JPS5830691Y2 - Inkjet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus that records an image by ejecting ink from the tip of a small diameter nozzle of a recording head onto the recording surface of a recording medium.

First, the principle of electric field jet inkjet, which is a typical technique for generating inkjet, will be briefly explained with reference to FIG. , the nozzle 3
It consists of an annular counter electrode 4 arranged concentrically with the nozzle 3 around the nozzle 3 and a high voltage DC power supply 5 for creating an electric field between the nozzle (if it is made of metal) or the ink and the annular counter electrode 4. The hydrostatic pressure of Ink 1 is set to such an extent that Ink 1 forms a meniscus at the tip of the nozzle.

When a high DC voltage is applied between the nozzle 3 or the ink 1 and the annular counter electrode 4 while the ink forms a meniscus, the ink 1 is ejected as a jet.

Although the jets differ depending on the physical properties of the ink 1, they all become regular fine particles at positions separated by light from the nozzles 3.

This is ink 1 that was creating a meniscus at the tip of the nozzle.
This is because the ink is drawn out as a jet by the electric field and becomes fine particles due to the surface tension of the ink 1.

This type of inkjet generation technology is used to record images by guiding fine particles of ink onto the recording medium P, and has been partially put into practical use in printers that form IJ socks characters (dot marks). Applications to plotters are also being considered.

Conventionally, the XY plotter described above uses a hollow pen, ballpoint pen, etc. as a recording tool, and records by moving the recording tool in the X and Y directions and controlling its up and down movement. The equipment has poor durability and must be replaced frequently, making high-speed recording and thin line recording difficult, and has many drawbacks such as uneven recording line density and easy noise generation. Ta.

Therefore, instead of the above-mentioned contact-type recording tool, an inkjet generating element is mounted on the recording head, and the turning on and off of the jet is used instead of the raising and lowering of the recording tool.

By the way, when inkjet generation technology is applied to an XY plotter, dust disposal on the recording medium becomes a problem.

That is, if dust adheres to the recording surface of the recording medium, it will be attracted to the nozzle by the electric field, disturbing the jet jetting, and even making the jet jetting impossible.

Further, even if the jet is ejected normally, image disturbances will occur on the recording surface.

The present invention has been made in view of the above points, and aims to provide an inkjet recording device that ejects a jet after removing dust that always adheres to the recording surface by blowing compressed air. .

Next, the present invention will be explained according to the drawings which are examples.

Fig. 2 shows an example in which the present invention is applied to an electric field jet inkjet XY plotter, and the recording surface is cleaned by blowing compressed air to remove dust on the recording surface of the recording medium. It is something.

The area surrounded by the dashed line is the recording head 6, and the recording head 6 is moved in the X and Y directions to record an image while ejecting a jet onto the recording surface.

This recording head 6 includes an ink tank 2 with a small-diameter nozzle 3 attached to its bottom surface, and an annular counter electrode 4 arranged concentrically with the nozzle 3 around the nozzle 3 for ejecting a jet. .

In the annular counter electrode 4, a large number of compressed air jet holes 7a are formed concentrically with the nozzle 3 and symmetrically with respect to the nozzle 3, and these compressed air jet holes 7a are connected to each other through a flexible pipe 8. It is connected to an air pump (not shown).

The nozzle 3 of the recording head 6 is equipped with a bias power supply 9 for forming a meniscus during standby, and a high-voltage pulse generator 1 for turning the jet on and off in response to a drawing command.
0. In order to record with a constant image width by utilizing the fact that the amount of ejected ink is approximately proportional to the applied voltage, a high voltage amplifier 11 is connected to superimpose a voltage corresponding to the recording speed. The counter electrodes 4 are grounded and constitute voltage applying means.

Therefore, when recording an image by moving the recording head 6 and the recording medium P relatively and ejecting ink from the tips of the small diameter nozzles 3 of the recording head 6 onto the recording surface of the recording medium P, the compressed air jet holes When compressed air is ejected from 7a,
As the recording head 6 moves relative to each other, dust on the ink-attached portion of the recording surface is scattered and removed in advance.

The compressed air jetting hole is not limited to the one described above, and as shown in FIG. good.

It should be noted that if the air is ejected from the compressed air ejection holes 7a and 7b in an outwardly expanding manner, the ink ejected toward the recording surface of the recording medium will be less affected by turbulence caused by the ejected air flow. It is preferable.

As is clear from the above description, the present invention is equipped with a recording surface cleaning means that blows compressed air around the small diameter nozzle of the recording head, so that dust can be reliably removed even when the recording head is moved. This is particularly useful when used in an XY plotter in which the recording head moves vertically and horizontally.

Further, the recording surface cleaning means can have a sufficient cleaning effect with a simple and inexpensive configuration.

Note that the present invention can be applied not only to an inkjet recording device that uses electric field jetting type inkjet technology, but also to an inkjet recording device that generates inkjet using other technologies.

It goes without saying that the present invention can also be applied to an inkjet recording apparatus with a fixed recording head.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle of electric field jet inkjet.
FIG. 2A shows the main parts of the first embodiment in which the present invention is applied to an electric field jet type inkjet XY plotter; the opening is a bottom view of the recording head; FIG.
Figure A is a diagram showing the main parts of the recording head, and Figure 3 is a bottom view. 1... Ink, 2... Ink tank,
3... Nozzle, 4... Annular counter electrode,
6... Recording head, 7a, 7b... Compressed air outlet, 8... Flexible pipe.

Claims (1)

[Scope of utility model registration request] In an inkjet recording device that records an image by moving a recording head and a recording medium relatively and ejecting ink from the tip of a small diameter nozzle of the recording head onto the recording surface of the recording medium, an inkjet recording device is connected to an air pump and is connected to an air pump. Compressed air jet hole forming means for jetting compressed air from an air pump toward the recording surface is disposed in an annular shape around the narrow diameter nozzle of the recording head, and blows away dust on the recording surface. Inkjet recording device.