Optical reflector assemblies for use optical rotary joints

1. An optical reflector assembly ( 50 ) for enabling optical communication between a rotor and a stator, said rotor having a longitudinal axis, comprising:

a first member ( 51 ) having a concave first reflective surface ( 52 ), a line (L) in a plane taken through said first reflective surface being configured as a portion of an ellipse having first and second focal points (F 1 , F 2 ), said first focal point (F 1 ) being positioned substantially coincident with said rotor axis;

a second member ( 53 ) mounted on one side of said first member ( 51 );

a third member ( 56 ) mounted on the opposite side of said first member ( 51 );

a fourth member ( 54 ) mounted on said second member ( 53 ) and having a second reflective surface ( 55 ) having a longitudinal axis;

receiving optics ( 58 ) mounted on said third member ( 56 ) such that an optical signal seen as originating from said first focal point (F 1 ), falling incident on said first reflective surface ( 52 ), and being further reflected toward said second reflective surface ( 55 ) will be further reflected toward said receiving optics; and

an optical fiber ( 59 ) having an entrance end and an exit end, said entrance end being arranged adjacent to said receiving optics; and

wherein said first reflective surface ( 52 ) is configured as a portion of an ellipsoid and said second reflective surface ( 55 ) is configured as a portion of a cone positioned at the second focal point (F 2 ) of said first reflective surface ( 52 ) such that an optical signal reflected by said first reflective surface ( 52 ) toward said second focal point (F 2 ) converges to a spot on said second reflective surface ( 55 ) and is reflected in a different direction as a function of the apex angle of said cone of said second reflective surface ( 55 ), the area of said spot on said second reflective surface being smaller than the area on said first reflective surface ( 52 ) where said optical signal is incident for reflection toward said second focal point (F 2 ).

2. An optical reflector assembly as set forth in claim 1 wherein said second reflective surface ( 55 ) has a longitudinal axis and wherein said receiving optics ( 58 ) is substantially aligned with said second reflective surface longitudinal axis.

3. An optical reflector assembly as set forth in claim 1 wherein said first member ( 51 ) is a plate having opposite planar surfaces.

4. An optical reflector assembly as set forth in claim 3 wherein said second member ( 53 ) has a planar surface arranged to engage one of said first member planar surfaces.

5. An optical reflector assembly as set forth in claim 4 wherein said third member ( 56 ) has a planar surface arranged to engage the other of said first member planar surfaces.

6. An optical reflector assembly as set forth in claim 1 wherein said second member ( 53 ) is a plate.

7. An optical reflector assembly as set forth in claim 1 wherein said third member ( 56 ) is a plate.

8. An optical reflector assembly as set forth in claim 1 wherein said conical second reflective surface ( 55 ) has an apex angle of about 45°.

9. An optical reflector assembly as set forth in claim 1 wherein said receiving optics ( 58 ) includes an aspheric lens and a ball lens.

10. An optical reflector assembly as set forth in claim 1 wherein said receiving optics ( 58 ) includes a pair of aspheric lenses.

11. An optical reflector assembly as set forth in claim 1 wherein a photodetector is arranged adjacent to said optical fiber exit end.