A parking space detecting device and method

This invention relates to a parking space detecting device and method. In a parking lot, each parking space is equipped with one parking space detecting device to detect whether there is a vehicle parked on the space. The parking space detecting device adopts a driving control circuit to drive a light-emitting unit to emit a light ray. The propagation line of the light ray goes through a reflection element on the parking space; so that the reflection element will reflect the light ray. The propagation line of the reflected light ray from the reflection element will goes through a photo-sensor which will detect the reflected light ray and produce one first sensing signal, and send the signal to the driving control circuit so that the driving control circuit will consider that there is no vehicle parked on the space; otherwise, the driving control circuit will consider that there is a vehicle parked on the space. All the parking space detecting devices on the parking lot will form a mesh network through each of