Motion picture projector with reduced picture jump

A motion picture projector substantially free of picture jump comprising:

• a gate assembly having a projection aperture;
• a light source for directing a beam of light through the projection aperture and onto a screen;
• intermittent advancing means for intermittently advancing film through the gate assembly so that successive frames of the film are advanced into alignment with the projection aperture and held stationary for a select period of time comprising:
• a rotatable intermittent sprocket for engaging the film so that rotation of the intermittent sprocket advances the film through the gate assembly;
• a rotatable star wheel connected to the intermittent sprocket so that rotation of the star wheel rotates the intermittent sprocket, said star wheel having a plurality of radially extending slots with a curved surface having a generally constant radius between adjacent slots;
• a rotatable cam adjacent the star wheel comprising a pin which engages a slot of the star wheel for rotating the star wheel a fraction of a rotation for each rotation of the cam and a ring comprising a tension area adjacent the pin having a curved surface of generally constant radius about the same as the radius of the curved surfaces of the star wheel for slidably engaging the curved surfaces of the star wheel for preventing backward rotation of the star wheel during engagement and aligning the slot of the star wheel with the pin of the cam, and a relief area of the ring remote from the pin having a generally constant radius less than the radius of the tension area to thereby allow the star wheel and the intermittent sprocket to rotate backwardly a select distance during at least a portion of each period of time that the pin of the cam does not engage the slot of the star wheel and the film is stationary, to reduce tension on the portion of the film in the gate assembly during those stationary periods;
• and
• means for rotating the cam.