Patent attributes
An optical system is mounted in a mobile communication terminal and a personal digital assistant (PDA) for a monitoring camera and a digital camera. The optical system includes: a first optical element formed in a meniscus shape entirely convex toward an object and having a positive refractive power; and a second optical element having an object-side surface convex toward the object and an image-side surface formed of a plane, wherein the second optical element includes: a fourth optical element having an object-side surface entirety convex toward the object on the optical axis; and a fifth optical element having an object-side surface in contact with an image-side surface of the fourth optical element, and an image-side surface and an object-side surface formed of planes respectively.