| 摘要 |
PURPOSE:To obtain a plastic optical transmission body by having such a refractive index gradient at which the refractive index decreases gradually from a central axis to a certain point toward the outside in a radial direction and increases thereafter by selecting the combination in which the refractive indices satisfy specific conditions, monomers, three kinds of which are easily copolymerizable successively, and the mixing ratio thereof. CONSTITUTION:The refractive indices of monomers M1, M2, M3 are n2 (refractive index of M2 homopolymer)<n3 (refractive index of M3 homopolymer) and n1 (refractive index of M1 homopolymer)>2. A prescribed amt. of the monomers M1, M2, M3 are mixed, and a prescribed amt. of a photopolymn. initiator [for example, benzoyl peroxide (BPO), benzoin methyl ether, etc.] are dissolved therein. The mixture is filled in a glass tube which has a prescribed bore (for example, about 2.9mm.) and is closed at one end, then the mixture is photopolymerized. A tubular UV lamp 1 is provided at the center of the device, and cylindrical light shielding plates are provided in the upper and lower parts of the lamp so that the mixture in the glass tube is irradiated only with the UV light released from the central part of the tube. |
