Liquid discharge head substrate, liquid discharge head and liquid discharge apparatus

A liquid discharge head comprising a liquid device, the liquid discharge device comprising:

• a discharging element configured to discharge a liquid;
• a driver configured to drive the discharging element;
• a conductive protection film covering the discharging element via an insulating film;
• and
• a controller connected to the protection film and configured to output a control signal that sets the driver in an inactive state when a change of a voltage of the protection film or a change in a current that flows to the protection film is detected.

A liquid discharge apparatus comprising a liquid discharge head and a controller, the liquid discharge head substrate comprises:

• a discharging element configured to discharge a liquid;
• a driver configured to drive the discharging element;
• and
• a conductive protection film covering the discharging element via an insulating film, wherein the controller is connected to the protection film and configured to output a control signal that sets the driver in an inactive state when a change of a voltage of the protection film or a change in a current that flows to the protection film is detected.

A liquid discharge device, comprising;

• a logic circuit;
• and
• a plurality of units, said plurality of units including (i) a discharging element configured to discharge a liquid, (ii) a driver configured to drive the discharging element, and (iii) a conductive protection film covering the discharging element via an insulating film, wherein
• a plurality of conductive protection films corresponding to the plurality of units are separated from each other between the plurality of units, and
• the logic circuit has an input node electrically connected to the conductive protection film and an output node electrically connected to the driver.

A liquid discharge apparatus, comprising:

• a logic circuit;
• and
• a liquid discharge head including a plurality of units, each of which includes (i) a discharging element configured to discharge a liquid, (ii) a driver configured to drive the discharging element, and (iii) a conductive protection film covering the discharging element via an insulating film, wherein
• a plurality of conductive protection films corresponding to the plurality of units are separated from each other between the plurality of units, and
• the logic circuit has an input node electrically connected to the conductive protection film and an output node electrically connected to the driver.