| 摘要 |
PROBLEM TO BE SOLVED: To attain the reversal mounting of a rising mirror, and to make workability satisfactory by forming either face corresponding to the two equal sides of the rising mirror as a face to be placed on an optical housing. SOLUTION: The cross-section of a rising mirror 4 is substantially formed like an isosceles triangle, and the face corresponding to the residual side other than the two equal sides of the cross-section is formed as the reflecting surface of light beams. Thus, even at the time of setting the face corresponding to any of the two equal sides as a setting face in an optical housing 1, the deviation of the angle of the reflecting surface can be prevented. |
