| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive light transmission tube which emits light having high luminance while having directivity from its lateral peripheral surface, maintains an excellent light emitting characteristic in spite of adhesion of stains, etc., and has excellent mass productivity. SOLUTION: This light transmission tube 1 has a tubular clad 3 and a core 2 composed of a material having the refractive index higher than the refractive index of this clad material, is spirally formed with a plurality of belt-like reflection layers 4a, 4B between the tubular clad 3 and the core 2 along the longitudinal direction thereof and is constituted to reflect and scatter the light passing the core 2 by these reflection layers 4A, 4B and to release the light to plural directions from the outer peripheral surface of the tubular clad 3 on the side opposite to the side formed with the reflection layers. The light transmission tube is produced by using a multicolor extruder, simultaneously introducing the core material, the clad material and the reflection materials contg. white pigments or scattering materials into the respective mouthpiece parts of the extruder and respectively simultaneously extruding the core material to a columnar shape, the reflection materials to plural belt forms on the outer peripheral surface of the columnar core material and the clad material to a tubular form covering the core material and the reflection materials. |
