| 摘要 |
A belt feeding apparatus includes a rotatable belt member; first and second stretching members for stretching the belt member; and steering means for steering the belt member, the steering means supports the belt member at a position adjacent to the first stretching member and to the second stretching member with respect to a rotational direction of the belt member, wherein the steering means includes rotatable portion rotatable with rotation of the belt member, a frictional portion, provided at each of opposite axial end of the rotation portion, for slidable contact with the belt member, supporting means for supporting the rotatable portion and the frictional portion, and a rotation shaft rotatably supporting the supporting means, wherein the steering means moves the belt member in the rotational axis direction by the supporting means rotating by a force produced by sliding between the belt member and the frictional portion; wherein the frictional portion is disposed substantially at a position where a plane parallel with a plane perpendicular to the rotational axis and a circumference of an ellipse formed when a sum of a distance between the first stretching member and the frictional portion and a distance between the second stretching member and the frictional portion, and wherein a steering force applied to the frictional portion is larger than a resisting force produced upon production of a steering amount per unit length, at a side toward which belt member is deviated when the belt member deviates in the rotational axis direction by the unit length.
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