Abstract: A timing signal generating device operates in response to angular displacement of a rotating shaft. The shaft has a disc provided with a reference mark and a plurality of timing marks apart from one another in a circumferential direction. A first detector is located adjacent to the disc to detect the reference mark and to reset a shift register. A second detector is also located adjacent to the disc to generate timing pulses in response to the timing marks and supply the pulses to the shift register. Each of plural logic gates has two input terminals each of which is connected to an output of a predetermined step of the shift register, so that an output signal outputted from each logic gate to the corresponding driving circuit for an operating device constitutes a timing signal carrying information including starting and terminating times of operation.