Abstract: First order diffraction lights reflected on a first signal face for reproducing an optical disc and further deflected by a spatial divide element converge to spots 21a to 21d on photo acceptance cells 9A to 9D of a photodetector 9, while diffraction lights reflected on the first signal face and further diffracted by other orders of diffraction except plus first-order and diffraction lights reflected on a second signal face become crosstalk lights. Therefore, an optical pickup device is adapted so that minus (?) first-order diffraction lights 23a to 23d from the first signal face and the spots 21a to 21d of the first order diffraction light from the second signal face are not radiated on the photo acceptance cells 9A to 9D.

Abstract: There is disclosed an optical pickup device including: a blue semiconductor laser which emits a first laser light having a wavelength of 450 nm or less to record on or reproduce from an extra-high density optical disc; a red semiconductor laser which emits a second laser light having a wavelength longer than that of the first laser light to record on or reproduce from a DVD having a low recording density; an objective lens; and an aberration correction element. The objective lens is designed for the extra-high density optical disc, and has a numerical aperture (NA) of 0.75 or more. The aberration correction element passes the first laser light as such and thereafter allows the light to be incident upon the objective lens, whereas the element limits an aperture with respect to the second laser light and diffracts the second laser light so as to correct an aberration with respect to the DVD and thereafter allows the light to be incident upon the objective lens.

Abstract: An aberration correction element is disposed between first to third laser light sources and an objective lens, first and second laser lights emitted from the first and second laser light sources are incident upon the aberration correction element in the form of parallel lights, and a third laser light emitted from the third laser light source is incident upon the aberration correction element in the form of a divergent light.

Abstract: An aberration correction element is disposed between first to third laser light sources and an objective lens, first and second laser lights emitted from the first and second laser light sources are incident upon the aberration correction element in the form of parallel lights, and a third laser light emitted from the third laser light source is incident upon the aberration correction element in the form of a divergent light.

Abstract: There is disclosed an optical pickup device including: a blue semiconductor laser which emits a first laser light having a wavelength of 450 nm or less to record on or reproduce from an extra-high density optical disc; a red semiconductor laser which emits a second laser light having a wavelength longer than that of the first laser light to record on or reproduce from a DVD having a low recording density; an objective lens; and an aberration correction element. The objective lens is designed for the extra-high density optical disc, and has a numerical aperture (NA) of 0.75 or more. The aberration correction element passes the first laser light as such and thereafter allows the light to be incident upon the objective lens, whereas the element limits an aperture with respect to the second laser light and diffracts the second laser light so as to correct an aberration with respect to the DVD and thereafter allows the light to be incident upon the objective lens.