Patent Number: 6,309,568

Title: Process method optical thermoplastic urethane resin lens and the lens

Abstract: A method of continuously fabricating a lens excellent in various opticalcharacteristics and having no nonuniformity in the characteristics over atotal of the lens and a lens fabricated by the method. A first step forforming thiourethane prepolymer and a second step for making thiourethaneprepolymer react with at least one urethane forming monomer are carriedout in an extruder or in a reactor having an extruding device at asucceeding step, extruded thermoplastic thiourethane-urethane copolymerfor optical use is elongated in a sheet-like shape, a lens precursor isformed by punching out the copolymer elongated in a sheet-like shape andthe lens precursor is pressed such that a predetermined curved face isprovided at least on one face of the lens precursor.

Inventors: Yang; Zhou (Milford, CT), Zhu; Zhenya (Stratford, CT), Lin; Yin-Nian (Milford, CT), Kobayashi; Tadashi (Fukui, JP), Saito; Yuyoshi (Fukui, JP)

Assignee:

International Classification:

Expiration Date: 10/32013