Liquid discharge head, liquid discharge device, liquid discharge apparatus, method for manufacturing liquid discharge head

Patent metadata

Field	Value
Publication number	US-12441108-B2
Application number	US-202318116316-A
Country	US
Kind code	B2
Filing date	Mar 2, 2023
Priority date	Mar 17, 2022
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A liquid discharge head includes a nozzle from which a liquid is to be discharged; a pressure chamber communicating with the nozzle; a substrate defining a side wall the pressure chamber; a diaphragm having a surface on the substrate, the diaphragm defining a part of a wall of the pressure chamber and a part of the nozzle; and a piezoelectric element on another surface of the diaphragm opposite to the surface of the diaphragm on the substrate, the piezoelectric element including: a piezoelectric portion configured to vibrate; and a pair of electrodes sandwiching the piezoelectric portion between the pair of electrodes, and an area of at least one of the pair of electrodes of the piezoelectric element is larger than an area of the pressure chamber in a plane of the diaphragm.

First claim

The invention claimed is:

1. A liquid discharge head comprising:
a nozzle from which a liquid is to be discharged;
a pressure chamber communicating with the nozzle;
a substrate defining a side wall the pressure chamber;
a diaphragm having a surface on the substrate, the diaphragm defining a part of a wall of the pressure chamber and a part of the nozzle; and
a piezoelectric element on another surface of the diaphragm opposite to the surface of the diaphragm on the substrate, the piezoelectric element including:
a piezoelectric portion configured to vibrate; and
a pair of electrodes sandwiching the piezoelectric portion between the pair of electrodes, and
an area of at least one of the pair of electrodes of the piezoelectric element is larger than an area of the pressure chamber in a plane of the diaphragm,
wherein:
the pair of electrodes includes:
a first electrode on the diaphragm; and
a second electrode farther than the first electrode from the substrate, and

an area of the second electrode is larger than the area of the pressure chamber in the plane of the diaphragm,
the pressure chamber and the piezoelectric element are circular in the plane of the diaphragm, and
an outer diameter of the second electrode is larger than an inner diameter of the pressure chamber.

2. The liquid discharge head according to claim 1 ,
wherein the second electrode covers the piezoelectric portion.

3. The liquid discharge head according to claim 2 ,
wherein the second electrode covers entirely the first electrode and the piezoelectric portion.

4. The liquid discharge head according to claim 1 ,
wherein an area of the first electrode is larger than the area of the pressure chamber in the plane of the diaphragm.

5. The liquid discharge head according to claim 4 , wherein:
the pressure chamber and the piezoelectric element are circular in the plane of the diaphragm, and
an outer diameter of the first electrode is larger than an inner diameter of the pressure chamber.

6. The liquid discharge head according to claim 1 ,
wherein an area of the piezoelectric portion is smaller than the area of the pressure chamber in the plane of the diaphragm.

7. The liquid discharge head according to claim 1 , wherein:
the pressure chamber and the piezoelectric element are circular in the plane of the diaphragm, and
an outer diameter of the piezoelectric portion is smaller than an inner diameter of the pressure chamber in the plane of the diaphragm.

8. The liquid discharge head according to claim 1 , wherein:
the pressure chamber has a quadrilateral shape in the plane of the diaphragm, and
at least one of the piezoelectric portion, the first electrode, or the second electrode has a quadrilateral shape in the plane of the diaphragm.

9. The liquid discharge head according to claim 1 , further comprising:
a first wire;
a second wire;
a first contact adjacent to an outer end of the first electrode, the first contact electrically connecting the first electrode and the first wire;
a second contact adjacent to an outer end of the second electrode, the second contact electrically connecting the second electrode and the second wire.

10. The liquid discharge head according to claim 9 , wherein:
the first electrode and the second electrode are circular, and
the first wire and the second wire are respectively drawn out at right angles to circumferential directions of the first electrode and the second electrode.

11. The liquid discharge head according to claim 10 , wherein:
the piezoelectric element is circular, and
the first wire and the second wire are disposed at an angle of 180 degrees to each other in a circumferential direction of the piezoelectric element.

12. The liquid discharge head according to claim 10 , further comprising:
a first extension wire extending outside the pressure chamber, the first extension wire connected to the first electrode; and
a second extension wire extending outside the pressure chamber, the second extension wire connected to the second electrode,
wherein:
the first contact is in a first region of the first extension wire outside the pressure chamber, and
the second contact is in a second region of the second extension wire outside the pressure chamber.

13. A liquid discharge device comprising:
the liquid discharge head according to claim 1 ; and
at least one of
a head tank configured to supply the liquid to the liquid discharge head,
a carriage mounting the liquid discharge head,
a supply unit configured to supply the liquid to the head tank,
a maintenance unit configured to maintain the liquid discharge head, or
a main scan moving unit configured to move the carriage in a main scanning direction.

14. A liquid discharge apparatus comprising:
the liquid discharge device according to claim 13 .

15. A liquid discharge apparatus comprising:
the liquid discharge head according to claim 1 .

16. A liquid discharge head, comprising:
a nozzle from which a liquid is to be discharged;
a pressure chamber communicating with the nozzle;
a substrate defining a side wall the pressure chamber;
a diaphragm having a surface on the substrate, the diaphragm defining a part of a wall of the pressure chamber and a part of the nozzle; and
a piezoelectric element on another surface of the diaphragm opposite to the surface of the diaphragm on the substrate, the piezoelectric element including:
a piezoelectric portion configured to vibrate; and
a pair of electrodes sandwiching the piezoelectric portion between the pair of electrodes, and
an area of at least one of the pair of electrodes of the piezoelectric element is larger than an area of the pressure chamber in a plane of the diaphragm,
wherein:
the pair of electrodes includes:
a first electrode on the diaphragm; and
a second electrode farther than the first electrode from the substrate, and

an area of the second electrode is larger than the area of the pressure chamber in the plane of the diaphragm,
the pressure chamber and the piezoelectric element are circular in the plane of the diaphragm, and
an outer diameter of the second electrode is larger than an outer diameter of the piezoelectric portion.

17. A method for manufacturing a liquid discharge head, the method comprising:
forming a diaphragm on a substrate, one surface of the diaphragm is on the substrate;
forming a piezoelectric element on another surface of the diaphragm, the piezoelectric element including a pair of electrodes and a piezoelectric portion between the pair of electrodes;
forming wires to be electrically connected to the piezoelectric element; and
forming a pressure chamber in the substrate while electrically connecting one of the pair of electrodes to a ground,
wherein:
the pair of electrodes includes:
a first electrode on the diaphragm; and
a second electrode farther than the first electrode from the substrate, and
an area of the second electrode is larger than the area of the pressure chamber in the plane of the diaphragm,
the pressure chamber and the piezoelectric element are circular in the plane of the diaphragm, and
an outer diameter of the second electrode is larger than an inner diameter of the pressure chamber.

18. The method for manufacturing a liquid discharge head, according to claim 17 ,
wherein the forming the pressure chamber uses a deep reactive ion etching process to form the pressure chamber in the substrate.

Assignees

• Kitaoka Naoko
• Tanaka Makoto
• Ricoh Co Ltd

Inventors

• Kitaoka Naoko
• Tanaka Makoto

Classifications

• B41J2/1626

  etching · CPC title

• B41J2/161

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• B41J2002/14491

  Electrical connection · CPC title

• B41J2002/1437

  Back shooter · CPC title

• B41J2/14233 Primary

  of film type, deformed by bending and disposed on a diaphragm · CPC title