DEVICE AND METHOD FOR MEASURING A SURFACE

摘要

A device for measuring a surface (2) comprises a light source (3), a light directing device (4-6), a detector arrangement (10) and an evaluation circuit (15). The light source (3) generates a sequence of light pulses with a repetition rate. The light directing device (4-6) is controllable to direct the sequence of light pulses onto a surface area (25) of the surface (2). The surface area may be selected from plural surface areas (25, 27). The detector arrangement is configured to receive at least one light signal (21-24) scattered and/or reflected by the surface area (25). The evaluation circuit (15) is coupled to the detector arrangement (10) and is configured to determine a phase difference between a reference signal (19) derived from the sequence of light pulses and a signal component of the at least one light signal (21-24), in order to determine a position of the surface area (25). In doing so, the phase difference is determined for the signal component which has a frequency corresponding to a multiple of the repetition rate.