| 摘要 |
<p>In a cine camera, the function of the main key in the handle and of the trigger key are interlinked in such a way that the trigger key cannot switch ON the film drive before all essential cameral functions (exposure automatic, sound recording automatic etc.) are ON. Before a shot ends, the main key switches the functions OFF only after the film drive has come to a standstill. This is achieved by a disc brake which couples the functions by a rectangular lug on the disc during the starting period. During the finishing period, a delay in its action is achieved by a silicone oil film on the two faces of the friction discs of the brake. The viscosity of the silicone oil used remains constant between -15 degrees C and +60 degrees C. The delay time of the brake ensures that no film is wasted by the main key acting too late at the start or cutting out too soon at the end.</p> |
