| 摘要 |
PROBLEM TO BE SOLVED: To provide a scanning optical device capable of restraining the curving of a scanning line without making the positioning accuracy in the case of assembly strict. SOLUTION: A laser beam emitted from a light source part 10 is deflected in a main scanning direction by a polygon mirror 20, formed into an image on a surface to be scanned 40 through a diffraction grating 25 and an fθlens 30 so as to form a scanning line. The emitting direction of the diffracted light from the grating 25 has wavelength dependency. By changing the wavelength, the angle in a subscanning direction of the laser beam going toward the surface 40 is changed. By applying modulation in accordance with plotting data while controlling the emitted light wavelength of a semiconductor laser according to the curve of the scanning line, the scanning line curved when it is not corrected can be converted into the linear scanning line passing through an optical axis. |
