Patent ID: 8820231

Claim:
A roll-to-roll printing apparatus comprising: at least three support rollers arranged in a polygonal shape; a looped pattern mask having a plurality of pattern sections passing through inner and outer surfaces thereof and disposed so as to interconnect the support rollers; a driver rotating the pattern mask; a transfer unit having an unwinder and a rewinder of a printing target and a backup roller that is disposed between the two support rollers adjacent to each other and outside the pattern mask and supports the printing target transferred from the unwinder to the rewinder; a printing unit disposed inside a loop formed by the looped pattern mask and discharging ink toward the printing target supported on the backup roller; and a tension adjusting means adjusting tension of the pattern mask, wherein the printing unit includes: a body that has a first segment provided with an internal cavity and an upper injection part for feeding the ink into the cavity, and a second segment coupled to the first segment and covering the cavity; a first shim plate that is interposed between the segments of the body and that has a downwardly opened discharge part formed at a part or all of a region opposite to the cavity of the first segment; and a second shim plate that has a screen part interposed between the first shim plate and the second segment and covering one side of the discharge part of the first shim plate, and a squeeze part extending downward from the screen part and pressing the pattern mask toward the backup roller.