Shape memory alloy actuation apparatus
First Claim
1. A shape memory alloy actuation apparatus comprising:
- a support structure;
a movable element;
a suspension system supporting the movable element on the support structure and guiding movement of the movable element relative to the support structure in a movement direction, the suspension system comprising plural resilient flexures connected between the movable element and the support structure in compression and arranged with the compressional forces generated in the resilient flexures balancing in a direction perpendicular to the movement direction, the plural resilient flexures being capable of supporting the movable element in two stable positions along the movement direction; and
two shape memory alloy actuators each arranged on contraction thereof to drive movement of the movable element in respective, opposite directions between the two stable positions.
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Accused Products
Abstract
A miniature camera lens actuation apparatus provides an auto-macro function in which a camera lens element has two focus positions. In one type of apparatus, a shape memory alloy actuator arranged to drive movement of the camera lens element relative to a support structure against an end-stop arranged to limit the movement. The shape memory alloy actuator is connected to one of the movable element and the support structure by a compliant connector. This limits the stresses on the shape memory alloy actuator and therefore increases its lifetime. In another type of apparatus, the suspension system supporting the movable element on the support structure provides the movable element with two stable positions along the movement direction.
23 Citations
18 Claims
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1. A shape memory alloy actuation apparatus comprising:
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a support structure; a movable element; a suspension system supporting the movable element on the support structure and guiding movement of the movable element relative to the support structure in a movement direction, the suspension system comprising plural resilient flexures connected between the movable element and the support structure in compression and arranged with the compressional forces generated in the resilient flexures balancing in a direction perpendicular to the movement direction, the plural resilient flexures being capable of supporting the movable element in two stable positions along the movement direction; and two shape memory alloy actuators each arranged on contraction thereof to drive movement of the movable element in respective, opposite directions between the two stable positions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification