Abstract: An optical pickup device includes a light source for generating light, a light path changing means for changing the traveling path of incident light, an objective lens for focusing incident light to form a light spot on a recording medium and having an incidence region of a predetermined size, a tracking mirror disposed on the light path between the light path changing means and the objective lens, for reflecting incident light emitted from the light source so that the light spot traces proper track positions of the recording medium, a lens unit consisting of at least two lenses which allow the light reflected from the tracking mirror to be incident on the incidence region of the objective lens, and a photo detecting unit for receiving light reflected from the recording medium and having passed through the objective lens and the light path changing means.

Abstract: An optical scanning apparatus for performing scanning by focusing a beam scattered by a bubble which moves at a predetermined speed within a closed loop fluid pipe, thereby forming an image. The optical scanning apparatus includes a light source for emitting light; a closed loop fluid pipe; a fluid contained in the fluid pipe, transmitting the light emitted from the light source; at least one bubble contained in the fluid pipe, scattering incident light; a pump installed at one side of the fluid pipe, circulating the bubble at a predetermined speed; and an image formation lens focusing the light emitted by the light source and scattered by the at least one bubble to form an image on a predetermined scanning line. Accordingly, the volume of the optical scanning apparatus can be reduced, and the optical scanning apparatus can be easily manufactured. Consequently, productivity can be increased.

Abstract: A disc balancing device and a method thereof. The disc balancing device includes a disc assembly having a driving source, and a disc rotatably disposed at the driving source, a displacement measurement unit measuring vibration in the rotation of the disc assembly, a phase angle measurement unit measuring a phase angle from a reference point of the disc assembly in the rotation of the disc assembly, an operation/control unit calculating an eccentric mass and an eccentric position of the disc assembly, by using the biased vibration measured in the displacement measurement unit and the phase angle measured in the phase angle measurement unit, and a laser cutter tracking and laser-cutting the side portion of the disc corresponding to the eccentric position according to the information from the operation/control unit, whereby the eccentric mass of the disc assembly is balanced to reduce vibration in the rotation.

Abstract: A variable capacitor and a memory device employing the same. The variable capacitor includes a first electrode formed above a substrate; a second electrode suspended with respect to the first electrode to be moved back and forth with respect to the first electrode; and an actuator for varying a capacitance. One end of the actuator is connected to the second electrode and mounted with respect to the substrate to move the second electrode with respect to the first electrode in accordance with a voltage signal input through a driving electrode exposed externally. The memory device includes a transistor having a source, a gate, and a drain formed above a substrate, which are spaced apart from each other, a capacitor connected to the source, and an actuator varying a capacitance of the capacitor.

Abstract: A PCMCIA card type recording apparatus includes a housing having a seating section on which a disk cartridge is seated, a disk driving section disposed in the housing to rotatably drive a recording medium in the disk cartridge seated on the seating section, a recording/reproducing unit disposed in the housing to record and reproduce data with respect to the recording medium, and a protection cover disposed at the housing to cover and protect the disk cartridge.

Abstract: A projection type image display apparatus includes a light source emitting light, a polarization device transmitting light polarized in one direction of incident light emitted from the light source, a reflection type image generating unit generating a color image from incident light and reflecting the generated color image to proceed along a path different from a path of the incident light, a light deflection device deflecting the image reflected by the image generating unit, and a projection lens unit magnifying and transmitting the image generated by the image generating unit and deflected by the light deflection device to proceed toward a screen. Thus, a full color can be realized with respect to the area of a pixel, and an efficiency in use of light and resolving power can be improved.

Abstract: A swing-arm type optical recording and reproducing apparatus and an optical disk applicable to the same. The optical disk includes a substrate having an information recording surface to record and reproduce an information signal, and a protective layer which is provided on the information recording surface and whose surface facing a slider is a flat even surface so that variations in a floating height of the slider can be reduced.

Abstract: A projection-type image display apparatus having a structure adapted so that the efficiency of the use of light and resolving power thereof can be enhanced is disclosed.

Abstract: An optical pickup includes a light source emitting a laser beam and an optical path changing unit altering a traveling path of an incident beam. An objective lens, disposed on an optical path between the optical path changing unit and an optical disk, focuses the incident beam from the light source to form a light spot on the optical disk of the objective lens. The optical pickup further includes a photodetector and an detecting-correcting unit, arranged on the optical path between the optical path changing unit and the objective lens, performing at least one of detecting the thickness of the optical disk and correcting aberration caused by thickness variations of the optical disk. The objective lens includes a first transmitting portion divergently transmitting an incident beam, where the first transmitting portion is at a relatively near-axis region from an optical axis of the objective lens.

Abstract: A data coding method of an optical disk having a dual spiral track including a first spiral and a second spiral which are disposed adjacent to each other and on which information can be simultaneously recorded. The data coding method includes the steps of utilizing a quaternary form depending on whether pits are formed or not on the first spiral and the second spiral, respectively, and using a modulated code for 8 bit—8 bit nonreturn-to-zero-inverted (NRZI) recording; and converting the 8-bit units into 10 channel bit units by adding 2 channel merging bits between the 8-bit units, and using a run-length-limited (RLL) code in which the minimum run of '0' data bits is 2.

Abstract: A master disk used in the manufacturing of optical disks and having a substrate and a photoresist layer coated on the substrate. The method for manufacturing the master disk includes the steps of: coating a first photoresist layer on a substrate; exposing the first photoresist layer according to patterns of a groove formation recess and a land formation protrusion corresponding to a groove and a land, respectively; etching the exposed substrate and the first photoresist layer, to thereby form the groove formation recess and the land formation protrusion on the substrate; coating a second photoresist layer on the substrate, to thereby form the groove and the land at positions corresponding to the groove formation recess and the pit formation protrusion, respectively; exposing the second photoresist layer according to a pattern of a pit where predetermined information is recorded; and etching the second photoresist layer, to thereby form the pit on the groove and the land.

Abstract: A method of initializing a phase transformation-type optical disk. The initialization method includes the steps of: (a) preparing a phase transformation-type optical disk in which a first dielectric layer, a recording layer including a small amount of crystalline structure in a major amorphous structure, a second dielectric layer and a reflective layer are sequentially deposited on a substrate; (b) irradiating a high power laser beam, which is enough to heat the recording layer to a temperature above its melting point, onto the optical disk, thereby transforming the crystalline structure in the recording layer into an amorphous structure; and (c) irradiating a lower power laser beam, which is capable of heating the recording layer to a temperature range above a recrystallization temperature and below its melting point, onto the optical disk, thereby transforming the amorphous structure of the recording layer into the crystalline structure.

Abstract: A master disk exposure device capable of projecting varying sized laser beams on a master disk, includes a slider for moving an optical fiber in a radial direction along the surface of a master disk. The optical fiber projects a beam emitted by a beam generator. The beam is passed through a shutter intermittently before being focussed by a focus lens once focused the beam is projected by the optical fiber onto the recording surface of the master disk.

Abstract: An optical recording medium manufacturing apparatus includes transfer means, a substrate transfer table transferred by the transfer means at a predetermined speed, a drum facing the substrate transfer table and rotating so that the speed of its outer circumferential surface is the same as the speed of a substrate transfer table, a stamp installed on the outer circumferential surface of the drum forming an information recording pit pattern, and resin supply means for injecting molten resin between the stamp and the substrate supported on the table. Since a multi-layer unit can be molded continuously by using the molten resin according to the present invention, there is the advantage of improved productivity.

Abstract: A multi-layer optical recording medium manufacturing method and apparatus thereof forms a resin layer having a second recording layer on a first recording layer. The first recording layer includes a reflecting layer and a first recording layer sequentially formed on a transparent substrate. The multi-layer optical recording medium manufacturing apparatus includes an upper and a lower mold on which is respectively fixed the transparent substrate and a stamp such that they are facing each other. Communicating holes formed in the transparent substrate and the stamp are formed in center portions of each of the molds. A punch member capable of vertical movement is established in the communicating hole of the lower mold, and resin supply established in the communicating hole of the upper mold. The above apparatus has the advantage of improving productivity of the manufacture of a multi-layer optical recording medium.

Abstract: An optical tape cassette and a player for using the cassette. The optical tape cassette includes a drum on which optical tape is wound and two tape reels for supplying and winding the tape. The cassette player includes a driver having two rotating members which can be connected to the drum and tape take-up reel for driving the drum and tape take-up reel, respectively, and an optical pickup for projecting a light beam onto the optical tape which is wound about the periphery of the drum, thereby realizing a simplified structure and easy handling for home use.

Abstract: A dual disc recording/reproducing apparatus and recording method. The apparatus includes a reproducing deck unit and a recording/reproducing deck unit with both being controlled by one control unit. The method comprises the steps of recording on a disc a first program and a disc playing time on the lead-in area thereof unless data is recorded on the disc, recording the data onto the next recording area of the lead-out area if data is already recorded on the disc, and then recording the lead-out to process a present lead-out area as a bad block area. The next step is recording a new lead-out at the end of the disc playing time, and then processing the previous and next blocks, including the present lead-out area, as a bad block during the recording of the data, processing the previous and next blocks, including the lead-in area, as a bad block, and then recording the data in the program memory area onto a new lead-in area.

Abstract: A method and apparatus for fabricating a read only optical disc enables mass production of a read only optical disc at low cost in a short period of time. The method includes a source disc fabricating step and a duplicating step of duplicating information of the source disc to a target disc. The source disc has a transparent substrate and a predetermined opaque write layer coated thereon, and write holes for transmitting light on the write layer, thereby storing information according to the arrangement of the write holes. The target disc has a photochromic write layer which has different absorption coefficients before and after the duplication. Here, the method uses an optical writing apparatus for optically forming the write holes of the source disc and a duplicating apparatus for optically duplicating the information from the source disc to the target disc.