A power transmitting mechanism assembly including a supporting plate; a first roller, which is rotatably attached to the supporting plate; a first plate, which contacts a first end of the first roller and is arranged to be able to rotate with respect to the supporting plate; a power generating unit, which generates power for rotating the first plate when a signal is applied; a second plate, which is arranged to contact a second end of the first roller; and a friction changing unit, which is attached to at least one of the first roller, the first plate, and the second plate and changes friction of a portion of a contacting surface between the first roller and the first plate or friction of a portion of a contacting surface between the first roller and the second plate.
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