LIQUID JETTING APPARATUS AND PIEZOELECTRIC ACTUATOR

• US 20140132677A1
• Filed: 11/11/2013
• Published: 05/15/2014
• Est. Priority Date: 11/12/2012
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: KONDO, Hirofumi
• Granted Patent: US 9,238,364 B2
• Time in Patent Office: Days
• US Class Current: 347/81
• CPC Class Codes: B41J 2/14201 Structure of print heads with piezoelectric elements
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2002/14491 Electrical connection
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/875 Further connection or lead arrangements, e.g. flexible wiring boards, terminal pins

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.

Claims

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 and an electrode, the piezoelectric body being arranged, on a surface of the channel structure, to face the pressure chamber, and the electrode being 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;

the cover member includes a cover body section covering the piezoelectric element and a wiring connection section extending from the cover body section along the surface of the channel structure while facing at least a part of the first wiring section;

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;

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; and

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.

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 the second wiring section includes a first portion and a second portion, the first portion being drawn from the surface, of the wiring connection section, facing the first wiring section through an inner surface of the cover body section, and the second portion being 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 and a side wall portion, the ceiling portion facing the surface of the channel structure with the piezoelectric element intervening therebetween, and the side wall portion being coupled to the wiring connection section so that the ceiling portion and the surface of the channel structure are connected to each other;

the through hole is formed in the ceiling portion of the cover body section; and

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

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;

a plurality of piezoelectric elements which correspond to the pressure chambers respectively are aligned in the predetermined direction;

the cover body section of the cover member covering the piezoelectric elements, which belong to one piezoelectric element array, commonly; and

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;

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

the driving device is provided in the ceiling portion of the cover body section; and

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;

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

the driving device is provided in the ceiling portion of the cover body section; and

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;

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;

the cover member includes two cover body sections covering the two piezoelectric element arrays respectively and the wiring connection section which is arranged to connect the two cover body sections; and

the first wiring sections, which are drawn from the two piezoelectric element arrays, are electrically conductive with the second wiring sections, which are formed in the two cover body sections, in the wiring connection section.

13. The liquid jetting apparatus according to claim 7, wherein the wiring connection section of the cover member is arranged on one side of the cover body section in a direction perpendicular to the predetermined direction in which the piezoelectric element array is aligned and is not arranged on the other side of the cover body section.

14. A piezoelectric actuator, comprising:

a piezoelectric element including a piezoelectric body which is arranged on a surface of a base material and an electrode which is provided in the piezoelectric body;

a driving device electrically connected to the electrode to drive the piezoelectric element;

a cover member joined to the surface of the base member 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 base member;

the cover member includes a cover body section covering the piezoelectric element and a wiring connection section extending from the cover body section along the surface of the base material while facing at least a part of the first wiring section;

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;

the wiring connection section is joined to the surface of the base material in a state that the second wiring section is electrically conductive with the first wiring section; and

a thickness, of the wiring connection section, in a direction of stacking of the base material and the cover member is thinner than a thickness, of the cover body section, in the direction of stacking of the base material and the cover member.