Process method optical thermoplastic urethane resin lens and the lens
US6309568A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 27, 1999 |
| Grant date | Oct 30, 2001 |
| Priority date | — |
| Expiry date | Oct 27, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2075/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of continuously fabricating a lens excellent in various optical characteristics and having no nonuniformity in the characteristics over a total of the lens and a lens fabricated by the method. A first step for forming thiourethane prepolymer and a second step for making thiourethane prepolymer react with at least one urethane forming monomer are carried out in an extruder or in a reactor having an extruding device at a succeeding step, extruded thermoplastic thiourethane-urethane copolymer for optical use is elongated in a sheet-like shape, a lens precursor is formed by punching out the copolymer elongated in a sheet-like shape and the lens precursor is pressed such that a predetermined curved face is provided at least on one face of the lens precursor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.