| 摘要 |
PURPOSE:To regulate a distance between mirrors and a rotary position of the mirrors by composing a rotary reciprocation selecting member for reciprocating an outer cylinder axially by the rotation of an operation cylinder when the outer cylinder is rotated around a central axis by the rotation of an operation cylinder and clamped integrally with a rotation stopper. CONSTITUTION:Inner and outer cylinders 11, 12 mounted with mirrors 18 opposed at both ends, an operation cylinder 32 movably engaged with the inner cylinder and engaged via threads with the outer cylinder, a rotation stopper 35 clamped via threads with the outer cylinder inserted slidably into an axially fixed groove 37, and a rotary reciprocation selecting member 38 for axially reciprocating the outer cylinder 12 by the rotation of the cylinder 32 when clamped integrally with the cylinder 32 coupled via threads with the outer cylinder 12, rotated around a central axis the outer cylinder 12 by the rotation of the cylinder 32 and integrally clamped with the stopper 36 are provided for the construction. Thus, a distance between the mirrors and a relative rotary position of the mirrors can be simply regulated. |
