PURPOSE: To prevent jamming by adding a film loop sensor switch to a motor drive circuit.

CONSTITUTION: A loop sensor switch SW3 is connected together with a magazine detecting switch SW1 and a release switch SW2 to the drive circuit of a film drive motor 1 and a capstan motor 7. The switch piece 4 thereof makes possible the detection of the film loops 3', 3" of the sagged state and diminished state between a film feed pawl 2 and capstan 6. Then, where a sound magazine is held loaded in the camera and its film loops are in the sagged state 3', the capatan motor 7 is driven through ON of the switches SW1, 2 and OFF of the switch SW3. When the film loops diminish and the loop sensor switch SW3 goes ON, the film motor 1 is driven to correctly feed the film 3, whereby jamming is prevented.