US 11,772,385 B2
Printing fluid recirculation
David Butinya Teixido, Sant Cugat del Valles (ES); Albert Crespi Serrano, Sant Cugat del Valles (ES); Marta Coma Vives, Sant Cugat del Valles (ES); and Jorge Millan Lafuente, Sant Cugat del Valles (ES)
Assigned to Hewlett-Packard Development Company, L.P., Spring, TX (US)
Appl. No. 17/417,724
Filed by Hewlett-Packard Development Company, L.P., Spring, TX (US)
PCT Filed May 28, 2019, PCT No. PCT/US2019/034096
§ 371(c)(1), (2) Date Jun. 23, 2021,
PCT Pub. No. WO2020/242450, PCT Pub. Date Dec. 3, 2020.
Prior Publication US 2022/0072867 A1, Mar. 10, 2022
Int. Cl. B41J 2/18 (2006.01); B41J 2/17 (2006.01); B41J 2/175 (2006.01)
CPC B41J 2/18 (2013.01) [B41J 2/175 (2013.01); B41J 2/1707 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A printing device comprising:
a printhead comprising a first port connected to a first flow path and a second port connected to a second flow path;
a first fluid pump to selectively create a negative fluid pressure between one of one or more printing fluid supplies and a first one of said first and second ports of said printhead;
a second fluid pump to selectively create a positive fluid pressure between one of said printing fluid supplies and a second one of the first and second ports of the printhead;
first and second regulators having first and second priming pumps and first and second regulator bags associated with the first and second ports of the printhead, wherein the second priming pump is configured to inflate the second regulator bag; and
a controller coupled to the second priming pump, wherein the controller is configured to perform a pulsed priming operation by providing pulsed signals to the second priming pump for a recirculation cycle time period to repeatedly inflate the second regulator bag to keep the second port of the printhead open over a threshold open position such that printing fluid within the printhead exits the printhead through the second port.