PURPOSE: To form a guide groove of an optical disc on a prescribed surface of a substrate with high dimension precision by arranging light shielding cylinder bodies between a light irradiating source and the disc substrate.
CONSTITUTION: Before irradiation of ultraviolet rays, a mask 16 is placed on the inside peripheral part of the substrate where it is unnecessary to stick a resin, and a shielding mask 17 having the same shape as the outside peripheral part of the substrate is placed on the outside peripheral part of the substrate, and a mask 9 is placed to be brought closely into contact with the outside of the mask 17. The mask 9 on the outside peripheral part 9 consists of concentrical cylinder bodies, and front and rear faces of three cylinder bodies are painted black to intercept the incident light from the peripheral part of an irradiating source 15 or the like. These light shielding masks are brought closely into contact with the substrate, and ultraviolet rays are irradiated from the light source in this state. A molded body is detached and the disc substrate is washed with ethanol thereafter to obtain the substrate on which the guide groove having a very sharp end part of the cured resin is formed. Thus, the resin hardened by light is stuck to only the required part of the substrate, and the boundary between the cured resin and the unhardened resin is distinct to improve the outward appearance after working, and the disc is assembled smoothly.
HAMADA MITSURU
NAKAJIMA MINORU
HIRANO HIROSHI
TSUGAWA IWAO
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