| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving mechanism using an electromechanical transducing element which can adjust a driving speed and a moving distance efficiently without lowering thrust. SOLUTION: In a driving mechanism wherein a driving pulse is supplied to a piezoelectric element 28 to let is extend and contract and then a driven member which is joined to a driving shaft 11 by friction fixed to the piezoelectric element 28 is driven by the extension and contraction of the piezoelectric element 28, the piezoelectric element 28 is divided into a plurality of blocks 28a, 28b, 28c and each of the blocks are made connectable to a driving circuit (a coarse adjustment circuit 23, a fine adjustment circuit 24) through switching devices SW1, SW2, SW3. A driving speed and a moving distance are adjusted by driving only a proper block according to a driving speed in high-speed driving or a moving distance in low-speed driving. In the case of high-speed driving, a control is so made that only part of the blocks may be driven to prevent the appearance of vibration noise of an audio frequency caused by the decline in a resonance frequency of the driving system. In the case of low-speed driving, there is no possibilities that vibration noise appears and so, all the blocks can be selected according to a moving distance. |
