JPS60109847A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To permit a high density recording even with the use of a relatively large nozzle by forming a portion of the wall which composes an orifice with flexible material and by connecting the flexible material and an ink chamber with an ink passage. CONSTITUTION:The ink sent through an ink supply route 7 fills an ink chamber 9, and an ink passage 25 from the ink chamber 9 to a nozzle 12 and ink passages 10 to the flexible material 11 are provided to form a recording head. The ink passages 10 are longer than the ink passage 25 and are designed to have a larger resistance of passage. In view of the above, the pressure wave applied to the ink chamber 9 by a piezoelectric element 8 is transmitted to the nozzle 12 first and, then, to the flexible material 11. In the above, when the pressure wave is transmitted to the nozzle 13 only, an ink column is discharged from the nozzle 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a non-impact recording device, and particularly to a recording head of an inkjet recording device that ejects ink particles.

[Technical background of the invention and one point] Inkjet type non-impact printers, which have the advantage of being less noisy than type type and wire dot type impact printers, have recently been attracting a lot of attention.

Inkjet recording is a method of recording by jetting ink particles onto a recording medium from a nozzle.

FIG. 1 shows an example of the prior art most relevant to the present invention. In this head, ink is sent from an ink supply path 1 into an ink chamber 3, forming at least a portion of a wall constituting the ink chamber. The increase in pressure within the ink chamber due to the deformation of the piezo element 2 is used to cause ink particles 5 to fly from the nozzle 4 in the direction of the recording paper 6. This type of recording head has a simple configuration of the ink droplet generation mechanism, and is therefore suitable for reducing the size and weight of the apparatus.

However, in this method, the diameter of the ink particles generated is larger than the nozzle diameter, so it is necessary to reduce the nozzle diameter in order to increase the recording density. Therefore, there is a drawback that the ink is likely to solidify and cause nozzle clogging.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned drawback f, and provides a recording head for an inkjet recording apparatus that can achieve high-density deployment even with nozzles having a relatively large inner diameter.

[Summary of the invention]

In this invention, a part of the wall surface that forms the nozzle is made into a flexible member, and immediately after the ink column is ejected from the nozzle outlet, the part of the wall that forms the nozzle is deformed using a piezo element or the like, and the cross-sectional area of the flow path of the nozzle is rapidly increased. By reducing
The volume of ink that forms ink particles is minimized,
A recording head for an inkjet recording device that generates small ink particles can be realized.

〔Effect of the invention〕

According to this invention, it is possible to generate ink particles smaller than those of a conventional recording head even if the nozzle inner diameter is the same. Therefore, when recording with ink particles of the same particle size, a nozzle with a larger nozzle diameter than that of a conventional recording head can be used, so that clogging is less likely to occur than in the conventional apparatus.

Furthermore, since the ink particles are more easily cut off when they leave the nozzle outlet, the rate at which ink particles are generated can be increased, making it possible to perform higher-speed recording than with conventional devices.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an embodiment of the recording head of the inkjet recording apparatus according to the present invention. This recording head uses ink sent through the ink supply path 7.

The ink chamber 9 is filled with nozzle 1 from this ink chamber.
The ink flow path 10 is longer than the ink flow path 25, and the flow path resistance is set to be larger. has been done. Therefore, the pressure wave applied to the ink chamber by the piezo element 8 first reaches the nozzle 12.
After that, it is transmitted to the town report member 11.

The conditions near the nozzle at this time are shown in Figures 3 (a) to (C).
I will explain in more detail. FIG. 3(C) shows a case where the pressure wave is transmitted only to the nozzle 13, and an ink column is ejected from the nozzle. In FIG. 3(b), a pressure wave is transmitted to the flexible member 14, deforming it in a state occurring at the time following FIG. 3(a), and a pressure wave is generated in the direction of arrow 17.26. Due to this pressure wave in the direction of arrow 17, the ink supply towards the nozzle is reduced and less ink is supplied to the ink column, so the base of the ink column begins to become thinner earlier than in the conventional nozzle.

Figure 3 TC) shows the state in which the removable member 14 has returned to its original shape, and because the cross-sectional area of the flow path has increased, the ink returns quickly in the direction of the arrow 19, and the ink returns to the nozzle exit. This will accelerate the cutting of the ink particles 27. Generated ink particles 27'f: Since the flow rate is reduced as shown in FIG. 3(b), the formed ink particles have a smaller particle size than a normal nozzle with the same inner diameter.

FIG. 4 shows a modification of the invention. In this case, the ink chamber 22 and the ink passage 24 are communicated with each other near the outlet of the nozzle 23. In this case, the pressure wave generated by the deformation of the piezo element 21 is transmitted through the ink passage, and a contracted flow is formed in the flow inside the nozzle as shown at 28 in FIG. 5, thereby obtaining the same effect as the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example of an inkjet recording head, FIG. 2 is a sectional view showing an embodiment of an inkjet recording head according to the present invention, and FIGS. FIG. 4 is a sectional view showing a modification of the present invention; FIG. 1M5 is a sectional view illustrating the state of the nozzle in a modification of the invention. 1.7.20... Ink supply path 2.8.21... Piezo element 3.9.22... Ink chamber 4.12, 13.23... Nozzle 5.27...・Ink particles 6...Recording paper 10.1
5, 24.25... Ink flow path 11.14... Possible member 28... Reduction agent Patent attorney rule Chika
Kensuke (1 person) Figure 1 Figure 2 Figure 3 Figure 3 (C) Figure 4 Figure 5

Claims (3)

[Claims] (1) an ink chamber, an orifice communicating with the ink chamber, and an ink supply mechanism for feeding ink to the ink chamber;
An inkjet recording head comprising a device for pushing out the ink in the ink chamber to eject ink particles from an orifice, wherein a part of the wall forming the orifice is made of flexible material, and the device for pushing out the ink in the ink chamber An inkjet recording head characterized in that the flexible member and the ink chamber are configured to be connected to each other by an ink passage so that the extruded ink can apply pressure to the flexible member. (2) The inkjet recording head according to claim 1, wherein the flow resistance of the ink passage formed between the flexible member and the ink chamber is greater than the flow resistance of the orifice. (3) Inkjet recording according to claim 1 or 2, wherein the length of the ink connection formed between the removable member and the ink chamber is longer than the length of the orifice. head.