| 摘要 |
PROBLEM TO BE SOLVED: To provide an exposure device which can be utilized for a high-speed color printer, which is large-sized and which is constituted so that the degree of the freedom of an image forming part is high with respect to the exposure device constituted so that plural light beams are used for scanning. SOLUTION: This exposure device includes an image forming system consisting of three first to third glass-made image forming lenses 23, 25 and 27 whose Abbe's number (ν) are >=60, <=28 and <=65. By making the laser beams L (Y, M, C and B) transmitted through the respective lenses into optical paths orthogonally mutually crossed in the rotary shaft direction of the polygon mirror of a deflection device 5 between the polygon mirror and the first image forming lens 23, the degree of the freedom of the optical path with respect to a shape required for the image forming part is enhanced and fluctuation of the beam diameter of the laser beams at an image forming position and the image forming position can be reduced.
|
