Belt device and image forming device

A belt device, comprising:

• a device main body;
• a driving roller and a driven roller;
• a belt that is endless and wound around the driving roller and the driven roller, and that rotates in the device main body by the driving roller being rotationally driven;
• and
• a cleaning unit including a cleaning blade disposed sandwiching the belt between the cleaning blade and the driven roller in a state in which a distal end portion of the cleaning blade abuts the belt,
• wherein:
• the driven roller includes, on one side in a width direction intersecting a transport direction of the belt, a moving member that inclines a rotary shaft of the driven roller when the moving member is pushed by a deviation of the belt and moved to the one side,
• the cleaning blade is provided in the cleaning unit with one side of the cleaning blade in the width direction parallel to the width direction intersecting the transport direction of the belt tiltable following tilting of the rotary shaft of the driven roller,
• the cleaning unit further includes a transport screw that transports toner removed from a front surface of the belt by the cleaning blade,
• another side of the cleaning blade in the width direction is a downstream side in a transport direction of the toner to be transported by the transport screw,
• the cleaning unit further includes, on the downstream side of the transport screw in the transport direction of the toner, a discharge port that discharges the transported toner,
• the cleaning unit further includes a collection container into which the toner removed from the front surface of the belt is collected,
• the collection container is provided detachably on the device main body,
• the discharge port is disposed in the collection container with the collection container attached to the device main body, and
• the driven roller does not include the moving member on another side in the width direction intersecting the transport direction of the belt.