Patent ID: 7883204

Claim:
An ink jet printer comprising: ink jet heads that discharge aqueous ink droplets onto a printing surface of a printing medium that is transported in a predetermined direction; a vapor supply unit that is provided at a downstream side of the ink jet heads in a direction in which the printing medium is transported and supplies vapor to a surface of the printing medium opposite the printing surface of the printing medium having the liquid droplets discharged from the ink jet heads in a non-contact manner; a vapor supply control unit that controls the supply of the vapor from the vapor supply unit to the printing medium according to the ratio of the number of nozzles discharging the ink droplets from the ink jet heads to the total number of nozzles; and a vapor electrostatic deposition unit that deposits the vapor supplied from the vapor supply unit to the surface of the printing medium opposite the printing surface of the printing medium using electrostatic force, wherein the vapor electrostatic deposition unit includes a printing medium charging unit for charging the printing medium, and wherein the vapor supply unit includes: a vapor generating unit that generates vapor on the side of the printing medium opposite the printing surface of the printing medium onto which the ink droplets are discharged from the ink jet heads; and a suction unit that sucks air from the printing surface of the printing medium to generate the flow of vapor from the side of the printing medium opposite the printing surface to the printing surface.