PURPOSE: To securely transmit the power of a motor to a changeover gear, and to prevent malfunction due to incomplete switching, by holding the motor powered up for a certain period after switching from a rewinding mode to a take- up mode.

CONSTITUTION: A gear 4 for film winding which engages a gear 1 driven by a motor M is provided with cams 5 and 6, and levers 8 and 9 are provided facing them. In a rewinding state, the gear 1 engages a gear 13 to lock the lever 8 by a rewinding lever 16, and at this point of time, the motor M rotates. In this state, when switching to a take-up mode is performed, the gear 1 moves up by a spring to engage the gear 4, and then the cams 5 and 6 rotate to rotate the levers 8 and 9 clockwise; and the lever 8 and lever 16 are disengaged from each other and the lever 8 engages the cam 5 to stop the motor M, obtaining the take-up mode. Thus, when the gear 1 engages the gear 4 again, the motor M does not stop immediately, so the engagement is secured to prevent malfunction due to incomplete switching.