Scanning optical apparatus and image forming apparatus wherein a route of the second laser beam reflected by the first rotating polygon mirror and a route of the third laser beam reflected by the second rotating polygon mirror cross each other in the optical box

摘要

A scanning optical apparatus includes two deflectors that are driven by motors to deflect laser beams. One of the deflectors is provided while inclined by about 10° from an attaching reference plane in an optical box, and the other deflector is provided in parallel with the attaching reference plane. An image forming apparatus provided with the image forming apparatus includes four photosensitive drums corresponding to Y, M, C, and K colors. In the image forming apparatus, the photosensitive drums corresponding to Y, M, C, and K colors are alternately irradiated with laser beam fluxes from the deflectors. Accordingly, the two photosensitive drums corresponding to the K and M colors are irradiated with one of the deflectors, and the two photosensitive drums corresponding to the C and Y colors are irradiated with the other deflector.