| 摘要 |
PURPOSE:To provide a compact camera by installing, in a fixed cylinder, an oscillator which consists of a ring-shaped piezoelectric element and an electrode divided and fixed in a peripheral direction on the surface of the element. CONSTITUTION:The third oscillator 17 is fitted in a position inside a ring-shaped sector 12 on the second substrate 19 for focusing driving of a photographing lens, and the inside is provided with a holding frame 7 of the first lens group 5 and the third rotating cylinder 13 to be screwed with a helicoid. The rotating cylinder 13 is prevented from falling off by the second substrate 19, and at an edge of the holding frame 7, there is a ring 15 which is engaged with a guide member 14 formed with a linear guide groove 14a. Thus, when the oscillator 17 is excited and the rotary cylinder 13 is rotated, the holding frame 7 is traveled straight in an optical axial direction for focusing. An electrostrictive revolutionary type ultrasonic motor whose rotor consists of rotary cylinders 2, 12, and 13 is formed out of three oscillators 3, 16, and 17. It is thus possible to provide an extremely compact camera because zooming, focusing, and opening and closing of a shutter can be performed. |
