Patent ID: 7492444

Claim:
An electric optical distance meter comprising: a light source for emitting a distance measuring light to a target placed on a measurement point; a light receiving device for receiving the distance measuring light reflected and returned from the target; a dividing means for dividing the distance measuring light emitted by the light source between an external optical path placed to and from the target and an internal optical path placed from the light source to the light receiving device; and a shutter for switching between the internal optical path and the external optical path; wherein the shutter has: a rotating axis; blocking plates which are arranged at two locations symmetric with respect to the rotating axis and alternately block the respective distance measuring lights entering the external optical path and the internal optical path; and an attenuation plate which is placed at one of the two locations between the blocking plates and attenuates the distance measuring light entering the internal optical path when the target is of a low reflectivity.