| 摘要 |
PROBLEM TO BE SOLVED: To effectively correct characteristic scanning line curvature due to the design of the optical scanning device. SOLUTION: The luminous flux from a light source side is made incident on the deflection reflecting surface 31 of an optical deflector 30 obliquely to the axis 30Ax of rotation of the deflection reflecting surface 31 and deflected at an equal angular velocity, and the deflected luminous flux is converged in a light spot on a scanned surface 50 to make an optical and symmetrical scan of a plane PIL containing the direction of the incidence of the luminous flux from the side of the light source 10 to the deflection reflecting surface 31 and the axis 30Ax of rotation. A scanning image formation optical system 41 converging the luminous flux from the light source 10 in a light spot on the scanned surface 50 has >=1 lens and also has a correction refracting surface 41B which corrects curvature of a scanning line as >=1 surface of the lens 41; and the correction refracting surface 41B is determined according to the incident position so that the characteristic tiltβ41 in vertical scanning cross section at the incident position of the deflected luminous flux on the correction refracting surface 41B corrects the scanning line curvature characteristic of the optical scanning device. |
