Liquid surface sensor and liquid surface detection method
AssigneeSeiko Epson Corporation
InventorChikara KOJIMA
Life of this patent
Estimating the term…
Abstract
A liquid surface sensor includes a hollow member having a first opening end and a second opening end, and a sensor unit provided so as to close the first opening end of the hollow member. The sensor unit includes a vibration plate, and a piezoelectric element which is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in a thickness direction of the vibration plate.
Claims8
A liquid surface sensor comprising:
- a hollow member that has a first opening end and a second opening end;
- and
- a sensor unit that is provided so as to close the first opening end of the hollow member,
- wherein the sensor unit includes a vibration plate, and a piezoelectric element that is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in order in a thickness direction of the vibration plate.
A liquid surface detection method of detecting a position of a liquid surface using a liquid surface sensor that includes a hollow member having a first opening end and a second opening end, and a sensor unit that is provided so as to close the first opening end of the hollow member, the sensor unit including a vibration plate, and a piezoelectric element which is provided on the vibration plate and is formed by laminating a first electrode film, a piezoelectric film, and a second electrode film in order in a thickness direction of the vibration plate, the method comprising:
- causing the liquid surface sensor to be disposed such that the second opening end of the hollow member is inserted into a liquid and the liquid surface is positioned in a predetermined position within the hollow member;
- and
- causing the liquid surface sensor to detect the position of the liquid surface based on a resonant frequency when the vibration plate vibrates in the resonant frequency corresponding to a distance between the liquid surface and the sensor unit.
Dependencies are inferred from the claim text.