Laser scanner and method for checking of its functionality

There is a laser scanner (10) having a light transmitter (12) for emitting a light beam (16) into a monitored zone (20), a light receiver (26) for generating a received signal from the objects in the monitored zone (20) diffusely reflected light beam (22 ), a rotatable deflector (18) for periodically deflecting the light beam (16, 22) for detecting the course of the movement of the monitored zone (20), an internal reference target (40) of the emitted light beam (16) in a first reference rotational position reflects deflection unit (18) with high intensity and in a second reference rotational position of the deflection unit (18) of low intensity within the laser scanner (10) to the light receiver (26) to produce a strong and a weak reference signal and (with an evaluation unit 36 ) indicated that is adapted to detect objects on the basis of the received signal as well as the operability of the laser scanner (10) based to consider the reference signal. In this case, the reference target (40) having a front surface (46) and against the front face (46) tilted on rear surface (48), wherein in the first reference rotation position, the front surface (46) the strong reference signal and in the second reference rotational position rear face (48) generates the weak reference signal.