PICKUP LENS AND UNIT INCLUDING THE SAME

PROBLEM TO BE SOLVED: To provide a pickup lens practically usable for at least three types of an optical disk.SOLUTION: A plurality of orbicular zones are present on a first face of the pickup lens. In the case where the face with the orbicular zones formed thereon is divided into a first area including an optical axis, a second area adjacent to the outside of the first area and concentric to it, and a third area adjacent to the outside of the second area and concentric to it, laser beams with wavelengths λ1, λ2, and λ3 in a range corresponding to the first area condense on information recording mediums of substrate thicknesses t1, t2, and t3 respectively. While laser beams of wavelengths λ1, and λ2 in a range corresponding to the second area condense on the information recording mediums of substrate thicknesses of t1 and t2 respectively, a laser beam of a wavelength λ3 in a range corresponding to the second area does not condense on the information recording medium of substrate thickness t3. While a laser beam of wavelength λ1 corresponding to the third area condenses on the information recording medium of substrate thickness t1, laser beams of wavelengths λ2, and λ3 in a range corresponding to the third area do not condense on information recording mediums of substrate thicknesses t2 and t3 respectively.