Dual-focus lens and electronic device having the same

Abstract

A dual-focus lens includes a stop and at least two lenses. One of the lenses is relatively close to the stop, and formed with a first transmission area and a second transmission area. When the at least two lenses are fixed without shifting any lens, an image beam reflected from a first object distance can pass through the first transmission area to form a clear optical image on an image formation area located at a fixed position, and an image beam reflected from a second object distance can pass through the second transmission area to form a clear optical image on the same image formation area, so as to achieve a purpose of providing double focuses without any active elements or changing the image formation distance. Physical structures of the first transmission area and the second transmission area can be selected from the group consisting of two different thickness areas formed on an inner circle and an outer ring of one of said lenses, two different curvature areas formed on the inner circle and the outer ring, a glass having an inner circular opening close to one of said lenses to substantially provide two different thickness areas, and one Fresnel lens area and one normal lens area formed on the inner circle or the outer ring to provide two different curvature areas.

Dependencies are inferred from the claim text.