# US 8,540,338 B2 · Printhead maintenance station including station backflush > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,338 B2 - Document ID: US8540338B2 - Status: Granted - Kind: B2 - Application number: 13/074,388 - Filed: 2011-03-29 - Published: 2012-10-04 - Granted: 2013-09-24 - Earliest claimed: 2011-03-29 - Assignees: Eastman Kodak Company - Applicants: John C. Loyd; Gregory J. Sexton - Inventors: John C. Loyd; Gregory J. Sexton - Web page: https://patentgrep.com/patent/US8540338B2 ## CPC - B41J 2/16552: {using cleaning fluids} - B41J 2/16532: {by applying vacuum only} - B41J 2/1707: {Conditioning of the inside of ink supply circuits, e.g. flushing during start-up or shut-down} - B41J 2/1721: {Collecting waste ink; Collectors therefor} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A maintenance station apparatus for a printhead including a nozzle face with the nozzle face including a nozzle array for jetting a liquid is provided. The maintenance station includes a capping unit including a drain and a waste liquid tank that receives a waste liquid from the capping unit. A valve is in fluid communication with the capping unit through a first fluid passage and in fluid communication with the waste liquid tank through a second fluid passage. The valve includes a first state that permits the waste liquid to flow from the capping unit through the valve to the waste liquid tank and a second state that prevents the waste liquid from flowing from the capping unit through the valve to the waste liquid tank. A cleaning liquid tank is in fluid communication with the valve through a third fluid passage and is configured to provide a cleaning liquid through the valve and into the first fluid passage when the valve is in the second state. ## Claims ### Claim 1 A maintenance station apparatus for a printhead including a nozzle face, the nozzle face including a nozzle array for jetting a liquid, the maintenance station comprising: a capping unit including a drain; a waste liquid tank that receives a waste liquid from the capping unit; a valve in fluid communication with the capping unit through a first fluid passage, the valve being in fluid communication with the waste liquid tank through a second fluid passage, the valve including a first state that permits the waste liquid to flow from the capping unit through the valve to the waste liquid tank, the valve including a second state that prevents the waste liquid from flowing from the capping unit through the valve to the waste liquid tank; and a cleaning liquid tank in fluid communication with the valve through a third fluid passage, the cleaning liquid tank being configured to provide a cleaning liquid through the valve and into the first fluid passage when the valve is in the second state. ### Claim 2 (depends on 1) The maintenance station of claim 1, wherein the cleaning liquid tank is positioned relative to the valve and the capping unit such that gravity causes the cleaning liquid to flow from the cleaning liquid tank through the valve and into the first fluid passage when the valve is in the second state. ### Claim 3 (depends on 2) The maintenance station of claim 2, wherein the cleaning liquid tank includes a liquid level control system. ### Claim 4 (depends on 3) The maintenance station of claim 3, the cleaning liquid tank further comprising: a float switch; and a cleaning liquid supply; wherein the float switch signals the cleaning liquid supply to replenish the cleaning liquid upon reaching a minimum cleaning liquid level. ### Claim 5 (depends on 1) The maintenance station of claim 1, the valve being a first valve, further comprising: a second valve located in the first fluid passage, creating an upstream portion of the first fluid passage and a downstream portion of the first fluid passage, the capping unit being in fluid communication with the first valve through the second valve, wherein the cleaning liquid tank is configured to provide the cleaning liquid through the first valve through the downstream portion of the first fluid passage, through the second valve, and into the upstream portion of the first fluid passage. ### Claim 6 (depends on 5) The maintenance station of claim 5, the capping unit being a plurality of capping units and the second valve being a plurality of second valves, corresponding to the plurality of capping units, further comprising: a manifold located in the downstream portion of the first fluid passage, whereby the plurality of second valves is in fluid communication with the first valve through the manifold. ### Claim 7 (depends on 5) The maintenance station of claim 5, wherein the first valve is a solenoid valve. ### Claim 8 (depends on 5) The maintenance station of claim 5, wherein the second valve is a solenoid valve. ### Claim 9 (depends on 1) The maintenance station of claim 1, wherein the valve is a solenoid valve. ### Claim 10 (depends on 1) The maintenance station of claim 1, wherein the cleaning liquid tank is vented to atmosphere. ### Claim 11 (depends on 1) The maintenance station of claim 1, further comprising: a pump that causes the waste liquid to flow from the capping unit through the valve and into the waste liquid tank, when the valve is in the first state. ### Claim 12 (depends on 1) The maintenance station of claim 1, wherein the capping unit and the nozzle face are moveable relative to each other. ### Claim 13 (depends on 1) The maintenance station of claim 1, wherein the liquid that is jetted is an ink. ### Claim 14 (depends on 13) The maintenance station of claim 13, wherein the ink comprises a pigment dispersion. ### Claim 15 (depends on 14) The maintenance station of claim 14, wherein the pigment dispersion comprises a magnetic pigment dispersion. ### Claim 16 (depends on 1) The maintenance station of claim 1, wherein the liquid is an ink used for magnetic ink character recognition. ### Claim 17 (depends on 1) The maintenance station of claim 1, wherein the cleaning liquid contains a dispersant. ### Claim 18 (depends on 17) The maintenance station of claim 17, wherein the dispersant is a dispersant for a MICR ink. ### Claim 19 (depends on 18) The maintenance station of claim 18, wherein the liquid jetted is a MICR ink.