JP3152262B2 - Ink jet recording head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head, and more particularly to a technique for positioning each member constituting the head.

[0002]

2. Description of the Related Art A piezoelectric vibrator is deformed in its longitudinal direction.
In recent years, with regard to an ink jet recording head which pressurizes ink in a pressure chamber and discharges the ink as ink droplets from a nozzle onto a recording medium, in recent years, there has been a demand for smaller and denser recording heads. Japanese Patent Application Laid-Open No. 58-119870 discloses a recording head of this type, in which a large number of piezoelectric vibrators are inserted into upper and lower guide holes on a support member side to form a base end portion and a distal end portion thereof. With such a mechanism, not only cannot each piezoelectric vibrator be arranged at a high density, but also the piezoelectric vibrators may have irregularities and inclinations in the longitudinal direction. Thus, there is a disadvantage that the ink ejection characteristics cannot be made constant.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide an ink jet recording head capable of positioning and coupling a plurality of piezoelectric vibrators as well as members constituting a recording head with high density and high precision.

[0004]

That SUMMARY OF THE INVENTION The ink jet recording head for the present invention is to achieve such a problem, a plurality of piezoelectric transducers that are arrayed on the surface of the fixing plate, before
The ink ejected by the piezoelectric vibrator to eject ink droplets
A cavity-forming substrate to form the click channel, positioning for positioning at least one of the fixed substrate and the piezoelectric vibrator in the direction of <br/> plane perpendicular to the displacement direction of said piezoelectric vibrators
A hole, and a top surface for fixing the cavity forming substrate.
And head configuration means .

[0005]

A positioning hole is formed in the head constituting means.
Therefore, the cavity forming base fixed to the head forming means
, A plurality of piezoelectric vibrators arranged at high density can be positioned with high accuracy.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIGS. 1 to 3 show the entirety of an ink jet recording head according to an embodiment of the present invention. This ink jet recording head is divided into strips on a fixed plate 2 as will be described later. 11, the head frame 3 for holding and holding each tip of the vibrator 11 and the fixing plate 2 and positioning and holding the same in the surface direction of the cavity forming base 5, and the positioning pins 34. And a cavity forming base 5 which is positioned and held on the head frame 3 through the cavity. It should be noted that reference numeral 38 in FIG.
Denotes a cover for supporting the outer peripheral edge of the cavity forming base 5, 28 denotes a lead frame, and 9 denotes a head substrate.

FIG. 4 shows the piezoelectric element plate 1 and the fixed plate 2. The fixed plate 2 made of a free-cutting ceramic or the like having an electrode film 24 on the upper surface has positioning portions 22, 2 on both sides.
2 and the center part is the second half support part 2 of the vibrator 11.
3, an electrode film 14 serving as one pole is provided on the lower surface and the rear end face, and an electrode film 15 serving as the other pole is provided on the upper face and the front end face (FIG. 5). The provided piezoelectric element plate 1 has its leading edge projecting a predetermined length beyond the rear half supporting portion 23, and the lower electrode film 14 is fixed to the fixing plate 2.
Is firmly bonded so as to be bonded to the electrode film 24. As shown in FIG. 4, the size of the piezoelectric element plate 1 is selected such that both sides overlap the fixing plate 2.

The piezoelectric element plate 1 is formed wider than the length of the nozzle array, and after being bonded to the fixed plate 2, is cut into a width corresponding to the pitch of the nozzles 61 by a cutting machine such as a wire saw. To form a plurality of transducers 11 #. At this time, the strip-shaped portions formed on both sides of these vibrators 11 # are configured as dummy vibrators 11, 12 used as positioning portions, while absorbing the deformation of both side edges generated at the time of cutting. You. The dummy vibrators 11 and 12 are fixed to the fixing plate 2 over substantially the entire length thereof and reinforced.

On the other hand, the electrode film 24 provided on the surface of the fixed plate 2
Are cut into a large number of signal electrodes 25 corresponding to the respective vibrators 11 # in the process of cutting, and the rear ends thereof are connected to the respective lead wires 26 #. Pulled out to the back. On the other hand, the electrode films that have been cut and left on both sides of the fixed plate 2 are connected to lead frames 28, 28 extending from the head substrate 9, and are connected to the common electrode 2.
6, 26. Then, the electrode film 1 of each transducer 11 #
By connecting the bridging piece 27 to the upper surface of the 5 and making the ends of the bridging piece 27 the common electrodes 26, 26, conduction with each transducer 11 is established.

Returning to FIGS. 1 and 2, the head frame 3 for positioning and holding these vibrators 11 together with the fixing plate 2 is formed in a cylindrical shape having a flared skirt portion 31 of an epoxy resin. The inside of the skirt portion 31 is used as a storage portion for the lead wires 26 and 28, and is configured to be stably mounted on the head substrate 9.

As shown in FIG. 8, the head frame 3 has, on its top surface 32, a wide portion 33a into which the fixing plate 2 is fitted with a small clearance δ in the thickness direction, and a small clearance η in the width direction. A positioning hole 33 having a “convex” shape in cross section, which is formed by a narrow portion 33 b into which the vibrator 11 is fitted, is formed. By positioning the dummy vibrator 11 in the width direction by the wide portion 33a, the vibrator 11 can be correctly positioned in the surface direction of the cavity forming base 5 positioned with the head frame 3 via the positioning pins 34. . Reference numeral 36 in the drawing indicates a guide slope formed in a tapered shape toward the positioning hole 33 in order to facilitate insertion of the piezoelectric element 1 and the fixed plate 2.

On the other hand, as shown in FIG. 5, a cavity forming base 5 positioned and held on the top surface 32 of the head frame 3 includes a nozzle plate 6 having nozzles 61 and a cavity forming plate for forming an ink flow path. 7 and an elastic plate 8 for pressurizing the ink in the pressure chamber 72. The fixing plate 12 is firmly adhered and fixed to the head frame 3 with an adhesive 55.

As shown in FIG. 3, the nozzle plate 6 in this embodiment is provided with two sets of nozzle arrays each composed of twelve nozzles 61 ° in two rows. A cavity forming plate 7 formed of a curable resin is laminated, and includes 12 rectangular pressure chambers 7 communicating with a common ink chamber 71.
2 ‥‥ are provided in four rows, and these nozzles 61
Are formed.

The elastic plate 8 laminated on the back surface of the cavity forming plate 7 is formed of a thin plate made of a highly rigid nickel electroformed or the like. The thick portion 82 is formed of an insulating photocurable resin material or the like so as to form a ring-shaped thin portion 81 along the line. Thereby, the vibrator 1 is positioned at the center of the thin portion 81.
An island-shaped thick portion 82a to be joined to the tip of the first portion is formed.
Also, in the regions on both sides where the pressure chambers 72 are not formed, as shown in FIG.
2b is formed.

On the other hand, as shown in FIGS. 2 and 3, the top surface 32 of the head frame 3 has two positioning pins 34,
34, and these positioning pins 34, 3
By fitting the recesses 51 into the recesses 4, the cavity forming base 5 is accurately positioned and mounted on the head frame 3.

In the ink jet recording head constructed as described above, first, the front edge of the plate-like piezoelectric element plate 1 is bonded to the fixing plate 2 by protruding the front edge thereof by a predetermined length. A cut is made and this is divided into twelve vibrators 11 #. Thereby, each vibrator 11 #
‥ will be arranged on the fixing plate 2 with the tips correctly aligned. And the dummy vibrators 11 and 12
Since it is fixed to the fixing plate 2 and reinforced over substantially the entire length, even if it is fitted in the above-described positioning in the width direction, it does not break or bend, and misalignment can be prevented.

Then, the recess 51 of the cavity forming base 5 is engaged with the positioning pin 34 erected on the head frame 3, and the cavity forming base 5 is mounted. Next,
The distal end of the vibrator 11 fixed on the fixed plate 2 is fitted into a positioning hole 33 provided on the top surface 32 of the head frame 3 and positioned in the width direction by the dummy vibrators 11 on both sides. Positioning in the thickness direction by the thickness of 2 Thus, each transducer 11 # is positioned in the plane direction. Further, the positioning of the vibrator 11 in the displacement direction is performed by bringing each end of the dummy vibrators 11 and 12 into contact with the thick portions 73 on both sides of the cavity forming plate 7 via the elastic plate 8.

FIG. 6 shows a second embodiment relating to the positioning of the vibrator 11 and the cavity forming base 5 with respect to each other. In this embodiment, the dummy vibrators 11 and 12 provided on both sides of the vibrator 11 are formed to have a wide width, and slits 13 and 13 are simultaneously formed on the distal end surfaces thereof. According to this embodiment, the direct coupling between the vibrator 11 and the cavity forming base 5 can further enhance the mutual positioning accuracy in the plane direction.

FIG. 7 shows a third embodiment relating to the positioning of the vibrator 11 and the cavity forming base 5. In this embodiment, the front edge of the plate-shaped piezoelectric vibrator 1 is adhered so as to coincide with the tip of a positioning portion 22 protruding on both sides of the fixed plate 2, and this piezoelectric element 1 is attached to a large number of vibrators 11.
正 し く, the tip of each transducer 11 ‥‥ is correctly aligned with the positioning portion 22, and
In this embodiment, the slits 21 are formed on the end surface of the elastic plate 8 and the positioning pins 52 on the lower surface of the elastic plate 8 are fitted into the slits 21. According to this embodiment, the vibrator 11 and the cavity forming base 5 The positioning accuracy in the mutual plane direction can be enhanced by the direct coupling with the substrate.

In summary, each transducer 11 and the head frame 3 and the cavity forming base 5 and the head frame 3
Positioning, that is, the vibrator 1 via the head frame 3
The positioning between 1 and the cavity forming base 5 has the following relationship.

[0021]

[Table 1]

[0022]

As described above, according to the present invention, a plurality of piezoelectric vibrators arranged in a row on the surface of a fixed plate , and a piezoelectric vibrator
To form an ink channel that ejects ink droplets when pressurized
Cavity forming base, positioning hole for positioning at least one of the piezoelectric vibrator and the fixed substrate in a direction perpendicular to the displacement direction of the piezoelectric vibrator , and cavity forming base
Construction of a head structure means having a top surface for securing the
Because it is, a plurality of piezoelectric vibrators which are densely arranged can be assembled easy and precisely correctly aligned state can Yabiti forming substrate to the tip.

[Brief description of the drawings]

FIG. 1 is a side view showing one embodiment of an ink jet recording head of the present invention in a cross section in the direction in which pressure chambers in the same row are arranged.

FIG. 2 is a diagram showing a cross-sectional structure of a head forming unit and a positioning region of a cavity forming base which constitute the preceding recording head.

FIG. 3 is a top view of the recording head.

FIGS. 4A to 4D are views showing a step of forming a piezoelectric vibrator.

FIG. 5 is a sectional view of a main part of the ink jet recording head.

FIG. 6 is a plan view showing another embodiment of the piezoelectric vibrator.

FIG. 7 is a sectional view showing another embodiment of the ink jet recording head.

FIG. 8 is a diagram showing an example of a positioning hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 11 Vibrator 12 Dummy vibrator 2 Fixing plate 22 Positioning part 3 Head frame 33 Positioning hole 5 Cavity forming base 6 Nozzle plate 7 Cavity forming plate 8 Elastic plate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Minoru Usui 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (56) References JP-A-3-234538 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (15)

(57) [Claims] 1. A plurality of piezoelectric vibrators arranged in a row on a surface of a fixed plate, a cavity forming base forming an ink flow path that is pressurized by the piezoelectric vibrators and ejects ink droplets, and the piezoelectric vibrators An ink jet recording head comprising: a positioning hole for positioning at least one of the fixed substrate in a direction perpendicular to a displacement direction of the piezoelectric vibrator; and a head forming means having a top surface for fixing the cavity forming base. . 2. The ink jet recording head according to claim 1, wherein a first positioning projection is formed on the top surface, and the cavity forming base is positioned by the first positioning projection. 3. The cavity forming base is provided with a second positioning projection, and the piezoelectric vibrator is also positioned by the second positioning projection in the surface direction of the cavity forming base. 3. The ink jet recording head according to item 1. 4. The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrators located on both sides of the plurality of piezoelectric vibrators arranged in the row direction are formed as dummy vibrators not involved in ink ejection. Ink jet recording head. 5. The ink jet recording head according to claim 4, wherein a concave portion for engaging with the second positioning convex portion is formed at a tip of the dummy vibrator. 6. An electrode film is formed on a surface of the fixing plate,
Further, the plate-shaped piezoelectric element plate positioned and fixed on the fixed plate is cut and divided, and the formation of the piezoelectric vibrator and the division of the electrode film are performed. 2. The ink jet recording head according to claim 1, wherein the signal electrodes correspond to each of the piezoelectric vibrators. 7. The ink jet recording head according to claim 1, wherein the positioning hole is formed as a holding portion for positioning the fixing plate. 8. The positioning hole has a surface perpendicular to the top surface of the head forming means, and the dummy vibrator contacts the vertical surface so that the tips of the piezoelectric vibrators are arranged in a row. The positioning according to claim 4 or 5, wherein
3. The ink jet recording head according to item 1. 9. A plurality of piezoelectric vibrators in which the same thick portions as those in contact with the piezoelectric vibrators are formed in both sides of the cavity forming base where ink droplets are not ejected, and the piezoelectric vibrators are arranged in a line. The piezoelectric vibrators located on both sides of the piezoelectric vibrator are formed as dummy vibrators that do not participate in the ejection of ink, and the dummy vibrators are brought into contact with the thick portion to position the piezoelectric vibrators in the displacement direction. The inkjet recording head according to claim 1. 10. The dummy vibrator according to claim 4, wherein a region corresponding to a displaceable region of the piezoelectric vibrator is fixed to the fixing plate and reinforced. 3. The ink jet recording head according to item 1. 11. The ink jet recording head according to claim 1, wherein a concave portion for positioning is provided in the cavity forming base. 12. The ink jet recording apparatus according to claim 2, wherein a positioning recess is provided in said cavity forming base, and positioning is performed with respect to said head constituting means by engagement with a first positioning projection. head. 13. A piezoelectric vibrator comprising a plurality of piezoelectric vibrators arranged in a row on a fixed plate, and a positioning hole for forming a clearance at least in a direction perpendicular to a displacement direction of the piezoelectric vibrator and a tip of the piezoelectric vibrator. Head forming means, and a cavity forming base forming an ink flow path for ejecting ink droplets when pressurized by the piezoelectric vibrator, wherein the piezoelectric vibrator is provided on the top surface of the head forming means by the positioning holes. An ink jet recording head positioned on the fixed cavity forming base. 14. A step of positioning and fixing a cavity forming base forming an ink flow path for discharging an ink droplet by being pressed by a piezoelectric vibrator on a top surface of a head forming means; A plurality of piezoelectric vibrators, and a dummy vibrator fixed to the fixed plate so as to be located on both sides of the plurality of piezoelectric vibrators, perform positioning of the vibrators in the row direction by the dummy vibrators, A step of inserting the piezoelectric vibrator into the cavity forming base by inserting the piezoelectric vibrator into the head forming means while performing positioning in a direction perpendicular to the row direction by the thickness of the fixing plate. Manufacturing method. 15. The method according to claim 14, wherein the piezoelectric vibrator is positioned by bringing its position in the displacement direction into contact with the dummy vibrator and the cavity forming base.