Patent ID: 8208813

Claim:
A machine, comprising: a first machine part; a second machine part which rotates relative to the first machine part about an axis of rotation; an optical signal transmitting device disposed on the first machine part to transmit data signals, the optical signal transmitting device incorporating an annular optical waveguide disposed concentrically to the axis of rotation; an optical signal receiving device disposed on the second machine part for receiving optical signals, wherein the annular optical waveguide is implemented and disposed such that light coupled by a light source into the annular optical waveguide exits from the optical waveguide at any locations on its circumference in direction of the second machine part, wherein the optical waveguide has a core and a cladding, the material constituting the core having a lower refractive index than the material constituting the cladding, wherein the cladding is broken over the entire circumference of the optical waveguide ring.