Patent ID: 6377293
Filing Date: 2002-04-23
Classification: F16C,G02B

Abstract:
A scanning unit of a laser printer comprising:a semiconductor laser diode for irradiating a laser beam; a collimator lens for making the laser beam, irradiated from the semiconductor laser diode, be parallel with an optical axis; a cylindrical lens for converting the parallel light passed through the collimator lens into a linear light which is in a horizontal direction with respect to a sub-irradiation direction; a polygon mirror for moving the linear light passed through the cylindrical lens at a constant linear velocity to perform a scanning operation; a scanning motor for rotating the polygon mirror at a constant velocity; a lens for forming an image, wherein the lens polarizes the linear light reflected by the polygon mirror in a main scanning direction and compensates a spherical aberration and focuses on a scanning face; a reflecting mirror, for reflecting perpendicularly the laser beam passed through the lens, for forming an image on a surface of a photosensitive drum; a horizontal synchronizing mirror for reflecting horizontally the laser beam passed through the lens, a light sensor for receiving the laser beam reflected by the horizontal synchronizing mirror so as to synchronize a point of time of forming the image on the photosensitive drum with a point of time of transferring a printing data; a cover for covering the polygon mirror and the scanning motor, wherein an inner portion of the cover is maintained in a vacuum state; and a rubber packing interposed between the cover and the housing of the scanning motor, and on at least a portion of an outer surface of the cover, for intercepting a noise; wherein the scanning motor is a magnetic bearing motor; and wherein the cylindrical lens is integrally formed on the cover, the cylindrical lens being disposed in an incidence course of the laser beam.