摘要 |
An optical slip ring comprises a housing made of low refractive index material which defines a hollow toroid (10) and a pair of passageways (15A, 15B) leading from the toroid (10). One passageway (15B) leaves the toroid (10) steplessly in a clockwise direction and passageway (15A) leaves the toroid (10) steplessly in an anti (counter-)clockwise direction. The toroid (10) and the passageways (15A, 15B) are filled with high refractive index fluid. The housing is formed in two portions which are mounted for relative rotation about an axis (13) perpendicular to the toroidal equatorial plane (12) and coincident with the center (14) of the toroid, each portion having an interface lying on a surface of revolution (which may be the toroidal equatorial plane (12) ) generated about the axis (13), one housing portion incorporating one passageway (15A) and the other housing portion incorporating the other passageway (15B). |