Image reading lens
AssigneeCanon Kabushiki Kaisha
InventorMotomu Fukasawa
Life of this patent
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Abstract
An image reading lens that is constructed of, in succession from the object side, a stop, a meniscus-shaped positive first lens having its convex surface at the image plane side, and a negative second lens having its concave surface at the image plane side. Both the lens surfaces of the first lens and at least one lens surface of the second lens are constructed of an aspherical surface. The shape of the object side aspherical surface of the first lens is formed so as to be inside a reference spherical surface.
Claims6
An image reading lens comprising, in succession from the object side, a stop, a meniscus-shaped positive first lens having its convex surface at the image plane side, and a negative second lens having its concave surface at the image plane side, the both lens surfaces of said first lens and at least one lens surface of said second lens each comprising an aspherical surface, the shape of the object side aspherical surface of said first lens being formed so as to be inside a reference spherical surface.
Dependencies are inferred from the claim text.