Reverse input blocking clutch

A clutch device for moving a driven member (30) between at least two predetermined prescribed positions. The device includes a rotational driving source and a reverse input blocking clutch comprising an input member (11) into which torque from said rotational driving source is input and an output member (12) connected to said driven member (30), for transmitting input torque applied to said input member (11) to said output member (12) while blocking transmission of reverse input torque applied at said output member (12) to said input member (11) and permitting slipping of said output member (12). The clutch includes restraining means (20) for elastically restraining rotation of said output member (12) at each of said prescribed positions.