摘要:
A printer includes a platen roller (20), a print head (10) for performing printing on a recording paper, a first detection switch (132) and a second detection switch (142) for detecting a position of the platen roller (20), and a potential detector (171) that detects electrical potential. Both of the first and second detection switch (132, 142) are switched off when the platen roller is mounted, and switched on when the platen roller is not mounted. One terminal of the first detection switch and one terminal of the second detection switch are connected to each other in parallel and grounded via a ground side resistor. A power supply (Vcc) is to be connected to another terminal of the first detection switch and another terminal of the second detection switch. The potential detector detects a potential between the one terminals of the first and second detection switches and the ground side resistor.