| 摘要 |
PURPOSE:To permit correction of the distortion of a scanning line of a scanning line of a laser beam printer by a simple device by providing a member which can deflect an optical path direction on an optical path of a beam and before a recording medium. CONSTITUTION:Since a dustproof member 7 is always given torsion, a transparent flexible member is used as far as a discrete member is used for the member to apply torsion thereto. Plastics such as acrylic polymethyl methacrylate (acrylic PMMA) and polycarbonate are used as the transparent flexible member. The distortion of the scanning line is max. nearly at the center when based on both ends. This distortion is measured by a CCD (charge coupled device) image sensor, etc., directed toward a potosensitive drum 8. The incident angle to the member 7 is, therefore, decreased to 0 at both ends (A, E) thereof and is maximized nearly at the center (C) by twisting the member 7, by which the distortion of the scanning line is corrected. |
