Still-camera film transport system with motor deenergization at end of film

摘要

A still-camera film transport system includes a perforation feeler and cooperating perforation-detecting switch generating a perforation signal. A motor speed sensor generates a signal indicative of whether the motor speed is above or below a certain level. A shutter-state switch generates a signal indicating whether the shutter is in set or unset state. A motor-control switch is controlled from the output of a logic-circuit stage which receives the above three signals. During normal operation before the film end is reached, the perforation signal is used to generate a deenergize-motor signal, but in dependence upon the shutter-state signal. When the film end is reached no further perforations follow, but the transport motor comes to a halt because it cannot pull the film further. The motor-speed signal indicates this and, when applied to the logic-circuit stage, causes the motor to be deenergized if the shutter is in set state.