公开(公告)号：US20090279183A1

公开(公告)日：2009-11-12

申请号：US11991904

申请日：2006-09-11

申请人： Shinichi Mihara ,  Kanato Adachi ,  Keisuke Ichikawa ,  Yasunobu Iga ,  Koji Matsumoto ,  Kazuaki Murayama ,  Keigo Matsuo ,  Nagata Hideki

发明人： Shinichi Mihara ,  Kanato Adachi ,  Keisuke Ichikawa ,  Yasunobu Iga ,  Koji Matsumoto ,  Kazuaki Murayama ,  Keigo Matsuo ,  Nagata Hideki

IPC分类号： G02B15/14 ,  G02B9/10

CPC分类号： G02B15/161 ,  G02B5/005

摘要： An image forming optical system according to the present invention is characterized in that, in an image forming optical system having a positive lens group, a negative lens group, and an aperture stop, the positive lens group is disposed at an image-plane side of the aperture stop, the positive lens group has a cemented lens which is formed by cementing a plurality of lenses, in a rectangular coordinate system in which, a horizontal axis is let to be Nd and a vertical axis is let to be νd, when a straight line indicated by Nd=α×νd+β (where, α=−0.017) is set, Nd and νd of at least one lens forming the cemented lens are included in both of areas namely, an area which is determined by a line when a lower limit value is in a range of a following conditional expression (1), and a line when an upper limit value is in a range of the following conditional expression (1), and in an area determined by following conditional expressions (2) and (3) 1.45

摘要翻译： 根据本发明的图像形成光学系统的特征在于，在具有正透镜组，负透镜组和孔径光阑的图像形成光学系统中，正透镜组设置在 孔径光阑，正透镜组具有通过将多个透镜粘合而形成的胶合透镜，在垂直坐标系中，使水平轴为Nd，纵轴为nud， 由Nd = alphaxnud +β（其中，α= -0.017）表示的直线，形成胶合透镜的至少一个透镜的Nd和nud包括在两个区域中，即由 下限值在下面的条件表达式（1）的范围内，并且当上限值在以下条件表达式（1）的范围内时，在由以下条件表达式（2）和 （3）1.45 <β1.330这里，Nd表示 折射率，nud表示阿贝数。