| 摘要 |
A lens mounting assembly includes a frame to retain a lens. In the frame, an axially opened annular recess is formed. The lens has an annular axial projection which is received in the recess. Sufficient clearance is formed between the recess wall and the lens periphery to permit thermal expansion of the lens. Interfitting between the projection and the recess enables mechanically accurate radial and axial positioning between the lens and the frame. Elastic means, i.e., elastic adhesive or elastic member, retains the lens to the frame allowing thermal expansion and/or contraction of the lens relative to the frame.
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