Patent ID: 9645355
Date: 2017-05-09
CPC Classifications: G02B

Claim:
1. A lens module, comprising: a first lens comprising a convex object-side surface and a convex image-side surface; a second lens comprising a concave object-side surface; a third lens comprising a meniscus shape; and a fourth lens comprising an inflection point formed on an image-side surface and a convex object-side surface, wherein a distance from an image-side surface of the third lens to the object-side surface of the fourth lens is less than 0.05 millimeters (mm), and wherein BFL, a distance from the image-side surface of the fourth lens to an image plane, and f, an overall focal length of an optical system including the first to fourth lenses, satisfy BFL/f<0.41, and BFL and f have a same unit of measure.