Abstract: A method and apparatus for compensating tilt. The tilt compensation method includes: obtaining one of a jitter best, an RF envelope, and a focus DC offset (FODC) from a detection signal of the ROM data region and determining whether the obtained value is within a tolerance range; and obtaining an initial skew compensation value using the obtained value when the obtained value is within the tolerance, changing the magnitude of current applied to an actuator designed to perform driving in at least three-axis directions to drive an objective lens of an optical pickup assembly in a radial tilt direction when the obtained value is not within the tolerance range, and repeating the obtaining of one of the jitter best, the RF envelope, and the FODC and changing the magnitude of the current until the obtained value is within the tolerance range.

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: An optical pickup apparatus includes a first light source to emit a first light beam having a predetermined wavelength, a first optical path changer to change a proceeding path of the first light beam, an objective lens to focus the first light beam on a recording medium, a diffraction member to divide the first light beam reflected by the recording medium into five light regions, the diffraction member having a first diffraction region having a wide width in a direction corresponding to a tangential direction of the recording medium and second through fifth diffraction regions sequentially arranged around the outside of the first diffraction region in a direction corresponding to a radial direction of the recording medium, and a first photodetector having first through fifth light receiving portions to receive the first light beam reflected by the recording medium.

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: An optical pickup for a recording medium includes a light source, an objective lens, a main photodetector, and a front photodetector. The configuration of the optical pickup enables converging or diverging of light to be incident on a plate beam splitter so that light can be received at an effective light receiving region of a front photodetector without interference due to internal reflection occurring in the plate beam splitter. In the alternative, a wedge beam splitter in the optical pickup includes first and second mirror planes at a predetermined angle to transmit and reflect incident light at a predetermined ratio. In the optical pickup, an amount of light that is exactly proportional to an output power of the light source can be detected, where the output power of the light source can be accurately controlled, thereby improving a linearity of the output power of the light source.

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: 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 method and apparatus for compensating tilt. The tilt compensation method includes: obtaining one of a jitter best, an RF envelope, and a focus DC offset (FODC) from a detection signal of the ROM data region and determining whether the obtained value is within a tolerance range; and obtaining an initial skew compensation value using the obtained value when the obtained value is within the tolerance, changing the magnitude of current applied to an actuator designed to perform driving in at least three-axis directions to drive an objective lens of an optical pickup assembly in a radial tilt direction when the obtained value is not within the tolerance range, and repeating the obtaining of one of the jitter best, the RF envelope, and the FODC and changing the magnitude of the current until the obtained value is within the tolerance range.

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: In a method and system for forming light beams onto a disc for a plurality of disc formats, a main beam is directed onto the disc. A side beam is directed onto the disc with a displacement from the main beam, with the displacement being a LCM (least common multiple) distance of respective track pitches for the plurality of disc formats. A tracking servo uses such main and side beams with stable operation for the plurality of disc formats.

Abstract: A laser power control device for use in an optical recording and/or reproducing apparatus that records data on and/or reproduces data from an optical recording medium by driving a laser diode with a laser diode driver.

Abstract: An optical pickup for a recording medium includes a light source, an objective lens, a main photodetector, and a front photodetector. The configuration of the optical pickup enables converging or diverging of light to be incident on a plate beam splitter so that light can be received at an effective light receiving region of a front photodetector without interference due to internal reflection occurring in the plate beam splitter. In the alternative, a wedge beam splitter in the optical pickup includes first and second mirror planes at a predetermined angle to transmit and reflect incident light at a predetermined ratio. In the optical pickup, an amount of light that is exactly proportional to an output power of the light source can be detected, where the output power of the light source can be accurately controlled, thereby improving a linearity of the output power of the light source.

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: An optical pickup apparatus includes a first light source to emit a first light beam having a predetermined wavelength, a first optical path changer to change a proceeding path of the first light beam, an objective lens to focus the first light beam on a recording medium, a diffraction member to divide the first light beam reflected by the recording medium into five light regions, the diffraction member having a first diffraction region having a wide width in a direction corresponding to a tangential direction of the recording medium and second through fifth diffraction regions sequentially arranged around the outside of the first diffraction region in a direction corresponding to a radial direction of the recording medium, and a first photodetector having first through fifth light receiving portions to receive the first light beam reflected by the recording medium.

Abstract: A method of controlling a balance of a photodetector capable of increasing light reception efficiency thereof in a compatible optical pickup and an apparatus thereof. The method includes installing first and second light sources in a single module; directing light supplied from the first or second light source and transmitted through a holographic optical element, an optical path changing unit, and an objective lens onto a disk corresponding to each light source, transmitting the light reflected from the disk through the objective lens, and the optical path changing unit to a photodetector, moving the photodetector so that the center of a first one of first and second spots received by the photodetector is concentric with the center of the photodetector; and moving the holographic optical element so that the center of the second received spot from the second light source is concentric with the center of the photodetector.