PURPOSE: To eliminate a noise and fluctuations of a projection on a screen by positioning axially a grooved cam and a sprocket accurately.

CONSTITUTION: When set screws 28 and 29 of rotating bodies 26 and 27 are loosened, the rotating bodies 26 and 27 rotate freely around a shaft 20 and move axially along male screws 24 and 25. Therefore, when the rotating bodies 26 and 27 move to right on the shaft 20, the rotating bodies 26 and 27 strike bearings 9 and 10 and stop, so the cam shaft 20 move to left in a case. Further, when the rotating bodies 26 and 27 move to left, the cam shaft 20 moves to right. Further, the rotating bodies 26 and 27 are outside the case 11, so the unit of this film feed device is assembled and then the position of the grooved cam 21 is moved and adjusted from outside.