| 摘要 |
PROBLEM TO BE SOLVED: To track a mirror surface with a low prised device by simple constitution by arranging a spectrum spreading element so that a spot formed by a laser beam tracks the rotation of the mirror surface and changing an electric signal imparted to a laser by a signal source. SOLUTION: In a raster output scanner 100, a signal source 106 imparts a variable electric signal to a semiconductor laser diode 102 of a variable wavelength radiating a laser beam 104 having a wavelength as a function of the electric signal, a spectrum spreading element 108 receives the laser beam 104, projects it on a rotating mirror surface so as to form a spot and the rotating mirror surface 110 of a polygon 111 sweeps the laser beam 104 on a photosensitive body 10 in the shape of a scanning line. The spectrum spreading element 108 is arranged so that the spot formed by the laser beam 104 tracks the rotation of the mirror surface and the electric signal imparted to the laser diode 102 by the signal source is changed. Consequently, the photosensitive surface is illuminated by the beam of uniform intensity by the simple constitution and the printed pattern of high picture quality is generated. |
