JPS61242845A - Charge control type ink jet recording device - Google Patents

Abstract

PURPOSE:To prevent occurrences of a change in discharge characteristics resulting from foaming and that of contamination of the devices etc. by providing an anti-foaming device having a lattice type heating portion within an ink circulating passage. CONSTITUTION:A foam breaking device 20 is provided in an ink circulating passage. The foam breaking device 20 consists of metal netting 21, high polymer netting 22 and nichrome wire 23; and foams generated by circulation of the ink are designed to pass through a lattice type heating position to be broken, solving all problems connected with foaming. As a matter of fact, moving of foams is temporarily interrupted by the lattice, and having all foams be in contact with the lattice to efficiently perform foam breaking, resulting in a constitution of a compact and high thermal efficiency heater. In addition, if foams are continuously exposed to melt and water-repellent high polymer, owing to differences in wetting characteristics of the members, foams become more susceptible to breaking. It is compact, and heat generation is small, therefore, change in properties of ink or increase in power consumption is not brought about, and a prolonged, stabilized printing is feasible.

Description

[Detailed description of the invention] Limbs and balls The present invention is a charge control type inkjet recording device.

More specifically, the present invention relates to defoaming of bubbles generated in the ink circulation path of a charge-controlled inkjet recording device.

In a charge control type inkjet recording device, ink sent from an ink supply section is ejected from a nozzle, and ink not used for printing is collected in a gutter and returned to the ink supply section again, thereby circulating the ink. and use it. For this reason, when the ink storage chamber is filled with bubbles and the bubbles flow into the ink head, the ink ejection properties are significantly deteriorated, and printing quality is adversely affected. Further, there are also problems within the ink supply system, such as staining the cartridge.

As a means for removing the above-mentioned bubbles, for example, in the invention described in JP-A-59-185657, a gas-liquid separation filter is used in the ink circulation path.
Further, in the invention described in Japanese Patent Application Laid-open No. 59-185658, a gas-liquid separator made of a spiral wire is used. However, none of the above gas-liquid separation means had a sufficient foam-breaking effect and could not be used at low temperatures.

The present invention was made in view of the above-mentioned circumstances.
In particular, this technology was developed for the purpose of solving various problems caused by bubbles in charge-controlled inkjet recording devices by passing the bubbles generated in the ink circulation path through a defoaming device with a grid-like heating section to break the bubbles. It is.

1. In order to achieve the above object, the present invention provides a charge control type inkjet recording device having an ink circulation path in which ink droplets not used for printing are captured and collected in a gutter for reuse, and in which a charge control type inkjet recording device is provided. This device is characterized by being equipped with a defoaming device having a grid-like heating section. below,
An explanation will be given based on an example of the present invention.゛FIG. 1 is an overall configuration diagram for explaining one embodiment of a charge control type inkjet recording apparatus according to the present invention.
1 is an ink tank, 2 is an ink supply pump, 3 is a main filter, 4 is an accumulator, 5 is a pulp, 6 is an ink temperature control unit, 7 is an inkjet head, 8 is a gutter, 9 is an ink recovery filter, 10 is an ink recovery In the pump, these 1 to 10 form an ink circulation path,
Ink circulates in the direction of the arrow. 11 is an ink viscosity control section, and 12 is an ink supply pump drive circuit.

13 is an ink temperature control circuit, 14 is an excitation circuit, 15 is a charging electrode, 16 is a charging control circuit, 17 is a deflection electrode, and 18 is a recording paper, which charges the ink droplets ejected from the ink jet head 7, as is well known The ink droplets that are not used for printing are charged and charged according to the printing information signal by the electrode 15, and are deflected by the deflection type 1i17 and recorded on the recording paper 18. 2 are collected and returned to ink tank 1 for reuse. In the charge-controlled inkjet recording apparatus as described above, when the ink sent out from the ink tank 1 circulates through the ink circulation path, ink droplets ejected from the inkjet head 7 are particularly captured by the gutter 8. When printing, air is sucked in with the ink and bubbles are generated in the ink, and when continuous printing is performed for a long time, the ink storage chamber is filled with bubbles.

When these bubbles flow into the ink head, the ink ejection performance is significantly deteriorated, adversely affecting print quality, and there are also problems in the supply system, such as staining the cartridge.

The present invention has been made to remove the above-mentioned air bubbles. In FIG. 1, 20 disposed in the ink circulation path is a bubble breaking device added according to the present invention. By using a lattice-shaped heating section in the foam-breaking device 20, defoaming can be performed more effectively.

2 and 3 are detailed views showing an example of the bubble breaking device 20 shown in FIG. 1, in which 21 is a metal mesh, 22 is a polymer mesh, 2
3 is a nichrome wire, and in the present invention, bubbles generated by ink circulation are broken by passing through a grid-like heating section, thereby solving various problems caused by bubbles. Although methods using heat and filters are known as general defoaming means, even greater effects were observed by using a lattice-shaped heating section.

In other words, you can get heat and filter effects at the same time, and
If the flow rate of bubbles is large using a heater alone, a high temperature and a large volume are required, but in the present invention, the flow of bubbles can be temporarily stopped by the grid section, and the bubbles are brought into contact with all the bubbles, so bubbles can be broken efficiently. This makes it possible to create a compact and highly efficient heater. They also discovered that when bubbles come into continuous contact with a metal and a water-repellent polymer, the bubbles become more likely to burst due to differences in the wettability of the members, and they completed the present invention.

Since this defoaming device is small and generates a small amount of heat, there is no change in the quality of the ink or a large increase in power consumption, and stable continuous printing for a long time is possible. Note that the metal part of the grid member used in the present invention is made of iron.

There are stainless steel, nickel, aluminum, copper, etc., and the polymer part is polyester and polypropylene.

Nylon, Teflon, etc. can be used.

On-vehicle ■ As the soil breaking foam device 20, a stainless steel mesh (32 mesh) with nichrome wire glued and a Teflon mesh (32 mesh) attached is used, and the pump and subtanter are connected as shown in Figure 1. Direct blank 19 3wt% glycerin 20-t% ethylene glycol
20wt% polyoxyethylene alkyl ether 0.62wt% sodium
Omazine 0.3 wt% purified water
A material having a composition of 61.08 wt% was used.

The printer was operated in an environment of 5°C and 5W of power was applied to the heating section to heat it. Even after continuous operation for more than 5 hours, the initial print quality of the image was maintained and the cartridge section was not stained by bubbles. I couldn't see it.

On the other hand, when the printer was operated in the same way with a rubber tube connected to the point where the bubble-breaking device in Figure 1 was attached, bubbles were removed from the tank after continuous operation for 30 minutes in an environment of 5°C. It overflowed.

Actual lid fork Similar to Example 1, a bubble breaking device was made by attaching nichrome wire to stainless steel (32 mesh), and attached to the same location.
When the printer was heated with 5W power in an environment of 5℃ and operated continuously, there was no image disturbance or overflow of bubbles.
The bottom of the cartridge was a little dirty with foam.

As is clear from the above description, the present invention makes it possible to solve problems such as changes in ejection characteristics and stains on equipment caused by bubbles generated due to ink circulation. There are advantages such as making it possible to use

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram for explaining one embodiment of the present invention, and FIGS. 2 and 3 are detailed diagrams of the bubble breaking device shown in FIG. 1. 1... Ink tank, 2... Ink supply pump, 3
...Main filter, 4...Accumulator, 5.
... Valve, 6... Ink temperature control unit, 7... Inkjet head, 8... Gutter, 9... Ink collection filter. lO... Ink recovery pump, 20... Foam breaking device, 2
1... Metal mesh, 22... Polymer mesh, 23... Nichrome wire.

Claims (2)

[Claims] (1) In a charge-controlled inkjet recording device having an ink circulation path in which ink droplets that are not used for printing are captured and collected in a gutter for reuse, the defoaming device has a grid-shaped heating section in the ink circulation path. What is claimed is: 1. A charge control type inkjet recording device comprising: (2) Claim (1) characterized in that the lattice-shaped heating section is composed of two layers of metal/water-repellent polymer.
Charge control type inkjet recording device as described in 2.