Liquid discharge head and liquid discharge apparatus

A liquid discharge apparatus, comprising:

• a liquid tank in which liquid is stored;
• a liquid discharge head including:
• a pressure chamber in which the liquid supplied from the liquid tank is stored,
• a diaphragm forming a bottom wall of the pressure chamber, the diaphragm having a nozzle opening through which the liquid supplied from the pressure chamber is discharged in a first direction,
• a drive element on a lower surface of the diaphragm in the first direction and configured to deform the diaphragm to change a volume of the pressure chamber,
• a protective film covering a lower surface of the drive element and the diaphragm in the first direction, the protective film having a first opening corresponding in position with the nozzle opening, and
• a liquid repellent film covering a lower surface of the protective film in the first direction, a sidewall of the first opening, and the lower surface of the diaphragm within the first opening, the liquid repellant film having a second opening aligned with the nozzle opening and having the same diameter as the nozzle opening, wherein
• a first thickness of the liquid repellent film on the lower surface of the protective film covering the drive element is thinner than a second thickness of the liquid repellent film on the lower surface of the diaphragm within the first opening;
• and
• a control circuit configured to apply a voltage to the drive element to change the volume of the pressure chamber.