| 摘要 |
PURPOSE:To constitute a scanning lens of wide angles of view and about 0.05- 0.01% linearities by consisting the sme of the negative Ist group, the IInd and IIIrd groups including a meniscus component directing its concave face to the entrance pupil, and the positive IVth group successively from the entrance pupil side, and setting three numerical value limitations. CONSTITUTION:This lens system consists of the negatige Ist group GI having an entrance pupil P in an apart position on the incident side and consisting of a positive lens and a negative lens from the incident side, the IInd group GII consisting of a meniscus single lens directing its concave face to the pupil P side, the IIIrd group GIII, and the IVth group GIV having positive refracting power. With the radii of curvature of the lens faces on both sides of the IIIrd group GIII defined as R5, R6, the conditions of the given equations are satisfied, and the curvature of field and higher order distortions when a negative distortion is given are corrected. |
