Liquid discharge head and liquid discharge apparatus

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.