Patent ID: 7558008
Filing Date: 2009-07-07
Classification: G02B

Abstract:
1. A photographing lens unit comprising: a first lens having positive refractive power; a second lens that is disposed on the image side with respect to said first lens and has negative refractive power; a third lens that is disposed on the image side with respect to said second lens and is a positive meniscus lens with a concave surface on the object side thereof; and a fourth lens that is disposed on the image side with respect to said third lens and is a negative meniscus lens with a convex surface on the object side thereof, wherein a surface shape of said third lens changes from a concave surface to a convex surface on the object side as the surface shape is away from an optical axis, and changes from a convex surface to a concave surface on the image side as the surface shape is away from the optical axis, and a surface shape of said fourth lens changes from a convex surface to a concave surface on the object side as the surface shape is away from the optical axis, and changes from a concave surface to a convex surface on the image side as the surface shape is away from the optical axis.