This paper is concerned with the design of a laser linear encoder with high head‐to‐scale alignment tolerance. It adopts 1-x telescope design that can increase by 6 to 20 times the head‐to‐scale tolerance of existing encoders of the same class. The optical design of the laser encoder can avoid effects from differences in polarization diffraction efficiencies. In other designs the non‐uniformity of the temperature field within the head‐to‐scale range yields a nonzero initial phase and thus decreases the measurement accuracy of the system. The misalignment of the polarizers for the circular polarization interferometer configuration makes for both inclined and elliptical quadrature signals in the output. For an encoder system which adopts an arctangent algorithm, this effect may lower the measuring resolution. The resolution of our laser encoder design is verified by experiments.
關聯:
Journal of the Chinese Institute of Engineers=中國工程學刊 24(4), pp.419-429
