Abstract: A compatible type optical pickup using a wedge type beam splitter that can record and/or reproduce information on/from optical recording media having different formats.

Abstract: A front photo detector (FPD) of an optical pick-up for an optical recording and playing apparatus having no gain selection switch, a simplified configuration, an improved prevention of an abnormal operation due to an error in gain selection, and improved reliability. The front photo detector includes a photo diode unit, a current-voltage amplifying circuit, and a voltage amplifying unit. The photo diode unit outputs current proportional to the power of the light emitted from one of a plurality of laser diodes. The current-voltage amplifying circuit converts the current output from the photo diode unit into a voltage. The voltage amplifying circuit amplifies the voltage output from the current-voltage amplifying circuit by a predetermined gain.

Abstract: A compatible optical pickup including an optical unit and a focusing unit. The optical unit emits a short wavelength light for high-density recording media and a long wavelength light for low-density recording media, directs the short and long wavelength light to a recording medium, receives lights reflected by the recording medium, and detects an information reproduction signal and/or an error signal from the received lights. The focusing unit focuses light received from the optical unit to form a light spot on a recording surface of the recording medium, diffracts the short wavelength light into a zero order light and the long wavelength light into a second order light to be used as effective light for recording and/or reproduction. Thus, a high-density recording medium and a low-density recording medium having different thicknesses can be compatibly used.

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: In order to improve the frequency characteristic of a laser power monitor device and the precision of laser power control when low-speed recording is performed, there is provided a laser power monitor device for an optical recording and/or reproducing apparatus, the laser power monitor device including a photo diode unit to receive part of a light emitted from a laser diode and output a current proportional to optical power, and a monitor circuit to receive the current output from the photo diode unit, convert the received current into a voltage, and outputs the voltage to an automatic laser power control circuit, and the photo diode unit includes a plurality of photo diodes connected to the monitor circuit to supply current to the monitor circuit.

Abstract: A compatible optical pickup, including first and second light sources for emitting lights with different wavelengths and first and second photodetectors for detecting an information signal and/or an error signal, and a method of detecting the amount of output light using the compatible optical pickup. The first photodetector monitors the amount of light output from the second light source, and the second photodetector monitors the amount of light output from the first light source. Since the first and second photodetectors are used to detect a signal for use in monitoring the amount of light output from each of the second and first light sources, no extra front photodetectors are required. Thus, the number of optical component parts included in the optical pickup can be reduced, thereby lowering the manufacturing costs for the optical pickup. Also, there is no need to secure a space in a base where a front photodetector is to be installed, so the base is simplified.

Abstract: Provided is a laser diode driving circuit which prevents low optical output power of a laser diode at high ambient temperature, and prevents damage to the laser diode at low ambient temperature by adjusting the limit of a laser diode driving current, which is input to a laser diode, based on an optical output power characteristic that decreases optical output power as the ambient temperature decreases. Such a laser diode driving circuit includes a laser diode driving unit, which outputs a laser diode driving current and a laser diode protection unit, which sets the limit of the laser diode driving current output from the laser diode driving unit and increases the limit of the laser diode driving current as the ambient temperature of the laser diode increases.

Abstract: An optical pickup, optical recording and/or reproducing apparatus including the same, and a method of realizing a tracking servo that is compatible between different types of optical data storage media. The optical recording and/or reproducing apparatus splits light from a light source into a main beam and four or more sub beams symmetrical with respect to the main beam, which are then emitted on an optical data storage medium, wherein the four or more sub beams include two first sub beams located close to the main beam and two second sub beams located away from the main beam, and detects a tracking error signal by a differential push-pull (DPP) method using detection signals of the main beam and the pair of first sub beams and of the main beam and the pair of second sub beams for ±R/RW and RAM type optical data storage media, respectively.

Abstract: Provided are an apparatus and method for stably generating a tracking error signal in an optical recording/reading system irrespective of a disc track pitch.

Abstract: An optical pickup includes a light source which emits light, a grating which separates a portion of the light emitted from the light source, a reflecting member which reflects another portion of the light emitted from the light source, a monitoring photodetector disposed on a traveling path of the light reflected from the reflecting member and which measures the reflected light, an optical path changer which changes an optical path of the light separated by the grating, an objective lens light which condenses the light the optical path of which is changed onto a disc, and a signal detecting photodetector which receives the light reflected from the disc.

Abstract: An optical pickup apparatus having compatibility with a recodable compact disk (CD-R) and a digital video disk (DVD), which uses a wavelength of one of a first light beam and a second light beam according to the recording medium to be used. In the optical pickup apparatus, laser light sources emit a first light beam having a relatively shorter wavelength for the. DVD and a second light beam having a longer wavelength for the CD-R, respectively. An objective lens has a predetermined focal length in accordance with the position of an information recording surface in the DVD. An optical path control unit controls the path of 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.

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: A drive chip integrated laser diode module including a laser diode module main body to generate and emit laser light, a plurality of first leads protruding outwardly from the laser diode module main body to receive electric power, a drive chip, a plurality of coupling holes in the drive chip in which each of the first leads is inserted, respectively, a plurality of inner connectors in the drive chip, electrically connected to each of the first leads, respectively, a plurality of second leads protruding outwardly from the drive chip, a main board, a plurality of lands provided on the main board, electrically connected to the second leads, and a through hole in the main board through which the laser diode module main body passes, wherein the drive chip and the main board are integrally formed with respect to the laser diode module main body.

Abstract: An optical pickup actuator and an optical pickup using the same, wherein the optical pickup actuator has: a lens holder, on which an objective lens is mounted; and a tilt photodetector, which is installed in the lens holder and receives a portion of light used to record and/or to reproduce information on and/or from a recording medium according to a relative tilt between the objective lens and the recording medium. The optical pickup actuator moves the objective lens in a tracking direction, a focusing direction, and a tilting direction. The optical pickup actuator can detect both tilt of the recording medium and tilt of the objective lens using the tilt photodetector, so the optical pickup can be applied to an optical recording and/or reproducing apparatus of high-density and/or high-speed.

Abstract: An optical pickup using a two-wavelength light source module includes a light source module, a collimating lens, and a first optical element. The light source module includes first and second light sources which emit first and second light beams of different wavelengths and are formed in a single package. The collimating lens directs the first and/or second light beams into convergent light or divergent light so that the convergent light or the divergent light is incident on the objective lens. The optical pickup is a finite optical system due to the collimating lens. The first optical element is disposed on the traveling paths of the first and second light beams, operates as a lens only for one of the first and second light beams, and corrects a position difference between the first and second light sources along a traveling direction of light.

Abstract: An optical disc recording method to record data on a disc using multiple speeds by dividing a disc region into an inner circumference region and an outer circumference region depending on radii of the disc, setting a multiple recording speed for each region; setting optical recording power in a lead-in region of the inner circumference region and a lead-out region of the outer circumference region, by performing optimum power controls therein; determining in which one of the divided regions data is to be recorded using an address detected from the disc, rotating the disc at the multiple recording speed set for the one region in which the data is to be recorded, and recording the data in the one region using the set optical recording power for the one region.

Abstract: A data recording or recording and reproducing apparatus and method for improving recording quality by recording and/or reproducing data which controls the varying of a recording optical power level based on the recording speed when recording data in a disc-type recording medium. The data recording apparatus includes a memory for storing discrimination information for discriminating a disc type as well as corresponding read power level information for each recording speed, a pickup driving unit for receiving information read out from the disc from a pickup or outputting a signal for controlling the pickup, and a system control unit for receiving discrimination information of an inserted disc from the pickup driving unit, determining the read power level based on the power information for each recording speed corresponding to the disc discrimination information, and outputting a signal reflecting the determined read power to the pickup driving unit.

Abstract: An optical pickup condenses a light emitted from a light source using an objective lens and irradiates the light on an optical recording medium to record data on the optical recording medium and/or to reproduce the data recorded on the optical recording medium. The optical pickup includes an optical element adjusting a convergence and/or a divergence of the light emitted from the light source and proceeded to the objective lens.

Abstract: A circuit protects a light element and prevents a breakdown of a laser diode (LD) when electric static discharge (ESD) occurs. The circuit protects the light element in a drive to control an operation of the light element, which radiates light onto a disc. Here, the drive includes a switch between an active node of the light element and a predetermined potential so that the switch is short-circuited in a normal state, but is open when the drive operates. The light element is protected from static electricity or a surge voltage in a manufacturing process thereof or under a user environment. As a result, the probability that the light element is broken down is remarkably reduced.

Abstract: An optical pickup to focus a light emitted from a light source using an objective lens, forming a light spot on a recording surface of a recording medium, and performing recording and/or reproducing operations using the light. The optical pickup includes a monitor photodetector and an optical element installed in front of the monitor photodetector to receive and to detect a portion of the light emitted from the light source to control an amount of light power output from the light source and to adjust at least one of an intensity, a beam profile, and a proceeding direction of the light incident on the monitor photodetector.