Patent ID: 7880981

Claim:
An imaging lens, comprising a first lens, a second lens and a third lens, wherein one of said first lens, said second lens and said third lens is a single lens formed of a curable resin material or a high softening temperature optical lens formation material, one of the remaining two lenses is a junction type compound lens comprising three sub-lenses, which are, a first sub-lens, a second sub-lens and a third sub-lens bonded in this sequence, and the other one of the two lenses is a junction type compound lens further comprising three sub-lenses, which are, a fourth sub-lens, a fifth sub-lens and a sixth sub-lens bonded in this sequence, in each of said two junction type compound lenses, said first sub-lens and said third sub-lens are formed of a curable resin material, said second sub-lens is formed of a high softening temperature optical lens formation material, said fourth sub-lens and said sixth sub-lens are formed of a curable resin material, and said fifth sub-lens is formed of a high softening temperature optical lens formation material, and the following Conditions (a-1) to (a-8) are satisfied: 0≦ |N 2 −N 1 |≦0.1 (a-1) 0≦ |N 2 −N 3 |≦0.1 (a-2) 0≦|ν 2 −ν 1 |≦30.0 (a-3) 0≦|ν 2 −ν 3 |≦30.0 (a-4) 0≦ |N 5 −N 4 |≦0.1 (a-5) 0≦ |N 5 −N 6 |≦0.1 (a-6) 0≦|ν 5 −ν 4 |≦30.0 (a-7) 0≦|ν 5 −ν 6 |≦30.0 (a-8) where N 1 : refractive index of said first sub-lens N 2 : refractive index of said second sub-lens N 3 : refractive index of said third sub-lens ν 1 : Abbe number of said first sub-lens ν 2 : Abbe number of said second sub-lens ν 3 : Abbe number of said third sub-lens N 4 : refractive index of said fourth sub-lens N 5 : refractive index of said fifth sub-lens N 6 : refractive index of said sixth sub-lens ν 4 : Abbe number of said fourth sub-lens ν 5 : Abbe number of said fifth sub-lens ν 6 : Abbe number of said sixth sub-lens.