A detection device, which includes a scanning module, a detection module operated at a distance from the scanning module, and an evaluation unit. The scanning module includes a laser light source for generating a laser beam, a deflection unit to deflect the beam, and a control unit for controlling the laser light source and the deflection unit, so that the beam is moved in a scanning pattern. The detection module includes a light detector, with which the light of the beam reflected on an object in the beam path is detected and converted into a received signal. The first laser light source is controlled so that the beam is modulated as a function of its deflection and in this way is provided with synchronization marks. The evaluation unit identifies these synchronization marks in the received signal and synchronizes the received signal with the deflection of the beam based on them.