JPS58219067A - Ink-supplying device for ink jet printer - Google Patents

Abstract

PURPOSE:To securely separate gases and avoid generation of stains with an ink or the like with a simple construction, by a method wherein bubbles existing in an ink is removed by providing an ink-supplying system with a gas-permeable film which permits air to pass therethrough but prevents liquids from passing therethrough. CONSTITUTION:The gas-permeable film 2 for separating gases and a liquid from each other is provided at an upper part of a main body 1 of an air trap. The film 2 may be, for example, a micro-porous film consisting mainly of a polyethylene resin. Bubbles contained in an ink 3 introduced from an ink tank are floated up by buoyancy, pass through the film 2, and are collected in an air chamber 4. Since the film 2 prevents the ink from passing therethrough, the ink will not leak to the exterior. A gas-permeable mesh 5 is provided above the air chamber 4 so that the pressure inside the chamber 4 will not become higher than the atmospheric pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink supply device for an inkjet printer, and particularly to an ink supply system that includes a bubble removal device to supply ink without air bubbles to an ink ejection head.

Generally, when air bubbles enter the ink in the ink supply path and are sent to the nozzle, the regular formation of ink particles from the nozzle is hindered, resulting in a very poor printing condition.

Conventionally, an ink tank has been provided with a cylindrical coarse-mesh filter and a fine-mesh filter to remove air bubbles, but this has the disadvantage of a complicated structure. Some filters allow waste ink to pass from the bottom to the top of the filter, and a bubble guide collects the bubbles in a collection chamber in the dirt section, and the ink is supplied from the outlet at the bottom, but after passing through the filter, the gas and liquid are removed. Because they are separated, there is a drawback that under conditions where the flow rate is high, air bubbles may flow toward the head and break up.

The present invention aims to provide an ink supply device for an inkjet printer that has an extremely simple configuration and is capable of reliably removing only air bubbles.

FIG. 1 is a schematic diagram of an ink circulation supply system of an inkjet printer to which the present invention is applied.

The ink in the ink tank 1 is pumped by the pump 2, pressure fluctuations are smoothed by the accumulator 3, and the valve 4 and filter 5 are
The ink is ejected as ink droplets from the ink jet head through the
It is charged according to the image information by a charging electrode (not shown), deflected by a deflection electrode according to the amount of charge, and printed on recording paper. Ink droplets that are not used for printing are captured and recovered by the gutter 7 and reused.

Figure 2 shows the ink tank 1 of the ink circulation supply system in Figure 1.
2 is a diagram showing a bubble removing device of the present invention provided between the pump 2 and the pump 2. FIG.

The air trap main body 1 is provided with an air permeable membrane 2 on the upper part that separates gas and liquid. As this air-permeable membrane, for example, a microporous membrane containing polyethylene resin as a main component may be used. Air bubbles contained in the ink liquid 3 entering from the ink tank rise due to buoyancy, pass through the air permeable membrane 2, and enter the air chamber 4.
is collected by.

Since the air-permeable membrane 2 does not allow ink to pass through, ink leakage to the outside does not occur. A permeable mesh 5 is provided above the air chamber 4 to prevent the pressure in the air chamber from exceeding atmospheric pressure. 6 is a set screw.

In FIG. 3, an air permeable membrane is provided in the filter 5 of FIG. 1. The filter body 10 includes a filter mesh 1.
An air permeable membrane 12 is provided above the filter mesh 1 to separate air bubbles upward in front of the filter mesh. In this case, since the ink is pressurized, the ink also passes through the air-permeable membrane, but air bubbles are separated more reliably than in the case where there is no membrane. The gas that has passed through the gas permeable membrane is released by occasionally opening the valve 13. 14 is a set screw.

As described above, according to the present invention, gas can be separated reliably with a simple configuration, stains such as ink are not generated, and contamination with external dust can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an ink circulation supply system of an Ishikjet printer, FIG. 2 is a diagram showing an embodiment of an air removing device according to the present invention, and FIG. 3 is a diagram showing an embodiment of an air removing device according to the present invention. It is a figure showing an example of. 1 Air trap body, 2.12 Air permeable membrane, 4 Air chamber, 5... Air permeable mesh, 10 Filter body, 12... Filter mesh. 400 Figure 1 Figure 2 Mehe V)'

Claims (3)

[Claims] (1) In an ink supply device for an inkjet printer that leads ink from an ink supply tank to an ink ejection head via a pump means and a valve means, an air permeable membrane is used that allows air to pass through the ink supply system but not liquid. An ink supply device for an inkjet printer, characterized in that it is provided to remove air bubbles mixed into ink. (2) The ink supply device according to claim (1), wherein the air removal means using the air permeable membrane is provided upstream of the pump means. (3). The ink supply device according to claim 1, wherein the air-permeable membrane is built into a filter section immediately in front of the ink jetting head.