Is there any sensor that can be used to measure distances between 0 - 4 meters (indoor) with an accuracy of 3mm. For some reason, I can't use ultransonic sensor because my target object is paper/plastic which are sound absorbing material and may not accurately reflect sound. Any help would be highly appreciated. Cost is not a concern but accuracy is what all I need.
I am presently using parallax LRF and it has error percentage between 6-10% of measuring distance.