Device for determining the spatial position of an object

Claim 1

Apparatus for sensing the orientation of an object having a limited range of motion about each axis of a triaxial coordinate system, said apparatus comprising: (a) first, second and third detection devices disposed on respective ones of the coordinate system axes for receiving light from the direction of the object, each device including means for measuring an angle of polarization of received light with respect to the respective axis; (b) polarized light sources disposed on the object including: (1) a first light source arranged to effect continuous illumination of the first detection device over the limited range of motion of the object; (2) a plurality of light sources, each arranged to effect illumination of at least one of the second and third detection devices over at least a part of the limited range of motion of the object, a first and second one of said plurality of light sources being arranged to collectively effect continuous illumination of the second detection device, over the limited range of motion of the object; (c) means associated with the plurality of sources for effecting production of individual light characteristics, independent of light source orientation, enabling distinction between light from different ones of the plurality of light sources; and (d) means associated with the detection devices for distinguishing between light from different ones of the light sources.