Abstract: Provided is a nozzle plate and methods of manufacturing the nozzle plate. The nozzle plate may include a substrate having a nozzle. The nozzle plate may also include a permittivity reducing area in an upper portion of the substrate around the nozzle, wherein the permittivity reducing area includes a plurality of porosities and a plurality of walls between the plurality of porosities. Additionally, the nozzle plate may include a protection layer on the substrate, wherein the protection layer covers the plurality of porosities and the plurality of walls.

Abstract: An inkjet printing apparatus according to example embodiments may include a flow channel plate including an ink inlet for introducing ink, a pressure chamber containing the introduced ink, and a nozzle connected to the pressure chamber and configured to eject ink. A piezoelectric voltage applier may apply a piezoelectric driving voltage to the piezoelectric actuator in such a way that the volume of the pressure chamber is reduced so as to eject an ink droplet. An electrohydrodynamic voltage applier may apply a first electrohydrodynamic driving voltage and a second electrohydrodynamic driving voltage to the electrohydrodynamic actuator. The first electrohydrodynamic driving voltage may generate a jet from the ink droplet such that the jet is ejected towards a printing medium, and the second electrohydrodynamic driving voltage (which has an opposite polarity to that of the first electrohydrodynamic driving voltage) may restore the ink droplet to the nozzle.

Abstract: Methods of adjusting ink ejection characteristics of an inkjet printing apparatus and driving the inkjet printing apparatus are provided.

Abstract: A piezoelectric inkjet head and a method of manufacturing the piezoelectric inkjet head. The piezoelectric inkjet head includes three single crystal silicon substrates bonded to each other. An upper substrate includes an ink inlet, a plurality of pressure chambers, and a plurality of piezoelectric actuators, a middle substrate includes a manifold, a plurality of restrictors, and a plurality of first dampers, and a lower substrate includes a plurality of nozzles. The middle substrate also includes a membrane that is formed under the manifold to mitigate a rapid pressure change in the manifold and if formed of a material different from the material used for forming the middle substrate. A cavity located under the membrane and at least one venting channel that connects the cavity to the outside are formed in the middle substrate or the lower substrate.

Abstract: A piezoelectric inkjet printhead that includes a flow channel plate; an ink flow channel that is formed in the flow channel plate and includes an ink inlet through which ink enters, a plurality of pressure chambers to which ink to be ejected is filled, a manifold which is a path for supplying ink from the ink inlet to the pressure chambers, a plurality of restrictors that connect the manifold to the pressure chambers, and a plurality of nozzles to eject ink from the pressure chambers to the outside; and a plurality of piezoelectric actuators formed on the flow channel plate to provide a driving power to each of the pressure chambers to eject ink to the outside, wherein the manifold includes a plurality of individual manifolds defined by a plurality of first barrier ribs, which respectively correspond to the pressure chambers.

Abstract: A method of driving a hybrid type inkjet printing apparatus according to example embodiments may use both a piezoelectric method and an electrostatic method. The method of driving may include a plurality of driving modes that are determined by adjusting the order, amplitude, and duration of a piezoelectric driving voltage to a piezoelectric actuator and an electrostatic driving voltage to an electrostatic force applying unit. As a result, ink droplets may be ejected in various sizes and shapes. In a first driving mode, a dome-shaped ink meniscus may be formed at an end portion of a nozzle and ink droplets having a smaller size than the nozzle may be ejected from a surface of the dome-shaped ink meniscus. In a second driving mode, a cone-shaped ink meniscus may be formed at an end of the nozzle, and ink droplets having a smaller size than those of the first driving mode may be ejected from a sharp end portion of the cone-shaped ink meniscus.

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: An inkjet printing device includes: a flow path plate, a piezoelectric actuator and an electrostatic force applicator. The flow path plate includes an ink inlet, a pressure chamber and a nozzle. The piezoelectric actuator is configured to provide a first driving force, and the electrostatic force applicator is configured to provide a second driving force. The disclosed inkjet printing devices and methods combine piezoelectric and electrostatic techniques.

Abstract: A simple structured thermal actuation pump for reducing energy loss is provided. The thermal actuation pump includes: a first chamber having at least one working fluid inlet and at least one working fluid outlet; a second chamber having at least one working fluid inlet and at least one working fluid outlet; and a thermoelectric element arranged between the first chamber and the second chamber and including one side being cooled and the other side being heated according to a direction of current for changing inside pressures of the first chamber and the second chamber.

Abstract: In a toilet bowl which includes a bowl body, a sitting member and a water reservoir, a new toilet bowl system usable for sitting facing front is disclosed, which comprises a bowl body having a longitudinal vertical opening, a backrest or chest support member which is provided apart from an upper side of the bowl body and the sitting member, a support handle which is installed at a side surface of the backrest or chest support member, a water reservoir which is not contacted with an upper side of the bowl body and the sitting member and stores water for flushing urine and feces, a water reservoir support member for supporting the water reservoir, and a chest support member support member which is engaged at the water reservoir and supports a backrest or chest support member support. A wheelchair user can more easily use in a forward facing posture while saving a space in a toilet room.

Abstract: A semiconductor device includes a substrate having a cell array region and a peripheral circuit region, a lower structure on the substrate in the cell array region, a first insulation layer on the substrate across the cell array region and the peripheral circuit region, the lower structure being covered with the first insulation layer, a capacitor on the first insulation layer in the cell array region, the capacitor including a lower electrode, a dielectric layer patter, and an upper electrode, a second insulation layer on the first insulation layer, the capacitor being covered with the second insulation layer, a first upper wiring structure on the second insulation layer, the first upper wiring structure being electrically connected to the capacitor and including an upper wiring and a mask pattern, and at least one dummy structure in the peripheral circuit region.

Abstract: A piezoelectric inkjet printhead having a channel forming plate including an ink channel having a pressure chamber coupled to a nozzle, a piezoelectric actuator including a lower electrode on the channel forming plate, a piezoelectric element on the lower electrode, and an upper electrode on the piezoelectric element, the piezoelectric actuator corresponding to the pressure chamber, an insulation element on the lower electrode and spaced apart from the piezoelectric element, a first electrode on the insulation element, and a temperature sensor on the first electrode, and a method of making the same.

Abstract: An inkjet printing device includes a flow path plate comprising a manifold to supply ink, a pressure chamber filled with the ink supplied from the manifold, and a nozzle via which the ink is ejected, a piezoelectric actuator which is disposed on a top surface of the flow path plate and includes a lower electrode, a piezoelectric layer, and an upper electrode that are stacked sequentially, a first electrostatic electrode to generate an electrostatic field, and a second electrostatic electrode which is disposed a predetermined distance apart from a bottom surface of the flow path plate to generate the electrostatic field between the first electrostatic electrode and the second electrostatic electrode.

Abstract: An inkjet printhead assembly including an inkjet printhead chip having an ink inflow hole, a frame having an ink supply hole, and an ink supply apparatus having a preheater and an ink supply outlet, wherein the frame is disposed between the inkjet printhead chip and the ink supply apparatus, the inkjet printhead chip is attached to the frame, and the ink supply hole is disposed between the ink supply outlet and the ink inflow hole, so as to channel ink between the ink supply apparatus and the inkjet printhead chip.

Abstract: A piezoelectric inkjet head and a method of manufacturing the piezoelectric inkjet head. The piezoelectric inkjet head includes three single crystal silicon substrates bonded to each other. An upper substrate includes an ink inlet, a plurality of pressure chambers, and a plurality of piezoelectric actuators, a middle substrate includes a manifold, a plurality of restrictors, and a plurality of first dampers, and a lower substrate includes a plurality of nozzles. The middle substrate also includes a membrane that is formed under the manifold to mitigate a rapid pressure change in the manifold and if formed of a material different from the material used for forming the middle substrate. A cavity located under the membrane and at least one venting channel that connects the cavity to the outside are formed in the middle substrate or the lower substrate.

Abstract: A header compression in a broadband wireless communication system is provided. A transmitter includes a compressor for compressing a header of a packet; a processor for appending a compression channel IDentifier (ID) to the packet; and a controller for identifying a Service Flow (SF) corresponding to the compression channel ID and processing the packet according to the SF. Accordingly, by using the ID of the compression channel in the header compression, the SF can be identified even in the header compression.

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: An inkjet printhead having a bezel structure to remove ink bubbles. The inkjet printhead includes a channel plate having an ink channel, actuators formed on the channel plate to provide driving forces to eject the ink, and an ink-supply bezel coupled to the channel plate. The ink-supply bezel includes an ink reservoir that is connected to an ink inlet and stores ink that is to be supplied to the ink channel, an ink supply port through which ink is supplied to the ink reservoir, and an air discharge port through which bubbles that are removed from the ink of the ink reservoir are discharged. The ink supply port and the air discharge port can be formed closed to both ends of the top surface of the ink reservoir, respectively. The ink supply port can have a bottom end lower than that of the air discharge port. The ink reservoir can include a sloped ceiling surface. Therefore, ink bubbles can be effectively removed from the ink before the ink is supplied to the ink channel.

Abstract: A piezoelectric inkjet printhead that includes a flow channel plate; an ink flow channel that is formed in the flow channel plate and includes an ink inlet through which ink enters, a plurality of pressure chambers to which ink to be ejected is filled, a manifold which is a path for supplying ink from the ink inlet to the pressure chambers, a plurality of restrictors that connect the manifold to the pressure chambers, and a plurality of nozzles to eject ink from the pressure chambers to the outside; and a plurality of piezoelectric actuators formed on the flow channel plate to provide a driving power to each of the pressure chambers to eject ink to the outside, wherein the manifold includes a plurality of individual manifolds defined by a plurality of first barrier ribs, which respectively correspond to the pressure chambers.

Abstract: An ink supply apparatus of an inkjet printing system includes an ink tank including a pressure port and an ink supply opening connected to a print head, a flexible ink package connected to the ink supply opening to accommodate ink, and a pressure supply device to supply a purging pressure to the ink package by supplying a pressure fluid to the ink tank.