| 摘要 |
PROBLEM TO BE SOLVED: To make an inclinable angle large, to make bearing rigidity high in a radial direction, and to prolong stroke in an optical axis direction so as to improve positioning accuracy by supporting the guide surface of a lens holding board by means of a static pressure bearing means in a non-contact state, and respectively and individually supporting driving means by means of a base board. SOLUTION: The inside peripheral surface of a fixing member 2 and the outside peripheral surface being the guide surface of the lens holding board 3 are supported in the non-contact state each other by the static pressure or pressure fluid jetted from a porous pad 7 being an annular porous drawing type static pressure bearing means held by the inside peripheral surface, and a lens 4 can freely reciprocate along the axis (Z axis) of the member 2 and the guiding member 3. By making the size of the pad 7 in the Z-axis direction small, the allowable value of the inclination angle to the Z axis can be made large. A Z linear motor is provided with rotors 51a to 51c and stators 52a to 52c, and disposed outside the member 2 in a peripheral direction at an equal interval; and the rotors 51a to 51c are driven in the Z axis direction in accordance with supplied current amount. |
