According to the present invention, there is provided an objective lens
for an optical head device which condenses two or more laser beams having
wavelengths corresponding to two or more optical recording mediums having
different thicknesses of transparent substrates on recording surfaces of
the optical recording mediums via one optical condensing system to record
information on the recording surfaces and/or reproduce the information on
the recording surfaces, the objective lens comprising: a refractive
surface including: a middle region which is formed in a middle portion of
the refractive surface centering on an optical axis of the objective lens
and which is used with respect to all of the optical recording mediums;
one or more peripheral regions which are concentrically formed outside
the middle region; and an aperture limiting ring band which is
concentrically formed between the middle region and the peripheral region
or between the peripheral regions.