Abstract: To connect N lenses to construct a lens unit for an imaging-device in series, (n?1)-th (where 2?n (integer)?N) lens having an outer periphery rim region which extends with a certain thickness from an outer periphery edge end portion of the lens region directing to the side of the adjacent nth lens and the outer periphery rim region which has a circular-arc tapered surface inclined with respect to an optical axis on a outer part of the lens region, and the nth lens having a bulgy-protrusion-shaped portion with head-top portion milled to be round along an outer part of the lens region on a surface of an outer periphery rim region opposed to the (n?1)-th lens are arranged, and lens position adjustment is made by putting the bulgy protrusion-shaped portion to the circular-arc tapered surface to perform point contact.

Abstract: The present invention aims to provide a lens drive unit installation structure which enhances dust resistance to improve reliability and realizes miniaturization and easiness to assemble. For achieving the purposes, the lens drive unit installation structure for installing a lens drive unit including: a lens holding frame for holding a lens, and a lens moving mechanism for slidingly move the lens holding frame in the direction of an optical axis using a drive source, wherein the drive source to be linked with the lens moving mechanism is arranged on the side of the lens holding frame view from the direction of the optical axis, and a partition is set between the lens holding frame and the drive source, thereby the lens and the drive source are arranged separately from each other.