JPS58151257A - Inkjet recording device - Google Patents

Abstract

PURPOSE:To obtain the titled device wherein an electrode structure is simplified and the integration in multiple constitution is easy, by providing a second electrode at the rear of a first electrode provided in the inner wall of a nozzle or in the vicinity of the wall through an ink layer, and applying a picture signal across both electrodes. CONSTITUTION:The first electrode 6 is provided in the inner walls of orifices 4 or in the vicinity thereof. The second electrode 7 is provided at the rear of an orifice plate part 3 in common with respect to the orifices. A third electrode 9 is provided at the back of recording paper 8 in common with the orifices and biased to a high voltage of 2-4kV. The second electrode 7 is grounded to a the ground level. The positive pulse shaped picture signal is imparted to the first electrode 6. A force generated by polarization and a coulomb's force act on ink 5 in the orifice 4. Ink drops are injected from the orifices 4 in response to the picture signal, and a picture is printed on the recording paper 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an inkjet recording device, and in particular, in an electric field on-demand type inkjet needle dispensing device, the electrode structure is simplified, thereby improving illumination in multi-configuration. This makes it easier to

Mr. Motoyama has already proposed an electric field on-demand type inkjet recording device (for example, in JP-A-5
(See Publication No. 6-8268 and Publication No. 56-8269.)
, conventional electric field on-demand, IIH reinkjet recording device has an orifice in the shape of a small bag (squeezed diameter) on the outlet side on an insulating substrate, and first and second electrodes are installed on the ink chamber side and the outlet side 1 of this orifice. An image signal is applied between the first @ electrode and the second electrode to cause ink droplets to be ejected from the orifice.

Therefore, in the conventional electric field on-demand type inkjet recording device, 1. When a plurality of orifices are provided in order to have a multi-printing configuration, the diameter of the orifice on the ink chamber side is large, so the accumulation effect is not improved. figure,
Furthermore, since the diameter of the ink chamber side electrode must be increased, there are drawbacks such as difficulty in integration.

The present invention has been made in order to eliminate the drawbacks of the prior art as described above. In particular, a first electrode is provided on or near the inner wall of a nozzle, and a second electrode is provided behind the first electrode via an ink layer. The electrode structure is simplified by providing a pole 2 and applying an image signal between the first electrode and the second electrode, thereby facilitating integration in the case of multi-configuration.

FIG. 1 is a side sectional view of a main part for explaining an embodiment of an inkjet recording apparatus according to the present invention, and FIG. 2 is a front view of the orifice plate section shown in FIG. static pressure ink supply tank; 2 is an inkjet head; 3 is an orifice plate; 4 is an orifice (nozzle);
1 is an ink layer, 6 is a first electrode, 7 is a second electrode, 8 is a recording paper, and 9 is a third electrode.
m) 4 is provided, the inner wall of which is provided with a 1st N, pole 6. A 21st r pole 7 common to the plurality of 111th poles is disposed behind the orifice plate portion 3 with an ink layer 5 interposed therebetween. They are disposed through a minute gap of 1 m, and the gap is filled with ink to form an ink layer.

Further, there is a recording paper 8 0.5 to 1.0011 degrees ahead of the orifice 4, and behind it there is a plate-shaped third paper common to each orifice. The third electrode 9 has a negative polarity of 2 to 4K.
It is biased to a high voltage of V. Here, the 21st pole 7 is grounded to the ground level, and the 21st pole 7 is grounded to the ground level.
When a pulsed image signal of positive polarity is applied to the ink, as will be described later, a force due to polarization and a force due to Coulomb force act on the ink in the orifice /i, 4 due to the electric field applied from the first to third electrodes. Ink droplets are ejected from the orifice 4 according to the image signal, and an image is printed on the recording paper 8. FIG. 2 is a front view of the orifice plate portion of FIG. 1, and as shown, lead terminals 6' for applying image signals are taken out from each first electrode 6, and , a second electrode 7 is provided at the rear of the orifice plate portion.
(indicated by broken lines in FIG. 2) is provided commonly to each orifice.

FIG. 3 is a schematic configuration diagram of main parts showing another measured example of the present invention;
FIG. 4 is a front view of the orifice shown in FIG. 3. In this embodiment, several orifices (nozzles) 4 shown in FIGS. 1 and 2 are constructed with a single slit 4'. A plurality of first electrodes 6a are provided independently on or near the inner wall of the orifice 4', and a third pole 9 is disposed between the orifice and the recording paper.
A high voltage of positive polarity is applied to the electrode, and a high voltage of negative polarity is applied to the first electrode. FIG. 4 is a front view of the orifice plate portion of FIG.
m gap, and the first electrodes 6a are arranged above and below in correspondence with the ink droplet ejection pitch.

In the electric field on-demand type inkjet recording apparatus as described above, the size of the ink dots to be ejected is determined by the first
can be controlled by changing the width or amplitude of the pulse voltage applied to the pole, and the force F acting on the ink at the orifice tip is Expressed by the exaggerated charge due to an external electric field (E: electric field strength), the polarization force shown in the first term acts due to the pulse voltage applied between the first cathode and the second electrode,
The Coulomb force shown in the second term acts due to the DC voltage applied to the third electrode, and due to both of these forces, a meniscus grows according to Roy's law at the orifice, and the concentration of the electric field from the 311< pole is accelerated accordingly. , flying of ink droplets occurs. In the electric field on-demand type inkjet recording apparatus described above, stable ink droplets can be formed by using ink having a resistance of 10@4 ΩG or less and 10 Ωa or less.

As is clear from the above six points, according to the present invention, it is possible to provide an electric field on-demand type inkjet recording device that has a simplified electrode structure and can be easily integrated in a multi-configuration. .

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of a main part of a tank for explaining an embodiment of an electric field on-demand type inkjet recording apparatus according to the present invention, FIG. 2 is a front view of the orifice plate section 3 of FIG. 1, and FIG. is a side sectional view of a main part showing another embodiment of the present invention,
FIG. 4 is a front view of the orifice plate portion of FIG. 3. 1. Static pressure ink supply tank, 2. Inkjet head, 3.
- Orifice plate part, 4.4' ・Orifice,
5... Ink layer, 6.6a... First electrode, 6' third electrode.

Claims (1)

[Scope of Claims] (1+ In an inkjet recording device that prints on recording paper by ejecting ink droplets from a nozzle of an inkjet head, a first
A second electrode having an Nt pole and located at a position opposite to the nozzle with an ink layer interposed behind the substrate having the nozzle.
a third electrode between the nozzle and the recording paper or on the back of the recording paper, and applying an image signal between the first electrode and the second electrode; An inkjet recording apparatus characterized in that an in-droplet is ejected from the nozzle by applying a voltage to the third electrode. Then, the front d1 and the second
Claim No. 1 (2) characterized in that the electrodes are common
The inkjet recording device according to item 1). (3) The nozzle is configured in the shape of a slit, and has a first number of first cage poles that are independently divided on or near the inner wall of the slit, and has a first number of first cage poles that are divided independently from each other on the inner wall of the slit or in the vicinity of the inner wall of the slit. The inkjet recording apparatus according to claim 1, wherein the second electrode is shared through an ink layer.