Patent ID: 8971164
Filing Date: 2015-03-03
Classification: G02B,G11B

Abstract:
1. An optical component for an optical pick-up for converging a laser beam having a particular wavelength onto a recording layer of an optical disc, comprising: a base material formed of a resin composition; an undercoating formed of five layers of thin films having a same main constituent, the undercoating being formed on a top surface of the base material; and a functional thin film formed on a top surface of the undercoating, wherein: each of a first layer, a third layer and a fifth layer of the undercoating is a thin film formed without introducing oxygen, and each of a second layer and a fourth layer is a thin film formed while introducing oxygen; and a film thickness of the undercoating falls within a range of 150 nm to 275 nm, and film thicknesses of the thin films constituting the undercoating are substantially equal to each other.