Abstract: An optical pickup includes an optical module that detects an information signal and/or an error signal by radiating light to a recording medium and receives light reflected by the recording medium. The optical module includes a light source; an optical path changer that changes a path of light emitted from the light source; a main photodetector that receives light that is reflected off a recording medium back to the optical module to detect an information signal and/or an error signal; and a hologram element that generates an astigmatism of the light incident onto the optical module. Since most optical elements of the optical pickup except an objective lens are packaged in the optical module, the entire structure of the optical pickup can be simplified and the number of bonding points for fixing the optical elements of the optical pickup on a base can be reduced.

Abstract: A compatible optical pickup includes a light source which emits a first light beam having a wavelength for a first recording medium; a twin light source which emits second and third light beams respectively having wavelengths for second and third recording media; a first objective lens which condenses the first light beam to form a light spot for recording and/or reproduction of the first recording medium; a second objective lens which condenses the second and third light beams to form light spots for recording and/or reproduction of the second and third recording media; an actuator which drives the first and second objective lenses; a first photo-detector which receives the first light beam reflected from a recording medium to detect an information signal and/or an error signal; and a second photo-detector which receives the second and third light beams reflected from a recording medium to detect information signals and/or error signals.

Abstract: A CD-DVD compatible optical pickup in which both on-axis and off-axis light form a circular light spot on a recording surface of an optical recording medium, and an optical recording and/or reproducing apparatus using the same. The CD-DVD compatible optical pickup includes an optical output module, an objective lens, an optical path conversion unit, a photodetector, and an actuator. The optical output module has a mount and light sources emitting light of different wavelengths. The objective lens focuses the emitted light onto two types of optical recording media. The optical path conversion unit between the optical output module and objective lens, converts incident light. The photodetector receives beams emitted from the light sources, reflected from the optical recording media, and then passed through the optical path conversion unit, detecting data and error signals. The actuator has a movable member, moving the objective lens and compensating focusing and tracking error signals.

Abstract: A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, which enables detection of a tracking error signal using one photodetector based on a three-beam method and by a differential phase detection method. The optical pickup system includes a light source, a diffractive optical element which diffracts a light beam incident from the light source and splits the same into at least three beams, a plate-type beam splitter which changes a propagation path of the light beam, and a photodetector including at least one main photodetector having at least four sections and a plurality of sub-photodetectors. The optical pickup system is constructed so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium.

Abstract: An optical pickup apparatus includes a light source module which emits a light beam, a beam splitter which reflects or transmits the light beam emitted from the light source module, an objective lens which focuses the light beam passing through the beam splitter onto a disc, and a photodetector which receives and detects the light beam reflected by the disc, wherein the light source module includes a first light source and a second light source that emit first and second light beams having different wavelengths and are formed into a single module. The optical pickup apparatus further includes a first grating which divides the first light beam emitted from the first light source into three beams of the first light beam and transmits the second light beam emitted from the second light source, and a second grating which transmits the first light beam emitted from the first light source and divides the second light beam emitted from the second light source into three beams of the second light beam.

Abstract: An optical pickup includes a light source which emits first and second lights having different wavelengths for a first recording medium and a second recording medium having a relatively large thickness, respectively, an optical path changer which alters a traveling path of incident light, and an objective lens which focuses the first and second lights on the recording medium. While the light source emits the first light, a photodetector is adjusted to be aligned with the optical axis for the first recording medium. The light source and/or a sensing lens are adjusted in the direction of the optical axis, and the tilt of the objective lens is adjusted. Next, while the light source is operated to emit the second light, the light source is adjusted in a rotating direction. As such, an optical axis alignment is completed for the first and second recording media.

Abstract: A compatible optical disk player and data recording and/or reproducing method includes a laser beam source including a first laser diode and a second laser diode, where the first laser diode emits a first laser beam of a first wavelength for recording and/or reproducing the data on/from a first optical disk including a first recording density, and the second laser diode emits a second laser beam of a second wavelength for recording and/or reproducing the data on/from a second optical disk including a second recording density. A diffraction grating selectively splits the first and the second laser beams into a main ray and two sub-rays depending on which optical disk is to be accessed. A photo-detector selectively receives the three rays of the first laser beam and the three rays of the second laser beam at different detecting portions for the data recording and/or reproducing and error detection and compensation.

Abstract: An optical pickup capable of multiple track scanning, including a light source having at least two vertical cavity surface emitting lasers (VCSELs) to emit at least two or more light beams and a light controlling device for controlling the focal position of a light formed on one type of recording medium of two formats of different thicknesses, is provided. The light emitted from each VCSEL is focused on adjacent tracks of the recording medium via a polarization beam splitter, the light controlling device and an objective lens in sequence, and the light reflected from the recording medium is received by a photodetector via the objective lens, the light controlling device and the polarization beam splitter. The number of photodetectors correspond to the number of VCSELs to receive lights corresponding to each track.

Abstract: An optical pickup which can be employed for different formats of a disk recording medium is disclosed. The optical pickup device includes a light source including first and second vertical cavity surface emitting lasers closely disposed to each other for emitting light having different wavelengths and different radiation angles, an objective lens for focusing the light emitted from the light source on a recording surface of a recording medium, a photodetector for detecting information signals and error signals by receiving the light reflected from the recording medium, a polarized beam splitter disposed on an optical path between the light source and the objective lens to redirect a proceeding path of incident light, and a wavelength plate disposed on the optical path between the objective lens and the polarized beam splitter to convert a polarization component of incident light.

Abstract: A method of scanning multiple tracks uses an optical pickup to simultaneously emit a plurality of beams on a plurality of tracks on a disk, and satisfies the equations: N.sub.j =(N.sub.b -1)N.sub.g -1 and N.sub.r =N.sub.b N.sub.g -1. Here, N.sub.j represents the number of jumped tracks, N.sub.b represents the number of light beams, N.sub.g represents the interval between the light beams, and N.sub.r represents the number of reproduced tracks during a reproduction period.

Abstract: An optical axis alignment apparatus of an optical pick-up device for measuring and adjusting a shift amount between a central axis of an objective lens and an optical axis of a laser beam emitted from a light source includes a first photodetector positioned to reciprocate along a central axis of the objective lens, for detecting a shift amount of an optical axis of the laser beam with respect to the central axis of the objective lens and for generating a first detection signal; a second photodetector for detecting a distribution of the laser beam emitted from the laser source and for generating a second detection signal; a beam splitter for splitting the laser beam at a predetermined angle to direct the laser beam to said first and said second photodetectors, respectively; a driving mechanism for reciprocating the first photodetector along the central axis of the objective lens; and mechanism for adjusting the position and the angle of the laser source in dependence upon reception of the first and second dete