Light-projecting/receiving unit and omnidirectional distance detecting apparatus

A driving system region which is a region where a light projector, a light receiver, and a signal processing circuit are installed together is disposed on one side of an optical system region comprising a light-projecting region and a light-receiving region, so that wires such as their mutual signal lines are kept from passing through the optical system region, whereby an omnidirectional distance detecting apparatus capable of complete 360-degree omnidirectional distance detection can be obtained. The influence of electric noise caused by the driving system of rotary mechanism and the like upon light-receiving signals and the like is suppressed, whereby the accuracy in distance detection can be improved.