| 摘要 |
PURPOSE:To remove the distortion in a scanning image by inclining a member supporting an optical system including the 1st and the 2nd deflectors. CONSTITUTION:A medium 7 to be scanned moves in the direction Y which is the sub-scanning direction. The scanning line lj in parallel with the moving direction h' of the medium 7 is obtd. by selecting the ratio in scanning speeds V1, V2 with the 1st deflector 3 and the 2nd deflector 5. If the ratio between the moving speed V0 of the medium 7 and a scanning speed V2 is so selected as to attain sin DELTAtheta DELTAtheta V2/V1, sinDELTAtheta=V0/V2, the scanning by the 2nd deflector 5 can perfectly follow up the movement of the medium 7. The respective scanning speeds V1, V2 and the moving speed V0 are so selected as to satisfy DELTAtheta V0/V2, V2<2>=V1.V0, and a base plate 1 is rotated around the axis parallel with the optical axis (g) of a scanning lens system 6 so as to be inclined by DELTAtheta, whereby the scanning pattern free from distortion is obtd. |
