Patent ID: 7079330
Filing Date: 2006-07-18
Classification: G02B

Abstract:
1. A lens for a digital camera, comprising: a first lens element being biconvex, and comprising a first aspheric surface and a second aspheric surface; a second lens element being biconcave, and comprising a third aspheric surface and a fourth aspheric surface; a third lens element being concavo-convex, and comprising a fifth aspheric surface and a sixth aspheric surface; and a fourth lens element comprising a seventh aspheric surface and an eighth aspheric surface, the seventh and the eighth aspheric surfaces being wavelike; wherein all of the lens elements are made of plastic, wherein each of the lens elements is symmetrically disposed about an optical axis of the lens, and wherein a refractive index n and a dispersion coefficient v of plastic material of the lens elements respectively satisfy the following requirements: 1.48<n<1.6, 25<v<66.