US 12,441,108 B2
Liquid discharge head, liquid discharge device, liquid discharge apparatus, method for manufacturing liquid discharge head
Naoko Kitaoka, Kanagawa (JP); and Makoto Tanaka, Tokyo (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by Naoko Kitaoka, Kanagawa (JP); and Makoto Tanaka, Tokyo (JP)
Filed on Mar. 2, 2023, as Appl. No. 18/116,316.
Claims priority of application No. 2022-043180 (JP), filed on Mar. 17, 2022; and application No. 2022-192148 (JP), filed on Nov. 30, 2022.
Prior Publication US 2023/0294402 A1, Sep. 21, 2023
Int. Cl. B41J 2/14 (2006.01); B41J 2/16 (2006.01)
CPC B41J 2/14233 (2013.01) [B41J 2/161 (2013.01); B41J 2/1626 (2013.01)] 18 Claims
OG exemplary drawing
 
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.