Optical fiber for illuminating, e.g. instrument panel comprises core, cladding with section allowing radial emission of light and sheath over both which has light-emitting section and also has radial ridge or groove at angle to it

摘要

Optical fiber comprises a core (2) and a cladding (6) which has a section (4) allowing radial emission of light. A sheath (3) covers both. This has a corresponding section allowing light emission and also has a radial ridge (5) or groove at a fixed angle to it. Independent claims are included for: (a) a similar fiber without intermediate cladding; and (b) a tool for extruding the fiber sheath with an outlet which has a plan which has a ridge or groove forming section.