Abstract: A four-axial driving actuator for an optical pickup with improved bobbin dynamic characteristics, in which the winding starting ports for a focus coil, tracking coil, and tilt coil are separate from one another, and the winding end ports thereof are combined as a common ground. The four-axial driving actuator includes: a base; a holder fixed on the base; a bobbin to which an objective lens is fixed; spring wires connected between the bobbin and the holder; and a magnetic driving unit driving the bobbin in the focus, track, or tilt direction with a focus coil, a tracking coil, and a tilt coil, wherein the magnetic driving unit comprises a circuit unit including winding starting ports for the focus coil, tracking coil, and tilt coil, and a common ground port at which winding end ports for the focus coil, tracking coil, and tilt coil are grounded, and the circuit unit applies a voltage to the tracking coil, tracking coil, and tilt coil.

Abstract: An adaptive interference suppression receiver for a DS/CDMA system includes: input signal generators outputting a part of received signals of receiver antennas that has a coding block's transfer code; adaptive filter blocks filtering a complex signal output from the input signal generators with a tab weight updated based on a constraint MMSE criterion and estimating phase and amplitude components of a specific user channel using the filtering output signal to generate a channel-estimated signal; a signal restorer combining the channel-estimated signal and the filtering output signal and restoring an original signal; a signal selector for selecting known training data signal or the restored signal; and error generators comparing the channel-estimated signal and the filtering output signal and calculating an error between the two signals.

Abstract: A disc cartridge includes a case accommodating a disc and having an aperture hole formed on a first surface of the case so that a recording/reproducing apparatus access a recording surface of the disc, and an open hole formed on a second surface to be open to an outside of the case, a shutter opening/shutting the aperture hole and installed in the case, a disc holder installed at a side defining the open hole to move up and down and covering a gap between an outer circumference of the disc and an inner surface of the side defining the open hole when the disc holder descends, and a shutter driving mechanism moving the shutter so that the aperture hole is open/shut. Thus, a passage through which dust is introduced toward an information area of the disc, and a gap formed at an outer circumference are blocked by the disc holder so that a possibility of contamination by dust can be reduced.

Abstract: A frictional variable transmission for a vehicle comprising a rotating unit rotated by an engine of the vehicle; a power-varying unit that varies, in a state of contacting the rotating unit, a rotational force transmitted from the rotating unit 21 by moving in a predetermined direction; a hydraulic clutch mounted off-center from the rotating unit, and varying between states of frictional contact with or separation from the power-varying unit by hydraulic pressure generated according to a depressed state of a clutch pedal, thereby controlling the transmission of rotational force of the power-varying unit; and a power transmitter linked to the movement of the hydraulic clutch, and transmitting a rotational force corresponding to an input state of rotational force transmitted through the rotating unit and the power-varying unit.

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: A disk cartridge includes a lower case having an opening formed thereon, an upper case installed at the lower case to be capable of being open and shut while pivoting, to accommodate a disk therebetween, a shutter installed at the lower case to be capable of sliding and opening and shutting the opening hole, a close covering member having an inclined surface installed at the shutter to be capable of sliding, closely contacting a non-information area disposed at an inner circumference of the disk when the shutter is closed, and being separated from the non-information area disposed at the inner circumference of the disk when the shutter is open. Thus, when the shutter is closed, introduction of dust is prevented so that the possibility of the information area of the disk being contaminated is lowered. Also, since the disk is fixed between the upper and lower cases, while the disk is carried, noise and damage can be reduced.

Abstract: A method of fabricating a thermoelectric element of enhanced thermoelectric performance is provided by improving the preparation of thermoelectric material and employing hot plastic working in combination. The method comprises the step (a) of mixing and heat-melting a raw material of a predetermined composition; the step (b) of turning the heat-melted material 106 into microglobules by either of scattering and spraying, and then quenching the microglobules, thereby providing a globular powdery thermoelectric material; and the step (c) of plastically deforming the thermoelectric material in a hot condition, thereby to bring crystal grains of the thermoelectric material into a crystal orientation affording an excellent figure of merit.

Abstract: A disk cartridge includes a case accommodating a disk, a cover installed at the case to be capable of being open and shut and having a hole formed thereon to be open to an outside of the cover, a shutter installed under the disk in the case to be capable of moving to open and shut an opening formed on the case, and a clamping member installed at the cover to seal the hole to clamp the disk. Thus, since the clamping member blocks the hole of the cover connected to the outside of the cover, possibility of intrusion of dust into the disk cartridge is reduced. Also, since there is no need to install the clamping member at the disk drive, the disk drive can be made simplified and slim.

Abstract: A disk cartridge includes a case which receives a disk thereon, a cover which is installed on the case and includes an opening, and a shutter which is movably installed in the case, in a lower direction of the disk, to open and close an aperture formed on the case. The disk cartridge has guide holes formed on the case along a trace of the shutter, and support members formed on the shutter. The support members are guided along the guide holes while having ends thereof interfering with peripherals of the guide holes. Therefore, since the peripherals of the guide holes interfere with the ends of the support members, the shutter is prevented from being deformed even where an external force is applied to the shutter through the aperture, in a closed state of the shutter.

Abstract: A micro actuator for moving a head device in a track direction of a recording medium by a magnetic force generated between the magnetic cores. In normal use, the micro actuator is mounted on an actuator arm which pivots in a track direction across a track of the recording medium. The slider moves above the recording medium and has an accommodating portion facing the recording medium. A first magnetic core is arranged to move in the accommodating portion, for supporting the head device. A second magnetic core, separated a predetermined distance from and facing the first magnetic core, is installed in the accommodating portion such that the center of the first magnetic core in a magnetic direction, which is perpendicular to the track direction and horizontal with respect to the surface of the recording medium, is offset from the center of the first magnetic core.

Abstract: A disk cartridge includes a case to accommodate a disk, and a shutter installed in the case to move under the disk, and to selectively open/shut an opening hole formed in the case. The disk cartridge includes a support portion to protrude from the shutter to support a non-information area of the disk. Thus, since the shutter contacts only the non-information area of the disk, the information area of the disk is protected during an operation of the shutter to open and shut the opening hole.

Abstract: A disk cartridge includes a case accommodating a disk and having a first hole, a cover installed at the case and having a second hole open to an outside of the cover, a shutter installed to be capable of moving with respect to the case disposed under the disk to open/shut the first hole formed on the case, and a plurality of protruding portions provided at the shutter to support a non information area provided at an outer circumferential side of the disk and having inclined surfaces inclined at a predetermined angle. When the shutter is opened, the disk descends along the inclined surfaces. When the shutter is shut, the disk ascends along the inclined surfaces to closely contact a portion of the cover disposed around the second hole of the cover. Thus, since the shutter contacts only a non-information area of the disk, an information area of the disk can be safely kept from being damaged during an operation of opening/shutting the first hole.

Abstract: A swing arm driving type optical recording/reproducing apparatus includes a base, at least one optical disk rotatably installed on the base, both sides of which are information recording surfaces and a plurality of optical pickups which are equal in number to the information recording surfaces so as to form light spots on the respective information recording surfaces of the optical disk. Each optical pickup includes a light source for irradiating light. The apparatus also includes optical path changing units respectively arranged on optical paths between the light sources and respective ones of the information recording surfaces for changing the traveling paths of the lights and objective lenses arranged between the optical path changing units and the respective information recording surfaces for condensing incident light on the respective information recording surfaces.

Abstract: A pickup actuator capable of significantly reducing rolling of the area, including: a pickup base, a lens holder having an objective lens mounted thereon, and lens holder driving means for driving the lens holder in directions for focusing and tracking on the pickup base. The lens holder driving means includes at least one magnet, a yoke for concentrating the magnetic flux of the magnet in the direction of the magnetic flux, and a driving coil having a focusing coil and a pair of tracking coils positioned between the magnet and the yoke. The respective widths of the magnet and the yoke are set at a rate of 1:0.8-1.2. Accordingly, the uniform magnetic flux area of the magnetic flux can be widely distributed in the width's direction of the yoke.

Abstract: A disk clamping apparatus for a disk player includes a turntable for receiving a disk, a disk clamper which clamps the disk placed on the turntable, and first and second magnetic bodies which are mounted in the corresponding turntable and the disk clamper and provide a clamping force to the disk by acting a reciprocal magnetic force on the turntable and the disk clamper. The first and second magnetic bodies are opposite to each other and partially overlap each other. In the disk clamping apparatus having the above structure, the variation in a clamping force caused by the variation in thickness of disks, received by the disk clamping apparatus, is very small. Accordingly, clamping and de-clamping of the disks having different thickness can be smoothly performed.

Abstract: An actuator for an optical pickup having a base on which a holder is fixed, a bobbin, a support member, and a magnetic circuit. A plurality of installation holes are formed in the bobbin such that a plurality of objective lenses to record and/or reproduce optical discs having different recording densities are installed at different heights. The support member has one end coupled to the bobbin and the other end coupled to the holder movably supports the bobbin. The magnetic circuit drives the bobbin in focusing and tracking directions. The magnetic circuit is divided into a first magnetic circuit to drive the objective lenses in the focusing direction, and a second magnetic circuit to drive the objective lenses in the tracking direction, thereby reducing the weight of a moving portion.

Abstract: A high density disc having a data area which is set such that compatibility is secured in the same drive while maintaining a superior recording and/or reproducing feature. The high density disc has a center hole, a clamping area, a data area where user data is recorded, a lead-in area located at the inner side of the data area, and a lead-out area located at the outer side of the data area. In the high density disc in which the diameter of the center hole is 10 mm or more, the inner diameter of the clamping area is characteristically within a range of 20-26 mm. Also, the inner diameter of the data area is characteristically within a range of 35-40 mm. Therefore, while a conventional disc drive is still used, the size of the high density disc decreases and a recording capacity can be increased.

Abstract: An apparatus and method for reducing a pattern jitter is provided that uses a local symmetry forcing wave signal. Pattern jitter is generated when a timing phase of a symbol signal is recovered. The apparatus can include a demultiplexer receiving a preamble and data signal. A nonlinear operation unit preferably only receives the preamble signal from the demultiplexer, and a locally symmetric wave generator preferably only receives the data signal from the demultiplexer. A buffer memory selects from an output signal of the nonlinear operation unit and an output signal of the locally symmetric wave generator. An input signal controller receives a control signal and outputs an input control signal to control the buffer memory and the demultiplexer. The apparatus and method that reduces pattern jitter is a system with reduced complexity and reduced cost to advantageously embody a very large scale integration VLSI or the like.

Abstract: A disk cartridge has a reflection portion to identify a kind of a disk in the disk cartridge. A disk drive apparatus has an optical detector to identify the kind of the disk by irradiating a beam to the reflection portion and detecting the reflected beam. The disk cartridge and the disk drive apparatus provide identification marks for identifying the kind of the disk by varying the angle and amount of a beam reflected from the reflection portions on the disk cartridge. Therefore, the kind of a disk and the type of a disk format are identified as well as the storage capacity of the disk.

Abstract: A compact high-density optical disc capable of securing recording/reproducing characteristics and high-density recording capacity. The high-density optical disc has a whole diameter of 80 mm or less to 28 mm, a whole thickness in a range of 0.3-0.7 mm, and a position where data starts being recorded in a range of 27-45 mm of the diameter. Thus, an existing disc drive can be used, the size of the high-density optical disc can be reduced, and high-density recording capacity can be secured.