Abstract: In an ink jet head, in order to make the occupying area of a chamber associated to each nozzle as small as possible, while maintaining a discharge ink drop volume, and on the other hand, to locate a number of nozzles with a high density, the plan view shape of a pressure plate provided to each chamber is so configured to fulfill the relation of 1:≦A≦2, where “A” is the ratio of an circumscribed circle diameter of the plan view shape of the pressure plate to an inscribed circle diameter of the plan view shape of the pressure plate. For example, the pressure plate is formed to have the plan view shape of a substantial square or a substantial rhombus. The chambers having such a feature are located in the form of a matrix. Thus, a stably driven, highly reliable ink jet head can be realized.

Abstract: In an ink jet recording head having a crystalline substrate in which at least one nozzle and at least one ink chamber formed in the crystalline substrate, a gap is provided in a connecting portion between the nozzle and the ink chamber below an opening portion of the nozzle such that a variation of the ink jetting function due to an axial deviation between the nozzle and the ink chamber is restricted by absorbing the axial deviation by the gap. The gap is formed such that extension lines of wall surfaces of the ink chamber formed by etching are positioned inside the gap.

Abstract: In an ink jet recording head including a silicon substrate and at least one ink chamber and at least one ink pool, which are formed in the silicon substrate with a partition wall therebetween, an opening portion is formed in a position corresponding to an apex of the ink pool of one surface of the silicon substrate on which an opening portion for etching the ink chamber is formed and anisotropic etching of the silicon substrate through the opening portion is performed such that an etching from a bottom of the ink pool and the etching from the opening portion are connected to each other immediately below the opening portion to absorb deviation between etching patterns on both surfaces of the silicon substrate to thereby reduce a variation of thickness of the partition wall and to reduce an influence of such deviation on an ink filling function and an ink jetting function of the ink jet recording head.

Abstract: A method of manufacturing an ink jet recording head. On one and the other surfaces of an ink supply plate, formed with a plurality of discrete ink supply ports and a corresponding number of discrete nozzle ports, a green sheet for a pressure chamber plate and a green sheet for an ink pool plate are laminated, respectively. The resulting lamination is then sintered. A vibration plate is subsequently adhered to the pressure chamber plate formed by the sintering step and a nozzle plate is adhered to the sintered pool plate.

Abstract: Characteristics of a droplet ejection apparatus are change depending on the shape or cone angle of the main ink ejection chamber of the apparatus, or on the diameter of the ejection aperture of main ink ejection chamber. Accordingly, operation of the droplet ejection apparatus varies with the shape, angle, or diameter of main ink ejection chamber. The shape of the aperture according to the present invention is circular or regular polygonal so that surface waves are synthesized at the central portion of the ejection aperture. Moreover, the cone angle of the main chamber is set to 65° or less from the plane vertical to the droplet ejecting direction and the diameter of the ejection aperture is set to a value 1.25 times or more larger than a desired droplet diameter.

Abstract: In an ink jet head including a substrate having a opening for a pressure chamber, a section of the opening is gradually increased from a front surface of the substrate to an intermediate level of the substrate and is gradually decreased from the intermediate level of the substrate to a back surface of the substrate. The opening at the front surface of the substrate serves as a nozzle.

Abstract: A portion of an ink jet recording head, which is formed by silicon material of a silicon substrate, is used as nozzles, ink chambers and a portion of an ink supply passage for supplying ink to the ink chambers and the remaining ink supply passage is formed of other material than the silicon material and connected to the portion of the ink jet recording head formed of the silicon material. A plurality of ink jet recording heads are formed as a unit block by a semiconductor fabrication process and cut out from a silicon substrate in block unit.

Abstract: Adhesive agent layers are respectively formed on top surfaces of a nozzle plate, a pool plate, a supply hole plate and a pressure chamber plate. A vibration plate and the four aforementioned plates including the adhesive agent layers are stuck together. When an adhesive agent is applied to each of the four aforementioned plates, the adhesive agent with high viscosity is applied to the circumference of the hole, and an adhesive agent layer with low viscosity is applied to a region which is other than the circumference of the hole.

Abstract: Any air trapped in a connection portion between adjacent ones of flow passage plates of an ink jet recording head in manufacturing the head.

Abstract: In an image recording device which records an image on a recording medium responsive to a desired gradation in each pixel and which includes a recording head for jetting an ink droplet having a diameter at a timing therefrom, the diameter of the ink droplet is modulated in response to the desired gradation in each pixel while the timing is modulated dependent on the modulated diameter. Thus, a position of impact of the ink droplet is not deviated, so that quality of image is not deteriorated.

Abstract: In an ink jet head, in order to make the occupying area of a chamber associated to each nozzle as small as possible, while maintaining a discharge ink drop volume, and on the other hand, to locate a number of nozzles with a high density, the plan view shape of a pressure plate provided to each chamber is so configured to fulfill the relation of 1≦A≦2, where “A” is the ratio of an circumscribed circle diamrter of the plan view shape of the pressure plate to an inscribed circle d ameter of the plan view shape of the pressure plate. For example, the pressure plate is formed to have the plan view shape of a substantial square or a substantial rhombus. The chambers having such a feature are located in the form of a matrix. Thus, a stably driven, highly reliable in jet head can be realized.

Abstract: Characteristics of a droplet ejection apparatus are changed depending on the shape or cone angle of the main chamber of the apparatus or the diameter of the ejection aperture of the apparatus and thus, the apparatus may not be normally operated depending on the setting of the shape, angle, or diameter.

Abstract: Nozzles for jetting ink droplets and ink chambers connected to the respective nozzles are formed in a substrate. Ink filling the ink chambers is pressurized. Ink pools are also formed adjacent to the ink chambers through partition walls, for supplying ink to the ink chambers. The partition wall makes a predetermined angle with respect to a surface of the substrate. The ink pools are formed adjacent to the ink chambers through thin partition walls. Further, the nozzles are arranged in a line and row matrix and the line of nozzles or the side of ink pools makes a constant angle with respect to a printing direction.

Abstract: In order to reduce a manufacturing cost of an ink jet type recording head by simplifying a structure of the ink jet type recording head and reducing the number of manufacturing steps thereof, to provide a capacity of an ink pool without increasing a size thereof, to make the freedom of nozzle layout high and to make the freedom of design by reducing a restriction on position and number of ink supply ports, the ink pool to which ink is supplied is formed in a rear surface of a nozzle plate having a front surface formed with a plurality of nozzles and an ink chamber plate is attached to the rear surface of the nozzle plate through discrete partition walls each defining a discrete space communicating with different one of the nozzles.

Abstract: In an ink jet head including a substrate having a opening for a pressure chamber, a section of the opening is gradually increased from a front surface of the substrate to an intermediate level of the substrate and is gradually decreased from the intermediate level of the substrate to a back surface of the substrate. The opening at the front surface of the substrate serves as a nozzle.

Abstract: An ink jet head is constructed by a plurality of combined units.

Abstract: A nozzle plate structure for an ink-jet printing head includes an annular projection formed around an opening edge of a nozzle that discharges ink. The annular projection has one or a plurality of notches in a circumference thereof. A method of manufacturing the nozzle plate is also disclosed.

Abstract: A piezoelectric actuator has a base, and an array of drive columns separated by grooves and each having a top surface for outputting a displacement force. Each of the drive columns is formed in a unitary body with an underlying portion of the base by a first block of a plurality of green sheets made of a piezoelectric material and stacked together. The base has additionally a second block of green sheets stacked between adjacent two of the first block at the portion of the base underlying the groove.

Abstract: Disclosed herein is a piezoelectric actuator comprising a plurality of driving columns separated by grooves in which the width of each driving column in the direction of the groove width widens from the displacement output surface to the substrate. The widening of the diving column width toward the substrate realizes a piezoelectric actuator having a high strength and a high reliability capable of stably and effectively generating an output displacement.

Abstract: An ink droplet eject apparatus comprises a plate-shaped member defining a conical ink droplet eject chamber increasing from an eject port to an opening, and a vibrating plate covering the opening. A spacer is disposed between the vibrating plate and the plate-shaped member surrounding the opening. An annular space is delimited by the spacer. An ink flow path is formed in the spacer. The vibrating plate is excited so as to generate an intermittent liquid flow of an ink W in the ink droplet eject chamber in the direction of the eject port. An actuator can arbitrarily control an amount of displacement of the vibrating plate and a generation time of displacement during the excitation.