JPH09300649A - Ink-jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the viscosity of ink constant by preventing solvent component from running short by a structure wherein the interior of an ink container is parted by a partition plate, which continues from the top surface in the container to below the liquid level of ink and the lower end of which does not touch the bottom surface of the container so as to facilitate the come-and-go of ink through the partition plate. SOLUTION: A container 1 has a nearly enclosed structure, the interior of which is parted into two parts by a partition plate 6 extending from the top surface of the container to below the liquid level of ink 4a. The lower end of the partition plate 6 is below the liquid level of the ink 4a at all times even when its liquid level rises and lowers and does not perfectly part the container so as to allow to freely come and go through the partition plate. When ink stock liquid 4b is supplied into an empty container 1, since the ink stock liquid 4b is supplied to the container 1 by means of a pump only, no air is mixed during the supplying of the liquid and no ink bubble 7 develops in the container 1. In order to carry out printing, ink 4a is passed through a circulating path 9a and flown from a nozzle 10 in the form of ink particles 12. The non-printed ink particles 12 are returned to the container 1.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to an ink jet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a container 1 is a box which has not been devised, and a liquid level detection sensor 8, a circulation path recovery 9b, an ink supply path 13, a solvent supply path 14 are provided.
It is known that the structure is in the same room.

[0003]

Characters printed by an ink jet recording apparatus are ink ejection pressure and ink particle flight due to changes in ink viscosity due to evaporation of solvent in the ink and changes in ink viscosity due to changes in physical properties of the ink itself. Since the speed changes and the amount of deflection of the charged ink particles changes, the print character height also changes. In the prior art, since air that enters from the gutter is mixed in the ink that is circulated and collected during operation, bubbles are generated on the ink surface when collected in the container. The bubbles are at a position higher than the actual ink surface, and the liquid level detection sensor detects the bubbling surface as the ink surface and stops the replenishment of ink and solvent, resulting in insufficient replenishment of solvent and increased ink viscosity. Will end up.

[0004]

[Means for Solving the Problems] Air is sucked from the gutter at the same time as the recovered ink. Therefore, ink and air are mixed in the circulation path recovery, which causes ink bubbles when the ink returns to the container. It is impossible to collect only ink from the gutter, and it is expensive to bleed air in the circulation path recovery, so it is considered that there is no method for preventing the generation of ink bubbles. Therefore, the present invention has focused on the following points in order to solve the problems of the prior art.

Since the generation of ink bubbles cannot be prevented, it is necessary to prevent the liquid level detection sensor from being affected by the ink bubbles. Connect the liquid level detection sensor and the circulation path recovery tip.
If you divide the container into two chambers with a partition plate that extends from the top of the container to below the ink level and the bottom end does not continue to the bottom of the container so that ink can easily pass in and out, the liquid level detection sensor will not be affected by ink bubbles. The problems of the conventional technology can be solved.

As described above, by providing the partition plate, it is possible to prevent ink bubbles from being generated in the liquid level detecting sensor section and to prevent the shortage of the solvent component, so that the ink viscosity can be kept constant.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The container 1 has a structure in which it is divided into two by a partition plate 6 extending from the upper surface to the lower surface of the ink 4a and is almost hermetically sealed. The lower end of the partition plate 6 is always below the liquid surface of the ink 4a even if the liquid surface of the ink 4a moves up and down, and the condition is that the ink 4a can freely move in and out without completely dividing the container 1. A liquid level detection sensor 8 for detecting the liquid level of the ink 4a is provided in the container 1, and an ink for printing characters or the like on the printing object is provided in the nozzle 1
A circulation path supply 9a for supplying 0, an ink replenishment path 13 for connecting with a substantially sealed ink container 2 for containing an ink stock solution 4b for replenishing the ink 4a which is insufficient due to printing, a solvent volatilized from the ink Solvent replenishing path 14 for connecting to a substantially sealed solvent container 3 in which a solvent 5 for replenishing is placed, ink particles 12 not used for printing
9b for collecting the circulation route for returning the gas from the gutter 11 to the container 1
Is installed. Liquid level detection sensor 8, circulation path supply 9
a is installed on one side divided by the partition plate 6 in the container 1,
The other ink replenishment path 13, solvent replenishment path 14, and circulation path recovery 9b are installed on the other side.

With this structure, the ink stock solution 4b is supplied to the empty container 1. At this time, the ink stock solution 4b is simply replenished to the container 1 by a pump (not shown).
No air enters in the middle of the container, and ink bubbles 7 do not occur in the container 1. For printing, the ink 4a passes through the circulation path supply 9a and is ejected as the ink particles 12 from the nozzle 10. Ink particles not printed here 12
Enters the gutter 11, passes through the circulation route recovery 9b, and enters the container 1
Is returned to. Since air is sucked into the gutter 11 at the same time as the ink particles 12, the circulation path recovery 9b is in a state in which the ink 4a and air are mixed. Therefore,
When it returns to the container 1, it becomes an ink bubble 7 when it falls on the liquid surface of the ink 4a. On the other hand, if the printing is continued, the ink 4a will be reduced, so the ink stock solution 4b is replenished from the ink container 2.
The replenishment amount at this time is only the amount of the ink 4a used for printing. The deficiency is considered to have evaporated the solvent component in the ink 4a, and the solvent 5 is replenished from the solvent container 3. That is, as shown in FIG. 2, the ink 4a is reduced by the ink shortage amount 15 from the initial level, and the ink amount 1 used for printing is 1
Only the ink stock solution 4b is replenished with 6, and the solvent 5 is replenished with the amount 17 of the solvent volatilized from the ink. Here, in the conventional technique, as shown in FIG.
Was attached to the periphery of the liquid level detection sensor 8 and caused a malfunction. However, by installing the partition plate 6, ink bubbles 7 do not occur around the liquid level detection sensor 8 and cause a malfunction. Could be removed.

[0010]

According to the present invention, even if ink bubbles are generated in the container, the liquid level detection sensor is not affected, and it is possible to prevent a shortage of the solvent component, so that the ink viscosity can be kept constant.
The quality of printed characters can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a flow of ink and a solvent that is an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an increase / decrease amount of ink and solvent which is an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a flow of ink and solvent which is an example of a conventional technique.

[Explanation of symbols]

1 ... Container, 2 ... Ink container, 3 ... Solvent container, 4a ... Ink, 4b ... Ink stock solution, 5 ... Solvent, 6 ... Partition plate, 7 ... Ink bubble, 8 ... Liquid level detection sensor, 9a ... Circulation path supply, 9
b ... Circulation path recovery, 10 ... Nozzle, 11 ... Gutter, 12
... Ink particles, 13 ... Ink supply route, 14 ... Solvent supply route.

Continued Front Page (72) Inventor Satoshi Kurihara 1-1-1 Higashitaga-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Electric Appliances Division, Taga Headquarters

Claims (3)

[Claims] 1. An ink jet recording apparatus having a container for flying characters to print characters or the like on an object to be printed and containing the ink, and a circulation path for returning ink not used for printing to the container. An ink jet recording apparatus, characterized in that a lower end that extends from the upper surface of the container to a position below the ink surface is divided by a partition plate that does not extend to the bottom surface of the container so that ink can easily move in and out. 2. An ink jet recording apparatus having, in addition to the container according to claim 1, an ink container for supplying the ink to the container and a solvent container for storing a solvent for supplying the ink to the container. . 3. A sensor for detecting the liquid level of the ink is provided in the container, and a replenishment port from the ink container, a replenishment port from the solvent container, and not used for printing are provided on a side where the sensor is not installed. With the ink return port, when the container is empty, ink is replenished from the ink container to the sensor detection surface, and when the device is operating, the ink used for printing is replenished with ink from the ink container, and the shortage, that is, The ink jet recording apparatus according to claim 1, wherein the solvent is replenished from the solvent container until the sensor detects it.