US 12,325,237 B2
Liquid discharge head and liquid discharge apparatus
Chikako Hatta, Kanagawa (JP); Shinichiroh Osanai, Kanagawa (JP); and Kohta Akiyama, Kanagawa (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by Chikako Hatta, Kanagawa (JP); Shinichiroh Osanai, Kanagawa (JP); and Kohta Akiyama, Kanagawa (JP)
Filed on Jun. 5, 2023, as Appl. No. 18/205,572.
Claims priority of application No. 2022-094326 (JP), filed on Jun. 10, 2022.
Prior Publication US 2023/0398780 A1, Dec. 14, 2023
Int. Cl. B41J 2/14 (2006.01)
CPC B41J 2/1433 (2013.01) 9 Claims
OG exemplary drawing
 
1. A liquid discharge head comprising:
a nozzle plate having multiple nozzle holes from which a liquid is to be discharged in a liquid discharge direction, the multiple nozzle holes arrayed in a nozzle array direction orthogonal to the liquid discharge direction; and
a pressure chamber communicating with the multiple nozzle holes,
wherein a volume Vmin of a virtual hemisphere S1 is 5×105 μm3 or more and 5×106 μm; or less, and
a volume Vmax of a virtual hemisphere S2 is five times or more and less than 1000 times the volume Vmin,
each of the multiple nozzle holes has a virtual center line,
the nozzle plate has an inner surface defining a wall of the pressure chamber, the inner surface having multiple openings of each of the multiple nozzle holes,
a spherical center is at an intersection between the virtual center line and an extension surface extended from the inner surface over the multiple openings,
the pressure chamber has surfaces:
in both directions in the nozzle array direction from the spherical center;
in a direction opposite to the liquid discharge direction from the spherical center; and
in both directions orthogonal to the nozzle array direction and orthogonal to the liquid discharge direction from the spherical center, and
the virtual hemisphere S1 has a radius rmin centered in the spherical center, the radius rmin having the shortest length from the spherical center to any one of the surfaces of the pressure chamber, and
the virtual hemisphere S2 has a radius rmax centered in the spherical center, the radius rmax having the longest length from the spherical center to any one of the surfaces of the pressure chamber.