Patent ID: 7457055

Claim:
A lens driving apparatus comprising: a first lens-barrel having a lens built thereinto; a second lens-barrel; an electromechanical conversion element that applies a driving force f 1 to the first lens-barrel and a driving force f 2 to the second lens-barrel; and a housing that supports the lateral surfaces of the first lens-barrel and the second lens-barrel such that a lens-barrel body is mounted slidably on the housing in the light axis direction of the lens, the lens barrel body being the first lens-barrel and the second lens-barrel connected via the electromechanical conversion element therebetween, wherein the electromechanical conversion element generates deformation which results in displacement in the light axis direction of the lens by applying a drive voltage, and wherein the first lens-barrel generates an inertia force IF 1 and a friction force FF 1 with the support surface of the housing by applying the driving force f 1 , and wherein the second lens-barrel generates an inertia force IF 2 and a friction force FF 2 with the support surface of the housing by applying the driving force f 2 , and wherein the lens-barrel body is driven to one side in the light axis direction of the lens, such that a relationship of f 1 <IF 1 +FF 1 as well as f 2 >IF 2 +FF 2 holds, when the electromechanical conversion element generates the deformation so as to increase an interval between the first lens-barrel and the second lens-barrel, and such that a relationship of f 1 >IF 1 +FF 1 as well as f 2 <IF 2 +FF 2 holds, when the electromechanical conversion element generates the deformation so as to reduce an interval between the first lens-barrel and the second lens-barrel, and wherein the lens-barrel body is driven to the other side in the light axis direction of the lens, such that a relationship of f 1 >IF 1 +FF 1 as well as f 2 <IF 2 +FF 2 holds, when the electromechanical conversion element generates the deformation so as to increase an interval between the first lens-barrel and the second lens-barrel, and such that a relationship of f 1 <IF 1 +FF 1 as well as f 2 >IF 2 +FF 2 holds, when the electromechanical conversion element generates the deformation so as to reduce an interval between the first lens-barrel and the second lens-barrel.