NON-CONTACT OPTICAL POLARIZATION ANGLE ENCODER

摘要

An optically coupled rotary encoder that is capable of measuring and encoding the angle rotation of a rotating or stationary object. A polarizer 114 rotates synchronously with the rotatable object and inputs broadband or single frequency unpolarized light 115 . The polarizer 114 outputs and directs polarized light 117 towards a plurality of fixed analyzers 116 and light detectors 120 . Each fixed analyzer 116 outputs and directs further polarized light 119 towards one of the light detectors 120 . Each light detector 120 outputs an electrical signal 122 to a phase processor 130 based upon one attribute of the further polarized light 119 . The phase processor 130 outputs a phase angle 132 with high resolution > 10 bit with high accuracy and frequency 5 Mhz. The system and method can operate in harsh environments having high temperatures, dirt and debris and is not susceptible to EMI/RFI.