US-12617218-B2 - Ink jet recording apparatus

US12617218B2US 12617218 B2US12617218 B2US 12617218B2US-12617218-B2

Abstract

An ink jet recording apparatus including an ink jet head for ejecting and attaching a radiation-curable ink jet composition to a recording medium and an irradiation unit for applying radiation to the recording medium to which the radiation-curable ink jet composition is attached under supply of an inert gas, wherein the irradiation unit has, successively in a transport direction of the recording medium, a nozzle face for ejecting the inert gas and an application face for applying radiation, and h 1 >h 2 , where h 1 is a distance from the recording medium to the nozzle face and h 2 is a distance from the recording medium to the application face.

Inventors

Toshiyuki Yoda
Kiyoshi Nakamura
Shohei NAMIKOSHI
Takuya OTA
Keita Hanawa

Assignees

SEIKO EPSON CORPORATION

Dates

Publication Date: 20260505
Application Date: 20230331
Priority Date: 20220401

Claims (2)

1 . An ink jet recording apparatus comprising: a plurality of ink jet heads for ejecting and attaching a radiation-curable ink jet composition to a recording medium; and a plurality of irradiation units for applying radiation to the recording medium to which the radiation-curable ink jet composition is attached under supply of an inert gas, wherein the irradiation units are provided in one-to-one correspondence with the ink jet heads, and each irradiation unit is located immediately downstream from a respective ink jet head, each of the irradiation units has a body that includes a recording-medium facing surface that defines a nozzle face and an application face such that the nozzle face and the application face are integral with the body, the nozzle face and the application face are arranged successively in a transport direction of the recording medium, and the nozzle face is configured for ejecting the inert gas and the application face is configured for applying radiation, the nozzle face is a first planar surface of the recording-medium facing surface, the application face is a second planar surface of the recording-medium facing surface, and the first and second planar surfaces are separated from each other by a third planar surface that extends orthogonally relative to each of the first and second planar surfaces such that h 1 >h 2 , where h 1 is a distance from the recording medium to the nozzle face and h 2 is a distance from the recording medium to the application face.
2 . The ink jet recording apparatus according to claim 1 , wherein the ink jet head and the irradiation unit each have a respective width larger than or equal to a width of the recording medium.

Description

The present application is based on, and claims priority from JP Application Serial Number 2022-061686, filed Apr. 1, 2022, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to an ink jet recording apparatus. 2. Related Art Ink jet recording methods have been rapidly developed in various fields since a high-definition image can be recorded by using a relatively simple apparatus. In this regard, various types of research have been performed on, for example, a method for curing a radiation-curable ink. For example, JP-A-2014-043010 discloses an ink jet recording method including a step of efficiently curing an ink jet ink by applying an active ray in a low-oxygen atmosphere. JP-A-2014-043010 discloses an LED light source unit surrounded by an inert gas blanket 2 having an oxygen-poor atmosphere. However, when such a blanket is used to reduce hindrance to curing due to oxygen, a recording apparatus has to be increased in size. SUMMARY According to an aspect of the present disclosure, an ink jet recording apparatus includes an ink jet head for ejecting and attaching a radiation-curable ink jet composition to a recording medium and an irradiation unit for applying radiation to the recording medium to which the radiation-curable ink jet composition is attached under supply of an inert gas, wherein the irradiation unit has, successively in a transport direction of the recording medium, a nozzle face for ejecting the inert gas and an application face for applying radiation, and h1>h2, where h1 is a distance from the recording medium to the nozzle face and h2 is a distance from the recording medium to the application face. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an aspect of an ink jet recording apparatus according to the present embodiment. FIG. 2 is a schematic diagram illustrating another aspect of the ink jet recording apparatus according to the present embodiment. DESCRIPTION OF EXEMPLARY EMBODIMENTS The embodiment according to the present disclosure (hereafter referred to as “the present embodiment”) will be described below in detail with reference to the drawings, as the situation demands. However, the present disclosure is not limited to this and can be variously modified within the bounds of not departing from the scope of the disclosure. In this regard, in the drawings, the same elements are indicated by the same references and duplicate explanations may be omitted. The positional relationship in the vertical direction, the horizontal direction, or the like is in accord with the positional relationship illustrated in the drawings, unless otherwise specified. Further, the actual dimensional ratios are not limited to the ratios illustrated in the drawings. 1. Ink Jet Recording Apparatus An ink jet recording apparatus according to the present embodiment includes an ink jet head for ejecting and attaching a radiation-curable ink jet composition (hereafter also referred to as simply “ink composition”) to a recording medium and an irradiation unit for applying radiation to the recording medium to which the radiation-curable ink jet composition is attached under supply of an inert gas, wherein the irradiation unit has, successively in a transport direction of the recording medium, a nozzle face for ejecting the inert gas and an application face for applying radiation, and h1>h2, where h1 is a distance from the recording medium to the nozzle face and h2 is a distance from the recording medium to the application face. Regarding a recording apparatus in the related art, since there is a relatively large space between a recording medium and a UV irradiation portion, when an ink composition ejected onto the recording medium is cured, polymerization is susceptible to being hindered due to oxygen. From the viewpoint of suppressing polymerization from being hindered, it is considered that curing is to be performed under low-oxygen-concentration circumstances by performing UV irradiation in a portion surrounded by a blanket or the like. However, when surrounded by a blanket, apparatus size is unfavorably increased. On the other hand, when not providing a surrounding blanket, since the efficiency of oxygen concentration reduction by the inert gas is poor due to the large space of the UV irradiation portion, hindrance to polymerization is not readily suppressed from occurring. In particular, when printing speed is increased, a sufficient effect of suppressing hindrance due to oxygen is not obtained, and, in addition, a large gas generator is required due to an increase in the amount of the inert gas used. On the other hand, in the present embodiment, an irradiation unit having a configuration in which a nozzle face for ejecting the inert gas and an application face for applying radiation satisfy a predetermined relationship is used. Consequently, the efficiency of oxygen concentration reduction