Patent ID: 8804131

Claim:
An optical angle-measurement device adapted to ascertain a relative movement between the scanning grating and the graduated disk device, comprising: at least one scanning grating arranged as a linear scanning grating; a graduated disk including a first and a second combined radial-circular grating as a measurement graduation and a mirror; and wherein the scanning grating is adapted to initially split an incident beam of rays into two partial beams of rays that propagate in a direction of the first combined radial-circular grating; wherein the first combined radial circular grating is adapted to diffract the partial beams of rays so that the diffracted partial beams of rays propagate in a direction of the mirror; wherein the minor is adapted to reflect the partial beams of rays in a direction of the second combined radial-circular grating so that the partial beams of rays propagate in a direction of the second combined radial-circular grating; wherein the second combined radial-circular grating is adapted to diffract the partial beams of rays so that diffracted partial beams of rays propagate in a direction of the scanning grating; and wherein the scanning grating is adapted to superpose the partial beams of rays.