| 摘要 |
PROBLEM TO BE SOLVED: To provide an oblique incidence optical scanner capable of preventing the curvature of field occurring because a light beam is curved and made incident on a long-length lens constituting a scanning optical system. SOLUTION: This scanner is provided with a light source generating the light beam, a deflector such as a rotary polygon mirror having a reflection surface reflecting and deflecting the light beam made incident from the light source at some angle to a subscanning direction, and the scanning optical system 23 forming the light beam reflected and deflected by the reflection surface 6 of the deflector into a beam spot on a surface to be scanned 17 and scanning the surface 17. The optical system 23 is provided with the long-length lens 16 arranged in front of the surface 17 and having refractive power at least in the subscanning direction, and a correction means consisting of a refraction prism 15 changing the light beam reflected and deflected by the reflection surface 6 of the deflector and drawing a conical locus to the light beam drawing a linear locus on the incident surface of the lens 16. |
