Patent ID: 7548676

Claim:
A method for forming an optical converter comprising the steps of: providing at least two light guide ribbon structures, with each light guide ribbon structure formed by the steps of extrusion roll molding a substrate by passing a melted thermoplastic material between a support and a pattern roller forming a pattern therein and cooling the melted thermoplastic material below the melting temperature of the thermoplastic material to form a substrate having a pattern of channels with each channel extending from an input edge to an output edge of said substrate, and forming light guides extending along each of the channels from the input edge to the output edge; and assembling the at least two light guide ribbon structures together in a stacked arrangement, wherein the step of assembling at least two of the light guide ribbon structures further comprises disposing an individual input spacer, which is an element separate and distinct from the light guide ribbon structure, proximate to the input edge and an individual output spacer, which is an element separate and distinct from the light guide ribbon structure, proximate to the output edge, and stacking said input spacer and said output spacer between at least two light guide ribbon structures, said input spacer and said output spacer separating the light guides of the adjacent light guide ribbon structure, and said input spacer having a different thickness than said output spacer.