An alignment mechanism comprising: a rotary unit including a first rotary axis; three power transmission mechanisms pivotably supported at three different positions (P11, P12, P13) at the rotary unit shifted from the first rotary axis; and three alignment action units that operate in response to transmission of the rotation of the rotary unit through corresponding ones of the three power transmission mechanisms, wherein each of the three power transmission mechanisms comprises: a first arm including a first end pivotably supported at a corresponding one of the three different positions (P11, P12, P13), and a second end located on the opposite side of the first end;and a second arm including a second rotary axis and pivotably supported on the second end of the first arm at a position different from the second rotary axis, characterized in that a shaft connected to the second arm with a center line of the shaft aligned with the second rotary axis and rotatable around the second rotary axis in interlocking relationship with the second arm; in that a third arm connected to an end of the shaft on the opposite side of an end of the shaft connected to the second arm, in that the three alignment action units are provided at respective tips of the third arms connected to the respective second arms of corresponding ones of the three power transmission mechanisms, and in that the respective second rotary axes of the three second arms are arranged at three positions (P21, P22, P23) separated from the rotary unit toward three different directions centered on the first rotary axis. a rotary unit including a first rotary axis; three power transmission mechanisms pivotably supported at three different positions (P11, P12, P13) at the rotary unit shifted from the first rotary axis; and three alignment action units that operate in response to transmission of the rotation of the rotary unit through corresponding ones of the three power transmission mechanisms, wherein each of the three power transmission mechanisms comprises: a first arm including a first end pivotably supported at a corresponding one of the three different positions (P11, P12, P13), and a second end located on the opposite side of the first end;and a second arm including a second rotary axis and pivotably supported on the second end of the first arm at a position different from the second rotary axis, characterized in that a shaft connected to the second arm with a center line of the shaft aligned with the second rotary axis and rotatable around the second rotary axis in interlocking relationship with the second arm; in that a third arm connected to an end of the shaft on the opposite side of an end of the shaft connected to the second arm, in that the three alignment action units are provided at respective tips of the third arms connected to the respective second arms of corresponding ones of the three power transmission mechanisms, and in that the respective second rotary axes of the three second arms are arranged at three positions (P21, P22, P23) separated from the rotary unit toward three different directions centered on the first rotary axis. a first arm including a first end pivotably supported at a corresponding one of the three different positions (P11, P12, P13), and a second end located on the opposite side of the first end;and a second arm including a second rotary axis and pivotably supported on the second end of the first arm at a position different from the second rotary axis, characterized in that a shaft connected to the second arm with a center line of the shaft aligned with the second rotary axis and rotatable around the second rotary axis in interlocking relationship with the second arm; in that a third arm connected to an end of the shaft on the opposite side of an end of the shaft connected to the second arm, in that the three alignment action units are provided at respective tips of the third arms connected to the respective second arms of corresponding ones of the three power transmission mechanisms, and in that the respective second rotary axes of the three second arms are arranged at three positions (P21, P22, P23) separated from the rotary unit toward three different directions centered on the first rotary axis.