Method for avoiding entrapment of air bubbles in a lens forming material and apparatus for carrying out the method
AssigneeNovartis AG
InventorsLukas Lomb, Roland Schmieder, Gabriela Cocora, Halina Heidrich, Axel Heinrich, Peter Hagmann
Life of this patent
Estimating the term…
Abstract
A method for avoiding the entrapment of air bubbles (5) in a lens forming material, in particular in a low viscosity lens forming material, in an ophthalmic lens manufacturing process using mold halves (2; 3) each having a lens forming surface (21; 31) comprises electrostatically charging a predetermined portion of the lens forming surface (21; 31) of the mold half (2; 3) prior to the predetermined portion of the lens forming surface (21; 31) coming into contact with the lens forming material (4).
Claims18
A method for avoiding entrapment of air bubbles (5) in a lens forming material (4), in an ophthalmic lens manufacturing process using mold halves (2;
- 3) each having a lens forming surface (21;
- 31), said method including the step of providing an electrostatic charge (60) on a predetermined portion of said lens forming surface (21;
- 31) of at least one of said mold halves (2;
- 3) prior to said predetermined portion of said lens forming surface (21;
- 31) coming into contact with said lens forming material (4);
- wherein said electrostatic charge (60) is provided on said predetermined portion of said lens forming surface (21;
- 31) of said at least one mold half (2;
- 3) by contacting said predetermined portion of said lens forming surface (21;
- 31) of said at least one mold half (2;
- 3) with a stamp (6) made of a material which is sufficiently far away in the triboelectric series from the material said at least one mold half (2;
- 3) is made of, and;
- further wherein said electrostatic charge is provided by contacting said predetermined portion with said stamp in a contact area having a diameter of from about 6 mm to about 8 mm.
An apparatus for avoiding entrapment of air bubbles (5) in a lens forming material (4) in an ophthalmic lens manufacturing process, the apparatus comprising a stamp (6) and a carrier for at least one mold half (2;
- 3), said stamp (6) and said carrier being arranged relative to each other in a manner such that said stamp (6) faces a predetermined portion of a lens forming surface (21;
- 31) of said at least one mold half (2;
- 3), wherein said stamp (6) is made of a material which is sufficiently far away in the triboelectric series from the material said at least one mold half (2;
- 3) is made of, and wherein said stamp (6) and said carrier of said at least one mold half (2;
- 3) are movable towards and away from one another in a manner to allow said stamp (6) to contact said predetermined portion of said lens forming surface (21;
- 31) of said at least one mold half (2;
- 3) in a contact area having a diameter of from about 6 mm to about 8 mm, and for a predetermined time period to provide said charges on said predetermined portion of said lens forming surface (21;
- 31) of said at least one mold half (2;
- 3).
Dependencies are inferred from the claim text.