Positioning device

摘要

An apparatus for displacing two members, including a first member (10; 514), a second member (30; 100; 230; 330; 506) which is supported by the first member such that the second member is displaceable relative to the first member, a third member (32; 332; 702; 508; 620) which is supported by the second member such that the third member is displaceable relative to the second member, a first drive source (12; 510) and a second drive source (14; 404; 512) which have respective output members and each of which is not movable relative to the first member, a mechanically motion-transmitting device (16-22, 34-37, 40, 62; 104; 234, 240; 334, 335, 340, 362; 406; 528, 552; 606-616, 618, 622, 624; 718, 740; 818, 820) which mechanically transmits respective motions of said respective output members to the second and third members while allowing the second and third members to be displaced relative to each other, and a displacement control device (70, 76, 78) which is connected to the first and second drive sources and which controls the first and second drive sources and thereby controls the displacement of each of the second and third members relative to the first member.