| 摘要 |
PURPOSE:To obtain a plastic optical transmission body of which the refractive index decreases in proportion to the square of the distance from a central axis over the entire part of said body by selecting a combination and mixing ratio of at least three kinds of monomers at which the monomers having the lower refractive indices are easier to copolymerize. CONSTITUTION:The figure indicating the example of the combination of ternary monomers is shown. The mixing ratio of the monomers varies with the kind of the monomers, the diameter of an optical transmission body, refractive index distribution, polymerizing conditions, etc. and is usually selected from the range of 20-90wt% M1, 2-40 M2 and 5-60 M3. A prescribed amt. of the monomers M1, M2, M3 are first mixed, and a prescribed amt. of a photopolymn. initiator (for example, benzoyl peroxide (BPO), benzoin methyl ether, etc.) is 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 is provided at the center of the device, and cylindrical light shielding plates are attached 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. |
