Liquid jetting apparatus and piezoelectric actuator

Patent metadata

Field	Value
Publication number	US-9238364-B2
Application number	US-201314076331-A
Country	US
Kind code	B2
Filing date	Nov 11, 2013
Priority date	Nov 12, 2012
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

There is provided a liquid jetting apparatus, including: a channel structure in which a liquid channel including a nozzle and a pressure chamber communicating with the nozzle is formed; a piezoelectric element including a piezoelectric body and an electrode; a driving device; and a cover member joined to the surface of the channel structure. A first wiring section connected to the electrode is formed on the surface of the channel structure, and the cover member includes a cover body section and a wiring connection section. A second wiring section is formed in the cover member. The wiring connection section is joined to the surface of the channel structure in a state that the second wiring section is electrically conductive with the first wiring section. A thickness, of the wiring connection section is thinner than a thickness of the cover body section.

First claim

What is claimed is:

1. A liquid jetting apparatus configured to discharge a liquid, comprising:
a channel structure in which a liquid channel, including a nozzle and a pressure chamber communicating with the nozzle, is formed;
a piezoelectric element including:
a piezoelectric body arranged, on a surface of the channel structure, to face the pressure chamber; and
an electrode provided on the piezoelectric body;

a driving device electrically connected to the electrode to drive the piezoelectric element; and
a cover member joined to the surface of the channel structure so that the cover member is stacked on the surface to cover the piezoelectric element;
wherein a first wiring section connected to the electrode is formed on the surface of the channel structure;
wherein the cover member includes:
a cover body section covering the piezoelectric element; and
a wiring connection section extending from the cover body section in a direction parallel to the surface of the channel structure while facing at least a part of the first wiring section;

wherein a second wiring section is formed in the cover member, the second wiring section being connected to the driving device and extending from the cover body section to a surface, of the wiring connection section, facing the first wiring section;
wherein the wiring connection section is joined to the surface of the channel structure in a state that the second wiring section is electrically conductive with the first wiring section;
wherein a thickness, of the wiring connection section, in a direction of stacking of the channel structure and the cover member is thinner than a thickness, of the cover body section, in the direction of stacking of the channel structure and the cover member; and
wherein the cover body section and the wiring connection section comprise electrically insulating material.

2. The liquid jetting apparatus according to claim 1 ;
wherein an anisotropic conductive adhesive joining the wiring connection section and the surface of the channel structure is arranged between the wiring connection section and the surface of the channel structure.

3. The liquid jetting apparatus according to claim 1 ;
wherein a through hole is formed in the cover body section; and
wherein the second wiring section includes:
a first portion which is drawn from the surface, of the wiring connection section, facing the first wiring section through an inner surface of the cover body section; and
a second portion which is drawn up to an outer surface of the cover body section through the through hole formed in the cover body section.

4. The liquid jetting apparatus according to claim 3 ;
wherein the cover body section includes:
a ceiling portion facing the surface of the channel structure with the piezoelectric element intervening therebetween; and
a side wall portion which is coupled to the wiring connection section so that the ceiling portion and the surface of the channel structure are connected to each other;

wherein the through hole is formed in the ceiling portion of the cover body section; and
wherein the driving device is provided on an outer surface of the ceiling portion of the cover body section.

5. The liquid jetting apparatus according to claim 3 ;
wherein the cover body section of the cover member covers the piezoelectric element with a spacing distance intervening therebetween.

6. The liquid jetting apparatus according to claim 1 ;
wherein a concave portion is formed in the cover body section; and
wherein the driving device is provided in the cover body section in a state of being accommodated in the concave portion.

7. The liquid jetting apparatus according to claim 1 ;
wherein a plurality of nozzles and a plurality of pressure chambers are formed in the channel structure, the pressure chambers being communicated with the nozzles respectively and aligned in a predetermined direction parallel to the surface of the channel structure;
wherein a plurality of piezoelectric elements which correspond to the pressure chambers respectively are aligned in the predetermined direction;
wherein the cover body section of the cover member covering the piezoelectric elements, which belong to one piezoelectric element array, commonly; and
wherein a plurality of first wiring sections are electrically conductive with a plurality of second wiring sections in the wiring connection section, the first wiring sections being respectively connected to electrodes of the piezoelectric elements covered with the cover body section, and the second wiring sections being formed in the cover body section.

8. The liquid jetting apparatus according to claim 7 ;
wherein the channel structure includes:
a liquid supply section which is connected to a liquid supply source; and
a common liquid chamber extending from the liquid supply section in the predetermined direction to be communicated with the pressure chambers aligned in the predetermined direction;

wherein the cover body section includes:
a ceiling portion facing the surface of the channel structure with each of the piezoelectric elements intervening therebetween; and
a side wall portion which us coupled to the wiring connection section so that the ceiling portion and the surface of the channel structure are connected to each other;

wherein the driving device is provided in the ceiling portion of the cover body section; and
wherein the side wall portion of the cover body section includes a high heat-resistance portion which is configured to have a heat resistance higher than that of a periphery.

9. The liquid jetting apparatus according to claim 8 ;
wherein the heat resistance of the side wall portion of the cover body section is higher at a position further away from the ink supply section in the predetermined direction.

10. The liquid jetting apparatus according to claim 8 ;
wherein the high-heat resistance portion of the side wall portion has a thickness in the direction of stacking of the channel structure and the cover member which is thinner than that of the periphery.

11. The liquid jetting apparatus according to claim 7 ;
wherein the channel structure includes:
a liquid supply section which is connected to a liquid supply source; and
a common liquid chamber extending from the liquid supply section in the predetermined direction to be communicated with the pressure chambers aligned in the predetermined direction;

wherein the cover body section includes:
a ceiling portion configured to face the surface of the channel structure with each of the piezoelectric elements intervening therebetween; and
a side wall portion which is coupled to the wiring connection section so that the ceiling portion and the surface of the channel structure are connected to each other;

wherein the driving device is provided in the ceiling portion of the cover body section; and
wherein the side wall portion of the cover body section includes a low heat-resistance portion having a heat resistance smaller than that of the side wall portion.

12. The liquid jetting apparatus according to claim 7 ;
wherein the pressure chambers are aligned in two arrays in the predetermined direction and the piezoelectric elements which correspond to the pressure chambers are aligned in two arrays in the predetermined direction;
wherein the first wiring sections are drawn from the electrodes, which respectively correspond to the piezoelectric elements aligned in the two arrays, to inner sides of two piezoelectric element arrays respectively;
wherein the cover member includes two cover body sections covering the two piezoelectric element arrays respectively and the wiring

Assignees

• Kondo Hirofumi
• Brother Ind Ltd

Inventors

• Kondo Hirofumi

Classifications

• B41J2/14201 Primary

  Structure of print heads with piezoelectric elements · CPC title

• B41J2002/14491

  Electrical connection · CPC title

• B41J2/14233 Primary

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• H01L41/0475

  Electricity · mapped topic

• H01L41/0973

  Electricity · mapped topic