Optical scanning device and image forming apparatus

An image forming apparatus that outputs a multicolor image, the image forming apparatus comprising:

• an optical scanning device that forms an electrostatic latent image on each of surfaces of a plurality of image carriers;
• developing devices that each develops the electrostatic latent image with toner of corresponding one of colors to obtain toner image;
• and
• transfer units that each transfers the toner image of corresponding one of the colors developed on the surface of the image carrier onto a recording medium in a manner that the toner images of the respective colors are overlapped on one another, wherein
• the optical scanning device comprising:
• a plurality of light sources;
• an optical deflector that deflects light beams emitted from the plurality of light sources to scan the surfaces of the image carriers and that includes reflection surfaces that deflect different light beams toward opposite sides of the optical deflector;
• and
• a light-shielding member provided in an area between incident light beams emitted from the plurality of light sources, and
• the light-shielding member is positioned such that a portion of the light-shielding member is in a light-shield area surrounded by a circumscribed circle of the optical deflector, a line tangent to the circumscribed circle and orthogonal to a Y direction, and the incident light beam, the Y direction being a direction parallel to a main scanning direction and passing through a rotation center of the optical deflector, the main scanning direction being a direction, in which the surfaces of the image carriers are scanned.