Injection molding of contact lenses
US4254065A · kind A · utility
Inventor
Key dates
| Filing date | Apr 4, 1979 |
| Grant date | Mar 3, 1981 |
| Priority date | — |
| Expiry date | Apr 4, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to lenses and more particularly relates to the method of forming prescription contact lenses of the single vision, bicurve, lenticular, bifocal and other types by injection molding. The lens is formed from a blank having a cylindrical configuration with a concave or convex surface. The concave or convex surface forms a surface such as the base curve of the completed lens minimizing finishing operations. The lens blanks are supplied to the practitioners in a series having a completed or substantially completed curved surface. The lenses are formed by injection molding closely controlling parameters such as injection pressure, time, and temperature to avoid internal stress in the lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.