Patent ID: 7376298

Claim:
Device for transmitting modulated optical signals between a first unit and a second unit, in which the first unit is supported to be rotatable relative to the second unit, comprising: a light source on the first unit for supplying optical energy; a light guide extending along a circular track on the first unit; at least one first light coupler connected to the light guide, for coupling light into or out of the light guide at a coupling-in or coupling-out position, respectively; at least one second light coupler disposed on the second unit and movable relative to the light guide, for coupling light into or out of the light guide; and wherein the at least one first light coupler comprises: an optical beam splitter for dividing optical energy supplied from the light source into similar light beams, of which a first light beam is coupled tangentially into the light guide to travel along a first light path extending along the light guide in a first direction, and a second light beam is coupled tangentially into the light guide to travel along a second light path extending along the light guide in a second direction opposite to the first direction, and wherein the beam splitter further comprises at least one optical switch provided for switching light from the light source into a selected light path in which at least one second light coupler is located; and at least one light deflecting means for deflecting the first light beam from the optical beam splitter to be tangentially directed into the light guide.