# US 2015/0145933 A1 · Printing apparatus and bubble exhaust method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0145933 A1 - Document ID: US20150145933A1 - Status: Published application - Kind: A1 - Application number: 14/531,045 - Filed: 2014-11-03 - Published: 2015-05-28 - Earliest claimed: 2013-11-22 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Hidehiko Kanda; Monta Matsui - Web page: https://patentgrep.com/patent/US20150145933A1 ## CPC - B41J 2/19: for removing air bubbles - B41J 2/16508: {connected with the printer frame} - B41J 2/16532: {by applying vacuum only} - B41J 29/38: Drives, motors, controls or automatic cut-off devices for the entire printing mechanism - B41J 2/17596: {Ink pumps, ink valves} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract An embodiment of this invention implements both suppression of occurrence of a print failure, and suppression of wasteful ink consumption along with bubble exhaust. Bubble sucking is performed as follows in a printing apparatus including a printhead in which a plurality of orifices are provided for discharging ink, an ink tank for supplying ink to the printhead through an ink channel, and a suction unit configured to suck ink from the orifices. A bubble is injected to the ink channel by using, for example, a pump and hollow needle. After injecting the bubble to the ink channel, the suction unit is operated to suck the injected bubble from the orifices. ## Claims ### Claim 1 A printing apparatus comprising: a printhead in which a plurality of orifices are provided for discharging ink; an ink tank for storing ink to be supplied to the printhead; an ink channel for supplying ink from the ink tank to the printhead; a bubble injection unit configured to perform a bubble injection operation to inject a bubble to the ink channel; a suction unit configured to perform a first suction operation and a second suction operation that is stronger than the first suction operation, to suck ink from the printhead; and a control unit configured to control the bubble injection unit and the suction unit, and cause the suction unit to perform the first suction operation for a predetermined time after causing the bubble injection unit to perform the bubble injection operation, and then to cause the suction unit to perform the second suction operation. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the ink channel includes: a horizontal portion arranged in a horizontal direction; and an upstream portion arranged at a position higher than the horizontal portion on an upstream side in an ink supply direction with respect to the horizontal portion, wherein the bubble injection unit is arranged at the upstream portion. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein a filter is arranged in the ink channel on an upstream side with respect to the bubble injection unit. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein the control unit controls the bubble injection unit such that a size of the bubble injected in the ink channel is not smaller than a size of a cross section of the horizontal portion. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein the suction unit includes: a cap capable of covering the orifice; and a first pump configured to perform the first suction operation and the second suction operation to suck ink from the printhead through the cap. ### Claim 6 (depends on 5) The apparatus according to claim 5, wherein the bubble injection unit includes: a hollow needle configured to be able to inserted into the ink channel; and a second pump configured to supply a gas to the ink channel through the hollow needle. ### Claim 7 (depends on 5) The apparatus according to claim 5, wherein the bubble injection unit includes: a third pump capable of pressurizing a gas and injecting the gas to the ink channel; and a valve configured to switch between a state where the third pump is communicated with the ink channel and a state where the third pump is not communicated with the ink channel. ### Claim 8 (depends on 5) The apparatus according to claim 5, wherein the bubble injection unit includes an air communication port capable of introducing air into the ink channel. ### Claim 9 (depends on 1) The apparatus according to claim 1, wherein the ink channel has a circular sectional shape. ### Claim 10 A printing apparatus comprising: a printhead in which a plurality of orifices are provided for discharging ink; an ink tank for storing ink to be supplied to the printhead; an ink channel for supplying ink from the ink tank to the printhead; a bubble injection unit configured to perform a bubble injection operation to inject a bubble to the ink channel; a suction unit configured to perform a suction operation to suck ink from the printhead; a first control unit configured to cause the suction unit to perform the suction operation after causing the bubble injection unit to perform the bubble injection; and a second control unit configured to cause the suction unit to perform the suction operation without causing the bubble injection unit to perform the bubble injection operation. ### Claim 11 (depends on 10) The apparatus according to claim 10, further comprising an acquisition unit configured to acquire an elapsed time since a previous suction operation is performed by the suction unit, wherein in a case where the elapsed time acquired by the acquisition unit exceeds a first time, the first control unit causes the suction unit to perform the suction operation after causing the bubble injection unit to perform the bubble injection operation, and in a case where the elapsed time acquired by the acquisition unit is not shorter than a second time that is longer than the first time, the second control unit causes the suction unit to perform the suction operation without causing the bubble injection unit to perform the bubble injection operation. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the ink channel includes: a horizontal portion arranged in a horizontal direction; and an upstream portion arranged at a position higher than the horizontal portion on an upstream side in an ink supply direction with respect to the horizontal portion, wherein the bubble injection unit is arranged at the upstream portion. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein a filter is arranged in the ink channel on an upstream side with respect to the bubble injection unit. ### Claim 14 (depends on 13) The apparatus according to claim 13, wherein the control unit controls the bubble injection unit such that a size of the bubble injected in the ink channel is not smaller than a size of a cross section of the horizontal portion. ### Claim 15 (depends on 10) The apparatus according to claim 10, wherein the suction unit includes: a cap capable of covering the orifice; and a first pump configured to perform the suction operation to such ink from the printhead through the cap. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the bubble injection unit includes: a hollow needle configured to be able to be inserted into the ink channel; and a second pump configured to supply a gas to the ink channel through the hollow needle. ### Claim 17 (depends on 10) The apparatus according to claim 10, wherein the ink channel has a circular sectional shape. ### Claim 18 (depends on 10) The apparatus according to claim 10, wherein the first control unit or the second control unit causes the suction unit to perform the suction operation until an amount of ink sucked from the orifice reaches a total volume of the ink channel. ### Claim 19 A method for exhausting a bubble in a printing apparatus including: a printhead in which a plurality of orifices are provided for discharging ink; an ink tank for storing ink to be supplied to the printhead; an ink channel for supplying ink from the ink tank to the printhead; a bubble injection unit configured to perform a bubble injection operation to inject a bubble to the ink channel; and a suction unit configured to perform a first suction operation and a second suction operation that is stronger than the first suction operation to suck ink from the printhead, comprising: performing the bubble injection operation by the bubble injection unit; performing the first suction operation for a predetermined time by the suction unit; and performing the second suction operation by the suction unit. ### Claim 20 A method for exhausting a bubble in a printing apparatus including: a printhead in which a plurality of orifices are provided for discharging ink; an ink tank for storing ink to be supplied to the printhead; an ink channel for supplying ink from the ink tank to the printhead; a bubble injection unit configured to perform a bubble injection operation to inject a bubble to the ink channel; and a suction unit configured to perform a suction operation to suck ink from the printhead, comprising: acquiring an elapsed time since a previous suction operation is performed by the suction unit; and determining whether or not to execute the bubble injection operation by the bubble injection unit before a next suction operation, based on the acquired elapsed time.