Ink Jet Printing Device

An ink jet printing device, comprising:

• a printing medium conveying mechanism having a support surface for supporting a printing medium, for conveying the printing medium in a specified direction;
• a head unit mounting an ink jet head;
• a head unit moving mechanism for moving the head unit reciprocally in a direction orthogonal to the conveying direction of the printing medium, and
• a controller,
• wherein the controller controls to feed the printing medium in a specified direction, to move the head unit in a direction of crossing the printing medium, to discharge the ink from the head unit toward the printing medium, and to print on the printing medium, and further a blower is provided at least at the backward side in the printing moving direction of the head unit, out of the both sides of the head unit, and the blower has an air nozzle for injecting air toward the printing medium, and the bottom of the blower is provided with a wall for bending the air injected from the air nozzle at right angle by Coanda effect, and generating a horizontal air stream in a direction nearly at right angle to the ink discharge direction toward a direction departing from the adjacent head unit, and the ink on the printing medium is dried by the horizontal air stream.

An ink jet printing device, comprising:

• a printing medium conveying mechanism having a support surface for supporting a printing medium, for conveying the printing medium in a specified direction;
• a head unit mounting an ink jet head;
• a head unit moving mechanism for moving the head unit reciprocally in a direction orthogonal to the conveying direction of the printing medium within a printing area and between the printing area and a waiting position;
• a controller;
• and
• a blower communicating with a solenoid valve opened and closed by the controller, for starting or stopping blowing by opening or closing of the solenoid valve, being coupled at least at the backward side in the printing moving direction of the head unit, out of the both sides of the head unit,
• wherein the controller controls to feed the printing medium in a specified direction, to move the head unit in a direction of crossing the printing medium, to discharge the ink from the head unit toward the printing surface of the printing medium, and to print on the printing medium, and the blower has an air nozzle for injecting air toward the printing medium, and the bottom of the blower is provided with a wall for bending the air injected from the air nozzle at right angle by Coanda effect, and generating a horizontal air stream in a direction nearly at right angle to the ink discharge direction toward a direction departing from the adjacent head unit, and the controller controls the solenoid valve as follows:
• when the head unit is at the waiting position or while moving from the waiting position to specified printing area, blowing by the blower is stopped, and when the head unit gets into the printing area, blowing by the blower is started, and when the head unit finishes printing on the printing medium, blowing by the blower is stopped.