Abstract: Disclosed is a method, system, and non-transitory computer-readable record medium for creating a chatroom according to a condition. The chatroom creation method may include providing an instant messaging service; registering a chatroom creation condition related to a specific account of the instant messaging service; retrieving at least one account of accounts of the instant messaging service that meets the chatroom creation condition; and automatically creating a chatroom of the specific account joined by the retrieved accounts.

Abstract: Provided is a method and system for providing an answer message to a query message. An answer message providing method may include managing a plurality of chatrooms of an instant messaging service; receiving a query message in a preset form from a first user of a first chatroom among the plurality of chatrooms; forwarding the query message to second users through the instant messaging service; receiving an answer message to the query message from at least one of the second users; and providing the received answer message to be displayed through the first chatroom.

Abstract: Disclosed is a method, system, and non-transitory computer-readable record medium for protecting content copyright in a chatroom. A content protection method includes adding, by at least one processor, a mark to content in a chatroom, the mark including chatroom information for identifying the chatroom in response to a user request from a user associated with the content in the chatroom, and executing, by the at least one processor, a function corresponding to the user request using the content to which the mark is added.

Abstract: Provided are a method, a system, and a non-transitory computer readable record medium for controlling joining a chatroom based on a location. The method may include identifying a first location of an electronic device at a first point in time; displaying a chatroom that uses a user location as a chatroom joining condition, and that allows a user of an electronic device to join based on the first location of the electronic device; and in response to a join request being input at a second point in time from the user to join the displayed chatroom, determining whether to allow the user to join the chatroom based on a second location of the electronic device at the second point in time at which the join request is input.

Abstract: Disclosed is a hydrophilic material oil fence having a double-porous mesh. The hydrophilic material oil fence having the double-porous mesh includes a floating body floating on a water surface, and a skirt coupled to an upper portion and a lower portion of the floating body and made of a hydrophilic material through which a hydrophilic fluid selectively passes. A mesh hole size of a partial region of the skirt and a mesh hole size of the other region of the skirt are different.

Abstract: A system and method of correcting an alignment error of an array inkjet head having a plurality of head chips to print a main scanning line can include determining a reference head chip, printing a plurality of reference lines in the main scanning direction to be separated from one another at a reference interval in a sub-scanning direction using the reference head chip, and printing a plurality of test lines which can be offset by a multiple m, where m is an integer, of a test interval with respect to the reference interval using other head chips, and determining one of the plurality of test lines that matches any of the plurality of reference lines of each of the head chips, and determining an amount of offset of the determined test line as an amount of offset of each head chip.

Abstract: A system and method of correcting an alignment error of an array inkjet head having a plurality of head chips to print a main scanning line can include determining a reference head chip, printing a plurality of reference lines in the main scanning direction to be separated from one another at a reference interval in a sub-scanning direction using the reference head chip, and printing a plurality of test lines which can be offset by a multiple m, where m is an integer, of a test interval with respect to the reference interval using other head chips, and determining one of the plurality of test lines that matches any of the plurality of reference lines of each of the head chips, and determining an amount of offset of the determined test line as an amount of offset of each head chip.

Abstract: An ink cartridge includes a residual ink sensing unit having a simple structure of an upper electrode plate and a lower electrode plate to accurately detect a capacitance between the upper and lower electrode plate. Therefore, data of a remaining amount of ink is reliably measured, there is less possibility that an ink bag is damaged when the residual ink sensing unit is installed in the ink bag, and damage to the ink cartridge and defective printing due to unstable supply of ink and the missing of the time for replacing the ink cartridge are prevented.

Abstract: A head of an inkjet printer is formed by bonding of a heater substrate and a nozzle plate. In order to bond the heater substrate where a heater thin film and a protecting film are vapor-deposited, and the nozzle plate where a nozzle is formed, an intermediate layer is formed by forming a thin film of glass on the heater substrate by vapor-depositing, and the nozzle plate is installed on the heater substrate. SiO2 is formed at an interface between the nozzle plate and the heater thin film due to heating and application of an electric field, and thus the nozzle plate and the heater substrate are bonded with an electrostatic force of SiO2. The nozzle plate and the heater substrate are bonded by using the intermediate layer made of the thin film of glass instead of a general polymer as the bonding layer, thereby preventing swelling of the polymer and isolation of layers of the head occurring due to ink penetration into interfaces of the layers.

Abstract: An array type inkjet head and a method of manufacturing the same are provided. The method includes providing a test head in which nozzle chips are mounted, printing ejection patterns on a printing medium according to various ejection timings of the nozzle chips by controlling the test head, classifying the nozzle chips into groups according to the ejection patterns, and assembling the nozzle chips that are classified in the same group having the same ejection pattern on the array type inkjet head. Since the array type inkjet head is manufactured by grouping together the nozzle chips having the same ejection pattern, poor printing results can be prevented.

Abstract: An inkjet print head chip capable of preventing an adhesive from flowing over a nozzle part during a connection work of a flexible printed circuit board thereto is provided with a nozzle part to have a plurality of nozzles formed therein; a plurality of connecting pads disposed at a side of the nozzle part and electrically connected to a plurality of ink firing portions formed under the nozzle part; and an overflow prevention dam disposed between the nozzle part and the plurality of connecting pads and to have a height higher than the plurality of connecting pads.

Abstract: A foam used in a print cartridge and a method of forming the same. The foam includes 0.1-5.0 wt % of silver nanoparticles, based on the total weight of the foam. The print cartridge has a deodorizing, antibacterial, and disinfectant function.

Abstract: A foam used in a print cartridge and a method of forming the same. The foam includes 0.1-5.0 wt % of silver nanoparticles, based on the total weight of the foam. The print cartridge has a deodorizing, antibacterial, and disinfectant function.

Abstract: An array printhead and an inkjet image forming device having the same. The array printhead includes a first member, a second member, and a third member. The first through third members sequentially overlap and couple to each other. The first member supplies ink of different colors to the second member and the second member separately receives the ink of different colors supplied from the first member and allows the ink to flow to the third member. The third member is mounted with a plurality of head chips on a lower surface thereof and the head chips have nozzles ejecting ink and forming a plurality of nozzle lines. The ink of different colors is supplied to the nozzle lines, respectively.

Abstract: An ink supplying device and an inkjet image forming apparatus including the same. The ink supplying device includes an ink containing unit, a printhead forming an image by ejecting ink onto a printing medium, the ink flowing from the ink containing unit into the printhead through an ink path, and an ultrasonic wave generator which is installed in one side of the ink containing unit and generates ultrasonic waves to remove gas from ink contained in the ink containing unit. Accordingly, since the gas is separated from the ink using ultrasonic waves without heating the ink, the temperature of ink is not increased, and thus, ink properties are not changed. Furthermore, the gas is removed from the ink while the ink passes through an air purging tube, and hence, the gas is prevented from being re-absorbed into the ink. That is, by removing bubbles and gas existing in the ink, an ejecting failure during ejection of ink droplets can be prevented, and thus, printing quality can be improved.

Abstract: An ink-jet printhead and a manufacturing method thereof include a substrate on which an ink chamber having a predetermined volume is formed, a passage for supplying ink to the ink chamber which is formed on a bottom of the ink chamber, a nozzle plate which includes a nozzle corresponding to a center of the ink chamber and at least two insulating layers formed on the substrate, a bubble guide formed inside the nozzle plate and extending from the nozzle into the ink chamber, and a heater which surrounds the nozzle and is disposed between the two insulating layers. A hydrophobic coating layer is formed on a surface of a uppermost layer of the nozzle plate, and a droplet ejecting portion that has a diameter smaller than that of the nozzle of the nozzle plate and is disposed on the same axis as the nozzle, is formed in the hydrophobic coating layer.

Abstract: An ink cartridge includes a container body to accommodate an ink and having a pipe at a lower end through which the ink is discharged, an ink holding member disposed in the container body to absorb the ink, and a negative pressure generation part stepped with respect to a reference bottom side in the container body to increase a negative pressure by compressing the ink holding member as approaching an inlet of the pipe.

Abstract: An ink cartridge includes a residual ink sensing unit having a simple structure of an upper electrode plate and a lower electrode plate to accurately detect a capacitance between the upper and lower electrode plate. Therefore, data of a remaining amount of ink is reliably measured, there is less possibility that an ink bag is damaged when the residual ink sensing unit is installed in the ink bag, and damage to the ink cartridge and defective printing due to unstable supply of ink and the missing of the time for replacing the ink cartridge are prevented.

Abstract: A wire bonding structure that electrically connects a printhead chip with a flexible printed circuit (FPC) using a wire includes a ball formed on a bonding pad provided on a surface of the printhead chip, a wire having a first end connected to the ball and a second end bonded to the FPC, the first end of the wire connected to the ball has a bent portion in which a first portion of the wire is bent over a surface of the bonding pad to overlap a second portion of the wire located over the surface of the bonding pad.

Abstract: An ink-jet printhead includes a substrate on which an ink chamber is formed, and a nozzle plate to cover the ink chamber, having a nozzle through which ink droplets are ejected from the ink chamber, and formed of a stack of a multi-layer insulating layer. The ink-jet printhead also includes a heater buried in the nozzle plate to surround the nozzle, an interconnection layer buried in the nozzle plate to electrically connect to the heater, and a coating layer formed of photoresist on the nozzle plate and having a through hole-type droplet guide connected to the nozzle of the nozzle plate. The droplet guide is formed through the coating layer, which has a sufficient thickness, and enables a meniscus of ink to be rapidly restored and stabilized, and ink droplets to be ejected at a high speed and high frequency. Also, the ink-jet printhead has improved resistance to abrasion and chemicals.