Liquid ejection head, image forming apparatus and method of manufacturing liquid ejection head

• US 20060209137A1
• Filed: 03/16/2006
• Published: 09/21/2006
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kachi, Yasuhiko, Kojima, Toshiya
• Granted Patent: US 7,815,294 B2
• Time in Patent Office: Days
• US Class Current: 347/68
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2/14282 of cantilever type
• CPC Class Codes: B41J 2002/14459 Matrix arrangement of the pressure chambers
• CPC Class Codes: B41J 2002/14491 Electrical connection
• CPC Class Codes: B41J 2202/11 characterised by specific geometrical characteristics
• CPC Class Codes: B41J 2202/18 Electrical connection established using vias

Abstract

The liquid ejection head comprises: a plurality of ejection ports which eject liquid; a plurality of pressure chambers which are respectively connected to the ejection ports; a plurality of piezoelectric elements which respectively deform the pressure chambers, the piezoelectric elements being arranged on sides of the pressure chambers opposite to sides thereof where the ejection ports are formed; a common liquid chamber which supplies the liquid to the pressure chambers, the common liquid chamber being arranged on the sides of the pressure chambers opposite to the sides thereof where the ejection ports are formed; a plurality of wiring members which have electrodes for driving the piezoelectric elements, respectively, each of the wiring members being formed in such a manner that at least a portion thereof rises through the common liquid chamber in a direction substantially perpendicular to a plane on which the piezoelectric elements are arranged; and a drive circuit which drives the piezoelectric elements, the drive circuit being arranged on a wall of the common liquid chamber opposite to a side thereof where the piezoelectric elements are arranged, wherein the electrodes and the drive circuit are composed and covered integrally with resin.

Claims

1. A liquid ejection head, comprising:

a plurality of ejection ports which eject liquid;

a plurality of pressure chambers which are respectively connected to the ejection ports;

a plurality of piezoelectric elements which respectively deform the pressure chambers, the piezoelectric elements being arranged on sides of the pressure chambers opposite to sides thereof where the ejection ports are formed;

a common liquid chamber which supplies the liquid to the pressure chambers, the common liquid chamber being arranged on the sides of the pressure chambers opposite to the sides thereof where the ejection ports are formed;

a plurality of wiring members which have electrodes for driving the piezoelectric elements, respectively, each of the wiring members being formed in such a manner that at least a portion thereof rises through the common liquid chamber in a direction substantially perpendicular to a plane on which the piezoelectric elements are arranged; and

a drive circuit which drives the piezoelectric elements, the drive circuit being arranged on a wall of the common liquid chamber opposite to a side thereof where the piezoelectric elements are arranged,

wherein the electrodes and the drive circuit are composed and covered integrally with resin.

2. The liquid ejection head as defined in claim 1, wherein the wiring members are formed so as to rise from the piezoelectric elements.

3. The liquid ejection head as defined in claim 1, wherein the wiring members are formed so as to rise from vicinity of the piezoelectric elements.

4. The liquid ejection head as defined in claim 1, wherein:

the ejection ports are arranged in a two-dimensional array; and

the wiring members are arranged two-dimensionally on the plane where the piezoelectric elements are arranged.

5. An image forming apparatus, comprising the liquid ejection head as defined in claim 1.

6. A method of manufacturing a liquid ejection head comprising:

a plurality of ejection ports which eject liquid;

a plurality of pressure chambers which are respectively connected to the ejection ports;

a plurality of piezoelectric elements which respectively deform the pressure chambers, the piezoelectric elements being arranged on sides of the pressure chambers opposite to sides thereof where the ejection ports are formed;

a common liquid chamber which supplies the liquid to the pressure chambers, the common liquid chamber being arranged on the sides of the pressure chambers opposite to the sides thereof where the ejection ports are formed;

a plurality of wiring members which have electrodes for driving the piezoelectric elements, respectively, each of the wiring members being formed in such a manner that at least a portion thereof rises through the common liquid chamber in a direction substantially perpendicular to a plane on which the piezoelectric elements are arranged; and

a drive circuit which drives the piezoelectric elements, the drive circuit being arranged on a wall of the common liquid chamber opposite to a side thereof where the piezoelectric elements are arranged, the method comprising the steps of;

forming a plurality of projecting conducting members corresponding to the electrodes, on a metal layer corresponding to a portion of the wall of the common liquid chamber opposite to the side thereof where the piezoelectric elements are arranged;

performing a first resin molding of molding resin over a surface of the metal layer on the side where the conducting members are formed, thereby covering side faces of the conducting members with the resin;

electrically separating the conducting members from each other by processing the metal layer;

installing the drive circuit at a prescribed position of the metal layer;

electrically connecting the drive circuit to the conducting members having been electrically separated from each other; and

performing a second resin molding of molding resin over a surface of the metal layer reverse to the surface thereof on which the conducting members are formed, thereby covering the surface of the metal layer and a surface of the drive circuit with the resin.

7. A method of manufacturing a liquid ejection head comprising:

a plurality of ejection ports which eject liquid;

a plurality of pressure chambers which are respectively connected to the ejection ports;

a plurality of piezoelectric elements which respectively deform the pressure chambers, the piezoelectric elements being arranged on sides of the pressure chambers opposite to sides thereof where the ejection ports are formed;

a common liquid chamber which supplies the liquid to the pressure chambers, the common liquid chamber being arranged on the sides of the pressure chambers opposite to the sides thereof where the ejection ports are formed;

a plurality of wiring members which have electrodes for driving the piezoelectric elements, respectively, each of the wiring members being formed in such a manner that at least a portion thereof rises through the common liquid chamber in a direction substantially perpendicular to a plane on which the piezoelectric elements are arranged; and

a drive circuit which drives the piezoelectric elements, the drive circuit being arranged on a wall of the common liquid chamber opposite to a side thereof where the piezoelectric elements are arranged, the method comprising the steps of;

installing the drive circuit at a prescribed position on a metal layer corresponding to a portion of the wall of the common liquid chamber opposite to the side thereof where the piezoelectric elements are arranged, the metal layer being formed with a prescribed wiring pattern;

forming a plurality of projecting conducting members corresponding to the electrodes, on the metal layer; and

molding resin over both surfaces of the metal layer, thereby covering the surfaces of the metal layer, a surface of the drive circuit and side faces of the conducting members, with the resin.