Patent ID: 6596985
Filing Date: 2003-07-22
Classification: G02B

Abstract:
A multi-beam scanning device comprising:a semiconductor laser array having a plurality of light emitting parts emitting multiple laser beams; a rotary deflector deflecting the laser beams emitted by the light emitting parts of the semiconductor laser array; and a focusing optical system focusing the deflected laser beams from the rotary deflector onto a scanned surface to form a plurality of beam spots that are separated on the scanned surface in a sub-scanning direction, the scanned surface being scanned simultaneously with the plurality of beam spots in a main scanning direction by a rotation of the rotary deflector, wherein the laser array is configured such that the light emitting parts are arrayed along a line that is at an inclination angle &phgr; to the sub-scanning direction, the inclination angle &phgr; measured in degrees and meeting the conditions 0&lE;&phgr;<90, and that a scanning line pitch P, an array pitch &rgr; of the light emitting parts of the laser array and a parameter K defined by the equation K=0.82&lgr;/&ohgr;z, â€ƒwhere &lgr; is a wavelength of the emitted laser beams and &ohgr;z is a target beam spot diameter in the sub-scanning direction, satisfy the following conditions: â€ƒ0.01/(&rgr;Â·cos &phgr;)<0.300.0110.030.