JPH04144751A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To reduce the number of parts and the number of manufacturing processes by a method wherein the non-bonding region of a vibration sheet film is positioned throughout the whole area of the outer peripheral edge of a flow passage base board, a head case is adhered on the surface thereof, and the flow passage base board, the vibration sheet, a pressure generating element, and an electrical wiring system, except the nozzle surface, are contained with the head case. CONSTITUTION:A flow passage base board 1, engraved by etching, and a vibration sheet 2 are bonded to a flow passage shape, communicated to an ink nozzle IN7 extending through in the direction of thickness to form a flow passage space 3. On the adhesion surface side of the vibration sheet 2 of the flow passage base board 1, the outer peripheral area of the vibration sheet 2 is an adhesion surface to a head case HC 6, and the region is formed to the whole area of the outer periphery of the flow passage base board 1. A piezoelectric element 4 on the vibration sheet 2 is securely adhered through the vibration sheet 2 on a flow passage space 3. Further, except a surface on which the nozzles IN 7 are arranged, the HC 6 is adhered to the flow passage base board 1 in a manner to close the flow passage base board 1, the vibration sheet 2, a piezoelectric elements 4, and an FPC 5 through which the piezoelectric elements are electrically wired.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of an inkjet recording head that forms an image on a recording medium by ejecting ink droplets.

[Conventional technology] Conventionally, the flow path board and the head case were connected using mechanical parts such as screws while the flow path board and the head case were inserted by inserting a gasket etc. between the flow path board and the head case while ensuring a seal to the inside of the head. Ta.

[Problems to be Solved by the Invention] However, in the conventional method, it is necessary to prevent ink from entering the inside of the head, ensure the reliability of the electrical wiring system, and increase the connection strength between the flow path board and the helad case. In order to achieve both these requirements, the number of parts such as screws and gaskets has increased, and the number of manufacturing steps has also increased. or,
Because they are screw-fastened, the flow path board and head case are either limited to the screw tightening torque, the tightening is limited to materials with strength and characteristics that can permanently withstand force, or the addition of metal parts with threaded parts. was necessary.

The present invention is intended to solve these problems, and its purpose is to provide a low-cost inkjet that ensures cost benefits by reducing the number of parts and manufacturing man-hours, sealing performance between the flow path substrate and the head case, and connection strength. The purpose is to provide a recording head.

[Means for solving the problem] In order to solve the problem, claim (1) of the present invention
) has a non-bonded area of the diaphragm over the entire outer periphery of the flow path substrate, a head case is adhered to that surface, and the diaphragm and the piezoelectric element provided on the diaphragm are connected to each other. and the head case is bonded so as to wrap around electrical wiring connected to the piezoelectric element.

Furthermore, the inkjet recording head according to claim (2) is the inkjet recording head according to claim (1), characterized in that the channel substrate and the head case are made of the same material and are joined by solvent adhesive or ultrasonic adhesive. do.

[Function] According to the structure of the present invention, the flow path substrate and the head case are bonded to each other over the entire outer periphery of the flow path substrate, so that the seal between the flow path substrate and the head case can be achieved without using screws, gaskets, etc. properties and connection strength can be ensured.

[Example] An example of the present invention will be explained with reference to the drawings. Figure 1 shows
FIG. 2 is a front view of a channel substrate 1 according to the present invention. A flow path substrate 1 has a plurality of ink jet nozzles 7 passing through it in the thickness direction, and a flow path shape communicating with each of the ink jet nozzles 7 is carved by etching, molding, etc., and a diaphragm 2. A channel space 3 is formed by bonding with adhesive or solvent. Further, on the side of the flow path substrate 1 to which the diaphragm 2 is bonded, the outer peripheral area of the diaphragm 2 shown by the diagonal line in the figure is the bonding surface to the head case 6 shown in FIG. It is formed all over the outer periphery of. FIG. 2 is a perspective cross-sectional view when the flow path substrate 1 shown in FIG. It is fixed by. This mechanical deformation of the piezoelectric element 4 causes a pressure change in the flow path space 3 filled with ink, and ink droplets are ejected from the ink ejection nozzle 7. In addition, the head case 6 is arranged on the first side so as to seal the flow path substrate 1, the vibration plate 2, the piezoelectric element 4, and the FPC 5 for electrically wiring the piezoelectric element 4, except for the surface where the ink jet nozzles 7 are arranged. It is bonded to the channel substrate 1 in the entire area of the shaded area shown in the figure. Further, the head case 6 is provided with an opening 6a, and the FPC 5 is pulled out through this opening 6a. The direction of the arrow in the figure is
It shows the direction in which ink droplets are ejected. FIG. 3 is a longitudinal sectional view of the inkjet recording head of the present invention shown in FIG. 2, showing the structure in more detail.

In the structure of the present invention, since the head case 6 is bonded to the entire outer periphery of the flow path substrate 1, ink leaked from the ink jet nozzle 7 to the nozzle surface side of the flow path substrate 1 due to a purge operation, etc., flows. The nozzle surface and end surface of the circuit board 1 are
It can be prevented from entering the inside of the head where the electrical wiring system (piezoelectric element 4, FPC 5) is formed. Furthermore, since the head case 6 is bonded to the entire outer periphery of the channel substrate 1, the bonding area is wide and covers a wide range, and the connection strength between the channel substrate 1 and the head case 6 is extremely strong. Become something. In addition, because the head case 6 is bonded directly to the channel substrate 1 without using the diaphragm 2, the bonding surface is free from the influence of the thickness dimensional accuracy of the diaphragm 2 and the surface accuracy such as waviness. It is possible to ensure flatness without receiving any damage, and the reliability of adhesion can be dramatically improved.

It should be noted that the adhesive surface on the outer periphery of the channel substrate 1 shown by the shaded area in FIG. 1 should have the same width over the entire circumference to ensure uniform sealing performance and uniform adhesive strength over the entire circumference. It is also desirable for this reason.

Next, FIGS. 4 to 7 are partial detailed cross-sectional views showing an embodiment of the adhesive portion between the flow path substrate 1 and the head case 6 of the inkjet recording head of the present invention.

First, the embodiment shown in FIG. 4 is a case where the outer shape of the flow channel substrate 1 and the outer shape of the head case 6 match, or the outer shape of the head case 6 is inside than the outer shape of the flow channel substrate 1, and the entire head The external shape of the device is minimized, which has the advantage of miniaturization.

Next, in the embodiment shown in FIG. 5, the adhesive surface on the side of the head case 6 is provided at a position that is carved one step further from the tip of the outer circumferential wall of the head case 6, as shown in the figure. In this structure, the end surface of the flow path substrate 1 is surrounded by the outer circumferential wall of the head case 6, and when the printer is in its complete state, there is a risk of accidental rubbing of the paper, collision of the head with the end surface of the paper, etc. The bonded portion can also be protected from impactful external forces. In addition, since the adhesive surface of the head case 6 is carved to match the outer shape of the flow path substrate 1, the flow path substrate 1 and head case 6 are not easily bonded when bonded.
The fitting can be performed with reference to the outer peripheral wall of the adhesive surface of the head case 6. That is, the channel substrate 1 is positioned with respect to the head case 6 by a throwing method, and the number of manufacturing steps during bonding can be significantly reduced.

Next, the embodiment shown in FIG. 6 has the same structure as the embodiment shown in FIG.
It protrudes toward the nozzle surface from the nozzle surface. This structure not only has the same effect as the embodiment shown in FIG. 5, but also prevents the tip of the outer circumferential wall of the head case 6 from protruding from the nozzle surface when the paper accidentally rubs against the printer. This also has the effect of preventing the paper from rubbing only against the tip of the outer circumferential wall of the head case 6 and causing damage to the nozzle surface due to direct contact with the paper.

Next, the embodiment shown in FIG. 7 has the same structure as the embodiment shown in FIG. Board 1
As shown in the figure, a groove 6b is cut in one step between the adhesive surface and the adhesive surface. This structure not only has the same effect as the embodiment shown in FIGS. 5 and 6, but also absorbs the adhesive etc. that protrudes when bonding the flow path substrate 1 and the head case 6 into the groove 6b. This prevents the adhesive surface from lifting, etc. caused by overflowing adhesive. In addition, on the outer circumferential wall of the head case 6, by separating the tip portion that protects the channel substrate 1 from the adhesive surface by the groove 6b, the thickness of the outer circumferential wall can be reduced. It is possible to prevent molding defects caused by differences in thickness, etc., and to more reliably ensure the flatness of the bonding surface of the head case 6. Therefore, the reliability of adhesion is greatly improved.

Further, the inkjet recording head according to claim (2) has the same structural details as the inkjet recording head according to claim (1) shown in FIGS. 1 to 7, and its effects are also the same. However, the channel substrate 1 and head case 6 are
For example, since they are made of the same material as polycarbonate and polysulfon, solvent bonding or ultrasonic bonding is possible, and the bonding surface has the same very strong sealing properties and connection strength as an integral part. In addition, in solvent bonding or ultrasonic bonding, since the flow path substrate 1 and the head case 6 are integrated, that is, there is no intervening adhesive made of different materials, ink containing strong alkali, solvent, etc. When using the ink, the ink comes into contact with the adhesive layer, and the adhesive layer does not deteriorate or erode or change its ink resistance over time. Therefore,
This is very effective in ensuring permanent connection strength including ink resistance and sealing performance between the channel substrate 1 and the helad case 6.

In addition, in solvent bonding or ultrasonic bonding, since the surfaces of the channel substrate 1 and the head case 6 are melted and crushed to connect them, reliable bonding can be achieved even if the bonding surfaces have a certain level of flatness, surface precision, etc. Therefore, the tolerance range of flatness, surface precision, etc. of the bonding surface between the channel substrate 1 and the helad case 6 can be widened, which in turn leads to a reduction in component costs.

[Effects of the Invention] As explained above, according to the present invention, a non-bonded region of the diaphragm film is provided over the entire outer peripheral edge of the flow path substrate, a head case is adhered to that surface, and a non-bonded region of the diaphragm film is bonded to that surface, excluding the nozzle surface. By enclosing the flow path board, diaphragm, pressure generating element, electrical wiring system, etc., it is possible to ensure sealing performance and connection strength between the head cases around the entire circumference of the flow path board without using screws, gaskets, etc. , Rouzou old needle; old 〒dake φshi817
It is possible to provide an inkjet recording head of 651 Reitomi d Ensei-su, Sei$-Misaki.

[Brief explanation of drawings]

FIG. 1 is a front view of a channel substrate of an inkjet recording head of the present invention. FIG. 2 is a perspective sectional view of the inkjet recording head of the present invention. FIG. 3 is a longitudinal sectional view of the inkjet recording head of the present invention. FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are partial detailed sectional views of the connecting portion between the flow path substrate and the head case of the inkjet recording head of the present invention. Flow path substrate diaphragm Flow path space Piezoelectric element PC Head case Head case opening Head case dug groove Fink jet nozzle or above

Claims (2)

[Claims] (1) A flow path space communicating with a plurality of ink jet nozzles is formed by joining a flow path substrate provided with a flow path and a diaphragm, and a piezoelectric material bonded on the diaphragm corresponding to each flow path is formed. Applying a pressure change to the flow path space by mechanical deformation of the element,
In the inkjet recording head that performs recording on a recording medium by jetting ink from the ink jetting nozzle, a non-bonding region of the diaphragm is provided over the entire outer periphery of the flow path substrate, and a head case is adhered to that surface; An inkjet recording head characterized in that the head case is bonded so as to enclose the diaphragm, a piezoelectric element provided on the diaphragm, and electrical wiring connected to the piezoelectric element. (2) The inkjet recording head according to claim 1, wherein the flow path substrate and the head case are made of the same material and are bonded by solvent bonding or ultrasonic bonding.