Patent ID: 6965465

Claim:
An optical scanning apparatus comprising: incidence optical means for causing a beam emitted from light source means to be incident on deflecting means; and scanning optical means for causing the beam reflected and deflected by said deflecting means to be imaged on a surface to be scanned, wherein said scanning optical means has two or more optical elements including a first optical element nearest to the deflecting means and a second optical element nearest to the surface to be scanned, said first optical element has positive power in the main scanning direction and negative power in the sub scanning direction, said second optical element has positive power in the sub scanning direction, and among the powers in the main scanning direction of said two or more optical elements included in said scanning optical means, the power of said first optical element in the main scanning direction is greatest, and wherein when the fθ coefficient of said scanning optical means in the main scanning direction is defined as k and the effective scanning width thereof is defined as W, k/W ≦0.6.