| 摘要 |
PURPOSE:To make the spreading angle and/or shape of the light beam from a laser light source adjustable by a transparent flexible member that can adjust curvature. CONSTITUTION:A coupling lens 12, a beam spreading angle correcting plate 13 which is a transparent flexible member permitting adjustment of curvature, a beam elliptical ratio converter 14, a beam expander 15, a rotary polyhedral mirror 16, an ftheta lens in a perpendicular direction, the 1st and 2nd mirrors, and a photosensitive drum 20 which is the surface to be scanned are disposed in front of a laser light source 11. The beam spreading angle correcting plate is bent around the optical axis in the direction parallel or perpendicular to the hetero-junction surface of the light beam, by which the spreading angle can be changed and the variance in the beam spreading angle can be adjusted. This device eliminates the need for adjustment by continuous changes for conversion of the elliptical ratio. This scanner is adaptable to elliptical ratio conversion and sectional dimention conversion other than to the adjustment of spreading angles. |
