous dots can be recorded in a direction perpendicular to a sheet feed direction. In addition, when the control electrodes at both sides of the middle hole are supplied with an OFF voltage at the same time, an image forming operation can be controlled without fog. Therefore, an image can be stably formed with excellent image quality.

Abstract: A carriage on which an ink tank is mounted is moved acceleratively. Next, under this accelerative movement, a period of time spent moving a designated distance is measured. Finally, the amount of ink fluids in the ink tank is detected by the measured period of time and a message related to the amount of ink fluids is displayed. With these procedures, in an ink jet recording apparatus in which the ink tank for storing ink fluids to be supplied to the recording head is mounted on the carriage, the amount of ink fluids remaining in the ink tank can be detected using simplified structure.

Abstract: An ink-cooled thermal ink jet printhead has an efficient heat exchanger located on the back side of the printhead that eliminates the need for heat sinks. All ink flowing to the firing chamber goes through the heat exchanger. The geometry of the heat exchanger is chosen so that almost all the residual heat absorbed by the printhead substrate is transferred to the ink as it flows to the firing chamber. Additionally, the pressure drop of the ink flowing through the heat exchanger is low enough so that it does not significantly reduce the refill rate of the firing chambers. The heat exchanger can have one or more active heat exchanger sides. The heat exchanger has little thermal mass itself and significantly reduces the thermal mass of printhead by eliminating the need for a heat sink. This reduces the warm-up time of the printhead to a fraction of a second.

Abstract: An image recording apparatus having aperture electrode body formed with a plurality of apertures through which toners pass to deposit onto an image receiving member. The aperture electrode body includes an insulative substrate having the apertures and control electrodes formed over the insulative substrate and each surrounding each aperture. The aperture electrode body has a nature of bending due to difference in thermal expansion coefficient of the insulative substrate and the control electrodes. To provide uniform bending, dummy electrodes are formed over the insulative substrate. The dummy electrodes includes a first set of dummy electrodes positioned at upstream side of the control electrodes with respect to a running direction of the image receiving member. The dummy electrode also includes a second set of dummy electrodes positioned beside the extreme end of the control electrode in the array direction of the apertures.

Abstract: An ink ejection device for ejecting ink comprises: a piezoelectric ceramic plate for defining an ink channel for containing ink, the piezoelectric ceramic plate deforming by application of an electric voltage thereto so as to change the volume in the ink channel and eject ink from the ink channel, the piezoelectric ceramic plate being formed by injection molding so that the piezoelectric ceramic plate having one surface with a surface roughness Rz (defined in Japanese Industrial Standard "JIS B 0601") of 1 .mu.m or less; and a metal electrode provided on the surface of the piezoelectric ceramic plate for applying the electric voltage to the piezoelectric ceramic plate.