Abstract: There is disclosed a power-saving sensor system such as a distance measurement sensor making use of light projection type triangulation. The sensor system has a sensor means and a CPU for controlling the supply of electrical power to the sensor means, accepting the output from the sensor means, and performing desired processing. The CPU turns on signals P1, P2, P3 in response to a trigger signal Tp from a timer circuit, thus supplying electrical power to a distance measurement module. A distance measurement IC within the module produces an emission signal when the operating signal P3 is turned on. This activates the sensor means to perform a measurement of a distance. The presence or absence of an object is determined from the detected distance value. According to the presence or absence, a transistor Tr2 is turned on or off. A signal indicating the distance or the presence or absence of an object is produced from a terminal T8.