JP2606955B2 - Ink jet recording head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink jet recording head.

[Prior Art] FIG. 5 is a sectional view for explaining an ink path of a recording head for a conventional ink jet printer, and FIG. 6 is a front view from a pressure generating chamber to an orifice of the recording head of FIG. It is a figure showing in the state which looked.

As shown in both figures, a slit 12 is formed in a plate 11 in the front part of a laminated body 10 formed by laminating a plurality of plates, and an orifice 14 and an ink A path 15 is formed. The ink introduction path 15 and the orifice 14 are formed so as to communicate with each other through the slit 12. The center of the slit 12 communicates with the orifice 14 as shown in FIG. The ink introduction path 15 communicates with an ink chamber 16 formed inside the laminate 10, and the ink chamber 16 communicates with an ink supply port 17 formed at the lower rear portion of the laminate 10.

A pressure generating chamber 18 is provided at a position below the orifice 14 at the rear of the laminated body 10, and the pressure generating chamber 18 and the orifice
14 is communicated with an ink passage 19. Ink passage
19 is formed in a crank shape by two horizontal parts and one vertical part. A vibrator 20 for generating pressure is provided behind the pressure generating chamber 18.

FIG. 7 is a diagram for explaining the operation of the recording head shown in FIG. When a voltage is applied from a voltage source 21 to a vibrator 20 as shown in FIG.
The ink in the pressure generating chamber 18 is pressurized. This pressure is transmitted through the ink passage 19, and the ink is discharged from the orifice 14 through the slit 12.
When the applied voltage is released, the bending of the vibrator 20 is restored, and the volume of the pressure generating chamber 18 returns to the original state. As a result, substantially the same amount of ink as the discharged ink is sucked into the ink passage 19 through the slit 12 and the orifice 14.

Generally, when printing using this type of recording head,
In some cases, air enters the print head, and the pressure generated in the pressure generating chamber 18 is absorbed by the air, so that ink is not ejected and a part of characters and numerals may be lost. To avoid such inconveniences,
Conventionally, negative pressure is generated inside the head by a negative pressure generating means such as a pump to expand and discharge the air that has entered the pressure generating chamber 18 or to apply a high-frequency high voltage to the vibrator 20. Had been exhausted by.

[Problems to be Solved by the Invention] However, according to the recording head having the structure shown in FIGS. 5 to 7, a long horizontal portion exists in the ink passage 19 connecting the pressure generating chamber 18 and the orifice 14. Air that has entered from the outside becomes bubbles 22 (FIG. 7) and easily stays in this horizontal portion, and it is not easy to remove the air even if a negative pressure is applied or high-frequency vibration is applied.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording head capable of efficiently discharging bubbles generated in an ink passage connecting a pressure generating chamber and an orifice inside the recording head.

[Means for Solving the Problems] According to the invention of the present application, the object described above is to provide a laminate in which a plurality of plates are laminated, an orifice opened on one surface of the laminate, and the other surface side of the laminate. A pressure generating chamber provided below the orifice and a plurality of holes penetrating each plate of the laminate in the thickness direction thereof are formed so as to communicate with each other, and communicate the pressure generating chamber with the orifice. This is achieved by providing an ink passage and communicating with the ink passage so that a hole penetrating through each plate becomes an upper position as approaching the orifice.

[Operation] The pressure generating chamber is provided below the orifice.
An ink passage communicating with the pressure generating chamber and the orifice is formed such that a plurality of holes penetrating each plate of the laminated body constituting the recording head in a thickness direction thereof communicate with each other, and a hole penetrating each plate. The ink passage communicates with the orifice so as to be closer to the orifice.
For this reason, the bubbles generated in the ink passage easily move in the orifice direction along the ink passage and are discharged to the outside.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view for explaining an ink path of an ink jet recording head according to a first embodiment of the present invention, and FIG. 2 is a front view from a pressure generating chamber to an orifice of the recording head of FIG. It is a figure showing in the state seen from.

As shown in both figures, a slit 32 is formed in a plate 31 at the front of a laminate 30 formed by laminating a plurality of plates, and an orifice 34 and ink A road 35 is formed. The ink introduction path 35 and the orifice 34 are formed so as to communicate with each other via the slit 32. The center of the slit 32 communicates with the orifice 34 as shown in FIG. The ink introduction passage 35 communicates with an ink chamber 36 formed inside the laminate 30, and the ink chamber 36 communicates with an ink supply port 37 formed at the lower rear portion of the laminate 30.

A pressure generating chamber 38 is provided below the orifice 34 at the rear of the laminate 30.
It communicates with 34 by an ink passage 39. Ink passage
Reference numeral 39 is mainly formed of a ramp that obliquely penetrates each plate of the laminate 30.

As described above, since the ink passage 39 is inclined obliquely from the pressure generating chamber 38 to the orifice 34, almost no horizontal portion exists in the ink passage 39. As a result, the air bubbles generated inside the pressure generating chamber 38 and the ink passage 39 are easily moved in the direction of the orifice 34 without remaining in the ink passage 39, and can be easily removed.

Such a laminated body 30 is formed by forming each hole in each plate of stainless steel or photosensitive glass by etching and laminating them, but is not limited thereto, and may be formed using a silicon wafer. Good.

In the present embodiment, the vibrator 40 has a thickness of 1 in the thickness direction.
It is mainly composed of a single piezoelectric body and a stainless steel plate, and is bent in the direction shown in FIG. 7 by the piezoelectric body and the stainless steel plate which contract when a voltage is applied. Such a piezoelectric body is formed by, for example, molding PZT (lead zircon titanate) into a chip shape, sintering, polarizing, and providing an electrode. However, the vibrator 40 is not limited to this kind of piezoelectric body, but may use other various vibrating elements.

 Next, the operation of the recording head of this embodiment will be described.

In FIG. 1, when a signal voltage is applied to the vibrator 40 from a signal source (not shown), the vibrator 40 bends toward the pressure generating chamber 38, and the ink in the pressure generating chamber 38 is pressurized. This pressure is transmitted through the ink passage 39, and the ink is discharged from the orifice 34 through the slit 32.
When the applied signal voltage is released, the bending of the vibrator 40 is restored,
The volume of the pressure generating chamber 38 returns to its original state. As a result, substantially the same amount of ink as ejected is supplied to the slit 32 and the orifice
Is sucked into the ink passage 39 via the

FIG. 3 is a sectional view for explaining the ink path of an ink jet recording head according to a second embodiment of the present invention, and FIG. 4 is a front view from the pressure generating chamber to the orifice of the recording head of FIG. It is a figure showing in the state seen from.

The difference between the second embodiment shown in FIG. 3 and the first embodiment is that the ink passage in the first embodiment is obliquely and smoothly inclined. In this case, the ink passage has a substantially oblique step shape.

In the second embodiment, as in the first embodiment, a slit 43 is formed in a front plate 42 of a laminated body 41 formed by laminating a plurality of plates.
Orifice 45 and ink introduction channel
46 are formed. Ink introduction channel 46 and orifice 45
Are formed so as to communicate with each other through the slit 43. The center of the slit 43 communicates with the orifice 45 as shown in FIG. The ink introduction path 46 communicates with an ink chamber 47 formed inside the laminate 41, and this ink chamber 47
47 communicates with an ink supply port 48 formed on the lower rear side of the laminated body 41.

A pressure generating chamber 49 is provided below the orifice 45 at the rear of the laminate 41, and the pressure generating chamber 49 and the orifice
45 is communicated with an ink passage 50. Ink passage
50 is formed by holes 50a to 50e vertically penetrating each plate of the stacked body 41 communicating with each other. A vibrator 51 for generating pressure is provided at the rear of the pressure generating chamber 49.

As described above, since the substantially oblique stepped ink passages 50 are formed through the respective stacked plates from the pressure generating chamber 49 to the orifice 45, a long horizontal portion does not exist in the ink passages 50. . As a result, the pressure chamber
Bubbles generated inside the ink passage 50 and the ink passage 50
It is easy to move in the direction of the orifice 45 without staying inside and can be easily removed.

In this embodiment, the ink passage is constituted by five plates. However, the number of plates is not limited to this, and may be any number as long as a substantially inclined stepped ink passage is constituted.

Next, the operation of the recording head according to the second embodiment is almost the same as that of the first embodiment, and the description is omitted.

Although one ink passage is shown in the first and second embodiments, a plurality of ink passages are actually provided along with the number of orifices and pressure generating chambers.

As described above, according to the above-described embodiment, not only is it easy to discharge air bubbles generated in the ink passage connecting the pressure chamber of the recording head and the orifice, but also by simply forming holes in each plate and stacking them. Since the ink passage can be formed, it is very easy to process.

[Effects of the Invention] As described above in detail, according to the present invention, an ink passage communicating with the pressure generating chamber and the orifice is formed by a plurality of holes penetrating each plate of the laminate in the thickness direction thereof. Since the plurality of holes communicate with each other so as to be located at an upper position as approaching the orifice, bubbles generated in an ink passage connecting the pressure generating chamber to the orifice can be efficiently discharged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining an ink path of an ink jet type recording head according to an embodiment of the present invention, and FIG. 2 is a front view from a pressure generating chamber to an orifice of the recording head of FIG. FIG. 3 is a cross-sectional view for explaining an ink path of an ink jet recording head according to a second embodiment of the present invention, and FIG. 4 is a diagram from a pressure generating chamber to an orifice of the recording head of FIG. FIG. 5 is a cross-sectional view for explaining the ink path of a recording head for a conventional ink jet printer, and FIG. 6 is a view from the pressure generating chamber of the recording head to the orifice in FIG. FIG. 7 is a diagram illustrating the operation of the recording head shown in FIG. 5 when viewed from the front. 30, 41 …… Laminated body, 31, 33, 42, 44 …… Plate, 32,
43 Slit, 34, 45 Orifice, 36, 47 Ink chamber, 37, 48 Ink supply port, 38, 49 Pressure generating chamber, 39, 50 Ink passage, 40, 51 ... vibrator.

Claims (1)

(57) [Claims] 1. A laminate in which a plurality of plates are laminated, an orifice opened on one surface of the laminate, and a pressure generating chamber provided below the orifice on the other surface of the laminate. A plurality of holes penetrating each plate of the laminate in the thickness direction thereof are formed so as to communicate with each other, and the ink supply passage communicating the pressure generating chamber and the orifice is provided. An ink-jet recording head, wherein the ink passage is communicated such that a penetrated hole is positioned at an upper position as approaching the orifice.