| 摘要 |
In a configuration constituted by two lens sheets, the ranges of levels of refractive index n and Abbe number nu of the image-side lens made of a biconvex lens are specified in order to realize an imaging lens constituted by two lens sheets which can attain a long back focus, a relatively wide angle of view, a high brightness, a small size, and a lower manufacturing cost. The imaging lens comprises, successively disposed from the object side to the image side, a concave lens and a biconvex lens, while at least one surface of the concave lens is an aspheric surface. Also, assuming that the refractive index and Abbe number of the biconvex lens are respectively n and nu , the following conditional expressions (1) and (2):1.55</=n(1)35</= nu (2)are satisfied.
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