Patent ID: 6985306
Filing Date: 2006-01-10
Classification: G02B

Abstract:
1. A photographing lens comprising a total lens system comprising, in sequence from the object side to the image plane side: an aperture stop with a predetermined aperture; a first lens group with an overall positive refractive power; a second lens group with an overall positive refractive power; and a third lens group with an overall positive refractive power; wherein: said first lens group is a cemented lens formed by bonding, in sequence from said object side to said image plane side, a first lens with a positive refractive power and a second lens with a negative refractive power; said second lens group is a third lens with a positive refractive power and an aspherical surface on at least one of an object-side surface and an image plane side surface; and said third lens group is a fourth lens with a positive refractive power and an aspherical surface on at least one of an object-side surface and an image plane side surface.