| 摘要 |
<p>The objective lens system with three lenses (9', 9", 9"') enclosed by metal sleeves (9', 9", 9"') has the three lenses stacked inside a housing sleeve(1) resting on a flange (3) at the bottom, projecting inwards. They are held down by springs (11) under an end ring (2) mounted inside the top. In line with each metal sleeve is a ring of air entry holes (4) through the side of the housing sleeve. Each ring of holes is connected separately by a line connected to a device (13) for supplying air under pressure. The joint faces (7) between the metal sleeves are enclosed by resilient bands (19).</p> |
