Patent ID: 8027103

Claim:
A lens assembly comprising: a plurality of lenses, a plurality of spacing rings each of which has a shape of a ring, and a ceramic lens frame having a hollow part which has openings formed at both ends thereof and into which the plurality of lenses and the plurality of spacing rings are inserted while sliding against an inner peripheral surface of the ceramic lens frame, the inner peripheral surface forming the hollow part, wherein the plurality of lenses are respectively disposed at a plurality of predetermined positions in the hollow part along a direction connecting said both ends so that peripheries of the plurality of lenses contact the inner peripheral surface, the plurality of spacing rings are disposed in the hollow part along said direction in such a manner that one of the plurality of spacing rings is positioned between two peripheries of each neighboring pair of the plurality of lenses and contacts the two peripheries and the inner peripheral surface, to dispose the plurality of lenses at the plurality of predetermined positions, and contact surface portions of the inner peripheral surface have at least one solid lubricant thereon, said contact surface portions contacting the peripheries of the plurality of lenses and the plurality of spacing rings.