| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need of urging a mover for mirror surface angle detection by a spring to move the mover along a male screw member, following a nut member, by causing the mover to be relatively rotatable to the nut member and not to be relatively rotatable to the male screw.SOLUTION: Through holes 17 and 17 are opened along the axial center of male screw members 16 and 18, and movers 90 and 92 are inserted into the through holes 17 and 17 in the axial direction in a freely movable way. The front end parts of the movers 90 and 92 are connected to the back positions of the front end parts of nut members 28 and 30 in a relatively rotatable around the axis. Position detectors 115 and 117 detect positions of the movers 90 and 92 in the direction along the male members 16 and 18 relative to a base member 12. |
