Abstract:
An optical pickup apparatus and an optical recording/reproducing system including the same, the optical pickup apparatus includes at least two optical systems for different types of optical recording media, one of objective lenses of the optical systems being offset from a central line of the optical recording medium, wherein the optical system including the offset objective lens having a diffraction grating diffracting light emitted from a light source to form a main beam and sub-beams, wherein the diffraction grating includes first and second diffraction regions having different grating patterns arranged alternately thereon, and a center of each sub-beam is arranged at a boundary of the first and second diffraction regions of the diffraction grating, and a center of the diffraction grating and an optical axis of the light source are adjusted to be coincided with each other, preventing generation of an alternating current in a Push-Pull signal of the sub-beams.
Abstract:
An optical pickup actuator including a multi-conductive suspension. The optical pickup actuator may include a base, a holder fixed to the base, a bobbin holding an object lens and having a plurality of driving coils, and a plurality of suspensions connected between the bobbin and the holder and movably supporting the bobbin toward the holder, wherein each of the suspensions may be a multi-conductive suspension including a flexible substrate and a plurality of wires, formed on the flexible substrate, applying currents to the coils.
Abstract:
A heat source having a device emitting heat, a case protecting and supporting the device, and a thermoelectric element absorbing the heat emitted from the device and dissipating the heat to an outside.
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. The laser power monitor device further includes a switch unit, wherein the switch unit is located between the photo diode unit and the monitor circuit to receive a signal on a current recording speed and switch so that the number of photo diodes supplying current to the monitor circuit is reduced as the recording speed is increased.
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. The optical pickup and optical recording and/or reproducing apparatus makes it possible to realize a tracking servo that is compatible between ±R/RW and RAM type optical data storage media having different track pitch dimensions based on DPP.
Abstract:
An optical recording and/or reproducing apparatus with an optical pickup actuator having high thrust. The optical pickup actuator may include a lens holder which holds an objective lens and is movably supported by a supporting unit, and a magnetic driving unit which drives the lens holder in a focusing direction, a tracking direction, and/or a tilting direction. The magnetic driving unit includes a surface-triple pole magnet portion and a coil portion. The surface-triple pole magnet portion has a plurality of polarized, i.e., differently magnetized, areas formed by facing sides of two magnets among three magnets. The coil portion includes tracking coils and tilt coils disposed to interact with the polarized areas of the surface-triple pole magnet portion and a focusing coil disposed to interact with a non-polarized area of the surface-triple pole magnet portion.
Abstract:
An optical recording and/or reproducing apparatus with an optical pickup actuator having high thrust. The optical pickup actuator may include a lens holder which holds an objective lens and is movably supported by a supporting unit, and a magnetic driving unit which drives the lens holder in a focusing direction, a tracking direction, and/or a tilting direction. The magnetic driving unit includes a surface-triple pole magnet portion and a coil portion. The surface-triple pole magnet portion has a plurality of polarized, i.e., differently magnetized, areas formed by facing sides of two magnets among three magnets. The coil portion includes tracking coils and tilt coils disposed to interact with the polarized areas of the surface-triple pole magnet portion and a focusing coil disposed to interact with a non-polarized area of the surface-triple pole magnet portion.
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 apparatus and method for detecting beam power generated by a plurality of light sources, using a single device. The apparatus includes a light-receiving unit that receives the beam power generated by one of a plurality of light sources, and an amplifying unit that selects a gain, amplifies the beam power received by the light-receiving unit according to the selected gain, and outputs the beam power amplified as a detected beam power. According to the apparatus and method, received beam power (or amplification gain) is amplified by a gain determined according to the characteristics of the respective light sources. Thus, it is possible to provide the detected beam power in consideration of a sufficient dynamic range for the each light source, thereby realizing effective APC.
Abstract:
A magnetic circuit, an optical pickup actuator, an optical recording and/or reproducing apparatus using the magnetic circuit, and method of the same, wherein the magnetic circuit includes a plurality of focus coil units each of which includes a first focus coil and a second focus coil, and a magnet including a plurality of magnet portions which interact with the plurality of focus coil units and each of which is polarized in a direction opposite to adjacent magnet portions thereamong. Here, electromagnetic forces act on the first and second focus coils in each focus coil unit in a same direction in response to focus driving signals and in opposite directions in response to tilt driving signals, with the first and second focus coils in each focus coil unit have different effective coil lengths.