Patent ID: 7474451

Claim:
An optical scanning device, comprising: a deflector configured to deflect a light flux emitted from a light source in a scanning plane perpendicular to an axis of rotation of the deflector, the deflector including a plurality of deflection surfaces and a plurality of first edges between the deflection surfaces; an optical system configured to direct the deflected light flux onto a subject surface; and a comma-shaped shielding member disposed close to the deflector, wherein the deflector includes an upper stage and a lower stage, and is configured such that each of a plurality of light beams meets a surface of the upper stage, or the lower stage, of the deflector at an angle that is perpendicular to the axis of rotation of the deflector; the optical system includes an upper layer lens corresponding to the upper stage of the deflector, and a lower layer lens corresponding to the lower stage of the deflector; and the comma-shaped shielding member includes a pointy forked portion extending parallel to the scanning plane towards the deflector from a column-shaped body of the comma-shaped shielding member, the pointy forked portion including an upper pointy shielding part corresponding to the upper stage of the deflector and having an upper edge line portion with an upper edge line substantially parallel to the axis of rotation of the deflector, and a lower pointy shielding part corresponding to the lower stage of the deflector and having a lower edge line portion, disposed below the upper edge line portion, with a lower edge line substantially parallel to the axis of rotation of the deflector and out of alignment with the upper edge line in the scanning plane, so that one of the plurality of first edges of the deflector does not pass the upper and lower edge lines of the comma-shaped shielding member in the scanning plane simultaneously, the upper pointy shielding part and the lower pointy shielding part configured to shield flare beams reflected by the upper layer lens and the lower layer lens, respectively.