| 摘要 |
PROBLEM TO BE SOLVED: To prevent the rotational vibration of a mirror caused by the deformation of a part for supporting a reflecting mirror. SOLUTION: Front and rear side plates for supporting both end parts of the reflecting mirror and a holder are interconnected with a reinforcing member having shape surrounding the mirror. The cross-sectional shape of the reinforcing member is L-shaped or U-shaped or circular-arc-shaped. |
