| 摘要 |
PURPOSE:To select the reading resolution over a wide range by switching the drive of an N-phase stepping motor into n1, n2,..., or nk phase exciting drive in matching a speed obtained in response to the required reading resolution. CONSTITUTION:A switching drive circuit of the stepping motor consists of a control circuit 11, an exciting signal generating circuit 12, a stepping motor driver 13 and a bi-phase stepping motor 7. Then the drive frequency region available is varied by switching the drive into the n1, n2,..., or nk phase exciting drive. Thus, even if the speed is limited to a prescribed speed at, e.g., the n1 phase excitation drive, the image sensor is moved at a larger speed by adopting the n2 phase exciting drive. Thus, the reading resolution of wider range is selected. |
