US-20260124837-A1 - GAS BUFFER TYPE MICRO INK STORAGE DEVICE AND INK-JET PRINTER INCLUDING SAME

US20260124837A1US 20260124837 A1US20260124837 A1US 20260124837A1US-20260124837-A1

Abstract

An ink storage device is proposed. The ink storage device is provided to store ink supplied to an inkjet head of an inkjet printer, and includes an ink storage unit, a gas buffer unit connected to the ink storage unit and a gas pressure control device, a gas valve adjusting connection between the ink storage unit and the gas buffer unit, a supply tube supplying ink in the ink storage unit to the inkjet head, a head valve adjusting connection between the ink storage unit and the inkjet head, an injection tube injecting ink into the ink storage device, and an injection valve opening and closing the injection tube. The ink storage unit and the gas buffer unit are separated from each other, so even when an ink storage space is tiny, the meniscus state can be maintained with the gas pressure control device applying sufficient negative pressure.

Inventors

Daigeon YOON
Dongkyun SHIN
Hyunbin Park
Youngho Jung
Seung Ryeol Lee
Sooyeon LIM

Assignees

GOSANTECH CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20250219
Priority Date: 20241106

Claims (12)

1 . A gas buffer-type micro-ink storage device storing ink supplied to an inkjet head of an inkjet printer, the ink storage device comprising: an ink storage unit storing ink; a gas buffer unit that is connected to the ink storage unit with a gas connection tube through which gas flows, and connected to a gas pressure control device with a pressure control tube so that the gas pressure control device provides a gas volume to adjust gas pressure; a gas valve that is enabled to adjust connection between the ink storage unit and the gas buffer unit; a supply tube configured to supply the ink stored in the ink storage unit to the inkjet head; a head valve configured to adjust connection between the ink storage unit and the inkjet head; an injection tube configured to inject ink into the ink storage device; and an injection valve configured to open and close the injection tube, wherein the injection tube is connected to the supply tube or at least to a portion where the supply tube and the ink storage unit are connected to each other, and according to operation of the head valve, ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
2 . The gas buffer-type micro-ink storage device of claim 1 , wherein in the supply tube, the head valve is installed to a position close to the inkjet head rather than a position to which the injection tube is connected, and the head valve is a 2-way valve.
3 . The gas buffer-type micro-ink storage device of claim 2 , wherein when ink is injected through the injection tube with the head valve closed, the ink injected into the injection tube is injected into the ink storage unit, and when ink is injected through the injection tube with the head valve opened and the gas valve closed, the ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
4 . The gas buffer-type micro-ink storage device of claim 1 , wherein in the supply tube, the head valve is installed at a position to which the injection tube is connected, and the head valve is a 3-way valve.
5 . The gas buffer-type micro-ink storage device of claim 4 , wherein when the head valve connects the injection tube and the ink storage unit to each other, ink injected into the injection tube is injected into the ink storage unit, and when the head valve connects the injection tube and the inkjet head to each other, the ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
6 . The gas buffer-type micro-ink storage device of claim 1 , further comprising: an ink discharge tube configured to discharge ink flowing into the gas buffer unit outward, and a discharge valve configured to open and close the ink discharge tube.
7 . An inkjet printer comprising a gas buffer-type micro-ink storage device, the inkjet printer comprising an inkjet head, a micro-ink storage device configured to supply ink to the inkjet head, and a gas pressure control device configured to control gas pressure in the micro-ink storage device, wherein the micro-ink storage device is a gas buffer-type micro-ink storage device comprising: an ink storage unit storing ink; a gas buffer unit that is connected to the ink storage unit with a gas connection tube through which gas flows, and connected to the gas pressure control device with a pressure control tube so that the gas pressure control device provides a gas volume to adjust gas pressure; a gas valve that is enabled to adjust connection between the ink storage unit and the gas buffer unit; a supply tube configured to supply the ink stored in the ink storage unit to the inkjet head; a head valve configured to adjust connection between the ink storage unit and the inkjet head; an injection tube configured to inject ink into the ink storage device; and an injection valve configured to open and close the injection tube, wherein the injection tube is connected to the supply tube or at least to a portion where the supply tube and the ink storage unit are connected to each other, and according to operation of the head valve, ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
8 . The inkjet printer of claim 7 , wherein in the supply tube, the head valve is installed at a position close to the inkjet head rather than a position to which the injection tube is connected, and the head valve is a 2-way valve.
9 . The inkjet printer of claim 8 , wherein when ink is injected through the injection tube with the head valve closed, the ink injected into the injection tube is injected into the ink storage unit, and when ink is injected through the injection tube with the head valve opened and the gas valve closed, the ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
10 . The inkjet printer of claim 7 , wherein in the supply tube, the head valve is installed at a position to which the injection tube is connected, and the head valve is a 3-way valve.
11 . The inkjet printer of claim 10 , wherein when the head valve connects the injection tube and the ink storage unit to each other, the ink injected into the injection tube is injected into the ink storage unit, and when the head valve connects the injection tube and the inkjet head to each other, the ink injected into the injection tube does not flow into the ink storage unit but is injected into the inkjet head.
12 . The inkjet printer of claim 7 , further comprising: an ink discharge tube configured to discharge ink flowing into the gas buffer unit outward, and a discharge valve configured to open and close the ink discharge tube.

Description

CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Korean Patent Application No. 10-2024-0155908, filed Nov. 6, 2024, the entire contents of which are incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION Field of the Invention The present disclosure relates to an ink storage device and an inkjet printer including the same. More particularly, the present disclosure relates to a micro-ink storage device for an inkjet printer, which stores and uses a small amount of ink, and an inkjet printer including the same. Description of the Related Art In general, inkjet printing technology sprays liquid ink in a form of droplets on a surface of a medium according to a shape signal. The inkjet printing technology creates patterns directly by spraying small volumes of droplets on a print object at a frequency of hundreds of times per second or more, by using electricity, magnetic force, or pneumatic pressure. This inkjet printing technology originated in the field of publishing printing to produce documents and advertisements, and has been increasingly used in industrial fields due to the ability to form highly precise droplet patterns. Specifically, in semiconductor and display fields, inkjet printing is used in a wide application range, such as forming complicated shape patterns on substrates or in solution processes of precisely dispensing ink in specific locations, and there is an effort to apply inkjet printing to create small, precise patterns in a variety of electronic devices. In order to eject ink by a precise amount in the inkjet printing process, ink in preparation for ejection in in the inkjet head should be maintained in a meniscus state, in which the ink has a concave surface due to capillary action at a nozzle inlet. To this end, the ink storage device is located higher than an inkjet head, whereby negative pressure is created in an ink storage tank to prevent ink from flowing down in the inkjet head, thereby maintaining the meniscus state. When the gas pressure control device does not maintain the meniscus state for the inkjet head through an ink storage unit, the precision of inkjet printing is reduced, or ink leaks from a nozzle of the inkjet head to cause contamination, interrupting inkjet printing and shutting down the entire production facility. Therefore, controlling gas pressure, which is performed in the ink storage unit to apply negative pressure to ink filled in the inkjet nozzle over the ink storage unit, is a very important part of an inkjet printing process. Meanwhile, in recent years, as application fields of inkjet printing have widened, configurations have been developed to apply inkjet printing to application fields that use very small amounts of ink. The recent industrial inkjet printing device has been developed into a form suitable for mass production while maintaining a basic characteristic of inkjet printing, which is precision, and the development has been made by providing an ink storage device for supplying ink to a head with a large capacity or constantly supplying ink to the ink storage device for supplying ink to a head. However, recently, as the industrial atmosphere of small-item mass production has changed to the industrial atmosphere of multi-product small-lot production, new requirements are required for the industrial inkjet printer. In the past, the main purpose was to perform a single process repeatedly for a long time using one type of ink in one industrial inkjet printer, but recently, there has been an increasing need for industrial devices that print extremely small amounts of ink and for performing inkjet printing while storing a small amount of ink due to properties of ink. Specifically, recently, there has been a growing demand for bio sensors and bio kits, such as diagnostic kits to check infectious diseases or check diagnose diseases, or test kits to check allergic reactions. Attempts have been made to apply inkjet printing to the manufacturing process for theses kits. However, while the manufacturing process of bio sensors and bio kits consumes a very small amount of ink per process, the ink used is perishable, so the amount of ink that can be stored at a time is very small. Therefore, it is difficult to apply currently developed inkjet printers. Specifically, compared to the storage capacity of currently developed inkjet printers, storage devices such as bio kits, etc. can only store a small amount of ink at a time, so normal inkjet printing cannot be performed, and simply reduction of the size of the ink storage device is not enough to control the meniscus state. Moreover, since the amount of ink stored in the storage device is very small, it is difficult to inject ink into the inkjet head initially or to continuously inject ink into the inkjet head during a purge process to remove internal air. DOCUMENT OF RELATED ART Patent Documents (Patent Document 1) Korean Patent Publication Application No.