PRESSURE MEASUREMENT DEVICE AND LIQUID TREATMENT DEVICE

• US 20140102206A1
• Filed: 10/15/2013
• Published: 04/17/2014
• Est. Priority Date: 10/16/2012
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: OSHIMA, Atsushi
• Application Number:
  US14/053,834
• Publication Number:
  US 20140102206A1
• Time in Patent Office: Days
• US Class Current: 73/715
• CPC Class Codes: G01L 7/08 of the flexible-diaphragm type
• CPC Class Codes: G01L 9/008 using piezoelectric devices piezoelectric resonators G01L9/0022; surface acoustic waves G01L9/0025

Abstract

A pressure measurement device adapted to measure a pressure of a liquid includes a flow channel having a flow channel resistance, a liquid containing chamber having a predetermined capacity and communicating with the flow channel, a pressure changing section adapted to change a pressure of the liquid containing chamber, a measurement section adapted to measure a period from when a pressure wave of the liquid in the liquid containing chamber becomes a predetermined value to next time the pressure wave becomes the predetermined value, the pressure wave occurring when the pressure changing section is in operation in a state in which the liquid is contained in the flow channel and the liquid containing chamber, and an acquisition section adapted to obtain the pressure based on the period measured by the measurement section.

Claims

1. A pressure measurement device adapted to measure a pressure of a liquid, comprising:

a flow channel having a flow channel resistance;

a liquid containing chamber having a predetermined capacity and communicating with the flow channel;

a pressure changing section adapted to change a pressure of the liquid containing chamber;

a measurement section adapted to measure a period from when a pressure wave of the liquid in the liquid containing chamber becomes a predetermined value to next time the pressure wave becomes the predetermined value, the pressure wave occurring when the pressure changing section is in operation in a state in which the liquid is contained in the flow channel and the liquid containing chamber; and

an acquisition section adapted to obtain the pressure of the liquid based on the period measured by the measurement section.

2. The pressure measurement device according to claim 1, wherein

the pressure changing section includes a piezoelectric element, and changes the pressure of the liquid containing chamber due to a force caused by a distortion of the piezoelectric element.

3. The pressure measurement device according to claim 2, wherein

the piezoelectric element is further distorted due to a pressure variation of the liquid containing chamber, and

the measurement section measures the period based on the distortion of the piezoelectric element.

4. The pressure measurement device according to claim 2, wherein

the measurement section drives the piezoelectric element, detects a current flowing through the piezoelectric element, and measures the period based on the current flowing through the piezoelectric element.

5. The pressure measurement device according to claim 4, wherein

the measurement section stops detecting the current flowing through the piezoelectric element while driving the piezoelectric element, and then detects the current flowing through the piezoelectric element after stopping driving the piezoelectric element.

6. The pressure measurement device according to claim 5, wherein

the measurement section includes

a resistor circuit adapted to measure the current flowing through the piezoelectric element, and

a switch circuit adapted to control whether or not the current flowing through the piezoelectric element is made to flow through the resistor circuit.

7. The pressure measurement device according to claim 1, wherein

the liquid is contained in a container,

the liquid containing chamber communicates with one end of the flow channel, and

the other end of the flow channel is connected to the container.

8. The pressure measurement device according to claim 7, wherein

the other end of the flow channel is detachably connected to the container.

17. A liquid treatment device comprising

the pressure measurement device according to claim 1.

9. A pressure measurement device adapted to measure a pressure of a liquid, comprising:

a flow channel having a flow channel resistance;

a liquid containing chamber having a predetermined capacity and communicating with the flow channel;

a pressure changing section adapted to change a pressure of the liquid containing chamber;

a measurement section adapted to measure a period from when a pressure wave of the liquid in the liquid containing chamber becomes a first peak to next time the pressure wave becomes a second peak with a same polarity as the first peak, the pressure wave occurring when the pressure changing section is in operation in a state in which the liquid is contained in the flow channel and the liquid containing chamber; and

an acquisition section adapted to obtain the pressure of the liquid based on the period measured by the measurement section.

10. The pressure measurement device according to claim 9, wherein

the pressure changing section includes a piezoelectric element, and changes the pressure of the liquid containing chamber due to a force caused by a distortion of the piezoelectric element.

11. The pressure measurement device according to claim 10, wherein

the piezoelectric element is further distorted due to a pressure variation of the liquid containing chamber, and

the measurement section measures the period based on the distortion of the piezoelectric element.

12. The pressure measurement device according to claim 10, wherein

the measurement section drives the piezoelectric element, detects a current flowing through the piezoelectric element, and measures the period based on the current flowing through the piezoelectric element.

13. The pressure measurement device according to claim 12, wherein

the measurement section stops detecting the current flowing through the piezoelectric element while driving the piezoelectric element, and then detects the current flowing through the piezoelectric element after stopping driving the piezoelectric element.

14. The pressure measurement device according to claim 13, wherein

the measurement section includes

a resistor circuit adapted to measure the current flowing through the piezoelectric element, and

a switch circuit adapted to control whether or not the current flowing through the piezoelectric element is made to flow through the resistor circuit.

15. The pressure measurement device according to claim 9, wherein

the liquid is contained in a container,

the liquid containing chamber communicates with one end of the flow channel, and

the other end of the flow channel is connected to the container.

16. The pressure measurement device according to claim 15, wherein

the other end of the flow channel is detachably connected to the container.