| 摘要 |
PURPOSE:To correct the ununiformity of an illuminance distribution without increasing the number of parts, by forming the front of a pair of re-image forming lenses by a correcting and refracting surface being coaxial to a pupil projection lens, and forming the rear face by a pair of image formation working surfaces on which convex surfaces are formed in parallel at a sensor side. CONSTITUTION:The front of a re-image forming lens 14 is a correcting and refracting surface for setting a light beam passing through the center of a diaphragm 15, in parallel to an optical axis 0, and it is coaxial to the optical axis 0. The rear faces 14b1, 14b2 of the re-image forming lens 14 are re-image formation working surfaces for forming a secondary image on a photoelectric converting element train 16, constituted as a pair of convex surfaces turned to the photoelectric converting element train 16. The re-image formation lens 14 is brought to integral molding by plastic, and by providing a plane part on the side part of the front side, it becomes the receiving surface of the diaphragm 15. Accordingly when the refracting power of the re-image formation working surfaces 14b1, 14b2, and effective image image height on the photoelectric converting element train 16 are denoted as phis and I, respectively, by setting phisI<0,2 the focusing accuracy is improved remarkably. Also, the number of parts does not increase, and the parts cost and the assembly cost do not increase. |
