Light beam scanning optical system

Abstract

Abstract PURPOSE:To correct an error due to the surface tilt of each reflecting surface of a deflector and to obtain excellent distortion characteristics and image plane flatness by interposing a spherical mirror and a cylindrical lens in the optical path from the deflector to the surface of a photosensitive body under specific conditions. CONSTITUTION:Luminous flux emitted by a light source is scanned by the deflector at an equal angular velocity, reflected by the spherical mirror 20, and converged on the surface of the photosensitive body through the cylindrical lens 7. In this case, inequalities I hold. In the inequalities I, RM is the radius of curvature of the spherical mirror, (s) is the distance from the reflection point of the luminous flux toward the center of a scanning area by the deflector to the convergence point after deflector reflection, and (d) is the distance from said luminous flux reflection point to the spherical mirror. Further, d2 is the center thickness of the cylindrical lens 7 and d3 is the distance from the projection surface of the cylindrical lens 7 to the convergence surface. Consequently, the error due to the surface tilt of the deflector can be corrected and the excellent distortion characteristics and excellent image plane flatness are obtained.

Inventors

• 👤 Muneo Kuroda
• 👤 黒田　宗男

Bibliographic Details