Patent ID: 7764452

Claim:
A method for manufacturing a cemented lens comprising at least a first lens and a second lens, the cemented lens cemented through cementing surfaces of the first and second lenses, said cementing surfaces being smooth optical surfaces and having different outer diameters, one of the cementing optical surfaces being a concave surface of one of the first and second lenses, the other of the cementing optical surfaces being a convex surface of the other of the first and second lenses, the method comprising: putting the cementing optical surfaces on each other; thereafter applying an adhesive to a circumferential end portion, to a joint formed between a circumferential edge of the smooth optical surface of the larger diameter lens and an outer circumferential end of the smooth optical surface of the smaller diameter lens, in a state where the first and second lenses are put on each other so as to bond the first and second lenses with each other through the adhesive, the circumferential end portion being located out of effective areas serving as chief optical paths of the first and second lenses; controlling said applying step such that a part of said adhesive penetrates between said concave surface and said convex surface but does not enter said effective areas, and another part of said adhesive protrudes to the outside of one of said first and second lenses, so as to bond said first and second lenses; and reducing a quantity of said adhesive which penetrates between said smooth optical surfaces of said lenses at said joint, by increasing a viscosity of said applied adhesive to have a value of 2,000 mPa·s or higher so that said adhesive does not reach said effective areas serving as chief optical paths for the first and second lenses.