Abstract: An optical pickup apparatus includes: a light-emitting element for emitting laser light; a collimating lens for causing incident laser light to be converted into an optical beam and for emitting the optical beam thus converted; an objective lens for converging onto a recording surface of a recording medium the optical beam from the collimating lens; a light-receiving element for receiving reflected light from the recording medium; a collimating lens holder for holding the collimating lens; supporting means for supporting the collimating lens holder so that the collimating lens holder can freely move in an optical axis direction of the collimating lens; driving means for driving the collimating lens holder by electromagnetic force; and an elastic member, provided between a housing and the collimating lens holder, for pulling back the collimating lens holder to a neutral position in the optical axis direction of the collimating lens.

Abstract: An optical pickup device has three different light sources, a holographic element, beam splitters, and first and second photodetectors. The beam splitters each change an optical path of a light beam coming from the associated light source toward a recording medium and match an optical axis of the changed optical path with an optical axis passing through the holographic element and the first photodetector. Reflected light from the recording medium is divided into zero-order diffraction light and first-order diffraction light by the holographic element. The first photodetector receives the zero-order diffraction light and obtains an RF signal and a tracking error signal. The second photodetector receives the first-order diffraction light and obtains a focusing error signal.

Abstract: In the optical pickup device, a luminous flux emitted from a blue-violet laser as S wave to a blue-violet PBS, passes through a half-wave plate, and is reflected by the blue-violet PBS and a total reflection mirror, before being applied to a BD disc via an objective lens. Luminous fluxes, which were emitted respectively from an infrared laser emitting device and a red laser emitting device and were reflected respectively by infrared and red PBSs, among aligned infrared, red and blue-violets PBSs, before reaching the blue-violet PBS, are reflected by the blue-violet PBS. The luminous fluxes emitted from the blue-violet laser emitting device as P waves pass the blue-violet PBS, and are respectively applied to a CD disc, a DVD disc, or a HD-DVD disc via an diffractive object lens. Thus, it becomes possible to write or read access to four kinds of discs with three wavelengths.

Abstract: An optical pickup device has three different light sources, a holographic element, beam splitters, and first and second photodetectors. The beam splitters each change an optical path of a light beam coming from the associated light source toward a recording medium and match an optical axis of the changed optical path with an optical axis passing through the holographic element and the first photodetector. Reflected light from the recording medium is divided into zero-order diffraction light and first-order diffraction light by the holographic element. The first photodetector receives the zero-order diffraction light and obtains an RF signal and a tracking error signal. The second photodetector receives the first-order diffraction light and obtains a focusing error signal.

Abstract: An optical pickup device according to the present invention having two light sources is capable of emitting lights having different wavelengths from each other for recording/reproducing information on/from an optical recording medium by using a light from the light source; wherein the two light sources both are capable of emitting either polarization lights in one polarization direction or polarization lights perpendicular to the one polarization direction, and each of the two light sources is arranged at a predetermined position depending on a polarization direction of the light to be emitted.