| 摘要 |
PROBLEM TO BE SOLVED: To make an optical scanner have a simple transmission optical system in the optical scanner on which a light beam is made incident twice by making mirrors form ing a bent optical path have the function of the rear group in the afocal optical system of a transmission optical system and the function of a lens for compensating a plane tilt and to reduce the number of sheets of the lenses. SOLUTION: This optical scanner is provided with a light beams light source, a rotary polygon mirror 4 having plural reflecting surfaces reflectingly deflecting a light beam from the light source, a transmission optical system 22 making the light beam reflectingly deflected by the first reflecting surface 5 of the rotary polygon mirror 4 transmissively incident on the second reflecting surface 6 of the mirror 4 and a scanning system making the light beam reflectingly deflected by the second reflecting surface 6 form and scan a beam spot on a surface to be scanned and is made to include reflection mirros which have curved faces 10, 13 in the transmission optical system. |
