Abstract: An ink-jet head is disclosed. The ink-jet head may include: a chamber containing an ink; a reservoir connected with the chamber to supply the ink to the chamber; a restrictor connected with the chamber and the reservoir to control a flow of the ink; a nozzle connected with the chamber to jet the ink, and located at a position corresponding to where a pressure supplied to the chamber is the maximum; and an actuator supplying a pressure to the chamber such that the ink is jetted. The ink-jet may be operated with a lower driving voltage, and the ink may be jetted in a more stable manner.

Abstract: A method and apparatus for calculating the natural frequency of an ink-jet head are disclosed. With a method of determining a natural frequency of an ink-jet head operated by a piezoelectric actuator by joining a sensor to the piezoelectric actuator, which includes supplying electrical power to the piezoelectric actuator; receiving data on the vibration of the ink-jet head as input from the sensor and storing the data; transforming the data and outputting a vibration waveform of the ink-jet head; and analyzing the vibration waveform and to determine the natural frequency of the ink-jet head ink-jet head, the natural frequency of the ink-jet head of high reliability may be determined. In addition, the time required for detecting natural frequency may be reduced.

Abstract: An inkjet printer head and fabricating method thereof are disclosed. An inkjet printer head, which includes: a lower board, in which a nozzle part and a restrictor are formed; an upper board attached to an upper portion of the lower board, in which an ink chamber and an ink inlet are formed; and a piezoelectric element joined to a membrane of the upper board, where the membrane is formed by the portions remaining after portions of the upper board are removed to form the ink chamber, is formed by attaching two boards by an attachment method that does not use a separate adhesion material, such as anodic bonding, for a simple and easy attachment, and for a strong head structure in which there are no chemical or physical reactions that may occur in adhesion layers.

Abstract: A method of manufacturing a nozzle for an inkjet head is disclosed. With the method of manufacturing a nozzle for an inkjet head, comprising (a) coating photoresist on an inkjet head structure comprising a nozzle part; (b) adjusting exposure conditions and performing exposure and developing on the nozzle part to remove a portion of the photoresist; (c) joining a hydrophobic layer onto the portion of the nozzle part where the photoresist has been removed; and (d) removing the photoresist remaining on the nozzle part, it is easy to control the depth of the hydrophobic layer to be uniform, and the depth to which the hydrophobic layer is deposited may be controlled even when the back surface of the nozzle has a complex shape, so that the uniformity and reproduction of the hydrophobicity-treated nozzles are improved.

Abstract: A nozzle for an inkjet head and manufacturing method thereof. With the nozzle for an inkjet head, including a first board in which a nozzle hole is perforated, a middle layer stacked on the first board and perforated in an area corresponding to the nozzle hole, and a second board stacked on the middle layer and perforated in an area corresponding to the nozzle hole, where a hydrophobic layer is joined onto the inner perimeter of the nozzle hole and onto the first board around the nozzle hole, the uniformity and reproduction quality may be improved of nozzles treated for hydrophobicity, as the depth of the hydrophobic layer may be controlled to be uniform and the deposition of the hydrophobic layer may be prevented at the back surface of the nozzles.