Two-beam scanning optical system.

摘要

A two-beam scanning optical system comprising two laser beams each having a polarization characteristic, a first polarization beam splitter (3) for compounding the two laser beams into one laser beam, a rotary polygonal mirror (4) for scanning the compounded laser beam, a second polarization beam splitter (6) for separating the compounded laser beam into two laser beams, and a lens system (5) for focusing the separated laser beams onto a surface of a sensitive drum (8) of a laser printer and onto a surface of an original document (7) to be read, respectively, so that said two separated laser beams scan the respective surfaces of the sensitive drum and the original document.