Method to manufacture a mold for lenses, and corresponding mold
The invention concerns a method to manufacture a mold ( 10 ) for forming contact lenses ( 100 ) using the technique of molding with molds of monomeric and/or polymeric material; such molds ( 10 ) comprise a male element ( 11 ) and a female element ( 12 ), which cooperate to define a cavity suitable to accommodate monomeric and/or polymeric material in the liquid state intended to form the lens ( 100 ), wherein the method provides to obtain, by means of laser processing, a plurality of grooves ( 23 ) in the male element ( 11 ) intended to form functional elements in relief ( 101 ) of the lenses ( 100 ). The invention also concerns a mold ( 10 ) for contact lenses ( 100 ) made of monomeric and/or polymeric material that can be obtained with the method as above.
1 . Method to manufacture a mold for forming contact lenses, comprising a male element and a female element, respectively with a convex surface and a concave surface, defining a cavity accommodating monomeric and/or polymeric material in the liquid state intended to form said lens, wherein said convex surface and said concave surface have at least two concentric zones, one internal and the other external, with radii of curvature different from each other and of wherein the method includes laser processing: in the external zone of said convex surface, a plurality of grooves having a shape and size mating with functional elements in relief to be made on the surface of said lenses,
in the internal zone of said convex surface, a plurality of concave elements being of a shape mating with constructive elements in relief to be made on the surface of said lenses, wherein the concave elements are configured as blind holes or similar cavities.
2 . Method as in claim 1 , wherein it provides to manufacture said elements by means of a molding technique within a metal forming matrix with a shape correlated to the convex surface of the male element and to the concave surface of the female element.
3 . Method as in claim 1 , wherein said laser processing is a processing that uses a femtosecond type laser and it is performed directly on the male element of the mold.
4 . Mold made of monomeric and/or polymeric material for forming contact lenses equipped with functional elements in relief, comprising a male element provided with a convex surface and a female element provided with a concave surface, cooperating to define a cavity accommodating monomeric and/or polymeric material in the liquid state intended to form the lens, said mold comprising said convex and concave surfaces each have at least an internal zone and an external zone, which are concentric and have different radii of curvature from each other, wherein said external zone of said convex surface comprises a plurality of grooves with a shape and size mating with said functional elements in relief to be made on the surface of said lenses, wherein said internal zone of said convex surface comprises a plurality of concave elements of a shape mating with constructive elements in relief to be made on the surface of said lenses, and wherein the concave elements are configured as blind holes or similar cavities.
5 . Mold as in claim 4 , wherein said radius of curvature of the external zone is larger than the radius of curvature of the internal zone and in that the difference between said radii of curvature is between 1 and 6 mm.
6 . Mold as in claim 4 , wherein said convex and concave surfaces have three zones, each one concentric with respect to the other with respect to a central axis of said mold, having respective radii of curvature different from each other, wherein said zones comprise an intermediate zone having a radius of curvature of transition between said internal zone and said external zone, said radius of curvature of the intermediate zone being larger than the radius of curvature of the internal zone and in that the difference between said radii of curvature is between 2 and 7 mm.
7 . Mold as in claim 4 , wherein said grooves have a length between 350 μm and 1000 μm, a width between 80 μm and 450 μm, a constant height between 5 μm and 25 μm, and the number of said grooves is between 2 and 340.
8 . Mold as in claim 4 , wherein said grooves are homogeneously distributed respectively on the entire external zone of said convex surface, according to a regular geometric pattern defined by a plurality of rows radiating from a central axis of said mold.
9 . Mold as in claim 4 , wherein said grooves are in the shape of one parallelepiped part or two separate parallelepiped parts, or two separate circular parts.
10 . Mold as in claim 4 , comprising, in correspondence with said external zone of said concave surface, at least one projecting element having a shape and size mating with at least one recessed element to be made on the front surface of said lenses, positioned in correspondence with a zone of separation into two distinct parts of said functional elements in relief.
11 . Mold as in claim 4 , comprising a tubular support element inserted around one of either the male element or the female element and configured to interfere with at least part of an internal wall of the other one of either the male element or the female element.
12 . Mold as in claim 11 , wherein the support element has an external lateral surface with a truncated cone shape with convergence oriented toward the internal wall with which it is configured to interfere.
13 . Mold as in claim 12 , wherein the internal wall, with which the support element is configured to interfere, has an inclined portion so as to couple with the external surface of the support element.
14 . Mold as in claim 11 , wherein the support element is made of polypropylene.
15 . Method as in claim 1 , wherein the blind holes or similar cavities have micrometric size.
16 . Method as in claim 1 , wherein the functional elements are configured as sensors configured to detect the presence of a determinate physiological parameter in the tear fluid.
17 . Method as in claim 1 , wherein the functional elements are configured as a reservoir containing a liquid which is gradually released into the eye to carry out a slow-release treatment.
18 . Mold as in claim 4 , wherein the blind holes or similar cavities have micrometric size.
19 . Mold as in claim 4 , wherein the functional elements are configured as sensors configured to detect the presence of a determinate physiological parameter in the tear fluid.
20 . Mold as in claim 4 , wherein the functional elements are configured as a reservoir containing a liquid which is gradually released into the eye to carry out a slow-release treatment.