Compact imaging objective having three single lenses

摘要

A compact imaging lens includes first to third single lenses G1 to G3 arranged in this order from the object side. The first single lens (G1) has a biconvex shape in the vicinity of the optical axis (Z1). The second single lens (G2) has a concave surface facing the object side and has negative refractive power. The third single lens (G3) has a meniscus shape with, in a vicinity of the optical axis, a convex surface facing the object side. The following set of inequalities are satisfied:
0.7 < f1/f < 1.3
0.2 ‰ D2/f < 0.5
where f denotes the focal length of the entire imaging lens, f1 denotes the focal length of the first lens G1 and D2 denotes the air interval (D2) along the optical axis (Z1) between the first lens (G1) and the second lens (G2).