| 摘要 |
<p>The instrument has two fixed mirrors (15, 16), a rotating mirror (38) and a pendulous mirror (27). The mirrors (15, 16, 38, 27) are contained in a cylindrical case (1) with a handle (2) and an eyepiece (3). The rotating mirror (38) is semi-transparent and semi-reflecting, and is situated between the two fixed mirrors (15, 16). The optical path from the sighted object to the eye of the observer passes partially through the rotating mirror (38) without deviation. The path also partially passes from the object to the eye of the observer after reflections by one face of the rotating mirror (38), by one fixed mirror (15), by the pendulous mirror (27), by the second fixed mirror (16) and then by the other face of the rotating mirror (38).</p> |
