JPH0229342A - inkjet recording device - Google Patents

Abstract

PURPOSE:To enhance the degree of integration of an ink jet recording head by a construction wherein a first electric field-generating means for causing a change in the shape of a meniscus of a recording material formed at a recording material-ejecting port and a second electric field-generating means for imparting a flight force to the meniscus changed in shape exert forces in different directions on the meniscus. CONSTITUTION:A bias voltage is constantly applied to each of a control electrode 2 and a first common electrode 3 so as to enable switching with a low voltage. With a voltage applied to the control electrode 2 from a driving power supply 7 according to a picture element signal, an electric field is generated in the vicinity of an ink-ejecting port 4, and a positive electric charge is induced on the surface of an ink 8, so that an ink meniscus 8' formed at the port 4 is normally in the state of a meniscus 8'' changed in shape by being pulled toward the first common electrode. When a bias voltage overcoming the electric field between the first common electrode 3 and the control electrode 2 is applied to a second common electrode 5, the meniscus 8'' is pulled toward the electrode 5, resulting in recording on a recording paper disposed on a front face of the electrode 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording device, and more particularly, to a head portion of an inkjet recording device, and can be used in printers and the like.

Figure 5 is a cross-sectional view showing an example of a head section of a conventional inkjet recording device. In the figure, 20 is an ink supply path communicating with an ink reservoir, and one end of the ink supply path 20 An ink discharge port 21 is provided, and the ink discharge port 2
1, an air outlet 22 is bored in the electrode plate 23. The air flow sent from the air supply path 24 flows into the air chamber 26 formed by the electrode plate 23 and the body 25.
The air flows out from the air outlet 22 through the air layer 27.

Ink is ejected or stopped by an electric field force generated by a signal source 28 into a space having a rapid change in pressure gradient caused by an air flow, and the ink is ejected or stopped by an electric field generated by a signal source 28. Although the ink is ejected through the ejection port 22 (see Japanese Unexamined Patent Publication No. 57-120452), ink mist may adhere to the electrode 23.

There is a risk that mist will float around the electrode 23, affecting the strength of the electric field and causing performance deterioration. In addition, some devices are equipped with a cleaning device to eliminate these drawbacks (see Japanese Patent Laid-Open No. 61-152457), but in all cases, the hole diameter of the air outlet provided in the electrode plate is at least Because it needs to be large enough for ink droplets to pass through,
It has been difficult to achieve high integration of inkjet recording heads. In addition, the common electrode and control electrode (ink ejection port)
A recording paper is interposed between
(Refer to Publication No. 9) had the disadvantage that the gap between the electrodes had to be large and that a high voltage was required.

1-One Lamp The present invention was made in view of the above-mentioned circumstances.
In particular, this was done with the aim of increasing the integration of the head, lowering the switching voltage of the recording signal to reduce costs, and improving the image quality of printing.

Furthermore, in order to achieve the above object, the present invention includes a J-th electric field generating means for causing a shape change in a recording material meniscus formed at a recording material ejection port, and a J.sup. and a second electric field force generating means for applying a flying force, and the first and second electric field force generating means are characterized in that the directions of forces exerted on the recording medium meniscus are different from each other.

Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a cross-sectional view of essential parts for explaining an embodiment of an inkjet recording apparatus according to the present invention. In FIG. A control electrode 3 is a first common electrode disposed opposite to and close to the ejection port 4 of the ink supply pipe 1; 5 is a control electrode that feeds the recording paper 6 substantially parallel to the control electrode 2 and the first common electrode 3; 7 is a drive power supply that supplies current to the control electrode; a bias voltage is always applied to the control voltage 2 and the first common electrode 3, and switching is performed at a low voltage. When a voltage is applied from the driving power supply 7 to the control electrode 2 in response to the 6-pixel signal that is set so that A charge is induced Jl,
An ink meniscus 8' is always formed in the ink discharge eye 4.

It is pulled toward the first common electrode and changes its shape to become a meniscus 8''. At this time, the second common electrode 5 is normally affected by the electric field between the first common electrode 3 and the control electrode 2. When a bias voltage set to a strong value is applied,
The meniscus 8″ is pulled toward the second common electrode 5,
attached to the recording paper 6 provided on the front surface of the second common electrode 5;
2 and 3 are cross-sectional views for explaining other embodiments of the inkjet recording apparatus according to the present invention, and FIG. 4 is a perspective view of the main part of FIG. 3.

In the figure, parts having the same functions as in FIG. 1 are given the same reference numerals as in FIG. 1.

In FIG. 2, the first common electrode 3 and the second common electrode 5 are arranged in the direction in which the ink 8 is ejected from the ejection opening of the ink supply pipe 1, which makes it easier for the ink 8 to fly. The response frequency is increased, and ink stains on the first common electrode 3 are reduced.

FIG. 3 shows that the second common electrode 5 is an ink meniscus 8''.
10 is an air flow supply pipe, and 11 is a recess provided in the discharge port 4 of the ink supply pipe 1. In this case, the jth,
The response is dramatically improved compared to the embodiment shown in FIG. 2 and FIG. 2, and the first common electrode 3 is free from contamination.

FIG. 4 is an enlarged perspective view showing the recess 11 shown in FIG. 3. The recess 11 provided in the ejection port 4 guides ink droplets so that they can easily fly.

As is clear from the explanation in Section 1.1, according to the present invention, the recording paper 6 is not interposed between the common electrode 3 and the control electrode 2; Compared to the case where the recording paper requires a gap of about 0.3 to 0.5 m, the gap can be reduced to 0.111 m or less, and the inkjet recording head can be highly integrated. Since there is no intervention, a strong electric field can be obtained with a small voltage, and therefore the switching voltage can be reduced, and the cost 1- of the drive circuit can be significantly lowered.

In addition, if an air flow 9 is generated at the end of the first common electrode 3 facing the ejection port 4 of the ink supply pipe 1, contamination due to ink mist etc. generated when ink is ejected from the ejection port 4 may occur. This improves reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts for explaining one embodiment of an inkjet recording apparatus according to the present invention, and FIGS. 2 and 3 are for explaining other embodiments of the inkjet recording apparatus according to the present invention, respectively. FIG. 4 is a perspective view of the concave portion of FIG. 3, and FIG. 5 is a diagram for explaining an example of a conventional inkjet recording apparatus. DESCRIPTION OF SYMBOLS 1... Ink supply pipe, 2... Control electrode, 3... First common electrode, 4... Discharge port, 5... Second common electrode,
6... Recording paper. Patent applicant Ricoh Co., Ltd.

Claims (1)

[Scope of Claims] 1. A first electric field force generation means that causes a shape change to a recording body meniscus formed at a recording body ejection port, and a second electric field force generation means that gives a flying force to the shape-changed meniscus. an inkjet recording apparatus, characterized in that the directions of forces exerted on the meniscus of the recording medium by the first and second electric field force generating means are different from each other. 2. The inkjet recording apparatus according to claim 1, wherein an air flow is applied to the first electric field force generating means or the second electric field force generating means.