Improvement of optical axis parallelism correction for laser rangefinder

The method of the traditional optical axis correction for laser-range-finder was improved. The angle which the eccentric ring（or eccentric frame）needs to adjust was calculated by the mathematical model of the optical axis parallel deviation and the eccentric ring（or eccentric frame）rotary angle. The correction of optic-axes parallel was realized by the optical axis correcting device. Two correcting methods (semiautomatic and fully automatic corrections) are presented. In the semiautomatic correcting method, a scale ring is attached to the lateral portion of the double eccentric structure, and the optical axis correction is realized by rotating the eccentric structure to a certain angle by the two eccentric sleeves. In the fully automatic correcting method, the double eccentric structures are controlled by two stepping motors to adjust the optical axes. The experimental research on a certain laser rangefinder is conducted. The results show that the optical axis error corrected by the method is within the maximal permitted range（0.25mrad）, the efficiency is increased by the improved method, and this method can meet the requirement of the practical need.