JPH06143567A - Ink jet head - Google Patents

Abstract

PURPOSE:To eliminate deformation of a nozzle plate at the time of pressurizing ink in the case of discharging the ink from a nozzle and improve ink discharging speed and discharged ink quantity by providing an auxiliary member made or a metal plate or a metal plate and photosensitive resin on at least one surface of the plate. CONSTITUTION:An ink jet head comprises a nozzle plate 13 having a nozzle 11 for discharging ink, an opposite plate 12 having an energy generator 14 used to discharge the ink from the nozzle 11, and a wall member 15 disposed at an intermediate between the plates 13 and 12 to form a pressure chamber 16 together with the plates 13, 12. An auxiliary member 19 made of a metal plate or a metal plate and photosensitive resin is provided at least on one side surface of the plate 13. As a result, deformation of the nozzle plate at the time of pressurizing ink in the case of discharging the ink from the nozzle is eliminated, and ink discharging speed and discharged ink quantity can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head used in an apparatus such as a printer which ejects ink drops to form an ink image on a medium such as recording paper.

[0002]

2. Description of the Related Art A so-called face eject type ink jet head having a nozzle plate having nozzles for ejecting ink is disclosed in, for example, Japanese Patent Laid-Open No. 4-1.
Many other examples of the '052 publication are disclosed. The outline of the structure will be described. FIG. 5 is a schematic sectional view of a face eject type inkjet head. Nozzle plate 13 provided with nozzles 11 for ejecting ink
A wall member 15 is joined to the middle of the counter plate 12 having the piezoelectric element 14 as an energy generator used for ejecting ink from the nozzle 11. A space defined by the nozzle plate 13, the counter plate 12, and the wall member 15 forms a pressure chamber 16, and a part of the wall member 15 forms a throttle channel 17.

In the ink jet head thus constructed, the opposing plate 12 is bent by the deformation of the piezoelectric element 14 due to charging and discharging, pressurizing the ink in the pressure chamber 16 and ejecting the ink from the nozzle 11.

[0004]

In such a face eject type ink jet head, when the opposing plate is bent to press the ink in the pressure chamber, the nozzle plate is deformed by receiving the pressure from the ink. However, there is a problem that the pressure used for ejecting ink is lost, which causes a decrease in ink ejection speed and a decrease in ejected ink amount. Also, in the case of an inkjet head with a high density of multiple nozzles, the nozzle spacing is narrow,
The deformation of the nozzle plate is transmitted to the adjacent nozzles, and the nozzle at the center of the nozzle array has a problem that the ink ejection speed and the ejected ink amount are significantly reduced as compared with the nozzles at the ends of the nozzle row.

One of the methods for solving these problems is to
There is a method of thickening the nozzle plate to eliminate the deformation of the nozzle plate. However, if the nozzle plate is made thicker, it becomes difficult to form the nozzle holes, so the accuracy of the position and shape of the nozzle holes deteriorates, the ejection characteristics become unstable, and the manufacturing cost increases due to a decrease in yield and the like.

The present invention solves this problem.
The purpose of this is to eliminate the deformation of the nozzle plate when the ink is pressed, and thus the ink ejection characteristics are good, and an ink jet head with uniform ink ejection characteristics between nozzles in the case of a multi-nozzle arrangement can be easily and easily manufactured. It is to provide at low cost.

[0007]

An ink jet head of the present invention includes a nozzle plate having nozzles for ejecting ink, and a counter plate having an energy generator used for ejecting ink from the nozzles. And a wall member that is located between the nozzle plate and the counter plate and that forms a pressure chamber with the nozzle plate and the counter plate, and an auxiliary member is provided on at least one surface of the nozzle plate. And

[0008]

The present invention will be described below with reference to specific examples, but the present invention is not limited thereto.

[Embodiment 1] FIG. 1 is a schematic sectional view of an embodiment of an ink jet head according to the present invention, and FIG. 2 is a perspective view thereof. In FIG. 2, as an example of a multi-nozzle arrangement, 3
The case of nozzle arrangement is shown.

As the material of the auxiliary member 19, a material having a high longitudinal elastic modulus and easy to process is preferable, and specifically, metal, particularly stainless steel, nickel and the like are preferable. The auxiliary member 19 is provided with a hole 20 at a portion corresponding to the nozzle 11, and the hole 20 is formed by a known method such as pressing, etching, wire electric discharge machining, or the like. Also, hole 2
Since the diameter of 0 may be larger than the diameter of the nozzle 11,
The accuracy of the position and diameter of the holes may be low, the holes 20 are easily processed, and the yield is improved. Further, although only one auxiliary member 19 is shown in FIG. 1, when a thick auxiliary member is required to eliminate vibration of the nozzle plate, a thin auxiliary member that is easy to process is used instead of the thick auxiliary member that is difficult to process. Since two or more sheets may be used, the yield is improved.

The auxiliary member 19 is attached to the nozzle plate 13 with a small amount of adhesive. Auxiliary member 19
After adhering the nozzle plate 13 to the nozzle plate 13, the nozzle plate 13, the wall member 15, and the counter plate 12 are joined. Alternatively, the nozzle plate 13, the wall member 15, and the counter plate 1
After joining the two, the auxiliary member 19 and the nozzle plate 13
May be attached. Further, although the auxiliary member 19 is bonded to the ejection surface side of the nozzle plate 13 in FIG. 1,
If necessary, it may be attached to the pressure chamber side of the nozzle plate 13 as shown in FIG. In this case, after the auxiliary member 19 and the nozzle plate 13 are bonded together with a small amount of adhesive, the auxiliary member 19, the wall member 15, and the counter plate 12 are joined.

[Embodiment 2] FIG. 4 is a schematic sectional view of another embodiment of the ink jet head according to the present invention.

The auxiliary member 19 is composed of an auxiliary member main body 21 and a hole forming portion 22.

As with the first embodiment, the material of the auxiliary member main body 21 is preferably a material having a high longitudinal elastic modulus and easy to process. Specifically, metal, especially stainless steel, nickel, etc. are preferable. The part corresponding to the hole forming part 22 is processed by pressing,
It is made by a known method such as etching. This portion is a hole larger than the hole 20 of the first embodiment, and may be connected to a hole next to the hole 20 in some cases, so that the processing is further facilitated.

As the material of the hole forming portion 22, a known photosensitive resin is used because it is easy to form the hole 20 and the position and diameter of the hole 20 are accurate. Hole forming part 2
The processing of the two holes 20 is made by a known photolithography process. If a thick auxiliary member is required as in the first embodiment, two or more auxiliary members 19 may be used.

The auxiliary member 19 is attached to the nozzle plate 13 with a small amount of adhesive as in the first embodiment. After adhering the auxiliary member 19 and the nozzle plate 13, the nozzle plate 13, the wall member 15 and the counter plate 1
Join two. Or the nozzle plate 13 and the wall member 15
The auxiliary member 19 and the nozzle plate 13 may be bonded together after the and the counter plate 12 are joined. Further, the auxiliary member 19 may be attached to the pressure chamber side of the nozzle plate 13 as in the first embodiment. In this case, after the auxiliary member 19 and the nozzle plate 13 are bonded together with a small amount of adhesive, the auxiliary member 19, the wall member 15, and the counter plate 12 are joined.

An ink jet head having 24 nozzles was prepared based on Examples 1 and 2, and the ink ejection speed and the ejected ink amount were measured. Further, as a comparative example, an ink jet head having 24 nozzles arranged without an auxiliary member was prepared, and the ink discharge speed and the discharged ink amount were measured. The results are shown in Table 1.

[0018]

[Table 1]

In each of Examples 1 and 2, good results were obtained that the ink ejection speed was high, the amount of ejected ink was large, and the difference between the maximum value and the minimum value between the nozzles was small. On the other hand, in the comparative example, the difference between the maximum value and the minimum value between the nozzles was large and it was not suitable.

[0020]

As described above, the ink jet head of the present invention has a nozzle plate having nozzles for ejecting ink and a counter plate having an energy generator used for ejecting ink from the nozzles. And a wall member located between the nozzle plate and the counter plate and forming a pressure chamber with the nozzle plate and the counter plate,
In the inkjet head including the above, an auxiliary member is provided on at least one surface of the nozzle plate.
Therefore, when the energy generated from the energy generator is used for pressurizing the ink, the pressure loss due to the deformation of the nozzle plate is eliminated, and high-speed printing by improving the ink ejection speed and high-density printing by improving the ejected ink amount are achieved. It will be possible. Further, since the deformation of the nozzle plate is not transmitted to the adjacent nozzles, stable ejection characteristics can be obtained over all nozzles even in the case of a multi-nozzle arrangement. Furthermore, since the nozzle plate is not thickened, processing becomes easier,
The accuracy of the position and shape of the nozzle hole is improved, the yield is improved, and the increase in manufacturing cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an inkjet head of the present invention.

FIG. 2 is a perspective view of FIG.

FIG. 3 is a sectional view of another embodiment of the inkjet head of the present invention.

FIG. 4 is a cross-sectional view of another embodiment of the inkjet head of the present invention.

FIG. 5 is a cross-sectional view of a conventional inkjet head.

[Explanation of symbols]

 11 Nozzle 12 Opposing Plate 13 Nozzle Plate 14 Piezoelectric Element as Energy Generator 15 Wall Member 16 Pressure Chamber 17 Throttling Channel 18 Common Ink Chamber 19 Auxiliary Member 20 Hole 21 Auxiliary Member Main Body 22 Hole Forming Part

Claims (1)

[Claims] 1. A nozzle plate provided with nozzles for ejecting ink, a counter plate provided with an energy generator used for ejecting ink from the nozzles, and located between the nozzle plate and the counter plate. An inkjet head comprising a nozzle plate and a wall member that forms a pressure chamber together with a counter plate, wherein an auxiliary member is provided on at least one surface of the nozzle plate.