Optical beam scanner and its manufacture

Abstract

Abstract PURPOSE:To lower the astigmatism and coma of scanning light and to reduce the jitter of the scanning light caused by mode hopping, by constituting an optical beam scanner in such a simple constitution that is composed of a semiconductor laser, hologram lens for aberration correction and hologram scanner. CONSTITUTION:Divergent spherical waves 4 coming out from a semiconductor laser 2 are made incident on a hologram lens 1 for aberration correction and diffracted waves 5 from the lens 1 are made incident on a discoidal hologram scanner 3 which rotates with a beam diameter DH. Diffracted waves 6 of convergent spherical waves from the scanner 3 form their image at an image forming point 7 on a photoconductive drum and perform scanning. In this constitution, the angle of diffraction of the hologram lens 1 is set in such a way that slippage of the image forming point caused by the hopping of the longitudinal-mode wavelength of the semiconductor laser 2 can be prevented. At the same time, the hologram lens 1 for aberration correction is prepared by using the laser light having a shorter wavelength than the semiconductor laser light has, so that the lens 1 can produce a wave surface having aberration which can offset astigmatism and coma produced by the hologram scanner 3 after receiving the divergent light coming out from the laser 2.

Inventors

• 👤 Shinya Hasegawa
• 👤 信也 長谷川
• 👤 Masayuki Kato
• 👤 雅之 加藤
• 👤 Fumio Yamagishi
• 👤 文雄 山岸
• 👤 Hiroyuki Ikeda
• 👤 池田　弘之
• 👤 Yushi Inagaki
• 👤 雄史 稲垣

Bibliographic Details