JP3379557B2 - Piezoelectric driver for inkjet recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric driving body for an ink jet recording apparatus, and more particularly to a pattern of external electrodes formed on the surface of the piezoelectric driving body.

[0002]

2. Description of the Related Art An ink jet recording apparatus in which ink droplets are ejected from nozzles by utilizing displacement in a longitudinal vibration mode is generally disclosed in Japanese Unexamined Patent Publication (Kokai) No. 4-1052. The tip of each piezoelectric vibrator dividedly formed corresponding to each nozzle arranged in line is brought into contact with the vibrating plate, and ink is applied between the nozzle plate and the vibrating plate by these vibrating plates that respond to the recording signal. The pressure is applied so that the ink is ejected from the nozzle as an ink droplet.

The piezoelectric driving body used in this type of ink jet recording apparatus is not only extremely difficult to mold because the vibrator must be finely divided and formed in accordance with each nozzle, but also the surface of the piezoelectric plate. There is a difficult problem in assembling that the flexible circuit board must be correctly aligned and bonded to the external electrode formed on the substrate.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
It is an object of the present invention to provide a new piezoelectric driving body for an inkjet recording apparatus, which can greatly improve this type of assembly work by increasing the degree of freedom in connecting the piezoelectric plate and the flexible circuit board.

[0005]

[ MEANS FOR SOLVING THE PROBLEMS] That is, the present invention
As a piezoelectric driving body for an inkjet recording apparatus for achieving the above-mentioned subject, a large number of vibrators having a free end side as an active part and a fixed end side as an inactive part
Comb by integrated with the dummy vibrator is located on the fixed end side
And forming the tooth shape, the vibrator, the external signal electrodes, the dummy vibrator in portion extending near the least even fixed end from the own Yoshitan side end face, the external signal electrodeposition from the fixed end side end surface
The outer common electrodes are formed on the portions of the poles that extend closer to the free ends than the edges of the fixed ends .

[0006]

Embodiments Now, the embodiments shown in the drawings will be described. FIG. 1 shows a bonded state of a piezoelectric driving body and a flexible circuit board according to an embodiment of the present invention, and FIG. 2 shows a sectional structure of the piezoelectric driving body.

In the drawings, reference numeral 1 is a piezoelectric vibrator assembly as a piezoelectric driving body. The assembly 1 is composed of a piezoelectric plate 2 formed by dividing the center portion in the width direction on the free end side into comb teeth and the piezoelectric plate 2. In order to attach the plate 2 to the ink jet recording apparatus, it is composed of a support plate 15 fixed to the rear surface of the rear end.

To explain this in more detail, the piezoelectric plate 2 comprises a piezoelectric material layer 3 in the form of a paste such as lead zirconate titanate or barium titanate, and this piezoelectric material layer 3.
By laminating the inner conductive layer 4 made of silver palladium or the like applied or vapor-deposited on the above, the free end side is constituted as the active part 5, and the fixed end side, that is, the base end side is constituted as the non-active part 6.
Further, a support plate 15 made of, for example, a paste-like free-cutting ceramic material made of the same material as the piezoelectric material is laminated on the back surface of the non-active portion 6 on the base end side, and the whole of them is integrally sintered by sintering. It is molded.

In this piezoelectric plate 2, a central portion in the width direction on the free end side is made into a vibrator forming region 7, and this portion is cut into comb teeth to form a large number of piezoelectric vibrators 8 ...
Dummy vibrators 9 and 9 having no slits are formed on both sides thereof, and this portion is inserted into positioning grooves provided on both sides of a piezoelectric driving body holding block (not shown). It is configured to be positioned and fixed to the holding block.

As shown in FIG. 1, the piezoelectric plate 2 reaches the upper surface of the vibrator forming region 7 from the lower surface of the active portion 5 to the vicinity of the rear end of the piezoelectric plate 2 via the end surface on the free end side. The external signal electrode 10 is formed so as to be electrically connected to the internal conductive layer 4, and the external common electrode 12 communicating with the electrode 11 provided on the end face on the base end side is formed on the upper surfaces of the left and right dummy vibrators 9, 9. Is formed over the vicinity of the front edge of the inactive portion 6 so that a small amount of non-conductive surface 13 is interposed between it and the external signal electrode 10.

Next, in the piezoelectric vibrator assembly 1, the piezoelectric plate 2 is separated by a dividing line L-L that connects at least the upper half B of the rear end face of the piezoelectric plate 2 from the joining edge A with the support plate 15. All parts on the active part 5 side and the upper half part of the non-active part 6 on the base end side on the support plate 15 are formed into a comb tooth shape with a gap corresponding to the arrangement pitch of the nozzles with a wire saw or a dicing saw. A large number of piezoelectric vibrators 8 ... Are formed by division.

On the other hand, the flexible circuit board 16 connected to the external electrodes 10 and 12 on the piezoelectric plate 2 is formed to have substantially the same width as the piezoelectric plate 2, and the piezoelectric vibrators 8 ... A large number of lead wires 17 connected to each of the external signal electrodes 10 cut together with the dummy vibrators 9 and 9 are provided on both sides thereof.
The lead wires 18 connected to the external common electrode 12 formed on the upper surface of are respectively formed so as to reach the front edge of the circuit board 16.

Reference numeral 19 in the figure denotes an insulating cover sheet attached to the lower surface of the flexible circuit board 16 except for the tip.

In the flexible circuit board 16 thus constructed, each lead wire 17 in the central portion is a piezoelectric vibrator 8.
.. are positioned in the width direction so as to correspond to the respective external signal electrodes 10 ..., And are attached so that their tip edges 16a are positioned at the inactive portion 6 of the piezoelectric plate 2.

As a result, the front edge 16a of the flexible circuit board 16 may be attached to any position of the zone Z surrounded by the front edge 12a of the external common electrode 12 and the front edge 10a of the external signal electrode 10. , Each lead wire 17 provided in the central portion of the flexible circuit board 16 ...
Is connected to each external signal electrode 10 on the piezoelectric vibrator 8,
In addition, each lead wire 18, 18 provided on the left and right of the circuit board 16
Will be connected to the external common electrodes 12, 12 on the dummy oscillators 9, 9.

By the way, FIG. 3 shows this piezoelectric vibrator assembly 1.
First, the piezoelectric material layer 3 is shown.
An external common electrode 32 and an external signal electrode 30 having the pattern shown in FIG. 7A are formed on a large-sized piezoelectric plate forming plate 22 formed by stacking the internal electrode 4 and the internal electrode 4.

That is, the piezoelectric plate forming plate 22 is provided with a plurality of external common electrodes 32, ...
1 is formed so as to communicate with 1 and at a distance corresponding to the width of the piezoelectric plate 2 so as to cover the surface of the non-active portion 6, while from the free end side, the lower surface of the active portion 5 to the free end side end surface. Among the external signal electrodes 30 that have reached the surface via, the external signal electrode 30a on the vibrator formation region reaches near the rear end edge of the piezoelectric plate forming plate 22, and the other portion 30b forms the non-conductive surface 33. The outer common electrode 32 is formed in a gear shape so as to surround the outer edge thereof.

Then, the piezoelectric plate forming plate 22 thus formed is cut along a line passing through the center of the external common electrode 32 to form a plurality of piezoelectric plates 2 ...

Finally, the supporting plate 15 is joined to the lower surface of the base end portion of each of the separated piezoelectric plates 2, and at least the upper half B of the rear end surface of the piezoelectric plate 2 is joined from the joining edge A with the supporting plate 15. All the parts on the active part 5 side of the piezoelectric plate 2 and the upper half part on the support plate 15 of the inactive part 6 on the base end side with the dividing line connecting them as a boundary are arranged with nozzles by a wire saw W or a dicing saw. A large number of piezoelectric vibrators 8 ... Are formed by division into comb teeth with a gap corresponding to the pitch.

[0020]

As described above, according to the present invention, the external signal electrode reaching from the end face on the free end side to the vicinity of the fixed end is formed on the surface of the piezoelectric plate in the vibrator forming region at the center in the width direction. , The external common electrodes reaching the vicinity of the edge of the non-active portion from the end surface on the fixed end side are provided on the extension portions on both sides of the extension portion, so that the entire lengthwise region formed so that both external electrodes mesh with each other. Can be used as a connection surface with the flexible circuit board, and the degree of freedom in assembling and joining the both can be greatly increased, and a separate component for connecting the external common electrode can be provided on the piezoelectric plate side. It is not necessary, and on the flexible circuit board side, it is possible to reduce the number of parts and to assemble by making it possible to form a series of lead wires connected to both external electrodes and cut it at any position to use it. sex It can be or improvement.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall view of a piezoelectric driving body showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a piezoelectric vibrator assembly.

3A to 3C are diagrams showing a method of forming a piezoelectric vibrator.

[Explanation of symbols]

1 Piezoelectric vibrator assembly 2 Piezoelectric plate 5 active section 6 Inactive part 8 Piezoelectric vibrator 9 Dummy oscillator 10 External signal electrode 12 External common electrode 15 Support plate 16 Flexible circuit board

Claims (4)

(57) [Claims] 1. A large number of vibrators each having a free end side as an active portion and a fixed end side as an inactive portion, and both side portions in a row direction of the vibrators.
Comb by integrated with the dummy vibrator is located on the fixed end side
And forming the tooth shape, the vibrator part to the external signal electrodes over the vicinity of the fixed end at least <br/> free end side end face, wherein the dummy vibrator, from the fixed end side end surface Previous
The fixed end side of the external signal electrode, closer to the free end than the edge.
A piezoelectric driving body for an ink jet recording apparatus , wherein an external common electrode is formed on each of the extended portions . 2. The external signal electrode is routed from one dummy oscillator to the other dummy oscillator via the side end surface of the piezoelectric plate.
The piezoelectric driving body for an ink jet recording apparatus according to claim 1, wherein the piezoelectric driving body is formed on a moving element. 3. A plurality of transducers on the free end side central portion divided form in a comb shape, and the fixed end of the piezoelectric plate obtained by forming a dummy vibrator arrangement direction both sides of the vibrator Support
Claims, characterized in that laminated integrally with lifting plate
2. A piezoelectric driving body for an inkjet recording device according to 1 . 4. With additionally provided a circuit board on the fixed end side of the piezoelectric plate, multi-and cut-split formed in the width direction central portion of the substrate
Claim, characterized in that each of the connected allowed <br/> Rutotomoni of the external signal electrodes the number of leads, a lead wire which is formed in the width direction both end portions of the base plate is connected to the external common electrode 1 A piezoelectric driver for the inkjet recording apparatus described in claim 1.