Method and apparatus for manufacturing large double-sided curved Fresnel lens
US7106528B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2002 |
| Grant date | Sep 12, 2006 |
| Priority date | — |
| Expiry date | Dec 3, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2011/005
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing a large double-sided curved Fresnel lens. The method includes a machining step (A) of performing ultra-precise three-dimensional machining on an upper mold and a lower mold to each have an upper transfer surface and a lower transfer surface engaging an upper surface and a lower surface of a thermoplastic resin plate, respectively. Further, the method includes a hot press molding step (B) of pressing the thermoplastic resin plate between the upper and lower molds by a predetermined pressure with the resin plate being held at a temperature higher than a softening temperature thereof and lower than a melting temperature thereof so that the thermoplastic resin plate is curved, and both lens surfaces for the double-sided Fresnel lens are respectively transferred to an upper surface and a lower surface of the thermoplastic resin plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.