Patent attributes
A decurl roller 22 of a decurl unit 20 is an axially rotatable member that eliminates curl of printing paper 24 drawn out of roll paper holders 21b. The decurl roller 22 is pressed by tension springs 23b, which are respectively spanned between the periphery of a roll paper shaft 21a of roll paper 21 and a roller shaft 22a of the decurl roller 22, to be continuously in contact with a cylindrical face of the roll paper 21 wound in a cylindrical roll. The decurl roller 22 moves to approach the roll paper shaft 21a with a decrease in remaining amount of the roll paper 21. As the remaining amount of the roll paper 21 decreases, the decurl roller 22 linearly moves along guide rails 23c, which are formed in support members 23a, toward an eccentric position from the roll paper shaft 21a to increase a contact area and a contact angle ∠PQR of the decurl roller 22 with the printing paper 24.
