Method of casting optical surfaces on lens blanks

• US 4,562,018 A
• Filed: 01/28/1985
• Issued: 12/31/1985
• Est. Priority Date: 01/28/1985
• Status: Expired due to Fees

• Current Assignee: Sunsoft Corporation
• Original Assignee: Charles W. Neefe
• Inventors: Neefe, Charles W.
• Primary Examiner(s): Lowe, James
• Application Number:
  US06/695,721
• Time in Patent Office: 337 Days
• Field of Search: 264/1.1, 264/2.2, 264/2.3, 264/2.5, 264/2.7, 425/808, 51/216 LP, 51/217 L, 51/284 R, 51/284 E
• US Class Current: 264/2.7
• CPC Class Codes: B29C 37/0003 Discharging moulded articles from the mould constructions for removing the articles B29C33/44
• CPC Class Codes: B29C 39/00 Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor B29C41/00 takes precedence
• CPC Class Codes: B29D 11/00942 where the lens material is mounted in a support for mounting onto a cutting device, e.g. a lathe, and where the support is of machinable material, e.g. plastics
• CPC Class Codes: Y10S 425/808 Lens mold

Abstract

This invention is a method of making cast lens blanks with an optical surface on one surface. A cylindrical resinous mold having an optical surface surrounded by an orientation ring present in the bottom is filled with the lens monomer. The liquid monomer is polymerized to form a solid. The lens blank is removed from the mold by cutting away the sides of the mold. The back of the blank is trued to the orientation ring by lathe cutting.

Claims

1. A method of casting resinous lens blanks having a finished concave optical surface by the steps of providing a cylindrical shaped resinous mold cavity having an inside diameter equal to or larger than the outside diameter of the lens blank and a curved optical surface aligned with a peripheral orientation ring present at the bottom of the resinous cylindrical shaped mold, filling the resinous mold with a selected liquid lens monomer covering the optical surface and the peripheral orientation ring, allowing the lens monomer to polymerize to form a solid monolithic mass adhering to the cylindrical sides of the mold and to the curved optical surface, cutting the cylindrical sides of the resinous mold from the sides of the solid lens blank, removing the lens blank from the optical surface of the resinous mold, truing the flat surface opposite the concave optical surface and the orientation ring parallel with the peripheral orientation ring.

4. A method as in claim 1 wherein the mold is closed to prevent evaporation of the liquid lens monomer.

6. A method as in claim 1 wherein the curved optical surface is a toric.

9. A method as in claim 1 wherein the curved optical surface is spherical.

12. A method as in claim 1 wherein the curved optical surface is aspheric.

2. A method of casting resinous lens blanks having a finished concave optical surface by the steps of providing a cylindrical shaped resinous mold cavity having an inside diameter larger than the outside diameter of the lens blank and a curved optical surface aligned with a peripheral orientation ring present at the bottom of the resinous cylindrical shaped mold, filling the resinous mold with a selected liquid lens monomer covering the optical surface and the peripheral orientation ring, closing the mold to prevent evaporation of the liquid lens monomer, allowing the lens monomer to polymerize to form a solid monolithic mass adhering to the cylindrical sides of the mold and to the curved optical surface, cutting the cylindrical sides of the resinous mold and the sides of the solid lens blank to the required lens blank diameter, removing the lens blank from the optical surface of the resinous mold, truing the flat surface opposite the concave optical surface and the orientation ring parallel with the peripheral orientation ring.

7. A method as in claim 2 wherein the curved optical surface is a toric.

10. A method as in claim 2 wherein the curved optical surface is spherical.

13. A method as in claim 2 wherein the curved optical surface is aspheric.

3. A method of casting lens blanks having a finished optical surface by the steps of providing a cylindrical shaped resinous mold having an inside diameter equal to the outside diameter of the lens blank and an optical surface aligned with a peripheral orientation ring present at the bottom of the resinous cylindrical shaped mold, filling resinous cylindrical shaped mold, filling the resinous mold with a selected liquid lens monomer covering the optical surface and the peripheral orientation ring, allowing the lens monomer to polymerize to form a monolithic mass adhering to the sides of the mold and to the curved optical surface, cutting the sides of the resinous mold from the sides of the solid lens blank, removing the lens blank from the optical surface of the resinous mold.

5. A method as in claim 3 wherein the mold is closed to prevent evaporation of the liquid lens monomer.

8. A method as in claim 3 wherein the curved optical surface is a toric.

11. A method as in claim 3 wherein the curved optical surface is spherical.

14. A method as in claim 3 wherein the curved optical surface is aspheric.