Patent ID: 7139138

Claim:
A lens device comprising: a lens barrel confining a barrel hole that extends along a barrel axis, said lens barrel having an end barrel section, said end barrel section having an end surface disposed radially relative to the barrel axis, an inner peripheral surface extending from said end surface parallel to the barrel axis, and a lens-abutting surface extending from said inner peripheral surface in radial inward directions relative to the barrel axis, said lens-abutting surface cooperating with said inner peripheral surface to configure said barrel hole with a lens-receiving compartment; a lens having a lens axis, and first and second lens portions opposite to each other along the lens axis and formed respectively with first and second lens surfaces, said first lens portion being disposed in said lens-receiving compartment such that said first lens surface abuts against said lens-abutting surface, said first lens portion having a radial dimension smaller than that of said inner peripheral surface, said second lens portion further having a lens peripheral surface that extends from said second lens surface along the lens axis; a guiding unit including a set of guiding studs formed on one of said first lens surface and said lens-abutting surface and spaced apart angularly from each other, and a set of guiding slots formed in the other of said first lens surface and said lens-abutting surface and spaced apart angularly from each other, said guiding slots receiving said guiding studs respectively therein and having dimensions larger than those of said guiding studs; and a positioning unit having an outer ring section and an inner ring section formed in said outer ring section, said outer ring section having a ring axis and being sleeved on said end barrel section of said lens barrel such that the ring axis is aligned with the barrel axis, said inner ring section engaging said lens peripheral surface of said second lens portion such that the lens axis forms a radial offset with the ring axis, wherein position of said lens in said lens-receiving compartment relative to the barrel axis is controlled by said inner ring section according to angular orientation of said inner ring section relative to the ring axis.