| 摘要 |
PURPOSE:To contrive the improvement in accuracy in positioning by arranging electrostrictive elements in the part where a rotational movement is converted into a straight movement in a movable stage device using electrostrictive elements. CONSTITUTION:In the device for moving a stage by transmitting rotation of a ball screw 10 to a nut part 11 converting it into a straight movement, a cutout 12 is arranged in the stage and the nut 11 is held and fixed to this cutout 12. Meanwhile, two electrostrictive elements 13a and 13b are arranged so as to hold the nut from both sides. For moving the stage, a rough movement is made by rotation of the ball screw 10 firstly, and nextly minute positioning is done by the electrostrictive elements 13a and 13b. The reason why the electrostrictive elements are arranged on both sides of the nut is to prevent a damage of the elements caused by eccentricity of the nut and to prevent a decline in the accuracy in positioning due to variation of temperature of the electrostrictive elements. |
