Patent ID: 7245437

Claim:
A collimator lens for an optical pickup, said collimator lens being located in a light path from a laser light source to an optical information recording medium to collimate a laser beam from said lasor light source, and comprising: a cemented glass lens formed by bonding together two glass lens elements comprising a biconvex lens and a meniscus lens; and an aspheric plastic lens in the form of a thin transparent synthetic resin film laminated on a surface of said biconvex lens located on the side of said optical information recording medium; when calculated on the basis of a composite focal length f=10 mm, said collimator lens having an axial aberration correction rate (a) and a numerical aperture NA as expressed by following formulas (1) and (2), (a) 2.2˜m/nm, (1) 0.4>NA≧0.12. (2)