本文介绍高精度绝对式19-bit、21-bit光电轴角编码器的工作原理、具体结构、精度和可靠性等.采用移相电阻链细分和分段多次校正的方法对提高绝对式编码器的分辨率、精度和可靠性是有效的手段之一.检测结果:19-bit编码器的分辨率准确度σ=±0.6″ ,测角准确变σ=±1.2″;21-bit编码器的分辨率准确度σ=±0.2″,测角准确度,σ=±0.62″.其中,19-bit绝对式编码器早已用于光测设备中. This paper introduces the working principle, structure, accuracy and reliability of high precision absolute 19-bit, 21-bit optical axis encoder.With the method of phase-shift resistance chain subdivision and multi-step correction, The resolution, accuracy and reliability of the encoder are one of the effective measures.Examination results: the resolution of the 19-bit encoder is σ = ± 0.6 “, the angle of measurement is accurately changed to σ = ± 1.2”; the 21-bit encoding Accuracy of the resolution of the device σ = ± 0.2 “, angular accuracy, σ = ± 0.62” Among them, the 19-bit absolute encoder has long been used in optical measurement equipment.