Patent ID: 7813610
Filing Date: 2010-10-12
Classification: B29C,B29D,B29L,G02B

Abstract:
1. A production method for a plastic optical medium comprising steps of: pouring a polymerizable composition in a hollow portion of a pipe; polymerizing said polymerizable composition while rotating said pipe, to form a first polymer layer on an inner wall of said pipe; and additionally performing a pair of said pouring step and said polymerizing step n−1 times (n is an integer at least two) to stack n-layers including said first polymer layer to a nth polymer layer in a concentric fashion, a difference of refractive indices between adjacent two polymer layers being at least 5×10 wherein each of said n-layers has a lower refractive index than that of the adjacent polymer layer at the outer side, and has a higher refractive index than that of the adjacent polymer layer at the inner side in the radial direction.