| 摘要 |
A belt unit includes an endless belt member, a first roller provided on an inner circumferential surface side of the belt member, and a stretching member provided on the inner circumferential surface side of the belt member. The stretching member is configured to stretch the belt member. A circumferential length of the belt member at a center portion in a widthwise direction of the belt member is shorter than a circumferential length of the belt member at an end portion in the widthwise direction of the belt member. |
