| 摘要 |
PROBLEM TO BE SOLVED: To provide a belt transporting unit in which the stance of a belt or the belt tension is stable when integrated into an image forming apparatus even when stored for a long period of time. SOLUTION: The image forming apparatus is provided with: a plurality of tensioning rolls 1 (1a, 1b); an endless belt 2 which is hung on the tensioning rolls 1; and a roll support varying mechanism 3 which supports the plurality of tensioning rolls 1 and makes at least one of the plurality of tensioning rolls 1 to be the variable tensioning roll 1b with variable arranged position. In this case, the roll support varying mechanism 3 varies the arranged position of the variable tensioning roll 1b between a use tension position P1 in which the endless belt 2 is hung at the tension which is necessary for use and a standby tension position P2 in which the endless belt 2 is hung at the tension which is reduced compared to that of the use tension position P1 and at the same time changing the position in the direction so that the tension of the endless belt 2 is made slack on the outer side of the arranged position of the endless belt 2 which is in the use tension position P1. COPYRIGHT: (C)2010,JPO&INPIT
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