Patent ID: 8102604

Claim:
A plastic lens for an optical pick-up device and for a blu-ray recording medium, the plastic lens being formed by an injection molding of a resin material, the plastic lens comprising: a first lens surface that is arranged at an optical recording medium side; a second lens surface that is opposed to the first lens surface; a flange part that is provided at peripheries of the first and second lens surfaces and comprises flange surfaces that are opposed to each other, the flange surface at the optical recording medium side comprising a projecting surface and a marking surface, the projecting surface projecting to the optical recording medium side when viewed from the first lens surface and the marking surface, the marking surface being configured to be a ring shape and positioned closer to the first lens surface than the projecting surface; and a first marking that is integrally formed on the marking surface by the injection molding and comprises a projecting shape that projects from the marking surface to the optical recording medium side, a level of a top end of the first marking being configured not to overreach a level of the projecting surface, wherein a periphery of the first marking is substantially surrounded by the marking surface, and an area of the marking surface surrounding the first marking is mirror-finished.