Coating of optical lens for blocking purposes

Abstract

Coating of the convex side of an optical lens for blocking purposes by dipping the downwardly facing convex side in a liquid coating material in a can, upwardly withdrawing the lens above the level of the coating material but below the lip of the can, and spinning the lens about its vertically disposed axis to spread the coating material by centrifugal force as a uniformly thin film over the convex side, to create an edge buildup of coating material to form a thickened bead-like peripheral or rim portion at the periphery of the convex side, and to spin-off excess coating material against the inside of the can for reuse. Upon spin-off of excess coating material the lens is withdrawn out of the can whereupon the film on the spinning lens dries sufficiently for handling within a few seconds time. The spinning operation is then discontinued and the lens may be positioned on a horizontal support with its coated convex side facing upwardly preparatory to blocking. To facilitate the lens coating operation, the lens is held on its concave side by a suction cup having the upper end of its vibration damping stem chucked in the drive shaft of a hand-held motor. To further facilitate the lens coating operation, a releasable vacuum source is operatively associated with the suction cup to pick up a lens for dipping and spinning and to release the suction cup from the lens without handling of the lens.

Dependencies are inferred from the claim text.