Method for microforming microstructured films and lenses

Patent metadata

Field	Value
Publication number	US-2025050570-A1
Application number	US-202218720501-A
Country	US
Kind code	A1
Filing date	Dec 13, 2022
Priority date	Dec 16, 2021
Publication date	Feb 13, 2025
Grant date	—

Abstract

A method of forming an optical element includes providing a forming insert in a thermoforming apparatus, the forming insert including a plurality of microstructures formed on a forming surface of the forming insert; heating the forming insert to a first predetermined temperature; disposing an element comprised of a polymer material in the thermoforming apparatus and in contact with the forming surface of the forming insert; and thermoforming, via the forming surface of the forming insert, the element, the molded element having microstructures formed on a surface thereof.

First claim

1 . A method of forming an optical element, comprising:
providing a forming insert in a thermoforming apparatus, the forming insert including a plurality of microstructures formed on a forming surface of the forming insert; heating the forming insert to a first predetermined temperature; disposing an element comprised of a polymer material in the thermoforming apparatus and in contact with the forming surface of the forming insert; and thermoforming, via the forming surface of the forming insert, the element, the thermoformed element having microstructures formed on a surface thereof.

2 . The method of claim 1 , wherein the thermoforming further comprises applying pressure, vacuum, and/or mechanical force to the element.

3 . The method of claim 1 , wherein the microstructures transfer a pattern of microprotrusions to the thermoformed element.

4 . The method of claim 1 , wherein the microstructures transfer a pattern of microcavities to the thermoformed element.

5 . The method of claim 2 , wherein the microstructures of the forming insert include microperforations.

6 . The method of claim 5 , further comprising applying the vacuum, using a vacuum system included in the thermoforming apparatus, to the element via the microperforations.

7 . The method of claim 6 , wherein a shape of the microperforations is circular, triangular, square, hexagonal, or octagonal.

8 . The method of claim 5 , wherein a diameter of the microperforations is between 0.5 micrometer to 2000 micrometers.

9 . The method of claim 2 , wherein applying the mechanical force further comprises applying a force to the element via a hydro-assist.

10 . The method of claim 2 , wherein applying the mechanical force further comprises applying a force to the element via a plug-assist.

11 . The method of claim 1 , wherein thermoforming the element further comprises holding the element against the forming surface for a predetermined length of time based on a material rheological relaxation.

12 . The method of claim 1 , wherein thermoforming the element further comprises direct/indirect heating the element via the forming surface to a second predetermined temperature.

13 . The method of claim 1 , wherein the element is a film or a lens.

14 . A thermoforming apparatus, comprising:
a forming insert including a plurality of microstructures formed on a forming surface thereof; a heating element heating the forming insert to a first predetermined temperature; and a pressure system, a vacuum system, and/or mechanical force system that supports thermoforming of an element to form microstructures on a surface thereof by applying a pressure, a vacuum suction and/or a mechanical force to an element in contact with the forming surface of the forming insert.

15 . The thermoforming apparatus of claim 14 , wherein the microstructures of the forming insert include microperforations.

Assignees

• Essilor Int

Inventors

• Drammeh Ahmed
• Tokarski Zbigniew
• Jallouli Aref

Classifications

• B29L2011/0016

  Lenses · CPC title

• B29C51/10

  Forming by pressure difference, e.g. vacuum · CPC title

• B29C2059/023

  Microembossing · CPC title

• B29L2011/00

  Optical elements, e.g. lenses, prisms · CPC title

• B29C51/00

  Shaping by thermoforming {, i.e. shaping sheets or sheet like preforms after heating}, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor {(blow moulding of tubular preforms B29C49/00, deforming of tubular or hollow preforms B29C67/0014)} · CPC title