Patent ID: 8564795

Claim:
A printer for conveying a sheet of a roll paper type to perform printing thereon, the printer comprising a transverse tension sensor for detecting that the sheet being discharged from a discharge port has deviated in a paper width direction orthogonal to a discharging direction, wherein the transverse tension sensor comprises: a pair of movable pieces, each of which is displaced when the sheet has been displaced to one side and another side in the paper width direction; and a sensor portion for detecting displacement of the pair of movable pieces as a state where the sheet has deviated in the paper width direction, wherein the pair of movable pieces are provided with guide portions, respectively, the guide portions being arranged in rear of the discharge port in the discharging direction so as to sandwich therebetween the sheet in the paper width direction; wherein the guide portions are biased by bias means inward in the paper width direction so as to have an interval therebetween corresponding to a width dimension of the sheet; wherein the bias means biases the guide portions with a biasing force larger than a force of discharging the sheet; and wherein conveyance of the sheet is stopped based on a detection signal of the transverse tension sensor.