| 摘要 |
PURPOSE: To provide an optical scanner suitable for an image forming device capable of providing a color image without color slippage at a low cost. CONSTITUTION: This device is provided with a light deflector 5 deflecting light in a prescribed direction, plural laser elements, an optical system before deflection incorporating a glass lens and a plastic lens and converting cross-sectional shapes of outgoing light from respective laser elements to prescribed shapes and an optical system after deflection incorporating two sheets of lenses 30a, 30b for forming images through respective lights deflected by the light deflector 5 on a prescribed image surface so as to scan at an equal speed. The power of two sheets of lenses 30a, 30b of the optical system after deflection are prescribed respectively to positive with respect to the direction orthogonally intersecting with the rotary axis of the reflection surface of the light deflector 5. Further, at least one piece of lens surface between respective lenses 30a, 30b is formed to the lens incorporating no rotation symmetrical surface. |
