INKJET PRINTING HEAD AND METHOD OF MANUFACTURING THE SAME

Abstract

Disclosed is an inkjet printing head which ejects ink in response to generation a bubble in the ink accompanying the action of heat from a heater, and which preferably allows ejection energy to be effectively used, and desired attachment accuracy of a movable valve to be secured and maintained. To this end, employed is a two-body structure formed of a substrate including the heater; and a valve retaining member having the movable valve. Then, the effective use of ejection energy is achieved by appropriately selecting the shape and dimensions of the movable valve. Furthermore, the desired attachment accuracy is secured and maintained by attaching the valve retaining member to the substrate by applying a photolithography process without using an adhesive agent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view schematically showing an internal structure of a printing apparatus provided with a printing head according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of the printing head according to the embodiment of the present invention;

FIG. 3 is a cutaway perspective view showing the vicinity of nozzles of an ejection element, which is a constituent element of the printing head according to the embodiment of the present invention;

FIGS. 4A and 4B, and FIGS. 5A through 13 are schematic diagrams for explaining a manufacturing process of the ejection element shown in FIG. 3;

FIG. 14A is a top view showing the printing head according to the embodiment in a state where a top plate is removed therefrom, FIG. 14B is a cross sectional view of the printing head taken along the line XIVB-XIVB of FIG. 14A, and FIG. 14C is an enlarged view of the portion XIVC of FIG. 14B;

FIG. 15A is a top view showing a printing head according to a comparative example in a state where a top plate is removed therefrom, FIG. 15B is a cross sectional view of the printing head taken along the line XVB-XVB of FIG. 15A, and FIG. 15C is an enlarged view of the portion XVC of FIG. 15B, and

FIG. 16 is a top view showing a printing head according to another embodiment in a state where a top plate is removed therefrom.

Claims

1. An inkjet printing head comprising: a substrate including a heater for causing thermal energy used for ejecting ink from a nozzle to act on the ink; anda valve retaining member including a movable valve which is provided corresponding to the nozzle, and which is capable of changing its position in response to generation a bubble in the ink accompanying the action of the thermal energy caused by the heater, whereinthe substrate includes a seat to which the valve retaining member is attached,the valve retaining member includes a hole penetrating from a bottom surface attached to the seat, and to a top surface opposite the bottom surface, andthe valve retaining member is fixed to the substrate by an adhesion portion formed by attaching a material having a thermal expansion coefficient equal to that of the seat so that the material is joined to the seat by passing through the hole from the top surface.

2. An inkjet printing head as claimed in claim 1, wherein the adhesion portion is formed by using a photolithography process.

3. An inkjet printing head as claimed in claim 1, wherein the seat and the adhesion portion are made of the same material.

4. An inkjet printing head as claimed in claim 1, further comprising: a plurality of the nozzles arranged therein; anda liquid chamber for supplying ink with which the plurality of nozzles commonly communicate, whereinthe valve retaining member is attached to the seat while facing the liquid chamber, anda dimension of the adhesion portion in an arrangement direction of the nozzles at the top surface of the valve retaining member is smaller than a dimension in a direction perpendicular to the arrangement direction.

5. An inkjet printing head as claimed in claim 1, wherein a plurality of the holes are provided so as to be distributed on the valve retaining member, andthe adhesion portion is formed by use of some of the plurality of holes.

6. A method of manufacturing an inkjet printing head including: a substrate having a heater for causing thermal energy used for ejecting ink from a nozzle to act on the ink; and a valve retaining member having a movable valve which is provided corresponding to the nozzle, and which is capable of changing its position in response to generation a bubble in the ink accompanying the action of the thermal energy caused by the heater, the method comprising the steps of: arranging the valve retaining member having a through hole on a seat being provided on the substrate; andfixing the valve retaining member to the substrate by applying a photolithography process, by forming an adhesion portion which passes through the hole from a top surface of the valve retaining member and is joined to the seat.

7. A method as claimed in claim 6, wherein the seat and the adhesion portion are formed by laminating and patterning a photosensitive resin film.