| 摘要 |
A periscope comprises an object window (4), a first reflector (5), a second reflector (6); and an intermediate port between the first reflector (5) and the second reflector (6). The first reflector is arranged to reflect light from the object window (4) towards the second reflector (6) through the intermediate port. The second reflector (6) is selectively movable between a first position of use in which the second reflector (6) reflects light from the first reflector towards a viewing position and a second position of use in which the second reflector (6) closes the intermediate port. |
