Patent attributes
To provide an objective lens and an optical pickup device which can thin the objective lens and a device on which the objective lens is mounted, and which can prevent that the pitch of the diffraction grating at the outer periphery of the objective lens becomes too small in the manufacturing procedure and so it becomes difficult to manufacture the Fresnel lens or which does not require a high-grade fine processing technique in order to minimize the pitch of the diffraction grating, in an objective lens which condenses a laser light emitted from a light source to irradiate on an optical disk, the outer periphery on the side surface of the objective lens in which the laser light is incident is formed by a refractive lens portion 7a and the inner periphery thereof is formed by a Fresnel lens portion 7b.
