| 主权项 |
1. A sheet feeder comprising:
a feed roller configured to rotate in a feeding direction; a transmission mechanism configured to transmit a first drive force to the feed roller to rotate the feed roller in the feeding direction, the transmission mechanism including a rotational shaft of the feed roller; a motor including a drive shaft configured to rotate in a forward direction and in a reverse direction opposite the forward direction to generate a second drive force; a reverse roller configured to contact the feed roller and rotate in the feeding direction and in a counter-feeding direction opposite the feeding direction upon receipt of the second drive force from the motor, the reverse roller being configured to rotate in the counter-feeding direction in response to rotation of the drive shaft in the reverse direction, the reverse roller being configured to rotate in the feeding direction in response to rotation of the drive shaft in the forward direction; and a driven part configured to be driven upon receipt of the second drive force from the motor in response to the rotation of the drive shaft in the forward direction, the transmission mechanism being configured to transmit the first drive force to the feed roller to cause the feed roller to perform a first operation for rotating the feed roller in the feeding direction in case that the reverse roller is rotated in the feeding direction and the driven part is driven in response to the rotation of the drive shaft in the forward direction, and after the feed roller performed the first operation, the transmission mechanism being configured to transmit the first drive force to the feed roller to cause the feed roller to perform a second operation for rotating the feed roller in the feeding direction in case that the reverse roller is rotated in the counter-feeding direction in response to the rotation of the drive shaft in the reverse direction. |
