SYNTHETIC RESIN LENS MANUFACTURING METHOD, REFORMED QUALITY SYNTHETIC RESIN MATERIAL MANUFACTURING METHOD AND OPTICAL PICKUP DEVICE

摘要

[PROBLEMS TO BE SOLVED] A synthetic resin material, which is small in decreasing degree of the transmissivity of red laser light due to accumulated irradiation of the red laser light but is large in decreasing degree of the transmissivity of blue-violet laser light due to accumulated irradiation of the blue-violet laser light, has been widely used as an objective lens material in compliance with the requirement for the red laser light. The synthetic resin material, however, has not been able to be put into practical use for an objective lens material in compliance with the requirement for the blue-violet laser light. It is an object to make the synthetic resin material usable as such an objective lens material for the blue-violet laser light. [MEANS FOR SOLVING THE PROBLEMS] An electromagnetic wave with a shorter wavelength than that of a blue-violet laser light is irradiated to a lens member made of a synthetic resin material so that the degree of the transmissivity change of the blue-violet laser light is adjusted in the lens member due to accumulated irradiation of the blue-violet laser light.