| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively attain a wide-angle lens system made small in size and light in weight, while holding satisfactory optical performance. SOLUTION: The wide-angle imaging lens is equipped with a first lens L1 which is a negative meniscus lens and has a convex surface on an object side; a second lens L2, at least one surface of which is an aspherical surface; and a third lens L3 which is a positive lens, and has a convex surface on an image side and at least one surface of which is an aspherical surface, in this order starting from the object side. The first lens L1 is made of a material having an Abbe number of 40 or larger, and the third lens L3 is made of a material having an Abbe number of 50 or larger. An aperture stop St is disposed in between the second lens L2 and the third lens L3. It is desirable that the first lens L1 be a glass spherical lens, and the second lens L2 and the third lens L3 be respectively plastic lenses whose both surfaces are aspherical. COPYRIGHT: (C)2007,JPO&INPIT
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