| 摘要 |
PURPOSE:To obtain an optical beam scanner with compensation for uneven scanning which is easy to manufacture and to adjust and is good in productivity, by measuring automatically the deviation of a light beam from the scanning orbit at every scanning for each reflection face of a rotary polygonal mirror, storing the deviation corresponding to each reflection face temporarily, then reading the same out and compensating and deflecting the light beam according to the deviation. CONSTITUTION:The parallel incident laser beam 4 from a laser light source is irradiated with an optical deflector 5 to the reflection face 8 of a rotary polygonal mirror 1, and the reflected beam from the face 8 is focused by a focusing lens 2 to a condensed laser beam 6 which is imaged on a surface 3 to be scanned. If the mirror 1 rotates clockwise as shown by an arrow, the beam 6 scans a photoelectric detector 7 before entering the surface 3 at every scanning. When the mirror 1 rotates further, the beam 6 scans the surface 3 horizontally. A driving part 9 is controlled by a signal processing unit 10 in accordance with the deviation detected with the detector 7, whereby the deflection of the deflector 5 is controlled. |
