DRIVER AND LEANS UNIT EMPLOYING IT

摘要

PROBLEM TO BE SOLVED: To shorten the overall thrust length of driver as much as possible by arranging a rotary member and a detection means within the thrust width of an oscillation wave drive means. ;SOLUTION: Upon rotation of a ring 19, a speed increasing gear 26 meshing a face gear part 19b disposed in the ring 19 rotates to cause rotation of a pulse plate 27. Rotation of the pulse plate 27 is detected by a photoelectric transmission switch 28 and the ring 19 is turned by a rotational angle designated based on a detection signal thus controlling the movement of a lens. In a conventional oscillation wave motor, inside diameter of an oscillation member 11 is larger than the inside diameter of rotor part (circumferential moving member 16, a rotary cylinder 17 and a rubber ring 18), and a dead space is formed between the inner circumference of rotor part and the outer circumference of a cylindrical body 7. When a rotation detecting means comprising the speed increasing gear 26, the pulse plate 27 and the photoelectric transmission switch 28 is contained in the dead space, space efficiency is enhanced without increasing the size.;COPYRIGHT: (C)1997,JPO