| 摘要 |
PURPOSE:To obtain an optical device which never causes deterioration of an image even when the angle of a roof type combined mirror is not precise, by arranging an image forming lens and the combined mirror so that the optical axis of the lens and the ridge of the mirror shift in position from each other. CONSTITUTION:The image forming lens 11 and roof type combined mirror 12 are arranged so that the optical axis of the lens and the ridge 14 of the mirror 12 shift in position from each other. Consequently, a light beam emitted from any point between points P3 and P4 on an object surface 10 is reflected by one reflecting mirror 12 and then reflected by the other reflecting surface 12b to form an image on an image surface 13. A roof type prism is usable instead of using the roof type combined mirror. |
