| 摘要 |
<P>PROBLEM TO BE SOLVED: To deal with increased weight of a driven member, and to prevent a decrease in driving accuracy in improving impact resistance, by providing a guide shaft extending parallel to a rod in a ultrasonic linear actuator where expansion and contraction of a piezoelectric element is transmitted to the rod and the driven member engaged with the rod by a predetermined frictional force is moved by means of a difference in speed at which the piezoelectric element is expanded and contracted. <P>SOLUTION: A holding member 706, as a driven member, with a focus lens 701 mounted thereon is guided by a guide shaft 710 and a rotation preventing pin 719 and driven by a rod 102. A connecting piece 103 is frictionally engaged with the rod 102 and is connected to a pair of supporting pieces 714 and 715 of the holding member 706 through an urging spring 104. If there is any tilt displacement between the rod 102 and the guide shaft 710, thus, the urging spring 104 absorbs the displacement so as to eliminate twisting of the connecting piece 103 and the holding member 706, and also prevents rattling of the connecting piece 103 and, therefore, a decrease in following accuracy, control accuracy, or the like. <P>COPYRIGHT: (C)2012,JPO&INPIT |
