JPH10138470A - Ink jet print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for coating the lower surface of a cover member with an electrode part, and the need for bonding the cover member with a piezoelectric through a conductive adhesive. SOLUTION: The ink jet printing head comprises a piezoelectric unit having grooves and walls formed by bonding first and second piezoelectrics 11, 12 through a conductive adhesive 10 and an electrode part, a cover member 33 being bonded to the second piezoelectric 12 of the piezoelectric unit to form a head unit, a nozzle plate 18 bonded to one end part of the head unit, and a common electrode member bonded to the other end part of the head unit through the conductive adhesive 10 and electrically interconnecting electrode parts 15 applied to the surface of each wall on the side of the cover member 33 of the second piezoelectric 12. Since the electrode parts 15 are interconnected, the cover member 33 is not required to be formed with an electrode part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet print head used in an ink jet printer.

[0002]

2. Description of the Related Art Conventionally, an ink jet print head used for an ink jet printer has been provided using a piezoelectric material. In this case, ink is ejected from a nozzle hole by a pressing force generated when the piezoelectric body is deformed, and a dot is formed by attaching an ink droplet to a medium.

In this type of ink jet print head, a plurality of grooves are formed in a piezoelectric body by groove processing, and a plurality of ink pressure chambers are formed by bonding a cover member and a nozzle plate to the piezoelectric body. It has become. 2 is a longitudinal sectional view of a conventional inkjet print head, FIG. 3 is a transverse sectional view of a conventional inkjet print head, FIG. 4 is a perspective view of a conventional cover member, and FIG. 5 is a perspective view of a conventional piezoelectric unit. 6 is a perspective view of a conventional head unit.

As shown in FIG. 1, an upper surface of a piezoelectric body 11a is covered with an electrode portion 14 made of a conductive material, so that a first piezoelectric body 11 serving as a base is
a, electrode portions 15 and 1 made of a conductive material
6 is covered with the second piezoelectric body 12 in the form of a thin plate.
Are formed, and as shown in FIG. 5, the first piezoelectric body 11 and the second piezoelectric body 12 are adhered by the conductive adhesive material 10 to form the piezoelectric body unit 61.

In order to form a plurality of ink pressurizing chambers 20, grooves are formed in the piezoelectric body unit 61 with a dicing saw or the like, so that a plurality of grooves 25 are formed and each of the grooves 25 is formed. A wall 27 is formed between 25. On the other hand, as shown in FIG. 4, the cover member 13 is formed by covering the lower surface of the cover member body 13a with an electrode portion 17 made of a conductive material. As shown in FIG. Second piezoelectric body 1 of body unit 61
2 are bonded by the conductive adhesive 10 to form the head unit 62. The electrode section 17 is formed by gold evaporation or the like. Further, the cover member 13 is
The first and second piezoelectric members 11 and 12 are formed of the same material as the first and second piezoelectric members 12 and 12 because the wall 27 is liable to undergo slip deformation as described later.

At one end of the head unit 62, a nozzle plate 18 having a plurality of ink discharge nozzle holes 19 corresponding to each groove 25 is adhered by a non-conductive adhesive material 23, The other end of the head unit 62 has a common ink chamber 2 for storing the ink 22.
1 are adhered by a non-conductive adhesive 23 to form an ink jet print head. At this time, the groove 25 is closed to form the ink pressurizing chamber 20. The common ink chamber 21 is made of a non-conductive synthetic resin or the like,
It is connected via an ink conduit 24 to an ink tank (not shown) or the like.

Next, the operation of the ink jet print head having the above configuration will be described. FIG. 7 is a first diagram showing the operation of the conventional inkjet print head, and FIG. 8 is a second diagram showing the operation of the conventional inkjet print head. In the figure, reference numerals 27a and 27b denote walls formed adjacent to each other, and the walls 27a and 27b are
a, the electrode part 14, the conductive adhesive 10, the electrode part 16, the piezoelectric body 12a, the electrode part 15, and the conductive adhesive 10 are sequentially laminated.

The electrode portion 15 coated on the upper surface of the piezoelectric body 12a is electrically connected to the electrode portion 17 via the conductive adhesive material 10, and further includes an electric conductor (not shown) and a conductive adhesive material. And the like to ground or midpoint potential. On the other hand, the electrode portion 14 that is coated on the upper surface of the piezoelectric body 11a is provided on the other end of the head unit 62 (FIG. 6) by a flexible cable, wire bonding, or the like (not shown) in a printer body (not shown). Connected to the control unit.

By the way, each of the piezoelectric bodies 11a, 12a
In a, a polarization process (poling) is performed in the width direction of the ink pressurizing chamber 20, and an electric field is applied in a direction perpendicular to the polarization direction, so that the walls 27a and 27b undergo sliding deformation. Thus, by applying a positive voltage + V to the electrode portion 14 on the wall 27a side and applying a negative voltage -V to the electrode portion 14 on the wall 27b side, respectively,
7b, an electric field as shown by an arrow in FIG. 7 is generated to deform the walls 27a and 27b in a direction in which the ink pressurizing chamber 20 expands. As a result, the ink 12 is supplied from the common ink chamber 21 (FIG. 3) to the ink pressurizing chamber 20.

Next, a voltage -V of a negative polarity is applied to the electrode portion 14 on the side of the wall 27a, and a voltage + V of a positive polarity is applied to the electrode portion 14 on the side of the wall 27b.
An electric field as shown by the arrow in FIG. 8 is generated in 7b to deform each of the walls 27a and 27b in a direction in which the ink pressurizing chamber 20 contracts. As a result, the ink 22 in the ink pressurizing chamber 20 is pressurized and discharged from the nozzle holes 19 of the nozzle plate 18 (FIG. 2).

When the application of the voltages + V and -V is completed and the electric field disappears, the walls 27a and 27b return to their original shapes, and the ejected ink 22 is supplied to the ink pressurizing chamber 2.
The ink droplets fly away from 0 as ink droplets and adhere to a medium (not shown) to form dots. In addition, 13a is a cover member main body. The voltages + V and -V are applied based on print data by a three-way switch or the like provided in the control unit.

[0012]

However, in the conventional ink jet print head, in order to connect the electrode portion 15 to the ground or the midpoint potential, the lower surface of the cover member 13 is subjected to gold deposition or the like. It is not only necessary to cover the part 17 but also the cover member 13
And the second piezoelectric body 12 need to be bonded by the conductive adhesive 10, which increases the cost.

The present invention solves the above-mentioned problems of the conventional ink jet print head and eliminates the need to cover the lower surface of the cover member with the electrode portion, and to bond the cover member and the piezoelectric body with a conductive adhesive. It is an object of the present invention to provide an ink jet print head which does not have any problems and can reduce the cost.

[0014]

For this purpose, in the ink jet print head according to the present invention, the first piezoelectric body and the second piezoelectric body are formed by bonding the first piezoelectric body and the second piezoelectric body via an electrode portion with a conductive adhesive. A piezoelectric body having a plurality of grooves, and a wall formed between the grooves, a cover member bonded to a second piezoelectric body of the piezoelectric body to form a head unit, A nozzle plate that is bonded to one end and has a nozzle hole formed corresponding to each of the grooves; and a conductive adhesive material that is bonded to the other end of the head unit using a second adhesive. And a common electrode member for electrically connecting the electrode portions coated on the surface of the piezoelectric body on the cover member side to each other.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of an ink jet print head according to the first embodiment of the present invention, and FIG. 9 is a cross sectional view of the ink jet print head according to the first embodiment of the present invention. Since the operation of the ink jet print head is the same as that of the conventional one, the description will be omitted with reference to FIGS.

In FIG. 1, reference numeral 11 denotes a first piezoelectric member serving as a base, 12 denotes a second piezoelectric member having a thin plate shape, and 33 denotes a cover member. The first piezoelectric body 11 is formed by covering an upper surface of a piezoelectric body 11a, that is, a surface on the second piezoelectric body 12 side with an electrode portion 14 made of a conductive material,
The second piezoelectric body 12 is provided with an electrode portion 15 made of a conductive material on the upper surface of the piezoelectric body 12a, that is, the surface on the cover member 33 side, and the lower surface of the piezoelectric body 12a,
The first piezoelectric body 11 and the second piezoelectric body 12 are bonded by a conductive adhesive material 10 by forming an electrode portion 16 made of a conductive material on the surface on the side of the piezoelectric body 11, respectively. A piezoelectric unit is formed.

In order to form a plurality of ink pressurizing chambers 20, grooves are formed on the piezoelectric body unit using a dicing saw or the like, and a plurality of grooves are formed. 27 are formed. Also, the cover member 3
3 and the second piezoelectric body 12 are bonded by a non-conductive adhesive 23 to form a head unit. Since the cover member 33 is integrated with the second piezoelectric body 12 and causes the wall 27 to undergo slip deformation as described later, the same material as the first and second piezoelectric bodies 11 and 12 is used. Is formed.

At one end of the head unit, a nozzle plate 18 having a plurality of nozzle holes 19 for discharging ink corresponding to each groove is provided with a non-conductive adhesive 23.
At the other end of the head unit, a common ink chamber 41 serving as a common electrode member for accommodating the ink 22 is adhered to the electrode portion 15 by the conductive adhesive material 10. Electrode part 1 by material 23
4. The ink jet print head is formed by being adhered to the piezoelectric body 12a and the cover member 33. At this time, the groove is closed to form the ink pressurizing chamber 20. The common ink chamber 41 is connected to an ink tank (not shown) or the like via an ink conduit 24.

By the way, unlike the conventional ink jet print head, the lower surface of the cover member 33 is not covered with the electrode portion 17 (see FIG. 4), and as shown in FIG. Reference numeral 15 is electrically connected to the common ink chamber 41 via the conductive adhesive 10. Therefore, the common ink chamber 41 is formed of a metal conductive material such as aluminum and copper.

When a plurality of grooves are formed in the piezoelectric body unit, wide side walls 66, 67 are formed on both side edges of the first piezoelectric body 11, and upper surfaces of the side walls 66, 67 are formed. The electrode portions 14a and 14b respectively covered with are formed as common electrodes. Further, electrical conductors 65 are bonded to both side edges of the piezoelectric body unit in order to electrically connect the common ink chamber 41 and the electrode portions 14a and 14b.

Therefore, the electrode portion 15 of each wall 27
Are connected to the common ink chamber 41 via the conductive adhesive 10, and further connected to ground or the midpoint potential via the electric conductor 65, the electrode portions 14a and 14b, the conductive adhesive, and the like. As described above, since it is not necessary to form the electrode portion 17 on the cover member 33, not only the cost of the ink jet print head can be reduced, but also the operation for manufacturing the ink jet print head can be simplified.

Further, since the common ink chamber 41 and the electrode portion 15 can be bonded by the conductive adhesive 10 and the common ink chamber 41 and the cover member 33 can be bonded by the non-conductive adhesive 23, the conductive adhesive 10 can be used less, and the cost of the inkjet print head can be reduced. In the present embodiment, the entirety of the common ink chamber 41 is formed of a conductive material. However, only the portion bonded to the second piezoelectric body 12 may be formed of a conductive material. it can.

Next, a second embodiment of the present invention will be described. FIG. 10 is a perspective view of an inkjet print head according to the second embodiment of the present invention. The first
Components having the same structure as that of the embodiment are denoted by the same reference numerals, and description thereof is omitted. In this case, the first piezoelectric body 11 and the second piezoelectric body 12 are bonded by a conductive adhesive 10, and the cover member 33 and the second piezoelectric body 12 are bonded by a non-conductive adhesive 23. The second piezoelectric body 12 includes a piezoelectric body (not shown) and an electrode section (not shown) coated on the upper surface of the piezoelectric body. Each of the second piezoelectric bodies 12 is connected to a ground or a midpoint potential. A ground plate 69 made of a conductive material such as a metal is disposed as a common electrode member between the walls 27. The ground plate 69 and the electrode unit 15 (FIG. 9) are screen-bonded or sheet-bonded with the conductive adhesive 30. Are bonded.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0025]

As described above in detail, according to the present invention, in the ink jet print head, the first piezoelectric body and the second piezoelectric body are bonded to each other by the conductive adhesive through the electrode portion. A plurality of grooves, a piezoelectric body unit having a plurality of grooves, and a wall formed between the grooves, a cover member bonded to a second piezoelectric body of the piezoelectric body unit to form a head unit, A nozzle plate that is bonded to one end of the head unit and has a nozzle hole formed corresponding to each of the grooves, and a nozzle plate that is bonded to the other end of the head unit by a conductive adhesive, And a common electrode member for electrically connecting the electrode portions coated on the cover member-side surface of the second piezoelectric body to each other.

In this case, an ink pressurizing chamber is formed by closing the groove of the piezoelectric body unit with a nozzle plate, and a voltage is applied to the electrode portion of the portion where the first piezoelectric body and the second piezoelectric body are bonded. Is applied, an electric field is generated on the walls, each wall is deformed, and the ink in the ink pressurizing chamber is ejected. Since the electrode portions of the respective walls, which cover the surface of the second piezoelectric body on the cover member side, are electrically connected to each other by a common electrode member.
There is no need to form an electrode portion on the cover member. Therefore, not only can the cost of the inkjet print head be reduced, but also the operation for manufacturing the inkjet print head can be simplified.

In addition, it is only necessary to dispose a conductive adhesive between the common electrode member and the electrode portion of each of the walls, which covers the surface of the second piezoelectric body on the cover member side. Since a non-conductive adhesive can be used between the member and the cover member, the amount of the conductive adhesive used can be reduced, and the cost of the inkjet print head can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an ink jet print head according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional inkjet print head.

FIG. 3 is a cross-sectional view of a conventional inkjet print head.

FIG. 4 is a perspective view of a conventional cover member.

FIG. 5 is a perspective view of a conventional piezoelectric unit.

FIG. 6 is a perspective view of a conventional head unit.

FIG. 7 is a first diagram illustrating the operation of a conventional inkjet print head.

FIG. 8 is a second diagram illustrating the operation of the conventional inkjet print head.

FIG. 9 is a cross-sectional view of the inkjet print head according to the first embodiment of the present invention.

FIG. 10 is a perspective view of an inkjet print head according to a second embodiment of the present invention.

[Explanation of symbols]

 10, 30 conductive adhesive material 11 first piezoelectric body 12 second piezoelectric body 14-16 electrode section 18 nozzle plate 19 nozzle hole 22 ink 27 wall 33 cover member 41 common ink chamber 69 ground plate

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Shigenori Koido 4--11-22 Shibaura, Minato-ku, Tokyo Inside Oki Data Corporation

Claims (3)

[Claims] (A) A first piezoelectric body and a second piezoelectric body are formed by bonding a first piezoelectric body and a second piezoelectric body via an electrode portion with a conductive adhesive, and are formed in a plurality of grooves and between the grooves. A piezoelectric unit having a wall, and (b) a second
A cover member adhered to the piezoelectric body to form a head unit; and (c) a nozzle plate adhered to one end of the head unit and provided with nozzle holes formed corresponding to the grooves. (D) a common electrode that is bonded to the other end of the head unit by a conductive adhesive, and electrically connects the electrode portions coated on the cover member side surface of the second piezoelectric body in each of the walls to each other. An ink jet print head comprising: an electrode member. 2. The ink jet print head according to claim 1, wherein the common electrode member is a common ink chamber made of a conductive material and containing ink. 3. The ink jet print head according to claim 1, wherein the common electrode member is a ground plate made of a conductive material.