Patent ID: 8520192

Claim:
A distance-measuring system, comprising: a light source; a light detector; measuring optics for projecting light emitted by the light source to a target and for guiding light reflected from said target towards the light detector; reference optics for guiding light emitted by the light source within the system towards the light detector as internal reference light; a variable attenuator for adjusting intensity of light incident on the light detector, the variable attenuator comprising an attenuating filter arranged in a beam path between the measuring optics and the light detector, and an actuator coupled to the attenuating filter for moving the attenuating filter; and an optical selector for selectively directing light guided by either the measuring optics or the reference optics to the light detector; wherein the optical selector is coupled to at least one of the actuator or the attenuating filter and moved by the actuator together with the attenuating filter; and wherein the light source is adapted for emitting light to both the measuring optics and the reference optics at the same time.