Multi-beam optical scanning device

Abstract

Abstract PURPOSE:To enable high-speed scanning with high efficiency without increasing the speed for deflecting light, by synthesizing the beams from the plural light sources differing in the polarization direction with a polarization beam splitter and scanning simultaneously plural scanning lines. CONSTITUTION:Lasers LD1, LD2 which are deflected respectively parallelly and perpendicularly to the plane of the figure are collimated by collimating lenses L1, L2 to parallel light which are made incident to a polarization beam splitter BS and are thereby synthesized. The laser LD2 transmitted through the splitter BS and the laser LD2 reflected by the same are deviated by an angle DELTAtheta=DELTAP/f (DELTAP is the pitch of scanning lines and (f) is the focal length of an ftheta lens) in this case. The synthesized light is reflected by a rotary polygonal mirror RM and is made into two scanning lines as it passes through the ftheta lens. A scanning plane 1 is scanned by said scanning lines. The same scanning speed as the speed obtained by doubling the number of revolutions of the mirror RM is thus obtd. Since the splitter BS is used for synthesizing the beams, the high efficiency is obtd.

Inventors

• 👤 Hiroyoshi Funato
• 👤 広義 船戸

Bibliographic Details