Patent ID: 7061675

Claim:
A focusing optic assembly comprising: a focusing optic defining an optical axis; a coarse drive unit for displacing said focusing optic along said axis; said coarse drive unit including a coarse belt drive for operatively connecting said coarse drive unit to said focusing optic; a fine drive unit for displacing said focusing optic along said axis; said fine drive unit including a fine belt drive for operatively connecting said fine drive unit to said focusing optic; a frame; said coarse drive unit including a coarse actuating element mounted on said frame for actuating said coarse belt drive; said fine drive unit including a fine actuating element mounted on said frame for actuating said fine belt drive; and, said coarse actuating element and said fine actuating element being disposed in said frame separated a distance from each other by a portion of said frame to preclude an inadvertent slipping from one of said actuating elements to the other during a manual focusing operation by a user of said focusing optic assembly.