PURPOSE: To move a recording pen at a high speed to convert a rotating motion to a linear motion at a high speed by a method wherein a ball bearing disposed in a groove of a rotating drum is moved in contact with the wall of the groove of the rotating drum to obtain a structure of a small friction and a smooth movement.

CONSTITUTION: A lower end part of a recording pen holder 4 is inserted into a groove 2 provided on the surface of a rotating drum and held so as to freely move in the groove 2. A ball bearing provided on the lower end of the recording pen holder 4 to ensure the movement of the holder 4 in the groove 2 with a small friction freely moves in contact with the wall of the groove 2 of the rotating drum. A bored guide plate 3 movably holds the barrel of the recording pen holder 4 in the bored hollow part thereof to guide it in parallel to the axial direction of the rotating drum. The bored guide plate 3 is fixed on the rotating drum so that the longitudinal direction of the bored hollow part coincides with the axial direction of the rotating drum. Simultaneously with the rotation of the rotating drum, the lower end of the recording pen holder 4 moves in one direction along the groove 2 through the ball bearing, whereby a circular motion is converted to a linear motion with a small friction.