JPS59227464A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To obtain a flat surface scanning type ink jet recording apparatus extended in the flight distance of ink droplets and imparting excellent image quality reduced in the turblence of a picture element, by providing an opposed electrode to this side of recording paper when viewed from an ink jet orifice. CONSTITUTION:The titled apparatus has a slit like ink jet orifice having a plurality of recording electrodes 2 in the vicinity of the outlet thereof, an opposed electrode 8 arranged so as to leave a minute gap from the ink jet orifice 1 and a means for feeding recording paper 10 to the opposite side of the ink jet orifice 1 with respect to the opposed electrode 8 so as to contact the same with the opposed electrode 8 or to leave the minute gap from said electrode 8. In this constitution, when signal voltage is applied to a recording electrode 2 corresponding to a picture signal, the ink at the part, to which voltage is applied, of the electrode is charged and receives the force by an electric field between the electrode 2 and the opposed electrode 8 to be formed into ink droplets and fly toward the opposed electrode 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plane scanning inkjet recording apparatus that prints one dot line at a time.

Inkjet recording devices that have nozzles lined up horizontally are difficult to implement at high voltages, and the nozzles are easily clogged; therefore, flat-scanning devices that print one dot line at a time are used instead. is proposed. This plane scanning inkjet recording device has an elongated slit-shaped ink ejection port with a length equal to the print recording width and a gap of about 50 gm, and the inner wall of the slit has a plurality of recording electrodes corresponding to the print pixels. The recording paper is inserted into the front of the slit section, and the back electrode is arranged behind it. When a signal pulse is applied between the back electrode and one or more arbitrarily selected recording electrodes, the ink near the recording electrode receives Coulomb force and flies out in the form of particles toward the back electrode. It collides with the recording paper to form recording pixels.

However, in such a conventional plane scanning inkjet recording device, the recording electrode and the back electrode face each other with the recording paper interposed in between, so the electric field formed between the two electrodes becomes weaker.
As a result, the flying distance of the ink is small, and the electrical repulsion between the ink droplets cannot be ignored, resulting in disadvantages such as misalignment of recorded pixels.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a plane scanning inkjet recording device that has a long flying distance of ink droplets, has little pixel disturbance, and has excellent image quality.

First--1 The configuration of the present invention will be described below based on examples.

Fig. 1 is an overall configuration diagram of an inkjet recording device according to the present invention, Fig. 2 is a perspective view of an ink ejection port, and Fig. 3 is a perspective view of a counter electrode. is the same as the width of the recording paper, and the width in the vertical direction is about 30 to 50f)#Lm. 2 is a recording electrode that corresponds to each pixel.It is divided into sections, its size is about 50~loo#Lm in width, and it is formed by copper plating on an insulating substrate. l 2
dots/mm. 3 is a signal source and each recording electrode 2
1 is connected to the desired recording electrode 2 according to the stroke number.
Apply a pulse voltage of 5 to 2.0. Reference numeral 4 denotes a pump that supplies ink 6 in the ink container 5 to the ink jetting port 1. The pump pressure is preferably such that the ink does not fly out from the slit and the ink that flies out is immediately replenished by signal application, and is 5 to 15 mmAq41. What is it? Further, as the ink 6, any ink used in conventional inkjet recording devices may be used, but in order to prevent current leakage between adjacent recording electrodes, an ink with low conductivity is preferable). Furthermore, in this embodiment, since the opening is large, so-called pigment-dispersed ink can also be used. Reference numeral 7 denotes a substrate, and a counter electrode 8 consisting of one electrode is formed at the tip thereof. Although this substrate 7 is pressed against the recording paper lO by means not shown in FIG. 1, a minute gap smaller than the diameter of an ink droplet may be provided between the substrate 7 and the recording paper. The surface of the counter electrode 8 is made of a material that repels ink, such as polytetrafluoroethylene (trade name: Teflon) for water-based ink.
It is coated with graphite fluoride. The gap between the counter electrode 8 and the recording electrode 2 is 0.2 to 1 mm, which is quite ample.
Narrower is better to improve image quality. 9 is recording paper 1
This is a platen roller that sends 0.

In such a configuration, recording i[
When a signal voltage is applied to the pole 2, the ink on the electrode portion to which the voltage is applied is charged, receives a force from the electric field between it and the counter electrode 8, becomes a droplet, and flies toward the counter electrode.

This ink droplet once sticks to the opposite electrode 8, but since the surface of the opposite electrode is coated with a material that repels ink, the ink droplet is repelled and sticks to the recording paper 10, where it is absorbed and recorded. will be carried out.

FIG. 4 is a diagram showing another embodiment of the present invention. In this embodiment, an air jet port 11 is provided and an air flow F is jetted from there to prevent ink droplets from directly hitting the counter electrode 8. This is what I did.

FIG. 5 shows still another embodiment of the present invention, in which a deflection electrode 12 for bending the path of ink is provided on the back side of the recording paper to prevent ink droplets from directly adhering to the counter electrode 8. be.

As described above, according to the present invention, in a flat scanning inkjet recording device that is less likely to be clogged, can easily be multi-headed, can perform high-speed recording, and can easily perform multicolor recording, the counter electrode Since the ink jet is placed in front of the recording paper when viewed from the side, the electric field formed between the recording electrode and the counter electrode increases, the flying distance of the ink increases, and the distance between the ink droplets increases. The influence of repulsive force can be ignored, resulting in less pixel disturbance and excellent image quality.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an inkjet recording apparatus according to the present invention, FIG. 2 is a perspective view of an ink ejection port, FIG. 3 is a perspective view of a counter electrode, and FIGS. 4 and 5 are other embodiments of the present invention. FIG. l... Ink ejection port, 2... Recording electrode, 3... Signal source, 4... Pump, 5... Ink container, 6...
Ink, 7...Substrate, 8...Counter electrode, 9...Platen roller, 10...Recording paper, 11...Air jet port, 12...Deflection electrode. Special applicant Ricoh Co., Ltd. Figure 4 5rllJ

Claims (4)

[Claims] (1) A slit-shaped ink jet in which a plurality of recording electrodes are formed in the vicinity of "Output 1", a counter electrode arranged with a small gap from the ink jet nozzle, and a counter electrode that is in contact with the counter electrode, or and means for conveying the recording medium to the opposite side of the ink ejection port with respect to the opposing fL pole across a minute gap, and applying a recording signal to a desired recording electrode among the plurality of recording electrodes, An ink sheet recording apparatus characterized in that only a desired portion of ink is turned into droplets and is caused to fly toward a recording medium. (2) The inkjet recording apparatus according to claim (1), wherein the surface of the counter electrode is coated with an ink-repellent material. (3) The inkjet recording apparatus according to claim (1), further comprising air blowing means for bending the course of ink droplets on the surface of the counter electrode. (4) A deflection electrode for bending the course of ink droplets is provided on the back surface of the recording body.
).