Patent ID: 6987724

Claim:
An optical pickup device comprising: a light source to emit light; an objective lens to focus the emitted light from the light source on a recording medium to form a light spot; an optical path changer disposed on an optical path of the emitted light between the light source and the objective lens, the optical path changer changing the optical path of the emitted light; a chromatic aberration correction lens disposed on the optical path between the light source and the objective lens, the chromatic aberration correction lens correcting a chromatic aberration occurring due to a change in a wavelength of the emitted light and/or due to an increase in a wavelength bandwidth of the emitted light, the chromatic aberration correction lens comprising a first lens having a positive power and a second lens having a negative power adjacent to each other, a total focal length of the chromatic aberration correction lens being infinite as compared to the objective lens; and a photodetector to receive the light reflected from the recording medium and then incident thereon through the optical path changer, wherein the second lens having the negative power and the first lens having the positive power are sequentially disposed from the light source, and the first and second lenses have similar powers and surfaces of the second and first lenses facing the light source and the objective lens, respectively, have negative radii of curvature, and a surface between the first and second lenses has a positive radius of curvature, the negative radii of curvature having magnitudes greater than the positive radius of curvature.