Table 1.

Comparison of performance parameters of rotary encoders based on different measurement methods.

Encoding Method	Number of Code Tracks	Resolution	Optical Characteristics			Monotropic	Algorithm Complexity	Response Speed
			Parallel Light	Focusing and Imaging	Detector
Gray Code	n	360/2n	No	No	Phototransistor	Yes	Low	Fast
Matrix code	2	360/2n	No	No	Phototransistor	Yes	Medium	Medium
single-ring Gray code	1	Approaching 360/2n	Yes	Yes	CCD or CMOS	Yes	High	Slow
M-sequence code	2	360/2n	Yes	Yes	CCD or CMOS	No	High	Slow
image encoding	0	Subpixel, ang-ular second level	Yes	Yes	CCD or CMOS	No	High	Slow