JPS63104844A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To obtain a highly reliable recording head which can be manufactured easily, by constructing the recording head with an ink cavity plate having an ink cavity window, a cover plate, a plurality of piezoelectric elements, a nozzle plate having an ink nozzle window and a baseboard having an ink supply groove. CONSTITUTION:An open ink supply groove 20A is arranged in a base board 20, while a nozzle plate 21 has a plurality of rows of ink nozzle windows 21A opening to the sideface and an ink cavity plate 22 has a plurality of rows of ink cavity windows 22A opening from one main face to another main face. A flexible cover plate 23 closes one of ink cavity windows 22A. Baseboard 20, ink nozzle plate 21, ink cavity plate 22 and cover plate 23 are laminated in that order, then they are heated in a vacuum thermal furnace and integrated. Thereafter, the cover plate 23 is jointed with a planar piezoelectric plate 24, then said plate 24 is cut to provide a piezoelectric element 24A which is fixed with a lead wire.

Description

Detailed description of the invention [Technical field to which the invention pertains] This invention relates to a multi-nozzle type inkjet recording method that uses pressure pulses generated by a piezoelectric effect to eject ink in an ink cavity from an ink nozzle in a liquid-temperature state. Regarding to, C.

[Prior art and its problems]

It has been known for a long time that ink in an ink cavity is ejected from an ink nozzle in the form of droplets by utilizing a piezoelectric effect. FIG. 5 is a sectional view of a conventional multi-nozzle inkjet recording device. In the figure, 1 is a piezoelectric element cylinder having a liquid chamber inside. One side of the liquid chamber 2 is an ink supply path 3, and the other side is an ink passage 4. A nozzle 5 is formed at the end of the ink passage 4. Ink is supplied from an ink supply port 6 and stored in a common supply chamber 7. In this recording head, a piezoelectric element cylinder 1 is embedded in a main body 8 made of epoxy resin. Therefore, by selectively driving the piezoelectric element cylinder 1,
The volume of the liquid chamber 2 of the piezoelectric element cylindrical body 1 is contracted, and the ink within the liquid chamber 2 is ejected through the nozzle 5.

By the way, in this prior art inkjet recording, a piezoelectric element cylinder 1 is used as a means for ejecting ink from a nozzle 5, but this piezoelectric element cylinder 1 is a cylinder made of a piezoelectric material, It is composed of an inner electrode and an outer electrode provided on the inner and outer sides of this cylindrical body. In order to reduce the size of inkjet recording, the piezoelectric element cylinder 1 must also be made smaller accordingly. However, miniaturization, that is, manufacturing a cylindrical body made of piezoelectric material with extremely small outer and inner diameters,
Furthermore, forming an inner electrode on the inside (inner wall surface) is extremely difficult in terms of manufacturing technology. For example, it is almost impossible to form the nozzle openings to a size of 40 μm x 40 μm and to make them so small that they can be arranged at 11-inch intervals.

That is, the outer diameter of the piezoelectric element cylindrical body 1 is at most Q5, and the inner diameter is even smaller than that. Moreover, an inner electrode must be formed on the inner wall surface. Such a thing is impossible even with current manufacturing technology. For this reason, the piezoelectric element cylindrical body 1 is configured to have a certain size, but as a result, the width L2 of the main body 8 becomes extremely large compared to the necessary width L1 of the nozzle part, as shown in FIG. It has the disadvantage of being Furthermore, a small piezoelectric element cylindrical body 1 is placed inside the epoxy resin body 8.
and #jIIltl ink supply path 3. Although it is possible to form a 4° ink passage nozzle 5, it is very difficult in practice.

Further, FIG. 6 shows a cross-sectional structure of an inkjet recording head according to another conventional technique. Reference numeral 11 in FIG. 6 is a head, and a pressure chamber 12. Ink passage 13. A nozzle 14 is formed, and an ink supply pipe 15 for supplying ink is connected to the pressure chamber 12 and the ink passage 13. The ink supply pipe 15 is further connected to an ink supply source 16. On the other hand, the back surface of the pressure chamber 12 is composed of a flexible plate 17 made of metal and an electro-mechanical conversion element (piezoelectric element) 18 bonded thereto. In this configuration, when not recording, the ink supply pressure is adjusted to maintain equilibrium with the surface tension of the ink so that the ink does not flow out from the nozzle 14. When a voltage pulse is applied to the piezoelectric element 18 in accordance with the information signal during recording,
The flexible plate 17 bends towards the inside of the pressure chamber 12. Due to the deformation of the flexible plate 17 at this time, when the rapid volume change that occurs in the pressure chamber 12 reaches the nozzle 14, small droplets of ink fly out according to the amount of change and are printed on recording paper, etc. . Ink replenishment is effected from the ink supply source 16 through the ink supply tube 15 by the negative pressure created when the flexible plate 17 returns to its original position.

As the piezoelectric element 18 shown in FIG. 6, a piezoelectric ceramic based on PZT (lead zirconate titanate) has conventionally been used. The drawbacks of this configuration are that the recording head is large and consumes a lot of energy, and piezoelectric elements made of PZT must be attached one by one to the pressure chambers by adhesive or other means, which is labor-intensive and costly. becomes. Also, the 6th
Even when the nozzles are multiplied in the structure shown in the figure, it is not practical due to the same drawbacks as described above.

[Purpose of the invention]

This invention has been made in view of the above points, and is a multi-nozzle inkjet recording head that is capable of downsizing the entire recording head, eliminates the need to attach piezoelectric elements one by one, is easy to manufacture, and is highly reliable. The purpose is to provide a method for producing the same.

[Key points of the invention]

The present invention provides an ink cavity plate having a plurality of ink cavity windows opening from one main surface to the other main surface: joined to the one main surface of the ink cavity plate; a flexible cover plate that bases one of the ink cavity windows on one main surface corresponding to the main surface; and a plurality of flexible cover plates joined at positions corresponding to the ink cavity windows on the other main surface of the cover plate. a piezoelectric element; an ink nozzle window that is joined to the other main surface of the ink cavity plate and that is open on one side of the ink cavity window that is perpendicular to the main surface and faces the ink cavity window; a nozzle plate having; joined to the other main surface of the nozzle plate;
a plywood board having an ink supply groove opening on one side facing the ink nozzle window and perpendicular to the main surface, applying an electric signal to the piezoelectric element to deform the flexible cover plate; The ink inside the ink cavity is ejected from an ink nozzle by increasing or decreasing the volume inside the ink cavity.

[Embodiments of the invention]

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment showing the configuration of the present invention.
is its cross-sectional view, and the figure (Bl is its longitudinal cross-sectional view).

Figure 2 is a perspective view of each member.

IBI in the figure is an ink cavity plate, tel in the figure is a nozzle plate, and TD in the figure is a cover plate.

In Figure 1, J is a plywood, and this plywood I has a second
As shown in the figure, an ink supply groove 2nA that opens on the side surface is provided. 21 is an ink nozzle plate having a plurality of rows of ink nozzle windows 21A opening on the side, and η
is an ink cavity plate having a plurality of rows of ink cavity windows 22A opening from one main surface to the other main surface; These materials are stainless steel, iron-nickel alloy, or nickel alloy, and their surfaces are plated, chemically polished, electrolytically polished, etc., as required. The ink supply groove 2OA of the base plate is machined with a grindstone.
Ink nozzle window 21A and ink cavity window 22A
can be microfabricated into a desired shape by etching, wire-cut electrical discharge machining, laser machining, etc.

Next, to the multi-nozzle inkjet recording of the present invention,
A method of manufacturing the board will be explained based on FIG. First, as shown in FIG. 3, the plywood 3+, the ink nozzle plate 21. After the ink cavity plate n and the cover plate 23 are stacked in this order, they are tightened using a jig (not shown). This is inserted into a vacuum heat treatment furnace and heated to cause diffusion bonding and integrate. Generally, the pressure when ejecting ink in an inkjet recording head is lo Kg, <tr? The bonding strength between each member of the head needs to be greater than this. In the present invention, it has been experimentally confirmed that the bonding strength between each member is at least 100 Ky/art' lV by setting the bonding conditions within the following range.

For tightening, apply pressure 2 to 10 d Heating temperature fioO' to 900°C Heating time 1 to 3 hours Vacuum degree 5 x 10 torr or less
As shown in ( ) 11 in FIG. 3, a flat piezoelectric plate 24 is joined or adhered to the cover plate Z3.

In this case, it is easiest to use an organic adhesive, but from the viewpoint of efficiently transmitting the distortion of the piezoelectric element to the cover plate, soldering is recommended.

Methods such as brazing are preferred. However, when the latter two are bonded, the temperature is higher than the Curie point of the piezoelectric material, so repolarization is required after the bonding. After bonding the piezoelectric plate 24 onto the cover plate, the piezoelectric plate is cut into a desired shape using a dicing saw so that the cover plate is deformed and the volume inside the ink cavity groove can be changed. A piezoelectric element 24A is used as shown in tcIK in FIG. This dicing saw has already been used to cut semiconductor wafers, and recently a cutting blade with a thickness of 15 μm has been developed. Therefore, with this dicing saw, the width of the piezoelectric plate is 0.2
It can be cut to lengths of 5m+++, and is effective in reducing the width of the ink cavity groove, allowing for a more compact structure for inkjet recording.

The piezoelectric plate 24 is cut to form a piezoelectric element 24A, and this piezoelectric element 24AK is connected to the multi-nozzle type of the present invention by attaching a lead wire connected to an external power supply as shown in FIG. The inkjet recording head is completed.When a pulse voltage is applied from outside the piezoelectric element 24AK to the inkjet arrangement having such a configuration, the piezoelectric element 24A is suddenly distorted, and this distortion causes the flexible cover plate to 23 is deformed toward the ink cavity groove side, and due to this deformation, the volume of the ink cavity 22A' defined by the ink cavity plate n and the cover plate B changes, and due to this volume change, ink is released from the ink nozzle 21A in the form of droplets. This can be ejected and printed on recording paper (not shown).

In the embodiment shown in FIGS. 1 to 3, as shown in detail in FIG. 4, the size of the ink nozzle window 21A is 40 μm×40 μm, and the ink nozzle g 21 A.

The interval C of 21A is, for example, one dragon.

Furthermore, the width of the ink cavity window 22A is 9.4ffl,
The width of the piezoelectric element 24A is approximately 0.31 mm, and a base plate is added.

Ink nozzle plate 21. inkki and bitay play)
22. The overall thickness L of the cover plate) 23 is approximately 1.
2 to 1.5 mmK is formed. The thickness of the piezoelectric element 24A can be arbitrarily selected, but it is 0.2 to Q.
, 5111 is sufficient.

In this way, the inkjet recording according to the present invention is as follows.
For example, if the nozzle spacing is 11 m, then [the nozzles are placed approximately at the center of the width of the ink cavity groove 22A,
Similarly, the distance between the center axes of the ink cavity grooves 22A is 11.
111, and as a result, it becomes extremely compact and can be configured to have multiple nozzles.

〔Effect of the invention〕

As described above, the present invention provides an ink nozzle plate having multiple rows of ink nozzle windows.

An ink cavity plate with multiple rows of ink cavity windows, plywood with ink supply grooves, and a cover plate are stacked and integrated by diffusion bonding.
The piezoelectric plate is bonded or glued onto the cover plate, and the piezoelectric plate is cut into the desired shape using a dicing saw to create the piezoelectric element, making it easy to use multiple nozzles and making the entire head compact. The present invention has the advantage of providing a simple and reliable multi-nozzle inkjet recording method and its manufacturing method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view and a vertical cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a plywood according to an embodiment of the present invention. A perspective view of an ink nozzle plate, an ink cavity plate, and a cover plate, FIG. 3 is a bean assembly process diagram showing the manufacturing method of the present invention, and FIG. 4 is a partially enlarged view of an embodiment of the present invention.
FIGS. 5 and 6 are sectional views of inkjet recording heads according to the prior art, respectively. 1: Piezoelectric element cylindrical body, 2: Liquid chamber, 3: Ink supply chamber, 4
: ink passage, 5: ink nozzle, 6: ink supply port,
7: Ink common supply chamber, 8: Epoxy resin body, 11:
To, main body, 12: pressure chamber, 13: ink passage, 14:
Ink nozzle, 15: ink supply pipe, 16: ink supply source, 17: flexible plate, 18: piezoelectric element, 20 = base plate, 21: ink nozzle plate, 22: ink cavity plate, 23 two cover plates, 24 = Piezoelectric plate, 20A: Ink supply groove, 21A: Ink nozzle window, 2
2A: Ink cavity window, 24A: Piezoelectric element. 24A: Piezoelectric power station t.

Claims (1)

[Scope of Claims] An ink cavity plate having a plurality of ink cavity windows opening from one main surface to the other main surface; joined to the one main surface of the ink cavity plate and corresponding to the main surface. a cover plate that closes one of the ink cavity windows on one main surface; a plurality of piezoelectric elements joined to the other main surface of the cover plate at positions corresponding to the ink cavity windows; the other of the ink cavity plates; a nozzle plate that is joined to a main surface of the nozzle plate and has an ink nozzle window on one main surface corresponding to the main surface that faces the ink cavity window and opens on one side perpendicular to the main surface; and a base plate having an ink supply groove that is joined to the main surface of the ink nozzle window and that is open on one side that faces the ink nozzle window and is perpendicular to the main surface.