Patent ID: 9645346
Date: 2017-05-09
CPC Classifications: G02B

Claim:
1. A doublet lens extending along a central lens axis, the doublet lens comprising: a first lens having a convex surface and an opposite surface, the opposite surface being opposite the convex surface, the opposite surface comprising a concave central portion and a peripheral portion extending radially outward from the central portion, the peripheral portion having a curved portion that extends radially inward to merge smoothly with the central portion; a second lens having a convex surface and an opposite surface, the opposite surface being opposite the convex surface, the opposite surface comprising a concave central portion and a peripheral portion extending radially outward from the central portion, the peripheral portion having a curved portion that extends smoothly radially inward, the curved portion forming a ridge that intersects with the central portion of the second lens to form a peak; wherein the curved portion of the peripheral portion of the first lens abuts the curved portion and the ridge of the peripheral portion of the second lens and wherein there is an airspace between the central portion of the first lens and the central portion of the second lens; wherein the peripheral portions of the first and second lenses are shaped to fit together such that the curved portion of the first lens abuts the curved portion of the second lens in a mating relationship that is shaped to prevent sliding of the first and second lenses relative to each other in a radial direction.