Abstract: A compatible optical pickup device includes a single light source to emit a light having a wavelength longer than 650 nm, an objective lens having a near axis area, a ring type annular lens area, and a far axis area to focus the light to form light spots suitable for a first relatively thin optical disk and a second relatively thick optical disk to form a first light spot having an FWHM (full width at half maximum) of 0.72 ?m or less for the first optical disk and a second light spot having an FWHM of 0.8 ?m or more for the second optical disk, an optical path changer to change a proceeding path of incident light, and a photodetector to receive light reflected by the optical disk and having passed through the objective lens and the optical path changer and to detect an information signal and/or an error signal.

Abstract: An apparatus for recording data on and reproducing data from the disk in which a recording area is divided into sectors, includes a reproducing signal generator for generating a reproducing signal including sum signals V1 and V2 of radial pairs, a sum signal RF_sum, and a push-pull signal RF_pp from an optical signal reflected from the disk, a header area detector for generating a header area signal including a header area from the reproducing signal, a first synchronous signal level detector for detecting a magnitude Ivfo1 of a first synchronous signal in the first header by being synchronized with the header area signal, a second synchronous signal level detector for detecting a magnitude Ivfo3 of a second synchronous signal in the second header by being synchronized with the header area signal, and a balance calculator for calculating the balance of the magnitude Ivfo1 and the magnitude Ivfo3.

Abstract: A data line switching circuit of an optical pickup device is disclosed. In order to drive multiple formats of optical disks, the data line switching circuit applies data signals of a corresponding format to the optical pickup device through a common connector by connecting data lines of the corresponding format to the common connector according to control signals from a control unit, thereby minimizing the number of terminals of the connector to obtain a miniaturized optical pickup device.

Abstract: An optical disk writing and reading apparatus and a method thereof is provided. The optical disk writing and reading apparatus has an optical pick-up for writing or reading data on an optical disk by using a laser light of a certain wavelength, an optical power calculation part for calculating an optical power of the laser light generated from the optical pick-up, and a micom operating the optical power calculation part by every certain time to detect the optical power of the laser light and adjusting the optical power of the laser light based on a preset optimum optical power to be optimized while writing the data on the optical disk.

Abstract: An optical pickup apparatus includes a first objective lens having a low numerical aperture (NA) suitable for a low density recording medium, a second objective lens having a high NA suitable for a high density recording medium, a first light source that emits short wavelength light which is focused onto an optical recording medium by the first and second objective lenses, a first photodetector that receives a returning reflected light from the optical recording medium, and a first optical path converter for selectively guiding part of the light emitted from the first light source towards the first or the second objective lens, and guiding the reflected light towards the first photodetector.

Abstract: An optical pickup device according to an embodiment of the present invention comprises a light source for projecting a beam of light to record and reproduce information with respect to an optical recording medium. A collimating lens is disposed on a path of the light to converge and convert the light into a parallel beam. An object lens condenses the parallel beam from the collimating lens and projects the parallel beam onto the optical recording medium. An optical element is disposed between the collimating lens and the object lens. A first actuator moves the collimating lens along the optical axis to thereby control a distance between the collimating lens and the optical element. A first controller drives the first actuator to find a position for the collimating lens, for reducing aberration generated in the light being projected to the optical recording medium. Accordingly, the aberration can be effectively prevented, thereby improving recording and reproducing performance of the optical pickup device.

Abstract: An optical pickup which is compatible with different types of media is disclosed. A plurality of light sources emit light with different wavelengths. Light path changers change the path of light emitted by the plurality of light sources so that the light is incident upon an objective lens. The objective lens focuses the incident light onto a recording medium. A collimating lens is disposed in front of the objective lens to collimate the incident lights. The collimating lens is movable to correct a spherical aberration. A diffractive optical element is disposed in a path of a light with a short wavelength and has a diffractive surface to correct a chromatic aberration.

Abstract: An optical pickup device and a focusing control method thereof are provided which can determine a DC offset caused by cross-talk of a focus error signal, eliminate the DC offset based on the determination, correct errors in a focus error signal of a main beam, which is caused by interference of side beams, so that optimal focus tracking can be performed. For this, the optical pickup device has at least one or more light sources, a diffraction optical element which diffracts light from the light source into a plurality of beams, an objective lens which condenses the plurality of beams diffracted by the diffraction optical element, a photo detector which detects the plurality of beams reflected from discs, and an auxiliary photo detector which detects the plurality of beams reflected from the discs to perform error correction of focus error detection signals obtained by the photo detector.

Abstract: An optical pickup apparatus having laser light sources emit a first light beam having a relatively shorter wavelength for a DVD and a second light beam having a longer wavelength for a CD-R, an objective lens having a focal length of an information recording surface in the DVD, an optical path control unit controls the light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit, and a phase shift unit between the optical path control unit and the objective lens and which shifts a phase of the second light to reduce the size of a beam spot which is formed the information recording surface in the CD-R.

Abstract: An optical pickup device includes a light unit for irradiating a light beam having a wavelength longer than 650 nm onto a recording medium and receiving and detecting a light beam reflected by the recording medium, and an objective tens formed of a single lens having an NA of 0.7 or more to form a light spot on the recording medium by condensing an incident light beam emitted from the light unit. A recording medium has a recording density of a DVD family or more and is formed of a material suitable for a long wavelength of 700 nm or more so that a reproduction signal by a reflectance of a recording surface is optimized. Thus, a compact high density optical recording/reproducing apparatus which is inexpensive and has high performance can be realized.

Abstract: A diffraction element for an optical pick-up apparatus is provided that enables more accurate focusing control. The diffraction element for an optical pick-up apparatus is divided into first and second regions, each being formed with a grid pattern in which grids are repeated with a predetermined pitch P. The grid pattern in at least one of the first and second regions is tilted by a predetermined angle with respect to a virtual line VL substantially perpendicular to a division line DL that divides the first and second regions.

Abstract: An optical pickup apparatus compatible with at least two types of optical recording media, using light beams having respective different wavelengths for recording and reading information, the optical pickup apparatus including two laser light sources to emit light beams having the different wavelengths, a holographic lens including a holographic ring to transmit the light beams incident in an inner region of the holographic ring, and to diffract a specific light beam among the light beams emitted from the laser light sources incident in an outer region relative to the inner region, an objective lens to focus the light beams passed through the holographic ring lens on the respective information recording surfaces of the two types of the optical recording media, optical elements to alter optical paths of the light beams reflected from the information recording surfaces of the optical recording media to corresponding photodetectors.

Abstract: An apparatus for recording data on and reproducing data from the disk in which a recording area is divided into sectors, includes a reproducing signal generator for generating a reproducing signal including sum signals V1 and V2 of radial pairs, a sum signal RF_sum, and a push-pull signal RF_pp from an optical signal reflected from the disk, a header area detector for generating a header area signal including a header area from the reproducing signal, a first synchronous signal level detector for detecting a magnitude Ivfo1 of a first synchronous signal in the first header by being synchronized with the header area signal, a second synchronous signal level detector for detecting a magnitude Ivfo3 of a second synchronous signal in the second header by being synchronized with the header area signal, and a balance calculator for calculating the balance of the magnitude Ivfo1 and the magnitude Ivfo3.

Abstract: An optical pickup compatible with recording media having different formats, the optical pickup includes a light device module having a first light beam source and a second light beam source to emit corresponding first and second light beams having different wavelengths, a hologram light coupler to separately guide the first and second light beams along the same optical path such that the first and second light beams go toward a corresponding one of the recording media, an optical path changing element to selectively alter the optical path of an incident light beam, and an objective lens disposed on an optical path between said optical path changing element the corresponding one of the recording media to focus the first and second light beam on the corresponding one of the recording media, and a photodetector to receive the first and second light beam incident from said optical path changing element.

Abstract: An optical pickup compatible with recording media having different formats, the optical pickup includes a light device module having a first light beam source and a second light beam source to emit corresponding first and second light beams having different wavelengths, a hologram light coupler to separately guide the first and second light beams along the same optical path such that the first and second light beams go toward a corresponding one of the recording media, an optical path changing element to selectively alter the optical path of an incident light beam, and an objective lens disposed on an optical path between said optical path changing element the corresponding one of the recording media to focus the first and second light beam on the corresponding one of the recording media, and a photodetector to receive the first and second light beam incident from said optical path changing element.

Abstract: An optical recording and pickup head having a flat plate lens of a staircase type diffraction grating structure is compatible with a DVD and a CD-RW.

Abstract: An optical pickup apparatus having laser light sources emit a first light beam having a relatively shorter wavelength for a DVD and a second light beam having a longer wavelength for a CD-R, an objective lens having a focal length of an information recording surface in the DVD, an optical path control unit controls the light beams so that the light beam emitted from one of the laser light sources is directed to the objective lens and the light output from the objective lens is directed to the optical detection unit, and a phase shift unit between the optical path control unit and the objective lens and which shifts a phase of the second light to reduce the size of a beam spot which is formed the information recording surface in the CD-R.

Abstract: An optical pickup includes a light source emitting a laser beam and an optical path changing unit altering a traveling path of an incident beam. An objective lens, disposed on an optical path between the optical path changing unit and an optical disk, focuses the incident beam from the light source to form a light spot on the optical disk of the objective lens. The optical pickup further includes a photodetector and an detecting-correcting unit, arranged on the optical path between the optical path changing unit and the objective lens, performing at least one of detecting the thickness of the optical disk and correcting aberration caused by thickness variations of the optical disk. The objective lens includes a first transmitting portion divergently transmitting an incident beam, where the first transmitting portion is at a relatively near-axis region from an optical axis of the objective lens.

Abstract: An optical pickup includes a light source emitting a laser beam and an optical path changing unit altering a traveling path of an incident beam. An objective lens, disposed on an optical path between the optical path changing unit and an optical disk, focuses the incident beam from the light source to form a light spot on the optical disk of the objective lens. The optical pickup further includes a photodetector and an detecting-correcting unit, arranged on the optical path between the optical path changing unit and the objective lens, performing at least one of detecting the thickness of the optical disk and correcting aberration caused by thickness variations of the optical disk. The objective lens includes a first transmitting portion divergently transmitting an incident beam, where the first transmitting portion is at a relatively near-axis region from an optical axis of the objective lens.

Abstract: A lens device which can be used as an objective lens in an optical pickup apparatus includes an objective lens provided along a light path facing a disc and having a predetermined effective diameter, and light controlling means provided along the light path for controlling the light in an intermediate region between near and far axes of an incident light beam, thus providing a simplified and inexpensive device for using discs of differing thickness in a single disc drive, by reducing the spherical aberration effect.