Ink discharge device, printing device, and method for controlling ink discharge device

An ink discharge device attached to a conveyance line which conveys a recording medium by using a conveyance device and which is provided with a plate device which performs printing by using a plate, the ink discharge device comprising:

• a head which prints an image based on image data by discharging ink from a nozzle to a printing surface of the recording medium conveyed by the conveyance device;
• a movement unit which makes the head move in a Z-axis direction which is a height direction when the printing surface of the recording medium is taken as a front face, and which moves the head at least in two axial directions;
• and
• a controller which, in accordance with an image to be printed or the recording medium, sets a discharge-time distance which is a distance between the nozzle and the printing surface during ink discharge, and which makes the movement unit move the head in the Z-axis direction to achieve the discharge-time distance set.