The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 2026
Filed:
Nov. 14, 2022
Hitachi High-tech Corporation, Tokyo, JP;
Nobuhiro Tsukada, Tokyo, JP;
Daisuke Kanai, Tokyo, JP;
Sho Iwasa, Tokyo, JP;
Yushi Harada, Tokyo, JP;
Yusuke Yota, Tokyo, JP;
HITACHI HIGH-TECH CORPORATION, Tokyo, JP;
Abstract
A liquid delivery pump delivers a liquid with high flow rate accuracy in consideration of solvent expansion, pressure dependent leakage of the solvent, and flow rate dependent leakage of the solvent. A liquid delivery pump includes first and second plunger pumps connected together, having respective first and second plungers. A pressure sensor measures a liquid delivery pressure (P2) from the second plunger pump, and a controller controls the driving of the first and second plungers. The controller obtains a moving speed (v1) of the first plunger and a moving speed (v2) of the second plunger using a parameter (C1, C0) depending on the liquid delivery pressures (P1, P2), the liquid delivery pressure, and a target flow rate of the liquid. The parameter (C1, C0) is a parameter of an expression representing a relationship between the liquid delivery pressure (P2) and a flow rate (Q0) of the liquid.