| 摘要 |
PURPOSE:To increase the degree of freedom for forming the surface and to simultaneously correct the curvature of image and the scan non-linearity by forming the reflecting surface of a polygon optical deflector by a curved surface by a specific higher order curve. CONSTITUTION:A polygon optical deflector 1 is provided with a reflecting surface 2 consisting of a higher order curved surface of an even order, and provided so that this reflecting surface 2 rotates centering around O. When coefficients of the even order higher order curved surface are denoted as an, an-2,...a0, this higher order curve is shown by f(x)=anX<n>+an-2X<n-2>+...+a0X0 (provided that n>=4 and a multiple of 2). In such a way, the degree of freedom is expanded, and the curvature of image and the scan non-linearity can be corrected. |
