Patent ID: 8264784
Filing Date: 2012-09-11
Classification: G02B

Abstract:
1. An optical system, comprising: a first lens having positive refractive power, with both surfaces thereof being convex; a second lens having negative refractive power, with both surfaces thereof being concave; a third lens having positive refractive power and a meniscus shape; and a fourth lens having negative refractive power, with both surfaces thereof being concave, all of which are disposed in order from an object to a front upper surface, wherein the refractive powers of the first lens to the fourth lens satisfy the following Conditional Expressions 1 and 6:  and where f1 is the focal distance of the first lens, f is the focal distance of the fourth lens, f2 is the focal distance of the second lens, and F is the entire focal distance of the optical system.