Abstract: A gap servo control method and apparatus for increasing a disturbance cancellation capability and decreasing the occurrence of an overshoot in a near-field optical disc drive include: generating an actuator driving signal of a transient response process by using a signal obtained by removing a disturbance contained in the gap error signal using a first band when a level of a gap error signal reaches a first level; and generating the actuator driving signal of the transient response process by using a signal obtained by removing the disturbance contained in the gap error signal using a second band when the level of the gap error signal reaches a second level.

Abstract: A compliant joint capable of achieving passive compliance for a robot in order to prevent an injury to a human by collision with the robot. The compliant joint includes a housing, a cam member rotatably mounted in the housing, a roller spring device mounted to the cam member to be compressed and extended, a guiding member formed in the housing to guide compression and extension of the roller spring device in accordance with rotation of the cam member, and a receiving recess formed at the guiding member to engage the housing and the cam member with each other by receiving the roller spring device and release the engagement by separating from the roller spring device. Accordingly, robustness of the robot can be maintained when an impact less than a predetermined magnitude is applied, while being suddenly decreased when an impact greater than the magnitude is applied.

Abstract: An optical disc apparatus, and a method of driving the same, includes a light focusing element disposed to focus light emitted from a light source onto a disc; an actuator to move the light focusing element toward or away from the disc according to a voltage applied to the actuator; a light intensity detection unit to detect the intensity of light reflected from the disc; a servo unit to generate a gap error signal and a third voltage, the third voltage being the sum of a first voltage and a second voltage, and to apply the generated third voltage to the actuator; and a control unit to control the servo unit to perform a gap pull-in operation when the light focusing element is moved toward the disc according to the gap error signal and the third voltage.

Abstract: An apparatus to acquire 3-dimensional geographical information of an underground pipe includes an in-pipe transfer unit which moves along the inside of the underground pipe, a sensing unit which senses 3-dimensional location information of the in-pipe transfer unit, and an information storage unit which stores a value measured by the sensing unit. Accordingly, the depth at which the underground pipe is located as well as 2-dimensional location information of the underground pipe is stored in the information storage unit so that maintenance and repair of the underground pipe can be carried out with greater efficiency.

Abstract: A gap pull-in method that minimizes overshoot due to a moving speed of a light focusing element and disturbance of a disk when the light focusing element is converted from an open loop state to a closed loop state during a gap pull-in of a near-field optical disk driver, and an optical disk driving apparatus using the method, the gap pull-in method including: generating an inverse actuator driving signal having a pulse duration and a pulse amplitude according to a moving speed of a light focusing element when an open loop state is changed to a closed loop state in the gap pull-in; and driving an actuator using the inverse actuator driving signal.

Abstract: A gap servo control method and apparatus for increasing a disturbance cancellation capability and decreasing the occurrence of an overshoot in a near-field optical disc drive include: generating an actuator driving signal of a transient response process by using a signal obtained by removing a disturbance contained in the gap error signal using a first band when a level of a gap error signal reaches a first level; and generating the actuator driving signal of the transient response process by using a signal obtained by removing the disturbance contained in the gap error signal using a second band when the level of the gap error signal reaches a second level.

Abstract: Disclosed herein is a multi-layerd light diffusion plate, in which the multi-layered light diffusion plate is manufactured by coextruding a transparent layer comprising an amorphous transparent thermoplastic resin and a light diffusion layer comprising an amorphous transparent thermoplastic resin and transparent particles, so that the manufacturing process thereof is simple and efficient, and which has excellent light transmissivity and light diffusivity, high brightness, and high brightness uniformity, thereby improving viewing angle characteristics, and to a liquid crystal display device comprising the same.

Abstract: Provided are a patterned magnetic recording medium and a method of self servo writing in which servo information is written on the patterned magnetic recording medium. The patterned magnetic recording medium includes: a data sector including a plurality of magnetic recording regions spaced apart from one another, wherein the magnetic recording regions constitute a plurality of tracks which are each shaped like a ring; and a servo sector on which servo information regarding the tracks is capable of being written along the tracks, wherein only to a part of the tracks of the servo sector, servo information regarding the part of the tracks is written in the form of a physical servo pattern which is formed by physically patterning a magnetic recording layer.

Abstract: Provided are a patterned magnetic recording medium and a method of recording track information onto the patterned magnetic recording medium. The patterned magnetic recording medium includes: a data sector comprising a plurality of magnetic recording regions which are spaced apart from one another, wherein the magnetic recording regions constitute a plurality of tracks which are each shaped like a ring; and a servo sector comprising servo patterned regions and correction code regions, which are each provided on each of the plurality of tracks, wherein information regarding a track that is to be actually used in a hard disk drive (HDD) is recorded on a correction code region of at least one track of the plurality of tracks.

Abstract: An optical disc apparatus, and a method of driving the same, includes a light focusing element disposed to focus light emitted from a light source onto a disc; an actuator to move the light focusing element toward or away from the disc according to a voltage applied to the actuator; a light intensity detection unit to detect the intensity of light reflected from the disc ; a servo unit to generate a gap error signal and a third voltage, the third voltage being the sum of a first voltage and a second voltage, and to apply the generated third voltage to the actuator; and a control unit to control the servo unit to perform a gap pull-in operation when the light focusing element is moved toward the disc according to the gap error signal and the third voltage.

Abstract: There is provided a compact optical disc apparatus having a small footprint actuator. A tracking coil of a swing arm-type actuator is disposed substantially perpendicular to an arm and on the opposite side to an optical disc loading slot with respect to the line connecting the center of rotation of the optical disc to the center of swing movement of the actuator. A pair of permanent magnets are disposed such that they face the tracking coil and they are opposite in polarity. The tracking coil is disposed on both the permanent magnets such that the tracking coil straddles the boundary of the pair of permanent magnets.

Abstract: A disc type determining apparatus in a disc recording and reproducing apparatus in which vibrations generated by rotations of a disc occur in a focus and tracking control actuator includes an error gain adjusting unit, which adjusts an amplitude of a focus and tracking error in order to maintain a constant amplitude of the focus and tracking error; a loop gain adjusting unit which compares the closed loop phase of the focus and tracking control loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking control loop; a vibration measuring unit which measures vibrations using the adjusted error and the output of a controller; and a disc type determining unit which extracts a predetermined signal to determine the type of a disc using the measured vibrations, measures the deflection, eccentricity, and mass eccentricity of a disc using the extracted signal.

Abstract: The present invention relates to a heat resistant light diffusion blend composition, and more precisely, a heat resistant light diffusion blend composition which is composed of a substrate resin prepared by blending styrene-maleic anhydride copolymer resin and polymethylmethacrylate resin and a light-diffusing agent composed of acrylic organic particles with a mean diameter of 1˜20 ?m alone or together with silicon organic particles with a mean diameter of 0.5˜20 ?m. Therefore, the heat resistant light diffusion blend composition of the present invention not only has high diffusivity and brightness but also excellent heat resistance, dimensional stability and mechanical properties with a low water absorption rate, so that this composition can be effectively used as a light diffusion plate and also be applied to a backlight for LCDs, lighting apparatus, signboards or glass showcases.

Abstract: A vibration quantity measuring apparatus and method, and a loop design method in which a vibration quantity generated in a focus and tracking loop is accurately measured to optimally design a focus and tracking loop of an optical disc drive. The vibration quantity measuring apparatus includes an error gain adjusting unit which adjusts an amplitude of a focus and tracking error which occurs where a disc rotates, so as to maintain the amplitude of the focus and tracking error constant, a loop gain adjusting unit which compares a closed loop phase of a focus and tracking loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking loop to compensate for a gain difference of an actuator, and a measuring unit which calculates and outputs a vibration quantity using an error adjusted by the error gain adjusting unit and the loop gain adjusting unit, and an output of a controller which controls a focus and tracking of the disc.

Abstract: A vibration quantity measuring apparatus and method, and a loop design method in which a vibration quantity generated in a focus and tracking loop is accurately measured to optimally design a focus and tracking loop of an optical disc drive. The vibration quantity measuring apparatus includes an error gain adjusting unit which adjusts an amplitude of a focus and tracking error which occurs where a disc rotates, so as to maintain the amplitude of the focus and tracking error constant, a loop gain adjusting unit which compares a closed loop phase of a focus and tracking loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking loop to compensate for a gain difference of an actuator, and a measuring unit which calculates and outputs a vibration quantity using an error adjusted by the error gain adjusting unit and the loop gain adjusting unit, and an output of a controller which controls a focus and tracking of the disc.

Abstract: A disc type determining apparatus in a disc recording and reproducing apparatus in which vibrations generated by rotations of a disc occur in a focus and tracking control actuator includes an error gain adjusting unit, which adjusts an amplitude of a focus and tracking error in order to maintain a constant amplitude of the focus and tracking error; a loop gain adjusting unit which compares the closed loop phase of the focus and tracking control loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking control loop; a vibration measuring unit which measures vibrations using the adjusted error and the output of a controller; and a disc type determining unit which extracts a predetermined signal to determine the type of a disc using the measured vibrations, measures the deflection, eccentricity, and mass eccentricity of a disc using the extracted signal.