To obtain a compact optical scanner whose scanning accuracy is high by constituting a laser light source so that plural semiconductor laser chips emitting laser light beams whose wavelength is different are arranged to be arrayed, separating the deflected laser light beams every wavelength and sending them toward plural scanning positions.
By the GaN system multichip semiconductor laser light source 101, the synthetic laser light beam including the laser light beams of four kinds of wavelength is outputted. Then, the synthetic laser light beam is spectrally split to four single laser light beams by dichroic mirrors 106-109 corresponding to the wavelength of the synthetic laser light beam. The images of four spectrally split single light beams are respectively formed on photoreceptor drums 110-113 so as to form spots. By the spots, the surfaces of the drums 110-113 are respectively scanned in a shaft direction according to the polarizing scanning of the synthetic laser light beam deflected by a polygon mirror 104. Since the optical axes of the synthetic laser light beams outputted from the light source 101 coincide, an accurate optical scanning action is realized.
NAKATSUKA SHINICHI
KOBAYASHI SHINYA
HITACHI KOKI KK