Patent ID: 6351336
Filing Date: 2002-02-26
Classification: G02B

Abstract:
An attachment lens for attachment to the object side of a main lens of a camera in order to enable photographs to be taken at shorter object distances than with the main lens itself, said attachment lens consisting of three lens elements having refractive power as follows, in order from the object side:a lens consisting of a first lens element having positive refractive power and a second lens element having negative refractive power, said first lens element and said second lens element being coupled to each other; and a third lens element having positive refractive power, wherein said first lens element has a meniscus shape with its convex surface on the object side, and said second lens element has a meniscus shape with its convex surface on the object side and the following condition is satisfied: ((&ugr;1+&ugr;3)/2âˆ’&ugr;2)&gE;20.0 where&ugr;1, &ugr;2 and &ugr;3 are the Abbe numbers of the first, second, and third lens elements, respectively, in order from the object side.