Ophthalmic lens containing a fresnel surface and method for manufacturing same
US9242418B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2011 |
| Grant date | Jan 26, 2016 |
| Priority date | — |
| Expiry date | May 3, 2032 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2011/005
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process is described for manufacturing an ophthalmic lens containing a Fresnel microstructured surface inside the lens. The Fresnel lens is injection molded with a mold insert having a heat conductivity lower than the thermoplastic material used to form the Fresnel lens. A second thermoplastic material is overmolded to the Fresnel lens to cover and protect the microstructured surface. The mold insert is made from nickel or a thermoplastic material. The resulting lens includes two layers having different refractive indices. The Fresnel lens may be made from polycarbonate while the overmold may be made from a poly(methyl methacrylate) or a thermoplastic polyurethane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.