Abstract: A disc cartridge for receiving a disc includes a case which accommodates the disc and at least one centering spring which prevents deviation of the disc in the case. Thus, a gap in which the disc moves in the disc cartridge is restricted so as to reduce a length in which a disc clamp of the disc contacts a disc clamp guide inside a disc drive system. Accordingly, the height of the disc clamp is reduced so as to reduce the thickness of the disc cartridge and miniaturize the disc cartridge.

Abstract: A color synchronization method and a color laser printer form a color image by forming an electrostatic latent image on a photosensitive body using a laser scanning unit, developing the electrostatic latent image, and transferring the developed image onto a transfer belt. The printer includes a light source which radiates light, a timing belt which rotates the photosensitive body, a plurality of timing displays, which are provided on the timing belt at a constant interval, and on which the light radiated from the light source is incident, and a light receiving portion which detects the light reflected or transmitted by the timing displays. Synchronization for each color is controlled in response to a signal received by the light receiving portion.

Abstract: A tray locking apparatus of a disc drive to lock a tray on which a disc is accommodated and which is inserted into a main body of the disc drive. The tray locking apparatus includes a locking pin provided at the main body, a locking lever rotatably installed at the tray and having a hook portion at one end thereof which is caught by the locking pin as the tray is inserted into the main body, an elastic member to elastically bias the locking lever in the direction in which the hook portion is caught by the locking pin, a driving mechanism to rotate the locking lever to escape from a position where the hook portion is caught by the locking pin when the tray is drawn, and a counter impact unit installed adjacent to the locking lever and having a moment to rotate in a direction opposite to that of the locking lever, so that when the locking lever is rotated by an impact in a direction to be unlocked, the counter impact unit rotates in the opposite direction and bumps against the locking lever.

Abstract: An optical disc drive that includes a driving unit including a spindle motor to rotate an optical disc, an optical pickup to access the optical disc, and a connection board connected to a computer. A control board to control the driving unit, is installed at an interface device of the computer, separate from the driving unit, and is connected to the connection board.

Abstract: A disc cartridge having a case to accommodate a disc, a shutter to open or close an opening formed in the case to enable a recording and/or reproducing job with respect to the disc, a discharge path provided at one side of the case to allow the flow of air formed therein during rotation of the disc, and an opening/closing mechanism to open/close the discharge path. Thus, since the discharge path through which the flow of air produced inside the cartridge during rotation of a disc is smoothly discharged to the outside is provided, contamination of the disc by foreign material such as dust can be considerably reduced.

Abstract: An actuator of a disc drive having a shock damping device includes an electro-magnet disposed on a cover of the disc drive, a magnetic material disposed on a load beam of the actuator, opposite to the electro-magnet, and a driving control portion controlling a driving of the electro-magnet by detecting an vibration of the load beam towards and away from an optical disc that is caused by an external shock. When the load beam is vibrated by the external vibration or shock to the disc drive, electricity is supplied to the electro-magnet, securing the load beam to the cover until the vibration ceases. Accordingly, even when there is external vibration or shock applied to the disc drive, possible damage to the disc or the actuator can be minimized or prevented.

Abstract: A latch type solenoid switch including a frame, a permanent magnet providing magnetic force to the frame, a coil unit which offsets the magnetic force of a permanent magnet when power is supplied, and a moving part which adheres to and detaches from the frame depending on the power supply to the coil unit. Anti-corrosion coating is applied to the surface of the frame and the moving part. The plating thickness on the contact surfaces between the frame and the moving part is thinner than on the other surfaces of the two bodies.

Abstract: An optical disk drive includes a case, a tray which is slidably provided to the case and receives an optical disk, and a ground member which is electrically connected to the case and contacts one side of the optical disk as the tray slides in or out of the case. In the optical disk drive, by removing a static electricity remaining on the optical disk through the ground member, where the tray is loaded, foreign materials such as dust can be prevented from adhering to the optical disk. Accordingly, a stable and accurate optical signal processing can be guaranteed, thereby improving the reliability of the optical disk drive and the optical disk.

Abstract: A disk drive including a spindle motor rotating a disk, a pickup unit accessing the disk, a frame where the spindle motor is installed, and a vibration absorber installed on the frame to absorb vibrations due to rotation of the disk, that vibrates in a direction in which an exciting force is offset in horizontal and vertical directions with respect to the frame. Thus, as the vibration absorber vibrates in response to vibration of the frame, in a direction to offset the vibration if the frame, the vibration of the frame can be reduced.

Abstract: A color synchronization method and a color laser printer form a color image by forming an electrostatic latent image on a photosensitive body using a laser scanning unit, developing the electrostatic latent image, and transferring the developed image onto a transfer belt. The printer includes a light source which radiates light, a timing belt which rotates the photosensitive body, a plurality of timing displays, which are provided on the timing belt at a constant interval, and on which the light radiated from the light source is incident, and a light receiving portion which detects the light reflected or transmitted by the timing displays. Synchronization for each color is controlled in response to a signal received by the light receiving portion.

Abstract: A color laser printer producing a color image using a single laser scanning unit includes a lighting unit including first and second laser diodes emitting beams of one polarization, a polarization prism transmitting or reflecting incident beams depending on a direction of polarization, and third and fourth laser diodes disposed in a different direction from the first and second laser diodes with respect to the polarization prism, a rotary polygon mirror that reflects the beam emitted along the same path from the lighting unit, an f-&thgr; lens that focuses the beam reflected by the rotary polygon mirror, first and second polarization beam splitters, each of which transmits or reflects the beam passing through the f-&thgr; lens depending on the direction of the polarization, and first through fourth photoconductive units on which the beams reflected and transmitted through the first and second polarization beam splitters are incident.

Abstract: A disc cartridge having a disc to record information and a case to accommodate the disc includes a cleaning unit installed inside the case and selectively contacting or being separated from the disc depending on a flow of air generated during a rotation of the disc, so that the cleaning unit removes foreign material adhering to a surface of the disc when contacting the disc. Since cleaning is automatically performed depending on the flow of air, inconvenient manual operation is not necessary. Furthermore, since the cleaning unit does not deviate from a disc area, miniaturization of the disc cartridge or disc recording and reproducing apparatus is possible.

Abstract: A tray guide mechanism for an optical disc drive guides a backward and forward movement of a tray installed to slide into and out of a housing made of a lower case and an upper case. The tray guide mechanism includes guide rails installed to slide into and out of both sides of the upper case, a guide rail supporting unit installed at both sides of the lower case, to prevent the guide rails from deviating from a backward and forward moving path, and rail combiners formed at both sides of the tray in a moving path of the tray, and combined with the guide rails to slide into the guide rails. The tray guide mechanism also includes a forward moving distance limiting unit to limit a moving distance of the tray and the guide rails in a direction to which the tray and the guide rails project to prevent the tray from detaching from the housing. The tray guide mechanism also includes vertical and horizontal restrainers to prevent vertical and horizontal movement of the tray.

Abstract: A tray locking apparatus of a disc drive to lock a tray on which a disc is accommodated and which is inserted into a main body of the disc drive. The tray locking apparatus includes a locking pin provided at the main body, a locking lever rotatably installed at the tray and having a hook portion at one end thereof which is caught by the locking pin as the tray is inserted into the main body, an elastic member to elastically bias the locking lever in the direction in which the hook portion is caught by the locking pin, a driving mechanism to rotate the locking lever to escape from a position where the hook portion is caught by the locking pin when the tray is drawn, and a counter impact unit installed adjacent to the locking lever and having a moment to rotate in a direction opposite to that of the locking lever, so that when the locking lever is rotated by an impact in a direction to be unlocked, the counter impact unit rotates in the opposite direction and bumps against the locking lever.

Abstract: A tray locking apparatus of a disc drive to lock a tray on which a disc is placed and which is inserted into a main body of a disc drive. The tray locking apparatus includes a locking boss provided at the main body, a locking plate installed at the tray to slide and having a locking portion provided at one side thereof which is caught by the locking boss as the tray enters the main body, an elastic member to elastically bias the locking plate in a direction in which the locking portion is caught by the locking boss, and a driving mechanism to make the locking plate slide to be out of a position where the locking portion is caught by the locking boss when the tray is drawn. Thus, even when an external impact is applied, the locking state can be firmly maintained. Also, electric power consumed for the locking and unlocking operations is reduced.

Abstract: An optical pickup device includes a light unit for irradiating a light beam having a wavelength longer than 650 nm onto a recording medium and receiving and detecting a light beam reflected by the recording medium, and an objective lens formed of a single lens having an NA of 0.7 or more to form a light spot on the recording medium by condensing an incident light beam emitted from the light unit. A recording medium has a recording density of a DVD family or more and formed of a material suitable for a long wavelength of 700 nm or more so that a reproduction signal by a reflectance of a recording surface is optimized. Thus, a compact high density optical recording/reproducing apparatus which is inexpensive and has high performance can be realized.

Abstract: A disc cartridge having a case to accommodate a disc, a shutter to open or close an opening formed in the case to enable a recording and/or reproducing job with respect to the disc, a discharge path provided at one side of the case to allow the flow of air formed therein during rotation of the disc, and an opening/closing mechanism to open/close the discharge path. Thus, since the discharge path through which the flow of air produced inside the cartridge during rotation of a disc is smoothly discharged to the outside is provided, contamination of the disc by foreign material such as dust can be considerably reduced.

Abstract: A host apparatus includes an ultrasound receiving unit receiving an ultrasound signal from a pointing apparatus and outputting an electric signal. A controlling unit calculates a position of a pointer on a display screen corresponding to a position of the pointing apparatus based on the electric signal from the ultrasound receiving unit, and outputs a control signal to the display screen to position the pointer at the calculated position of the display screen.

Abstract: A disk cartridge is provided. The disk cartridge includes a case for containing a disk and a transparent window installed to seal the case. An external light accesses the disk through the transparent window of the disk cartridge. However, foreign matter such as dust is prevented from entering the disk cartridge.

Abstract: A key switch of a keyboard of the present invention includes a key cap and an elastic body which supports and allows the key cap to elastically move up and down. The elastic body is a band shaped structure and includes end portions which are pivotally supported above a substrate, a central portion bulged to contact a bottom surface of the key cap, and curved portions having a curvature opposite to that of the central portion disposed between corresponding ones of the end portions and the central portion. The curved portions of the elastic body are deformed at a position lower than an upper surface of the substrate. Therefore, the overall height of the key switch can be reduced, allowing for the manufacture of a slimmer keyboard unit.