# US 2013/0278688 A1 · Fluid circulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278688 A1 - Document ID: US20130278688A1 - Status: Published application - Kind: A1 - Application number: 13/923,185 - Filed: 2013-06-20 - Published: 2013-10-24 - Earliest claimed: 2011-02-07 - Assignees: FUJIFILM Dimatix, Inc. - Applicants: FUJIFILM Dimatix, Inc. - Inventors: Andreas Bibl - Web page: https://patentgrep.com/patent/US20130278688A1 ## CPC - B41J 2/175: Ink supply systems {; Circuit parts therefor} - B41J 2/04501: {Control methods or devices therefor, e.g. driver circuits, control circuits} - B41J 2/14233: {of film type, deformed by bending and disposed on a diaphragm} - B41J 2/17513: {Inner structure} - B41J 2/17553: {Outer structure} - B41J 2/17556: {Means for regulating the pressure in the cartridge} - B41J 2/17566: {Ink level or ink residue control} - B41J 2/17596: {Ink pumps, ink valves} - B41J 2/18: Ink recirculation systems - B41J 2002/14491: {Electrical connection} - B41J 2002/17516: {comprising a collapsible ink holder, e.g. a flexible bag} - B41J 2202/12: with ink circulating through the whole print head - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract Among other things, an apparatus for use in fluid jetting is described. The apparatus comprises a printhead including a flow path and a nozzle in communication with the flow path that has a first end and a second end. The apparatus also includes a first container fluidically coupled to the first end of the flow path, a second container fluidically coupled to the second end of the flow path, and a controller. The first container has a first controllable internal pressure and the second container has a second controllable internal pressure. The controller controls the first internal pressure and the second internal pressure to have a fluid flow between the first container and the second container through the flow path in the printhead according to a first mode and a second mode. In either mode, at least a portion of the fluid flowing along the flow path is delivered to the nozzle when the nozzle is jetting. The first mode has the first internal pressure higher than the second internal pressure and the second mode has the second internal pressure higher than the first internal pressure. The fluid flows from the first container to the second container according to the first mode and flows from the second container to the first container according to the second mode. ## Claims ### Claim at position 1 1-13. (canceled) ### Claim 14 A method for use in fluid jetting, the method comprising: delivering a first portion of a fluid at a controlled flow rate along a first flow path from a first container to a second container, the first portion of the fluid in the first flow path passing by a second flow path in a printhead along a first direction, the second flow path fluidically connecting the first flow path to a nozzle such that a second portion of the fluid passing through the first flow path being is delivered through the second flow path to the nozzle when the nozzle is ejecting the fluid delivered from the first container; and delivering a third portion of the fluid at a controlled flow rate along a third flow path from the second container to the first container, the third portion of the fluid in the third flow path passing by the second flow path in the printhead along a second direction opposite to the first direction, the second flow path fluidically connecting the second flow path to the nozzle such that a fourth portion of the fluid passing through the third flow path is delivered through the second flow path to the nozzle when the nozzle is ejecting the fluid delivered from the second container. ### Claim 15 (depends on 14) The method of claim 14, further comprising maintaining a pressure difference between an internal pressure of the first container and an internal pressure of the second container. ### Claim 16 (depends on 15) The method of claim 15, further comprising maintaining each internal pressure of the first and second containers to be lower than an atmospheric pressure. ### Claim 17 (depends on 16) The method of claim 16, wherein the pressure difference between either internal pressure of the first and the second containers and the atmospheric pressure is maintained to be smaller than the pressure difference between the internal pressure of the first container and the internal pressure of the second container. ### Claim 18 (depends on 15) The method of claim 15, wherein the first and second containers are flexible and the pressure difference is maintained by applying different pressures to exterior surfaces of the flexible first and second containers. ### Claim 19 (depends on 14) The method of claim 14, further comprising sensing a fluid level in the first and second containers and selecting a fluid delivery direction from the first and second directions based on the sensed fluid level. ### Claim 20 (depends on 19) The method of claim 19, wherein delivering the fluid in the selected direction comprising adjusting the internal pressures of the first and second containers. ### Claim 21 An apparatus for use in fluid jetting, the apparatus comprising: a printhead including a flow path and a nozzle in communication with the flow path, the flow path having a first end and a second end; a first container fluidically coupled to the first end of the flow path, the first container having a first controllable internal pressure; a second container fluidically coupled to the second end of the flow path, the second container having a second controllable internal pressure, the first container and the second container each being a self-contained fluid reservoir; and a controller to control the first internal pressure and the second internal pressure to have a fluid flow between the first container and the second container through the flow path in the printhead, at least a portion of the fluid flowing along the flow path is delivered to the nozzle when the nozzle is jetting, the first internal pressure being higher than the second internal pressure. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the first internal pressure and the second internal pressure are both lower than atmospheric pressure. ### Claim 23 (depends on 21) The apparatus of claim 21, wherein the first container is in a first chamber and the second container is in a second chamber, and the first and second containers are flexible and contain substantially no air. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein each of the first and second chambers is connected to a vacuum source to provide adjustment to the first and second internal pressures. ### Claim 25 (canceled) ### Claim 26 (depends on 21) The apparatus of claim 21, wherein the first container contains the fluid and the second container is empty before use. ### Claim 27 A method for use in fluid jetting, the method comprising: flowing a fluid at a controlled flow rate from a first container through a flow path in a first flow direction, the flow path configured such that a first portion of the fluid flows from the first container to a second container and a second portion of the fluid flows from the first container to a nozzle when the nozzle is ejecting the fluid delivered from the first container; and reversing a direction of flow of the fluid in the flow path such that the fluid flows from the second container through the flow path in a second flow direction opposite the first flow direction, the flow path configured such that a first portion of the fluid flows from the second container to the first container and a second portion of the fluid flows from the second container to a nozzle when the nozzle is ejecting the fluid delivered from the second container.