# US 7,744,200 B2 · Inkjet printer and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,200 B2 - Document ID: US7744200B2 - Status: Granted - Kind: B2 - Application number: 11/586,020 - Filed: 2006-10-24 - Published: 2007-05-24 - Granted: 2010-06-29 - Earliest claimed: 2005-11-24 - Assignees: Brother Kogyo Kabushiki Kaisha - Inventors: Katsunori Nishida - Web page: https://patentgrep.com/patent/US7744200B2 ## CPC - B41J 2/16526: {by applying pressure only} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract An inkjet printer includes a print head having a plurality of nozzles; a plurality of ink cartridges storing inks of different colors, respectively, to be supplied to the print head; and a pressure applying section for applying pressure in an ejecting direction to the inks in the nozzles of the print head by supplying compressed air to the ink cartridges, and the pressure applying section has a pump for supplying compressed air to the ink cartridges through an air channel provided between the ink cartridges and said pump; and a charge tank provided in the air channel, for temporarily keeping the compressed air, and, after increasing the pressure in the ink cartridges, charge tank and air channel by the supply of compressed air from the pump, the compressed air is released to the print head and the pressure is applied to the inks in the nozzles of the print head. ## Claims ### Claim 1 An inkjet printer comprising: a print head having a plurality of nozzles; a plurality of ink cartridges storing inks of different colors, respectively, to be supplied to said print head; and a pressure applying section for applying pressure in an ejecting direction to the inks in the nozzles of said print head by supplying compressed air to said ink cartridges; wherein said pressure applying section comprises: a pump for supplying compressed air to said ink cartridges through an air channel extending between said ink cartridges and said pump; and a charge tank provided in said air channel, for temporarily keeping the compressed air; and wherein, after increasing pressure in said plurality of ink cartridges, said charge tank, and said air channel simultaneously by the supply of compressed air from said pump, the compressed air is released to said print head and the pressure is applied to the inks in the nozzles of said print head; wherein said pressure applying section further comprises an atmospheric air release valve provided for said charge tank or said air channel, a pressure applying valve provided in an ink channel between said print head and each of said ink cartridge, and a controller for controlling said pump, said atmospheric air release valve, and said pressure applying valve; and wherein said controller performs control so that, after increasing pressure in said ink cartridges, charge tank, and air channel by driving said pump for a certain time, said pressure applying valve is opened to apply the pressure to the inks in the nozzles of said print head, said atmospheric air release valve is opened after elapse of a certain time, and the compressed air in said charge tank is released to atmosphere. ### Claim 2 (depends on 1) The inkjet printer according to claim 1; wherein said print head moves reciprocally in a direction orthogonal to a recording medium feeding direction during printing; wherein a wiper for wiping a nozzle surface, on which the nozzles are formed, of said pint head and a flushing tank for ejecting excess ink are provided on one side of a reciprocal movement path; and wherein a cap for covering the nozzle surface during non-printing is provided on the other side. ### Claim 3 (depends on 1) The inkjet printer according to claim 1; wherein a plurality of said charge tanks are provided for said ink cartridges, respectively. ### Claim 4 (depends on 3) The inkjet printer according to claim 3; wherein each of said charge tanks has a tank capacity which is set according to a flow resistance in an ink channel between said print head and said ink cartridge corresponding to said each charge tank. ### Claim 5 (depends on 3) The inkjet printer according to claim 3; wherein each of said charge tanks is constructed integrally with a casing constituting said each ink cartridge. ### Claim 6 (depends on 1) The inkjet printer according to claim 1; wherein said controller controls said pressure applying section according to a degree of print defect so as to change a magnitude of pressure to be applied to the inks in the nozzles of said print head. ### Claim 7 (depends on 6) The inkjet printer according to claim 6; wherein said controller changes the magnitude of the pressure by changing an amount of compressed air to be kept in said ink cartridges, said charge tank and said air channel. ### Claim 8 (depends on 1) The inkjet printer according to claim 1; wherein said pressure applying section is configured to increase pressure in said plurality of ink cartridges to the same pressure by supplying compressed air from said pump. ### Claim 9 An inkjet printer comprising: a print head having a plurality of nozzles; a plurality of ink cartridges storing inks of different colors, respectively, to be supplied to said print head; and a pressure applying section for applying pressure in an ejecting direction to the inks in the nozzles of said print head by supplying compressed air to said ink cartridges; wherein said pressure applying section comprises: a pump for supplying compressed air to said ink cartridges through an air channel extending between said ink cartridges and said pump; and a charge tank provided in said air channel, for temporarily keeping the compressed air; and wherein, after increasing pressure in said plurality of ink cartridges, said charge tank, and said air channel simultaneously by the supply of compressed air from said pump, the compressed air is released to said print head and the pressure is applied to the inks in the nozzles of said print head; wherein said pressure applying section further comprises an atmospheric air release valve provided for said charge tank or said air channel, a pressure applying valve provided in an ink channel between said print head and each of said ink cartridges, and recovery control means for controlling said pump, said atmospheric air release valve, and said pressure applying valve; and wherein said recovery control means performs control so that, after increasing the pressure in said ink cartridges, charge tanks and air channel by driving said pump for a certain time, said pressure applying valve is opened to apply the pressure to the inks in the nozzles of said print head, said atmospheric air release valve is opened after elapse of a certain time, and the compressed air in said charge tank is released to atmosphere. ### Claim 10 (depends on 9) The inkjet printer according to claim 9; wherein said recovery control means controls said pressure applying section according to a degree of print defect so as to change a magnitude of pressure to be applied to the inks in the nozzles of said print head. ### Claim 11 (depends on 10) The inkjet printer according to claim 10; wherein said recovery control means changes the magnitude of the pressure by changing an amount of compressed air to be kept in said ink cartridges, said charge tank, and said air channel. ### Claim 12 A method of controlling an inkjet printer comprising: a print head having a plurality of nozzles; a plurality of ink cartridges storing inks of different colors, respectively, to be supplied to said print head; a pump for supplying compressed air to said ink cartridges through an air channel extending between said ink cartridges and said pump; and a charge tank provided in said air channel, for temporarily keeping the compressed air; said method comprising the steps of: increasing pressure in said plurality of ink cartridges, said charge tank, and said air channel simultaneously by the supply of compressed air from said pump; and applying the pressure to the inks in the nozzles of said print head by releasing the compressed air to said print head; wherein said inkjet printer further comprises an atmospheric air release valve provided for said charge tank or said air channel, a pressure applying valve provided in an ink channel between said print head and each of said ink cartridge, and a controller for controlling said pump, said atmospheric air release valve, and said pressure applying valve; and wherein said controller performs control so that, after increasing pressure in said ink cartridges, charge tank, and air channel by driving said pump for a certain time, said pressure applying valve is opened to apply the pressure to the inks in the nozzles of said print head, said atmospheric air release valve is opened after elapse of a certain time, and the compressed air in said charge tank is released to atmosphere.