摘要 |
An optical image scanner includes a scan head that is mounted onto a guide member with a bias torque that reduces uncertainty in position of the scan head. A drive member, such as a belt or cable, is attached to the scan head with an offset relative to a centerline of the guide member. A tensioning device ensures that the drive member asserts force on the scan head at each of the attachment points. As a result, a bias torque is placed onto the scan head, relative to the guide member, reducing uncertainty in position. For bidirectional movement, the biasing torque is the same for either direction of travel.
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