US-12623464-B2 - Inkjet recording device

US12623464B2US 12623464 B2US12623464 B2US 12623464B2US-12623464-B2

Abstract

In an inkjet recording device ( 1 ), an intermediate flow passage ( 53 ) is connected to a downstream section of a first flow passage ( 89 ), and is in communication with a recording head ( 52 ) and a second flow passage ( 90 ). A communicating flow passage ( 54 ) includes a first branch flow passage ( 54 A) that supplies ink from the intermediate flow passage ( 53 ) to the recording head ( 52 ), a second branch flow passage ( 54 B) that causes the ink to circulate from the recording head ( 52 ) to the second flow passage ( 90 ), and a third branch flow passage ( 54 C) that causes the ink to flow from the intermediate flow passage ( 53 ) to the second flow passage ( 90 ). Opening/closing valves ( 96 ), ( 55 A), ( 55 B), ( 55 C) are respectively provided to a third flow passage ( 91 ) and the first branch flow passage ( 54 A), the second branch flow passage ( 54 B), and the third branch flow passage ( 54 C).

Inventors

Noriaki Furukawa
Shunsuke Yamasaki
Kaori Kitayama
Yuko Yano

Assignees

KYOCERA DOCUMENT SOLUTIONS INC.

Dates

Publication Date: 20260512
Application Date: 20230314
Priority Date: 20220324

Claims (4)

1 . An inkjet recording device comprising: one, or more, recording head having a plurality of nozzles for ejecting ink onto a recording medium; an ink container for containing the ink supplied to the recording head; a first sub-tank for temporarily storing the ink supplied from the ink container; a second sub-tank for temporarily storing the ink supplied from the first sub-tank; a circulating pump for moving the ink from the first sub-tank to the second sub-tank; a pressurizing part for pressurizing interior of the second sub-tank to supply the ink from the second sub-tank to the recording head; a depressurizing part for depressurizing interior of the first sub-tank to circulate the ink from the recording head to the first sub-tank; a syringe into which the ink flows from the second sub-tank and from which the ink flows out toward the recording head, the syringe enabled to apply to the ink a maintenance pressure higher than a recording pressure applied to the ink by the pressurizing part; a first flow passage along which the ink flows from the first sub-tank to the circulating pump to the second sub-tank to the syringe and up to the recording head; a second flow passage along which the ink circulates from the recording head to the first sub-tank; and a third flow passage for coupling together an upstream side of the recording head in an ink flow direction of the first flow passage and a downstream side of the recording head in an ink flow direction of the second flow passage; an intermediate flow passage connected to a downstream point in the ink flow direction of the first flow passage so as to be communicated with the recording head and the second flow passage; and a communicating flow passage including a first branch flow passage for supplying the ink from the intermediate flow passage to the recording head, a second branch flow passage for circulating the ink from the recording head to the second flow passage, and a third branch flow passage for circulating the ink from the intermediate flow passage to the second flow passage, wherein the third flow passage as well as the first branch flow passage, the second branch flow passage, and the third branch flow passage composing the communicating flow passage are each equipped with an opening/closing valve.
2 . The inkjet recording device according to claim 1 , further comprising: a waste liquid flow passage connected to one of the first sub-tank and the second sub-tank; a waste liquid tank connected to a downstream end of the waste liquid flow passage; and a waste liquid pump for moving the ink to the waste liquid tank via the waste liquid flow passage.
3 . The inkjet recording device according to claim 2 , wherein the waste liquid flow passage is equipped with an opening/closing mechanism.
4 . The inkjet recording device according to claim 1 , wherein the pressurizing part includes: a pressurizing chamber which is communicated with the second sub-tank; a pressurizing pump for making air flow into the pressurizing chamber to pressurize the chamber; and a pressurizing sensor for detecting an internal pressure of the pressurizing chamber, and the depressurizing part includes: a depressurizing chamber which is communicated with the first sub-tank; a depressurizing pump for making air flow out from within the depressurizing chamber to depressurize the chamber; and a depressurizing sensor for detecting an internal pressure of the depressurizing chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage of International Application No. PCT/JP2023/009810, filed Mar. 14, 2023, which claims the benefit of Japanese Application No. 2022-049046, filed Mar. 24, 2022, in the Japanese Patent Office, the disclosures of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to an inkjet recording device. BACKGROUND ART An inkjet recording device includes a recording head for ejecting ink onto a paper sheet or other recording medium to record images. For example, at shipping from a factory, there are some cases, with the inkjet recording device, where the ink supply side is emptied for prevention of liquid leaks while the recording head side is filled with transport liquid for quality assurance of flow passages. For this occasion, in the inkjet recording device, the ink supply side and the recording head side may be provided so as to be fittable and removable by means of a coupling or the like. The conventional inkjet recording device disclosed in patent document 1 includes a removable coupling for each of two places, one on a supply path along which ink supplied from a supply unit to recording heads passes, and the other on a circulation path along which ink returning from the recording heads to the supply unit passes. An upstream-side portion on the supply path and a downstream-side portion on the circulation path, which are to be connected to the two couplings, respectively, are connected to each other by a bypass path that allows the two sides to be communicated with and intercepted from each other. As a result, at a product arrival time of the inkjet recording device, ink can be circulated to and filled into the supply unit not via recording heads but via the bypass path. Thereafter, connecting the two couplings with each other to make the supply path and the circulation path communicated with each other, and moreover replacing reservation liquid of the recording heads with ink, makes it possible to suppress involvement of foams in the ink of the recording heads. CITATION LIST Patent Literature Patent Document 1: JP 2019-171648 A SUMMARY OF INVENTION Technical Problem In the above-described conventional inkjet recording device, a clamp for opening and closing ink flow passages is provided on the bypass path. Then, for replacement with different ink, replacement work is carried out while ink quantity within a sub-ink tank for ink storage is being decreased gradually. However, because the ink in the bypass path cannot be replaced, the clamp opening/closing operation by manual work needs to be exercised again and again. Also, for reduction of ink consumption during the replacement, ink needs to be drawn out from a supply unit. In this situation, it would be necessary to remove the coupling, with which the supply unit and the recording heads are connected together, in order to prevent meniscus collapses of ink within the recording heads, and to discharge ink exclusively by using suction jigs or the like. As seen in these cases, there have been problems in terms of more laborious work, increases in ink consumption, and increases in required time, involved in replacement with different ink. The present invention having been accomplished in view of the above-described issues, an object of the invention is to provide an inkjet recording device that makes it possible to realize more convenience of work, decreases in ink consumption, and reduction in required time during replacement work with different ink. Solution to Problem In order to solve the above problems, an inkjet recording device of the present invention includes a recording head, an ink container, a first sub-tank, a second sub-tank, a circulating pump, a pressurizing part, a depressurizing part, a syringe, a first flow passage, a second flow passage, a third flow passage, an intermediate flow passage, and a communicating flow passage. The recording head, which is provided one or more in number, has a plurality of nozzles for ejecting ink onto a recording medium. The ink container contains the ink supplied to the recording head. The first sub-tank temporarily stores the ink supplied from the ink container. The second sub-tank temporarily stores the ink supplied from the first sub-tank. The circulating pump moves the ink from the first sub-tank to the second sub-tank. The pressurizing part pressurizes interior of the second sub-tank to supply the ink from the second sub-tank to the recording head. The depressurizing part depressurizes interior of the first sub-tank to circulate the ink from the recording head to the first sub-tank. The syringe, into which the ink flows from the second sub-tank and from which the ink flows out toward the recording head, is enabled to apply to the ink a maintenance pressure higher than a recording pressure applied to the ink by the pressurizing part. Along the first flow passage, the ink flows from the first sub-tank to