| 摘要 |
PROBLEM TO BE SOLVED: To obtain a scanner suitable for an image forming apparatus such as a laser printer which is inexpensive and compact while it provides a sufficiently high image quality and in which curvature of field is more excellently corrected. SOLUTION: The optical scanner has: a light source which radiates a plurality of luminous fluxes; a first optical system which copes with the plurality of light sources and converts the luminous fluxes from the light sources into desired forms; an optical deflector 55 which deflects and scans the plurality of luminous fluxes on one and the same deflecting reflection surface; a second optical system 54 which is arranged between the first optical system and the optical deflector 55 and forms a line image on the deflecting reflection surface of the optical deflector 55; and a third optical system which focuses a plurality of deflected light beams on faces 58 to be scanned which are different from one another, respectively, wherein the luminous fluxes emitted form the first optical system corresponding to the plurality of faces to be scanned include at least two luminous fluxes having different conversion states in the direction corresponding to main scanning. The luminous fluxes having different conversion states can include a luminous flux converted into a convergent luminous flux, and a luminous flux converted into a divergent luminous flux. COPYRIGHT: (C)2008,JPO&INPIT |
