| 摘要 |
PURPOSE:To eliminate restriction due to a member to be driven in case of detecting whether the member to be driven is present or not, by constitution such that the drive frequency of a stepping motor is changed over to detect whether the member to be driven in a driving state is present or not. CONSTITUTION:When a selection motor 39 as a stepping motor is rotationally driven while the drive pulse corresponding to two rotations of a type wheel 38 is applied on a first drive frequency f0, a wheel sensor 79 discriminates whether a reading signal which has detected a shutter plate 76a is inputted twice or not during rotational driving. When the type wheel 38 is not mounted, the selection motor rotates twice without making a misstep and, when said wheel 38 is mounted, the inertia moment of the type wheel 38 acts as a load to cause the selection motor 39 to make a misstep and a reading signal is not inputted twice from the wheel sensor 79. Therefore, when the reading signal is inputted twice, it is judged that the type wheel 38 is absent to display an error and, thereafter, a printer is stopped to transfer to the error processing. |
