Patent ID: 7561347

Claim:
A subminiature optical system comprising: a first lens that is a biconvex lens with a positive refractive power; a second lens with a negative refractive power, the second lens formed in a meniscus shape convex toward an object side; a third lens with a positive refractive power, the third lens formed in a meniscus shape convex toward an image side; and a fourth lens with a negative refractive power, wherein a size in a direction of an optical axis satisfies Condition 1, and the refractive power of the first lens satisfies Condition 2, 1.2 <TL/f< 1.3 Condition 1, and 0.6 <f 1 /f <0.8 Condition 2 where TL indicates a length from an aperture stop to an image-side surface, f indicates an effective focal length of the overall optical system, and f 1 indicates a focal length of the first lens.