Fresnel lens manufacturing apparatus
US5840352A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1996 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Aug 19, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/102
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus for producing a Fresnel plate has a mold assembly comprising movable and stationary molds coupled with each other. The mold assembly includes a Fresnel forming face formed on the inside of the movable mold. Melted resin is injected into the mold assembly for forming the Fresnel plate. At least one movable slit is formed through, and arranged inside, the movable mold along a circle concentric with the Fresnel plate and in intermittent or continuous fashion. The movable slit is used for blowing compressed air toward the Fresnel plate. The slit closely surrounds the center of the Fresnel plate. Ejector pins surround the Fresnel plate outside its Fresnel forming face.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.