Patent ID: 7408725
Filing Date: 2008-08-05
Classification: G02B

Abstract:
1. A single focus lens comprising: in order from an object side of the single focus lens, a first lens having positive power and having a convex surface on the object side; a second lens of a negative meniscus lens and having a concave surface of the object side on its paraxial axis; and a third lens of an aspherical lens having a convex surface on the object side on its paraxial axis, wherein the single focus lens satisfies conditions (1) to (7): wherein f represents a focal length of the single focus lens; f1 represents a focal length of the first lens; νdA represents Abbe number of the first lens; νdB represents Abbe number of the second lens; NdA represents a refractive index at the d-line of the first lens; NdB represents a refractive index at the d-line of the second lens; RA represents a paraxial radius of curvature of an object-side surface of the first lens; L represents a distance along an optical axis between the object-side surface of the first lens and an image-forming position; and D represents a maximum image height.