Abstract: A method to form a thick layer by screen printing and a method to form a piezoelectric actuator of an inkjet head. The method to form the thick layer including forming a guide groove in a surface to a predetermined depth, and forming the thick layer by applying a material to the surface inside the guide groove through screen printing. The method to form the piezoelectric actuator including forming an insulating layer on a top surface of a vibration plate and forming a guide groove in the top surface of the vibration plate or an insulating layer to a predetermined depth at a position corresponding to each of a plurality of pressure chambers, forming a lower electrode on the top surface of the insulating layer; forming a piezoelectric layer inside the guide groove by screen printing, and forming an upper electrode on a top surface of the piezoelectric layer.

Abstract: A method to form a thick layer by screen printing and a method to form a piezoelectric actuator of an inkjet head. The method to form the thick layer including forming a guide groove in a surface to a predetermined depth, and forming the thick layer by applying a material to the surface inside the guide groove through screen printing. The method to form the piezoelectric actuator including forming an insulating layer on a top surface of a vibration plate and forming a guide groove in the top surface of the vibration plate or an insulating layer to a predetermined depth at a position corresponding to each of a plurality of pressure chambers, forming a lower electrode on the top surface of the insulating layer; forming a piezoelectric layer inside the guide groove by screen printing, and forming an upper electrode on a top surface of the piezoelectric layer.

Abstract: A piezoelectric inkjet printhead includes a manifold, a chamber array including a plurality of chambers in connection with the manifold and arranged along at least one side of the manifold, a vibrating plate to cover the plurality of chambers, and a plurality of piezoelectric actuators formed on the vibrating plate to change pressures of corresponding ones of the plurality of chambers by vibrating the vibrating plate. The plurality of chambers includes a plurality of pressure chambers disposed in a center portion of the chamber array and having corresponding ink ejecting nozzles, and at least two dummy chambers, one disposed on each side of the chamber array and having corresponding dummy nozzles that do not eject ink. A plurality of trenches may be formed in the vibrating plate between each of the piezoelectric actuators.

Abstract: A piezoelectric actuator of an inkjet head and a method of forming the piezoelectric actuator. The piezoelectric actuator is formed on a vibration plate to provide a driving force to each of a plurality of pressure chambers. The piezoelectric actuator includes a lower electrode formed on the vibration plate, a piezoelectric layer formed on the lower electrode at a position corresponding to each of the pressure chambers, a supporting pad formed on the lower electrode, the supporting pad contacting one end of the piezoelectric layer and extending away from the one end of the piezoelectric layer, and an upper electrode extending from a top surface of the piezoelectric layer to a top surface of the supporting pad. The upper electrode is bonded to a driving circuit above the supporting pad to receive a voltage from the driving circuit. The piezoelectric layer may have substantially the same length as the pressure chamber.

Abstract: A display device includes a display panel displaying an image, a driving circuit substrate electrically connected to the display panel and having a contact member mounted on one side thereof, a frame accommodating the display panel and the driving circuit substrate and having a through hole, and an accommodating member arranged below the frame and coupled to the frame, wherein the contact member contacts the accommodating member through the through hole.

Abstract: Provided are a nozzle plate of an inkjet printhead and a method of manufacturing the same. The nozzle plate includes: a substrate including a plurality of nozzles; and a plurality of first grooves formed on the surface of a substrate around the nozzles. In this structure, ink remaining on the surface of the nozzle plate can be efficiently removed.

Abstract: A method of poling a piezoelectric actuator, which can improve the uniformity of a plurality of piezoelectric actuators. In the method, a plurality of piezoelectric actuators are prepared for poling. Then, at least two preliminary poling processes are performed on the prepared piezoelectric actuators under different preliminary voltages and displacements of the piezoelectric actuators subjected to each of the at least two poling processes are measured. A relationship between a voltage and a displacement for each of the piezoelectric actuators is established. Poling voltages are calculated so that the piezoelectric actuators can have the same target displacement. Formal poling is performed on the piezoelectric actuators under the calculated poling voltages. The displacements of the piezoelectric actuators, which have completed the formal poling, are measured.

Abstract: The present invention relates to an aminomethyl polystyrene resin wherein aminomethyl group is grafted only on the surface of polystyrene resin, and a preparation process for the same. More particularly, the present invention is directed to a process for preparing aminomethyl polystyrene resin wherein aminomethyl group is grafted only on the surface of polystyrene resin, which comprises a step for grafting amidomethyl group to surface of polystyrene resin and a step for hydrolysis of the amidomethyl group grafted on the surface of polystyrene resin.

Abstract: An inkjet printhead that uses a non-aqueous ink. The inkjet printhead includes a flow channel plate having an ink channel, and a nozzle plate which is combined with the flow channel plate and has a plurality of nozzles through which the non-aqueous ink is ejected, wherein a non-wetting coating film is formed on inner walls of the ink channel and the nozzles.

Abstract: An inkjet head including a plurality of restrictors to reduce crosstalk. The inkjet head includes a channel plate in which an ink channel is formed, an actuator formed on the channel plate, and an ink-supply bezel including a manifold. The ink channel includes an ink inlet to receive ink from the manifold, reservoirs to store ink received through the ink inlet, chambers filled with ink supplied from the reservoirs, nozzles to eject ink filled in the chambers, first restrictors connecting the reservoirs to the chambers, and second restrictors connecting the reservoirs to the ink inlet. Each of the reservoirs includes a first reservoir and a second reservoir that are separated by a central separation wall, and the separation wall includes a third restrictor connecting the first and second reservoirs. Therefore, crosstalk caused by a back flow of ink and transmission of a pressure wave can be prevented during ejection of ink.

Abstract: A piezoelectric type inkjet printhead includes an upper substrate including a pressure chamber to be filled with ink that is to be ejected, a reservoir to store ink that flowed in from an ink container, a restrictor connect the reservoir to one end of the pressure chamber, an intermediate substrate comprising a damper formed on a portion of the intermediate substrate, which corresponds to other end of the pressure chamber, a lower substrate comprising a nozzle to eject ink and formed in a portion of the lower substrate, which corresponds to the damper, a hydrophobic layer formed on a bottom of the lower substrate, and a piezoelectric actuator formed on the upper substrate to supply driving power to eject ink to the pressure chamber, wherein the nozzle is formed in the lower substrate at a predetermined depth from a bottom surface of the lower substrate.

Abstract: A method of forming a high density thick piezoelectric layer and a piezoelectric device the same. The method of forming the thick piezoelectric layer includes: forming a seed layer on a substrate by coating a sol including a piezoelectric material; primary heat-treating the seed layer; forming the thick piezoelectric layer by coating a paste that includes a piezoelectric material on the seed layer using a screen printing method; and secondary heat-treating the thick piezoelectric layer at a temperature higher than the primary heat-treating temperature. The piezoelectric material included in the sol has a composition identical or similar to the composition of the piezoelectric material included in the paste. The density of the thick piezoelectric layer is increased by particles of the piezoelectric material that penetrate into the thick piezoelectric layer from the seed layer in the secondary heat-treating, and thus, a high density thick piezoelectric layer can be formed.

Abstract: A gate driving unit connected to odd-numbered gate lines and a gate driving unit connected to even-numbered gate lines are sequentially operated, and a common voltage signal is inverted when the operation states of the two gate driving units are changed, thereby minimizing a number of changes in the voltage level of the common voltage signal supplied to a display panel during one frame, reducing power consumption of the display device, and allowing pixels of the display panel to perform line inversion.

Abstract: A unit block for a core using soft magnetic metal powder, a core having excellent high-current DC bias characteristics using the unit block, and a method of producing the core are disclosed. The unit block is used to produce cores applied to an active filter for PFC, a three-phase line reactor, or an inductor for automotive electronics. A method of producing the core comprises mixing sendust alloy, High Flux, MPP, or silicon steel powders, which have an average particle size of 175 gm or less, with a solid lubricant; compacting a mixture at a pressure of 10-18 tons per unit area; heat-treating the compacted mixture at 600-800° C. for 1-2 hours to form the unit blocks each having a length of 3-10 cm, a width of 1-5 cm, and a height of 1-5 cm; and attaching the unit blocks using a heat- and fire-resistant adhesive.

Abstract: A method to form a thick layer by screen printing and a method to form a piezoelectric actuator of an inkjet head. The method to form the thick layer including forming a guide groove in a surface to a predetermined depth, and forming the thick layer by applying a material to the surface inside the guide groove through screen printing. The method to form the piezoelectric actuator including forming an insulating layer on a top surface of a vibration plate and forming a guide groove in the top surface of the vibration plate or an insulating layer to a predetermined depth at a position corresponding to each of a plurality of pressure chambers, forming a lower electrode on the top surface of the insulating layer; forming a piezoelectric layer inside the guide groove by screen printing, and forming an upper electrode on a top surface of the piezoelectric layer.

Abstract: A piezoelectric actuator of an inkjet head and a method of forming the piezoelectric actuator. The piezoelectric actuator is formed on a vibration plate to provide a driving force to each of a plurality of pressure chambers. The piezoelectric actuator includes a lower electrode formed on the vibration plate, a piezoelectric layer formed on the lower electrode at a position corresponding to each of the pressure chambers, a supporting pad formed on the lower electrode, the supporting pad contacting one end of the piezoelectric layer and extending away from the one end of the piezoelectric layer, and an upper electrode extending from a top surface of the piezoelectric layer to a top surface of the supporting pad. The upper electrode is bonded to a driving circuit above the supporting pad to receive a voltage from the driving circuit. The piezoelectric layer may have substantially the same length as the pressure chamber.

Abstract: A piezoelectric inkjet printhead includes a manifold, a chamber array including a plurality of chambers in connection with the manifold and arranged along at least one side of the manifold, a vibrating plate to cover the plurality of chambers, and a plurality of piezoelectric actuators formed on the vibrating plate to change pressures of corresponding ones of the plurality of chambers by vibrating the vibrating plate. The plurality of chambers includes a plurality of pressure chambers disposed in a center portion of the chamber array and having corresponding ink ejecting nozzles, and at least two dummy chambers, one disposed on each side of the chamber array and having corresponding dummy nozzles that do not eject ink. A plurality of trenches may be formed in the vibrating plate between each of the piezoelectric actuators.

Abstract: The present invention relates to a process for preparing tritylated polystyrene resin. More particularly, the present invention is directed to a process for preparing tritylated polystyrene resins, comprising a step for tritylating polystyrene by reacting polystyrene resin with benzophenone dichloride or substituted benzophenone dichloride to introduce trityl group on the benzene moiety of the polystyrene.

Abstract: Disclosed herein is a linear compressor. In the linear compressor, outer cores are seated on core seating depressions provided on upper and lower surfaces of a bobbin. The outer cores are firmly held on the bobbin through a molded part which is provided through an injection molding process to fill spaces between the bobbin and the outer cores. Therefore, the outer cores are prevented from being removed from the bobbin even when vibrations occur during an operation of the linear compressor, thus keeping gaps between a moving part and the outer cores constant.

Abstract: The present invention relates to a process for preparing tritylated polystyrene resin. More particularly, the present invention is directed to a process for preparing tritylated polystyrene resins, comprising a step for tritylating polystyrene by reacting polystyrene resin with benzophenone dichloride or substituted benzophenone dichloride to introduce trityl group on the benzene moiety of the polystyrene.