| 摘要 |
A fixed focal lens for a CCTV(Closed Circuit TV) camera is provided to enhance resolution and minimize length and outer diameter of the camera by bonding two lenses inside a second lens group. First and second lens groups are sequentially placed from an object. The first lens group includes first and second lenses. The first lens has a negative refractive index and includes an object surface with a positive refractive index and a convex upper surface. The second lens has a negative refractive index and includes both concave side surfaces. The second lens group includes third, fourth, fifth, and sixth lenses. The third lens has a positive refractive index and includes both convex side surfaces. The fourth lens has a positive refractive index and includes both convex side surfaces. The fifth lens includes an object surface with a negative refractive index and a convex upper surface. The sixth lens is connected between the object surface of the fourth lens and the upper surface of the fifth lens. The sixth lens has a positive refractive index and includes both convex side surfaces.
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