Abstract: A laser scanning unit includes a light source for emitting a plurality of laser beams, a rotating polygon mirror for deflecting the plurality of laser beams in a predetermined direction, an f? lens for transmitting the deflected laser beams to be scanned onto the surfaces of a plurality of photosensitive drums, and a beam splitter disposed at a rear end of the f? lens for splitting the laser beams. The laser scanning unit may be used for a tandem image forming apparatus.

Abstract: A beam detector includes a beam detection sensor to receive a light beam emitted from a light source of a light scanning unit and to generate a synchronous signal, a slit member having a slit formed therein to control a time to generate the synchronous signal of the beam detection sensor by adjusting an amount of the light beam received by the beam detection sensor, and a holder in which the slit member is installed. The slit is extended in a vertical direction and, a pair of surfaces form the slit and face each other, one of the pair of surfaces at which a scanned light beam arrives first is inclined in the vertical direction.

Abstract: A laser beam generating apparatus of a laser scanning unit, including: a laser diode; a collimate lens for converting a laser beam emitted from the laser diode to a parallel light; a collimate lens holder for disposing the collimate lens on an optical axis of the laser beam; a base for mounting the laser diode and the collimate lens holder thereon; and a supporting means formed on the base to provisionally fix the collimate lens holder. Since a dedicated implement complements an ultraviolet (UV) bond to provisionally fix the collimate lens holder in the calibration position, assembling errors can be prevented although the UV bond changes in volume while being hardened, thereby improving productivity and quality of goods.

Abstract: A multibeam laser scanning apparatus which can easily align the positions of a plurality of laser beams, thus improving workability and productivity. The multibeam laser scanning apparatus comprises a multibeam light source unit which has a diode unit including a laser diode emitting a plurality of laser beams, a rotating member for supporting the diode unit, and a fixing member for rotatably supporting the rotating member. The rotating member is turned at a predetermined angle to align the positions of the plurality of laser beams and is fixed to the fixing member. The positions of laser beams are aligned in a sub-assembly line for assembling the multibeam light source unit. The assembled multibeam light source unit is simply mounted into a frame in the main assembly line for completing the assembly of a laser scanning apparatus.

Abstract: A multi-beam laser scanning unit capable of increasing assembly efficiency and productivity by making easy position alignment between a plurality of laser beams. The multi-beam laser scanning unit according to an embodiment of the present invention comprises a laser diode unit for discharging a plurality of laser beams, a rotational member for supporting the diode unit and rotating to a substantially aligned position between a plurality of the laser beams, a fixing member for supporting the rotational member in a rotatable manner, a temporary joining part for maintaining joining status between the rotational member and the fixing member in such a way that the rotational member easily rotates but cannot move very well at the rotated position once rotated when the rotational member rotates for position alignment between a plurality of the laser beams, and a fixing part for fixing the rotated rotational member to the fixing member.

Abstract: A multi-beam laser scanning unit includes a plurality of laser diodes to emit laser beams, and a rotary polygon mirror to deflect the laser beams emitted from the plurality of laser diodes in a scan direction of a photoconductive medium. The plurality of laser diodes are arranged in a line so that a connecting line of focal points formed by the laser beams forms a vertical line or substantially a vertical line on the photoconductive medium. The multi-beam laser scanning unit may further include a plurality of delay circuits connected to the laser diodes to delay a beam emission time of a first-emitted laser beam among the plurality of laser beams emitted from the laser diodes.

Abstract: A compression ratio of an engine is varied by changing a position of a crankshaft relative to a piston in accordance with an operational condition of the engine.

Abstract: A plurality of slits are formed on an interior circumference of a piston ring, such that a piston ring can be easily mounted to a piston, and a piston ring mounted with such a piston ring may be easily installed in a cylinder. Additionally, such a piston ring maintains contact to an interior wall of a cylinder during cylinder bore deformation.

Abstract: A compression ratio of an engine is varied by changing a position of a crankshaft relative to a piston in accordance with an operational condition of the engine.