Droplet jet head and droplet jet apparatus

A droplet jet head comprising:

• a nozzle substrate having a plurality of nozzle holes that eject droplets;
• a cavity substrate having recesses whose bottoms serve as diaphragms, the recesses serving as ejection chambers for storing the droplets;
• an electrode substrate having separate electrodes opposed to the diaphragms and driving the diaphragms;
• a reservoir substrate having a recess serving as a common droplet chamber for supplying droplets to the ejection chambers, through holes for transferring the droplets from the common droplet chamber to the ejection chambers, and nozzle communicating holes for transferring the droplets from the ejection chambers to the nozzle holes;
• and
• a driver IC that supplies a driving signal to the separate electrodes;
• wherein
• the cavity substrate has a hole;
• and
• the driver IC is housed in the hole.

A droplet jet head comprising:

• a nozzle substrate having a plurality of nozzle holes that eject droplets;
• a cavity substrate having recesses whose bottoms serve as diaphragms, the recesses serving as ejection chambers for storing the droplets;
• an electrode substrate having separate electrodes opposed to the diaphragms and driving the diaphragms;
• and
• a driver IC that supplies a driving signal to the separate electrodes;
• wherein
• the cavity substrate has a hole;
• and
• the driver IC is housed in the hole.