公开(公告)号：US10960658B2

公开(公告)日：2021-03-30

申请号：US16094448

申请日：2016-07-11

Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.

Inventor： Daryl E. Anderson ,  James Michael Gardner ,  Michael W. Cumbie ,  Scott A. Linn ,  Berkeley Fisher

IPC: B41F31/02 ,  B41L27/04 ,  G01F23/24 ,  G01F23/26 ,  B41L39/02 ,  G01F23/22

Abstract: A method of detecting a level of printable fluid in a container includes, with at least one sensing location on a die in thermal contact with the printable fluid in the container, sensing a voltage of a capacitor over time as current from the capacitor leaks through a field effect transistor (FET). The FET and capacitor are associated with the sensing location. The method may further include, based on the voltage of the capacitor over time and a threshold voltage, determining whether the printable fluid is present at the at least one sensing location.

公开(公告)号：US10955299B2

公开(公告)日：2021-03-23

申请号：US16490975

申请日：2017-04-24

Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.

Inventor： Daryl E Anderson ,  James Gardner ,  Berkeley Fisher

IPC: B41J2/165 ,  G01L1/16 ,  B41J2/045

Abstract: A fluid ejection die includes a plurality of nozzles to eject fluid drops and a plurality of strain gauge sensors to sense strain. Each strain gauge sensor corresponds to a nozzle and passes the sensed strain to a controller to determine the health of the nozzle based on the sensed strain.

公开(公告)号：US10933648B2

公开(公告)日：2021-03-02

申请号：US16094101

申请日：2016-04-29

Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.

Inventor： Daryl E. Anderson ,  James Michael Gardner ,  Berkeley Fisher ,  Michael W. Cumbie

IPC: B41J29/38 ,  B41J2/175 ,  G01F23/24

Abstract: An example printing cartridge includes a fluid container, a plurality of sensing locations in thermal contact with the fluid container, a voltage comparator to output time-based information based on a comparison of a sensed voltage generated at a selected sensing location of the plurality of sensing locations to a threshold voltage, the time-based information representative of whether a fluid is present at a fluid level associated with the selected sensing location, and a counter to convert the time-based information to a digital code based on a number of clock cycles.

公开(公告)号：US20190118527A1

公开(公告)日：2019-04-25

申请号：US16094448

申请日：2016-07-11

Applicant: HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P.

Inventor： Daryl E. Anderson ,  James Michael Gardner ,  Michael W. Cumbie ,  Scott A. Linn ,  Berkeley Fisher

IPC: B41F31/02 ,  B41L27/04 ,  B41L39/02 ,  G01F23/24 ,  G01F23/26

Abstract: A method of detecting a level of printable fluid in a container includes, with at least one sensing location on a die in thermal contact with the printable fluid in the container, sensing a voltage of a capacitor over time as current from the capacitor leaks through a field effect transistor (FET). The FET and capacitor are associated with the sensing location. The method may further include, based on the voltage of the capacitor over time and a threshold voltage, determining whether the printable fluid is present at the at least one sensing location.