Liquid ejection head and liquid ejection apparatus

A liquid ejection apparatus comprising a liquid ejection head comprising:

• at least one head chip including a plurality of heating elements on a first surface of a substrate;
• a nozzle layer having nozzles correspondingly disposed above respective heating elements and in a facing relation with said heating elements;
• a barrier layer selectively disposed between the head chip and the nozzle layer;
• a plurality of individual ink ejection reservoirs, each disposed between a heating element and a respective nozzle, the reservoirs being defined, at least in part, by the barrier layer;
• a common flow path communicating with the reservoirs and supplying liquid to the reservoirs, the common flow path extending in a depth direction of the head chip beyond the plane of the individual reservoirs and at least along one longitudinal end of the substrate;
• and
• a liquid storage chamber disposed on at least one region of the first surface of the substrate excluding a region on which the reservoirs are disposed, the liquid storage chamber being defined, at least in part, by the barrier layer, the liquid storage chamber communicating with the reservoirs at least indirectly via the common flow path, the liquid storage chamber storing liquid such that part of the nozzle layer is in contact with the liquid, wherein healing energy is applied to the heating elements to generate bubbles in the liquid contained in the reservoirs, and the generated bubbles expel liquid in the reservoirs through the nozzles.

A method of forming an image on a printing medium via ink ejection comprising the steps of:

• providing at least one head chip including a plurality of heating elements on a first surface of a substrate;
• providing a nozzle layer having nozzles correspondingly disposed above respective heating elements and in a facing relation with said heating elements;
• forming a barrier layer selectively disposed between the head chip and the nozzle layer;
• forming a plurality of individual ink ejection reservoirs, each disposed between a heating element and a respective nozzle, the reservoirs being defined, at least in part, by the barrier layer;
• providing a common flow path communicating with the reservoirs and supplying liquid to the reservoirs, the common flow path extending in a depth direction of the head chip beyond the plane of the individual reservoirs and at least along one longitudinal end of the substrate;
• providing a liquid storage chamber disposed on at least one region of the first surface of the substrate excluding a region on which the reservoirs are disposed, the liquid storage chamber being defined, at least in part, by the barrier layer, the liquid storage chamber communicating with the reservoirs at least indirectly via the common flow path, the liquid storage chamber storing liquid such that part of the nozzle layer is in contact with the liquid, and
• driving said liquid ejection head to ejection ink by applying a driving energy to the heating elements to generate bubbles in the liquid contained in the reservoirs, and the generated bubbles expel liquid in the reservoirs through the nozzles.