Sheet supply device and sheet supply method

A sheet supply device for supplying a sheet of a first roll from the first roll around which the sheet of the first roll is wound, and a sheet of a second roll from the second roll around which the sheet of the second roll is wound, the sheet supply device comprising:

• a first support shaft that supports the first roll at a center position thereof;
• a second support shaft that supports the second roll at a center position thereof;
• a joining mechanism that joins the sheet of the second roll to the sheet of the first roll;
• and
• a controller that controls driving of the joining mechanism such that the sheet of the first roll is joined to the sheet of the second roll when a remaining quantity of the sheet of the first roll is equal to or less than a preset remaining quantity in a state in which the sheet of the first roll is supplied,
• wherein
• the joining mechanism includes a second shaft drive source that rotatably drives the second support shaft, an adhesion member detector that detects a position of an adhesion member provided on an outer peripheral surface of the second roll in a rotation direction of the second roll, an outer diameter detector that detects an outer diameter of the second roll, and a pressing mechanism that presses the sheet of the first roll against the adhesion member of the second roll, and
• the controller includes a shaft control unit that controls driving of the second shaft drive source such that the second roll is rotated, an adhesion member position determination unit that determines the position of the adhesion member in the rotation direction of the second roll on the basis of a result of detection from the adhesion member detector in a state in which the second roll is rotated by the shaft control unit, and an outer diameter determination unit that determines the outer diameter of the second roll in a portion where the adhesion member is positioned on the basis of the result of detection from the outer diameter detector in a state in which the position of the adhesion member determined by the adhesion member position determination unit is positioned within a detection range of the outer diameter detector, and the controller controls the driving of the pressing mechanism such that the sheet of the first roll is pressed against the adhesion member of the second roll on the basis of the outer diameter of the second roll determined by the outer diameter determination unit.