Patent ID: 7940479

Claim:
A positioning device comprising a first lens positioning assembly and a second lens positioning assembly, wherein: the first lens positioning assembly comprises a lens support subassembly and a bi-directional positioning guide; the lens support subassembly comprises a translating rod; the bi-directional positioning guide comprises a coiled spring defining an inner periphery; the coiled spring is canted relative to a longitudinal axis of the rod; the inner periphery of the coiled spring engages in a spring loaded state an outer periphery of the rod such that the coiled spring provides a frictional force about the outer periphery of the rod; the frictional force provided by the coiled spring about the outer periphery of the rod is sufficient to hold the rod within the inner periphery, but permit infinitely variable bi-directional movement of the rod through the inner periphery under an applied force; the second lens positioning assembly comprises an electromagnetic linear actuator comprising a stationary component and a bi-directionally moveable component electromagnetically coupled to each other; and the electromagnetic linear actuator of the second lens positioning assembly is configured to adjust bi-directionally a position of the lens support subassembly of the first lens positioning assembly relative to a vertical position of a lens supported by the lens support subassembly.