To make a mark invisible in visible ray region and to enable to mark in the area of effective diameter of a lens surface by providing one of a thin film of a stealth type one-dimensional code or a two-dimensional code, which is colorless and transparent in the visible ray region, on the lens surface.
One of the stealth type one-dimensional code or the two-dimensional code colorless and transparent in the visible ray region is provided on the lens surfaces 1, 2. In such a case, it doesn't matter whether the lens surfaces 1, 2 are spherical or non-spherical. Further, it does not matter the arranging position of the stealth code 5 is inner side or outer side in the lens effective diameter. The stealth code 5 is a stealth type two-dimensional code formed by vapor depositing ITO by a mask vapor depositing method and having about 200 thickness. As a result, the stealth code 5 is invisible in the visible ray region in the discriminable lens 10. Then, the marking enables in the area of the effective diameter of the lens surfaces 1, 2 to miniaturize the outside diameter or the outside shape.
HARUHARA MASAAKI
SHIMIZU KAORU
NAGAI HIDEO
Next Patent: OPHTHALMIC LENS MATERIAL