Patent ID: 7471472

Claim:
A lens system assembling method for assembling a lens system by fixing the positions of two mutually opposing lenses such that the spacing between the two lenses is set at a predetermined distance, the method comprising the steps of: providing a spacing jig which includes a first receiving face and a second receiving face formed so as to be oriented towards the same direction spaced apart by the predetermined distance, the first receiving face having a shape corresponding to the shape, with a complementary concave/convex pattern, of the opposing lens face of a first lens, which is one of the two lenses, and the second receiving face having a shape corresponding to the shape, with the same concave/convex pattern, of the opposing lens face of a second lens, which is the other lens of the two lenses, and a lens holding member capable of holding the second lens without blocking light passing through the second lens, the lens holding member including a lens receiving face having a shape corresponding to the shape, with a complementary concave/convex pattern, of the opposing lens face of the second lens; holding the first lens with the lens holding member, with the opposing lens face of the first lens being brought into close contact with the first receiving face of the spacing jig, and the lens receiving face of the lens holding member being brought into close contact with the second receiving face of the spacing jig; removing the spacing jig from the first lens and the lens holding member holding the first lens; and abutting the second lens to the lens receiving face of the lens holding member such that the opposing lens face of the second lens is brought into close contact with the lens receiving face.