JP2718010B2 - Inkjet head for printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] In an ink jet head for an ink jet printer, a novel structure of an ink passage formed in a flow path plate,
In particular, with regard to the method at the time of its manufacture, the object is to prevent displacement of the position of the support wall constituting the ink passage when joining the plates constituting the ink jet head and to form an accurate passage shape and a chart, A passage plate formed with an etching process to form a common ink chamber and a plurality of ink passages each having a nozzle at the tip and communicating with the common ink chamber. A vibration plate, and an ink jet head for an ink jet printer, which is formed by integrally joining three-layer plates of a substrate supporting a lower part of the flow path plate, wherein an ink passage formed in the flow path plate Is formed by a half-etched portion leaving a part of the plate thickness of an inlet area connected to the common ink chamber and the nozzle area, and a middle portion of the half-etched part being removed. Configured to be formed by the grayed portion. The present invention relates to a novel structure of an inkjet head for an inkjet printer. In particular, the present invention relates to a method for forming an ink passage having an ink jet nozzle in a flow path plate. [Prior Art] As shown in FIGS. 4 and 5, an ink jet head includes a common ink chamber 1, a plurality of ink passages 2 communicating therewith, and a flow path plate 4 formed by etching an ink jet nozzle 3; A substrate 5 supporting this from below and a diaphragm 6 covering the lid from above are joined in a sandwich manner to three stainless steel plates, and an ink supply device 7, a piezoelectric element 8 and Is configured.
Then, vibration is applied to the vibration plate 6 by applying a pulse to the piezoelectric element 8 as necessary, and the ink supply device 7
The ink supplied to the nozzles 3 is ejected as small droplets, and necessary characters and images are printed on paper. In this ink jet head, the production accuracy of the nozzles 3 and the ink passages 2 formed in the flow path plate 4 is a crucial factor that affects the quality of the ejected ink droplets and, consequently, the quality of the obtained print. is there. These are formed together with the common ink chamber 1 by an etching process on a stainless plate having a thickness of about 100 μm, which constitutes the substrate 5.
At this time, the common ink chamber 1 and the ink passage 2 are completely removed by etching. However, only the tip region of the nozzle 3 which requires a cross-sectional accuracy is, as shown in FIG.
It is formed by a so-called "half-etching" technique, which is corroded to half the thickness of the sheet and then left behind. Therefore, the flow path plate 4
In the manufacturing process, the support wall 2 ′ between the adjacent ink passages 2 is in a state of being supported in a cantilever manner by the half etching region H remaining at the tip of the nozzle 3. [Problems to be Solved by the Invention] Each of the plates 4, 5, and 6 is subjected to nickel plating, laminated in the order described above, heated under pressure to melt the nickel plating layer, and integrally. Diffusion bonded and fixed. Since the support wall 2 'has a relatively long dimension and the minimum width thereof is about 0.3 mm, it is easy to move unexpectedly at the time of plating or at the stage of preparing for joining, so that the shape of the flow path is designed. And tended to be damaged. This naturally deteriorates the characteristics of the flow path, which is not preferable. [Means for Solving the Problems] An object of the present invention is to provide a structure of an ink jet head capable of manufacturing a channel plate having excellent stability in order to solve such disadvantages of the related art. And That is, the present invention provides a flow path plate in which a thin plate is etched to form a common ink chamber and a plurality of ink passages each having a nozzle at the tip and communicating with the common ink chamber. A vibration plate for mounting a piezoelectric element, and an ink jet head for an ink jet printer configured by integrally joining a three-layer plate of a substrate supporting a lower portion of the flow path plate, wherein the flow path An ink passage formed in the plate is formed by a half-etched portion leaving a part of the plate thickness of an inlet region connected to the common ink chamber and the nozzle region, and a middle portion of the half-etched portion removed. The present invention relates to an inkjet head characterized by being formed by: [Operation] Each ink passage of the head of the present invention has a nozzle region corresponding to both ends thereof and an inlet region from the common ink chamber,
Since it is connected to the supporting wall adjacent thereto by the half-etched portion, each supporting wall is in a state of being supported at both ends by this, and the position is stably fixed, and the plating and joining processing of each plate are performed. In this case, the flow path is prevented from being shifted, and an ink path having a predetermined shape and size is formed. Further, if a structure is adopted in which an island portion having the original thickness which is not etched at all is left at the center of the half-etched portion in the entrance area of the ink passage, the pressing force is sufficient when the three plates are joined. Since it is given also to the region, the joining state is perfect, which is preferable. Hereinafter, the present invention will be described in more detail based on preferred embodiments shown in the drawings. Embodiment FIG. 1 is a plan view of a flow path plate 4 of an inkjet head according to an embodiment of the present invention. This flow path plate 4 is the fourth
As in the conventional example shown in FIGS.
And a plurality of ink passages 2 branched therefrom and nozzles 3 constituting outlets thereof are formed by etching, and a vibration plate and a substrate (not shown) are laminated and fixed in a sandwich manner on the upper and lower sides thereof and incorporated into the head. . To form the ink passage 2, first, a plate made of unprocessed stainless steel having a thickness of about 100 μm is coated with a photoresist or the like to cover the region of the support wall 2 ′ between the ink passages and the ink passage 2 and the common ink chamber. Patterning is performed so as to expose 1 and the like. At this time, care should be taken so that the inlet area of the ink passage 2 branched from the common ink chamber 1 and the area of the nozzle 3 corresponding to the outlet of the passage 2 have a narrow exposure width. When the corrosive liquid is sprayed from above and left for a certain period of time, the common ink chamber 1 and the intermediate area of the ink passage 2 which are exposed over a wide area are eroded at a high speed by the corrosive liquid and completely fall off. On the other hand, in the nozzle region and the inlet region having a narrow exposure width, only a part is eroded so that the corrosive liquid gradually penetrates from the exposed portion to form an arc-shaped cross-section, and a so-called “half-etched” portion H is formed. It is formed.
This state is shown in FIG. 2 and FIG. As described above, in the present invention, each ink passage 2 is interconnected with the adjacent support wall 2 'by the half-etched portions H formed in the inlet and outlet areas at both ends, so that the ink passage 2 is only halfway in the outlet area. An etched portion is formed, thereby having a very stable position holding property as compared with a conventional channel plate in which each support wall is held in a cantilever manner.
For this reason, in the subsequent nickel plating process and the laminating / joining process of each plate, the accident that the ink passage is displaced or deformed is drastically reduced, and the manufacturing accuracy of the head is improved. FIG. 3 shows an inlet area of the ink passage 2 in the flow path plate of the head according to the second embodiment of the present invention. In this example as well, a half-etched portion H is formed in this region, but a portion X which has not been subjected to any etching process is left in an island shape at the center of the half-etched portion. The purpose of the island-shaped portion X is to ensure that the pressing force applied from above and below the plates at the time of joining the above-mentioned plates is sufficiently applied to the island-shaped portion X and that the joining is performed well. It is necessary that the size of the island-shaped portion X is regulated to such an extent that a passage having a width of about 2 to 3 times or more the exit width of the nozzle 3 is left in the ink passage 2 around the island portion X. If the size of the island exceeds this, the flow of ink is blocked, and good ink ejection from the nozzles cannot be obtained. With this configuration, the integrity of each plate is properly ensured. [Effects of the Invention] As described in detail above, according to the present invention, the inlet and outlet regions corresponding to both ends of each ink passage formed in the flow path plate by the etching process are formed as a half-etched portion with the adjacent support wall. , The position of the support wall is fixed, the position of the ink passage is not shifted or the shape is changed during the subsequent plating process or joining process, and the manufacturing accuracy is improved. I do. In addition, when an unprocessed island portion is left in the half-etched portion in the entrance region, the pressing force is sufficiently transmitted in the bonding process.
It is desirable that the bonding be performed firmly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a flow path plate of an ink jet head of the present invention, FIG. 2 is an enlarged view of an ink passage inlet portion, and FIG. 3 is an ink of another example of the present invention. FIG. 4 is an enlarged view of an inlet portion of a passage, FIG. 4 is a plan view of a channel plate of a conventional ink jet head, FIG. 5 is a side sectional view thereof, and FIG. 6 is an enlarged view of a nozzle region. DESCRIPTION OF SYMBOLS 1 ... Common ink chamber, 2 ... Ink passage, 3 ... Nozzle, 4 ... Flow path plate, 5 ... Substrate, 6 ... Vibration plate, 7 ... Ink supply device, 8 ... Piezoelectric element, X ... island-shaped part, H ... half-etched part.

   ────────────────────────────────────────────────── ─── Continuation of front page    (56) References JP-A-61-29552 (JP, A)                 JP-A-58-124666 (JP, A)                 Actual opening 58-1747 (JP, U)

Claims (1)

(57) [Claims] A flow path plate formed by etching a thin plate to form a common ink chamber (1) and a plurality of ink passages (2) each having a nozzle (3) at the tip and communicating with the common ink chamber (1). (4) A three-layer plate of a vibrating plate (6) for covering the upper part thereof and mounting the piezoelectric element (8) and a substrate (5) for supporting the lower part of the flow path plate (4). An ink jet head for an ink jet printer, which is formed by joining together, an ink passage (2) formed in the flow path plate (4) has an inlet area connected to the common ink chamber (1). The nozzle (3) region is formed by a half-etched portion leaving a part of the plate thickness, and an intermediate portion is formed by a completely etched portion removed. 2. 2. An ink jet head according to claim 1, wherein an island portion (X) that is not etched at all is left at the center of the half-etched portion in the entrance area of the ink passage (2). .