Patent ID: 8963970
Filing Date: 2015-02-24
Classification: G02B,G03G

Abstract:
1. An image forming apparatus that forms an image by developing an electrostatic latent image formed on a surface of a photosensitive member, comprising: a laser light source configured to emit a laser beam for forming the electrostatic latent image; a separation unit configured to separate the laser beam emitted from the laser light source into a plurality of laser beams including at least a first laser beam and a second laser beam; a scanning unit configured to deflect the first laser beam separated by the separation unit such that a laser beam corresponding to that emitted from the laser light source scans the photosensitive member; a lens configured to guide the first laser beam deflected by the scanning unit onto the photosensitive member; a detection unit configured to detect occurrence of wavelength variation of the second laser beam separated by the separation unit, wherein the second laser beam is different from the first laser beam deflected by the scanning unit; a magnification detection unit configured to detect a magnification of the electrostatic latent image in a direction of scanning of the first laser beam on the photosensitive member deflected by the scanning unit, the electrostatic latent image being formed by scanning of the first laser beam on the photosensitive member deflected by the scanning unit; and a correction unit configured, in a case where the detection unit has detected the occurrence of wavelength variation of the second laser beam during a scanning cycle, to correct the magnification of the electrostatic latent in a scanning cycle next to the scanning cycle during which the occurrence of wavelength variation of the second laser beam has been detected, based on correction data of the magnification of the electrostatic latent in a scanning cycle during which no occurrence of wavelength variation of the second laser beam has been detected and which is previous to the scanning cycle during which the occurrence of wavelength variation of the second laser beam has been detected, and, in a case where the detection unit has detected no occurrence of wavelength variation of the second laser beam during a scanning cycle, to correct the magnification of the electrostatic latent in a scanning cycle next to the scanning cycle during which no occurrence of wavelength variation of the second laser beam has been detected, based on correction data of the magnification of the electrostatic latent in the scanning cycle during which no occurrence of wavelength variation of the second laser beam has been detected.