Ink jet recording apparatus

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.