Patent ID: 7199947

Claim:
A fixed focal length digital camera lens comprising a first lens group facing an object side with all of the lenses therein having only spherical surfaces, wherein said first lens group has at least three lenses with a first composite focal length F 1 ; a second lens group facing an image side with all of the lenses therein having only spherical surfaces, said second lens group being optically coupled to said first lens group, wherein said second lens group has at least three lenses with a second composite focal length F 2 , and wherein said first lens group and said second lens group alone provide a fixed third focal length F of the fixed focal length digital camera lens, wherein said first composite focal length F 1 , said second composite focal length F 2 , and said fixed third focal length F satisfy the following inequality relations: 0.277< F/F 1<0.308 0.457< F/F 2<0.537 and wherein the fixed focal length digital camera lens has a fixed third focal length F to back focal distance BFD ratio that satisfies the following inequality relation: BFD/F< 0.6.