Liquid ejection head and image forming apparatus including the liquid ejection head

A liquid ejection head comprising:

• a channel plate including a separate liquid chamber communicating with a nozzle to eject droplets of liquid, a fluid resistance portion communicating with the separate liquid chamber, and a liquid introducing portion communicating with the fluid resistance portion to introduce the liquid from a common liquid chamber;
• a diaphragm member having a thin layer and a thick layer, the thin layer forming a wall face of each of the separate liquid chamber, the fluid resistance portion, and the liquid introducing portion, the thin layer including a vibration area facing the separate liquid chamber;
• and
• a piezoelectric member arranged to deform the vibration area facing the separate liquid chamber, the piezoelectric member having a portion opposing the liquid introducing portion at one end in a longitudinal direction of the separate liquid chamber perpendicular to a lateral direction of the separate liquid chamber,
• wherein the thin layer of the diaphragm member has a thin portion forming the wall face of the liquid introducing portion,
• the thick layer of the diaphragm member has a first thick portion formed along the longitudinal direction of the separate liquid chamber on a first face of the thin layer opposite a second face of the thin layer opposing the liquid introducing portion, and
• in a plan view, the thin portion forming the wall face of the liquid introducing portion is divided by the first thick portion formed along the longitudinal direction of the separate liquid chamber.