A rotational force transmission mechanism has: a rotation-inputting member freely rotative and driven in a predetermined first direction and a second direction opposite the first direction by a predetermined operating member a first rotation-transmitting member for receiving a rotational driving force supplied from the rotation-inputting member in the first direction a second rotation-transmitting member, disposed to face the first rotation-transmitting member, for receiving a rotational driving force supplied from the rotation-inputting member in the second direction a connection section disposed so that the rotational force acts in the direction in which the first rotation-transmitting member and the second rotation-transmitting member face each other, the connection section in the facing position transfers the rotational driving force received by the first rotation-transmitting member in the first direction to the second rotation-transmitting member and transfers the rotational driving force received by the second rotation-transmitting member in the second direction to the first rotation-transmitting member and a rotation-outputting member rotated and driven by the first rotation-transmitting member in the second direction, and rotated and driven by the second rotation-transmitting member in the first direction.
