| 摘要 |
PURPOSE:To provide an inexpensive scanning optical system with high accuracy, easy to assemble and unnecessitating the use of an f.theta lens by adopting a curved mirror having a power only in the scanning direction in a scanning optical system used for a laser printer and a laser FAX, etc. CONSTITUTION:A relay optical system introduces a light beam from a light source part 1 to a rotary deflector 3, the rotary deflector 3 scans the light beam from the relay optical system on a scanning surface 5, a curved mirror 4 having a power only in a main scanning direction is arranged between the rotary deflector 3 and the scanning surface 5 and the relay optical system makes the light beam incident on the rotary deflector 3 while keeping a prescribed angle to the scanning surface 5. A lens 6 having a power in the sub- scanning direction is preferably provided in the relay optical system and between the scanning surface 5 and the curved mirror 4. |
