Abstract: An optical scanning apparatus scans a target surface with a light beam along a main scanning direction. The apparatus includes a light source, an optical deflector which includes a rotating multi-faceted mirror, each surface of the multi-faceted mirror acting as a reflecting surface to deflect the light beam from the light source, and a scanning optical system configured to guide the light beam deflected by the optical deflector to the target surface. An angle which is formed between the light beam toward the reflecting surface of the optical deflector and the corresponding reflecting surface and which includes a reflected light reflected from the corresponding reflecting surface is always obtuse.

Abstract: An optical scanning device includes: a light source device that emits five light beams corresponding to four basic colors and a single specific color; and five scanning optical systems corresponding the five light beams. One light beam in a first waveband among the light beams corresponding to the four basic colors enters one scanning optical system of the five scanning optical systems. The one scanning optical system includes a dichroic mirror that transmits a light beam in a second waveband different from the first waveband. An angle ?b formed between a normal to the incidence plane of the dichroic mirror and orthogonal projection to an assumed plane orthogonal to the main scanning corresponding direction of the incident path of the light beam to the incidence plane of the dichroic mirror is set at an angle of 0° or more and an angle of 45° or less.

Abstract: An optical scanning device includes: a light source device that emits five light beams corresponding to four basic colors and a single specific color; and five scanning optical systems corresponding the five light beams. One light beam in a first waveband among the light beams corresponding to the four basic colors enters one scanning optical system of the five scanning optical systems. The one scanning optical system includes a dichroic mirror that transmits a light beam in a second waveband different from the first waveband. An angle ?b formed between a normal to the incidence plane of the dichroic mirror and orthogonal projection to an assumed plane orthogonal to the main scanning corresponding direction of the incident path of the light beam to the incidence plane of the dichroic mirror is set at an angle of 0° or more and an angle of 45° or less.

Abstract: An optical scanning apparatus scans a target surface with a light beam along a main scanning direction. The apparatus includes a light source, an optical deflector which includes a rotating multi-faceted mirror, each surface of the multi-faceted mirror acting as a reflecting surface to deflect the light beam from the light source, and a scanning optical system configured to guide the light beam deflected by the optical deflector to the target surface. An angle which is formed between the light beam toward the reflecting surface of the optical deflector and the corresponding reflecting surface and which includes a reflected light reflected from the corresponding reflecting surface is always obtuse.