Patent ID: 7952979

Claim:
A coupling lens incorporatable into an optical head for collecting laser light emitted from a plurality of light sources and having different wavelengths on an information recording layer of different types of optical information recording mediums respectively, the coupling lens comprising a first lens and a second lens which are substantially in close contact with each other such that optical axes thereof match each other and designed such that the laser light having different wavelengths are refracted by the close contact face, and also including three lens faces crossing the optical axis; wherein: the three lens faces are: a first lens face, which is a face of the first lens which is not in contact with the second lens, a second lens face, which is a contact face of the first lens and the second lens which are substantially in close contact with each other, and a third lens face, which is a face of the second lens which is not in contact with the first lens; at least one of the first lens face, the second lens face and the third lens face is formed to have an aspheric shape; in an effective area of at least one of the first lens face, the second lens face and the third lens face, a first effective area encompassing the optical axis and a second effective area located outside the first area are formed to have different aspheric shapes; and the coupling lens is afocal for the shortest wavelength among the different wavelengths of the laser light.