| 摘要 |
<p>A spacer for assembling a lens system has cylinders positioned between the lens elements and inside the containing tube. The cylinders are made of a strong pliable material which can withstand high temperatures, as are used for sterilising medial equipment, and which does not damage the lens material where the cylinders touch the lenses. The spacers have a similar thermal expansion coefficient as the lens elements. Suitable materials for the spacer include ceramics, metals and plastics, with or without graphite loading. The spacers can be coated.</p> |
