| 摘要 |
PROBLEM TO BE SOLVED: To provide a fisheye lens which achieves a super wide angle by a small number of component lenses. SOLUTION: In the fisheye lens comprising a lens system constituted of three lenses, a first concave lens, a second concave lens, a diaphragm and a third convex lens are arranged in order. The first lens positioned nearest to an object side is a glass lens having a high refractive index and its both surfaces are spherical. The second lens is a resin lens or a molded glass lens and has aspherical shape. The fisheye lens has such a super wide angle that a horizontal viewing angle is 160°or more and has such brightness as F/3 or more. The entire length of the fisheye lens is shorter than that of an imaging element, and the aberration thereof is corrected relative to a certain single wavelength in a near infrared region. COPYRIGHT: (C)2008,JPO&INPIT
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