US 11,691,431 B2
Fluid circulation and ejection
Si-lam Choy, Corvallis, OR (US); Michael W. Cumbie, Corvallis, OR (US); and Chien-Hua Chen, Corvallis, OR (US)
Assigned to Hewlett-Packard Development Company, L.P., Spring, TX (US)
Filed by Hewlett-Packard Development Company, L.P., Spring, TX (US)
Filed on Mar. 18, 2022, as Appl. No. 17/699,050.
Application 17/699,050 is a continuation of application No. 16/761,273, granted, now 11,292,265, previously published as PCT/US2017/064380, filed on Dec. 2, 2017.
Prior Publication US 2022/0203696 A1, Jun. 30, 2022
Int. Cl. B41J 2/18 (2006.01); B41J 2/14 (2006.01)
CPC B41J 2/18 (2013.01) [B41J 2/14145 (2013.01); B41J 2202/12 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method comprising:
supplying fluid under pressure, via a fluid supply passage and a fluid supply channel extending from the fluid supply passage, to a single orifice fluid ejector on a microfluidic die with a pressurized fluid source remote from the microfluidic die, the single orifice fluid ejector having a thermal fluid actuator, a drive chamber, and a fluid discharge channel connecting the drive chamber to a fluid discharge passage in the microfluidic die;
maintaining a pressure gradient across a drive chamber of the single orifice fluid ejector to circulate fluid through the drive chamber, inhibit particle settling within the drive chamber, and transfer heat out of and away from the thermal fluid actuator and drive chamber; and
directing fluid along a bypass channel directly connecting the fluid supply passage to the fluid discharge passage, the bypass channel extending across a back side of the fluid ejector to carry excess heat away from the fluid ejector, the bypass channel comprising a gap between a substrate of the microfluidic die and an interposer layer, wherein the interposer layer includes the fluid supply channel and the fluid discharge channel.