Opto-electronic rotary encoder

(57) A summary rotary encoder has a scale (22) which rotates to a pair of reading heads (14). Each of a reading head projects light on a scale, and generates the intermittent optical pattern like interference fringes in 検光格子 (40). This interference fringes and 検光格子 act mutually so that a series of synthetic vernier scale stripes which enter into a structure detector array (100) may be produced. In one case of the operation, 検光格子 is formed so that it may act each other on which attach an angle and are prolonged so that straight line composition stripes may be produced / the interference fringes and mutual. The error for eccentricity rotation of a scale (22) decreases with the pitch in which synthetic stripes decrease.