Print medium-conveying device and inkjet printing device

A print medium-conveying device comprising:

• a drum that conveys a print medium by winding a sheet-like print medium around an outer peripheral surface and performing rotation;
• a pressure roller that presses a front surface of the print medium wound around the outer peripheral surface of the drum and makes a back surface of the print medium contact the outer peripheral surface of the drum;
• a back tension giving device having an adsorption holding surface to which the front surface of the print medium is adsorbed and held, which adsorbs and holds the front surface of the print medium to the adsorption holding surface in a position immediately before entry between the drum and the pressure roller, and gives back tension to the print medium;
• a print medium information acquisition device which acquires information of the print medium;
• and
• a control device which controls ON/OFF of adsorption of the print medium by the back tension giving device, based on the information of the print medium acquired by the print medium information acquisition device, wherein:
• the print medium is a paper and the information of the print medium acquired by the print medium information acquisition device is thickness and paper type of the print medium;
• and
• the control device compares the thickness of the print medium acquired by the print medium information acquisition device and a threshold set beforehand for each paper type, turns on the adsorption of the print medium by the back tension giving device when the thickness of the print medium acquired by the print medium information acquisition device is less than the threshold, and turns off the adsorption of the print medium by the back tension giving device when the thickness is equal to or greater than the threshold.