An optical scanning apparatus includes mechanisms for light modulation, light imaging, light deflecting, and light scanning. The light modulation mechanism includes at least one light modulation device including light modulation elements, and is configured to emit modulated light. The light modulation elements are arranged in a single-dimension formation in a first direction orthogonal to a light axis of the modulated light. The light imaging mechanism transfers the modulated light as light of an object to form an image of the object on an image screen. The light deflecting mechanism deflects the light of the object in a direction orthogonal to the first direction and the axis of the light. The light scanning mechanism is disposed on a passage of the deflected light to scan that light.