US 8,350,959 B2 · Camera lens actuation apparatus

Abstract

A camera lens actuation apparatus for driving motion of a camera lens supported on a support structure by a suspension system. The apparatus incorporates a subassembly comprising SMA wire connected to at least one mounting member which is mounted to the support structure. At least one pair of lengths of SMA wire are held in tension between the camera lens element and the support structure at respective acute angles to the optical axis applying a tensional force having a component along the optical axis. The lengths of SMA wire in the pair are held at angle as viewed along the optical axis. There may be plural pairs with a balanced arrangement in which the forces generated have no net component perpendicular to the optical axis and generate no net torque around any axis perpendicular to the optical axis. A control circuit controls heating of the SMA wire in response to a measure of its resistance.

Claims36

Dependent claims

A camera lens actuation apparatus comprising:

a support structure;
a camera lens element supported on the support structure by a suspension system which guides movement of the camera lens element relative to the support structure along the optical axis of the camera lens element;
and
at least one pair of lengths of SMA wire held in tension between the camera lens element and the support structure, the lengths of SMA wire in the pair being coupled to one of the camera lens element and the support structure at a common point and extending therefrom at acute angles of opposite sign relative to the optical axis as viewed radially of the optical axis, the lengths of SMA wire in the pair extending at an angle of less than 180° relative to each other as viewed along the optical axis.

1 more element

A camera lens actuation apparatus comprising:

a support structure;
a camera lens element supported on the support structure by a suspension system which guides movement of the camera lens element relative to the support structure along the optical axis of the camera lens element;
and
a plurality of equal lengths of SMA wire held in tension between the camera lens element and the support structure at respective acute angles to the optical axis of the same magnitude applying a tensional force having a component along the optical axis, a set of half the lengths of SMA wire being inclined at an acute angle of a first sign and a set of half the lengths of SMA wire being inclined at an acute angle of a second, opposite sign as viewed radially of the optical axis, the lengths of SMA wire in each set being arranged with rotational symmetry around the optical axis, whereby the lengths of SMA wire are held in positions and orientations around the optical axis such that the forces generated between the camera lens element and the support structure by the lengths of SMA wire when heated by a current of the same value in each length of SMA wire have a net component along the optical axis but have substantially no net component perpendicular to the optical axis and provide substantially no net torque around any axis perpendicular to the optical axis and further provide substantially no net torque around the optical axis.

1 more element

Dependencies are inferred from the claim text.

Camera lens actuation apparatus

Life of this patent

Camera lens actuation apparatus

Life of this patent

Abstract

Claims36