公开(公告)号：US11230112B2

公开(公告)日：2022-01-25

申请号：US16764283

申请日：2018-01-25

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

Inventor： Matthew J. Janssen ,  James R. Cole

IPC: B41J2/175

Abstract: In some examples, an apparatus includes a pressure sensor, and a controller to determine, based on pressure data from the pressure sensor, an amount of time to depressurize a fluid supply from a first pressure to a second pressure, and determine a level of a fluid in the fluid supply based on the amount of time to depressurize the fluid supply from the first pressure to the second pressure.

公开(公告)号：US20220118772A1

公开(公告)日：2022-04-21

申请号：US17431316

申请日：2019-06-28

Applicant: Hewlett-Packard Development Company, L.P.

Inventor： Matthew J. Janssen ,  James R. Cole

IPC: B41J2/175

Abstract: In one example in accordance with the present disclosure, a method of determining a printing fluid level is described. According to the method, an on-time of a pump is determined. The pump maintains a fixed pressure in a pressurized reservoir. From the on-time, a fluid level in the pressurized reservoir is determined.

公开(公告)号：US11235582B2

公开(公告)日：2022-02-01

申请号：US16650256

申请日：2017-09-25

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

Inventor： Matthew J. Janssen ,  James R. Cole ,  James W. Ring

IPC: B41J2/175

Abstract: A technique includes coupling outlets of a first ink supply and a second ink supply together to provide ink to a printhead of a printer; and pressurizing the first ink supply and the second ink supply with air so that an air pressure of the first ink supply has a different air pressure than an air pressure of the second ink supply. The technique includes monitoring an ink-to-air differential pressure of the first ink supply or the second ink supply; and detecting an ink state for the printer based on the monitored ink-to-air differential pressure.

公开(公告)号：US20210197576A1

公开(公告)日：2021-07-01

申请号：US16650256

申请日：2017-09-25

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

Inventor： Matthew J. Janssen ,  James R. Cole ,  James W. Ring

IPC: B41J2/175

Abstract: A technique includes coupling outlets of a first ink supply and a second ink supply together to provide ink to a printhead of a printer; and pressurizing the first ink supply and the second ink supply with air so that an air pressure of the first ink supply has a different air pressure than an air pressure of the second ink supply. The technique includes monitoring an ink-to-air differential pressure of the first ink supply or the second ink supply; and detecting an ink state for the printer based on the monitored ink-to-air differential pressure.