# US 9,518,566 B2 · Shape memory alloy actuation apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,566 B2 - Document ID: US9518566B2 - Status: Granted - Kind: B2 - Application number: 14/402,576 - Filed: 2013-05-21 - Published: 2015-05-21 - Granted: 2016-12-13 - Earliest claimed: 2012-05-25 - Assignees: Cambridge Mechatronics Limited - Applicants: Cambridge Mechatronics Limited - Inventors: Robin Eddington; James Howarth; Andrew Benjamin David Brown - Web page: https://patentgrep.com/patent/US9518566B2 ## CPC - F03G 7/06143: {Wires} - F03G 7/0665: {controlled displacement, e.g. by using a lens positioning actuator} - G02B 27/0025: {for optical correction, e.g. distorsion, aberration} - G02B 27/646: {compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68)} - G03B 5/00: Adjustment of optical system relative to image or object surface other than for focusing - H04N 23/687: {by shifting the lens or sensor position} - G03B 2205/0015: by displacing one or more optical elements normal to the optical axis - G03B 2205/0076: using shape memory alloys - F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An SMA actuation apparatus moves a movable element relative to a support structure in two orthogonal directions using a total of four SMA actuator wires each connected at its ends between the movable element and the support structure and extending perpendicular to the primary axis. None of the SMA actuator wires are collinear, but the SMA actuator wires have an arrangement in which they are capable of being selectively driven to move the movable element relative to the support structure to any position in said range of movement without applying any net torque to the movable element in the plane of the two orthogonal directions around the primary axis. Accordingly, it is possible to drive movement whilst balancing the forces to limit torque around the primary axis. ## Claims ### Claim 1 A camera apparatus comprising: a support structure; an image sensor fixed to the support structure; a camera lens element comprising one or more lenses arranged to focus an image on the image sensor, the camera lens element having an optical axis and being supported on the support structure in a manner allowing movement of the camera lens element relative to the support structure across a range of movement in two orthogonal directions perpendicular to the optical axis of the camera lens element; and a total of four SMA actuator wires each connected at one to the camera lens element and at the other end to the support structure in an arrangement wherein none of the SMA actuator wires are collinear, and wherein the SMA actuator wires are capable of being selectively driven to move the camera lens element relative to the support structure to any position in said range of movement in two orthogonal directions perpendicular to the optical axis of the camera lens element, in a manner in which each SMA actuator wire applies a torque around the optical axis, but without the SMA actuator wires applying any net torque to the camera lens element in the plane of the two orthogonal directions around the optical axis of the camera lens element. ### Claim 2 (depends on 1) The camera apparatus according to claim 1, wherein the at least one lens has a diameter of at most 10 mm. ### Claim 3 (depends on 1) The camera apparatus according to claim 1, wherein the camera lens element comprises a lens carrier on which the one or more lenses are supported in a manner in which at least one of the one or more lenses is movable along the optical axis of the camera lens element. ### Claim 4 (depends on 1) The camera apparatus according to claim 1, further comprising: a vibration sensor arranged to generate output signals representative of the vibration of the apparatus; and a control circuit arranged to generate drive signals for the SMA actuator wires in response to the output signals of the vibration sensor for driving the movement of the camera lens element to stabilize the image sensed by the image sensor, and to supply the generated drive signals to the SMA actuator wires. ### Claim 5 (depends on 4) The camera apparatus according to claim 4, wherein the control circuit is arranged to generate drive signals for driving the movement of the camera lens element to stabilize the image sensed by the image sensor without applying any torque to the camera lens element in the plane of the two orthogonal directions around the optical axis of the camera lens element. ### Claim 6 (depends on 1) The camera apparatus according to claim 1, further comprising a control circuit arranged to generate drive signals for the SMA actuator wires, and to supply the generated drive signals to the SMA actuator wires. ### Claim 7 (depends on 6) The camera apparatus according to claim 6, wherein the control circuit is arranged to generate drive signals for driving the movement of the camera lens element without applying any torque to the camera lens element in the plane of the two orthogonal directions around the optical axis of the camera lens element. ### Claim 8 (depends on 6) The camera apparatus according to claim 6, wherein the control circuit is arranged to generate drive signals for driving the movement of the camera lens element whilst applying a predetermined amount of torque to the camera lens element in the plane of the two orthogonal directions around the optical axis of the lens element. ### Claim 9 (depends on 8) The camera apparatus according to claim 8, further comprising a suspension system supporting the camera lens element on the support structure in said manner allowing movement of the camera lens element relative to the support structure in two orthogonal directions each perpendicular to the optical axis of the camera lens element, wherein the suspension system applies a torque to the camera lens element in the plane of the two orthogonal directions around the optical axis of the camera lens element and the predetermined amount of torque applied by the generated drive signals compensates for torque applied by the suspension system. ### Claim 10 (depends on 1) The camera apparatus according to claim 1, wherein the four SMA actuator wires are arranged in a loop at different angular positions around the optical axis of the camera lens element, successive SMA actuator wires around the optical axis of the camera lens element being connected to apply a force to the camera lens element in alternate senses around the optical axis of the camera lens element. ### Claim 11 (depends on 1) The camera apparatus according to claim 1, wherein the four SMA actuator wires consist of two pairs of SMA actuator wires wherein the first pair of SMA actuator wires is arranged to be capable of being selectively driven to drive the camera lens element relative to the support structure in a first direction in said plane, and to generate a net torque to the camera lens element in said plane around the optical axis of the camera lens element, and the second pair of SMA actuator wires is arranged to be capable of being selectively driven to drive the camera lens element relative to the support structure in a second direction in said plane transverse to the first direction, and to generate a net torque to the camera lens element said plane around the optical axis of the camera lens element that is in an opposite sense to the first pair of SMA wires. ### Claim 12 (depends on 11) The camera apparatus according to claim 11, wherein within each pair of SMA actuator wires, the two SMA actuator wires are arranged on opposite sides of the optical axis of the camera lens element. ### Claim 13 (depends on 1) The camera apparatus according to claim 1, wherein each of the SMA actuator wires extends perpendicular to the optical axis of the camera lens element. ### Claim 14 (depends on 13) The camera apparatus according to claim 13, wherein the SMA actuator wires extend in a common plane. ### Claim 15 (depends on 1) The camera apparatus according to claim 1, further comprising a suspension system supporting the camera lens element on the support structure in said manner allowing movement of the camera lens element relative to the support structure in two orthogonal directions each perpendicular to the optical axis of the camera lens element. ### Claim 16 (depends on 15) The camera apparatus according to claim 15, wherein the suspension system comprises a plurality of beams extending transverse to said two orthogonal directions. ### Claim 17 (depends on 16) The camera apparatus according to claim 16, wherein the beams extend parallel to the optical axis of the camera lens element. ### Claim 18 (depends on 16) The camera apparatus according to claim 16, wherein the beams are formed by wires. ### Claim 19 An SMA actuation apparatus for moving a movable element relative to a support structure in two orthogonal directions, the SMA actuation apparatus comprising: a support structure; a movable element supported on the support structure in a manner allowing movement of the movable element relative to the support structure across a range of movement in two orthogonal directions perpendicular to a notional primary axis extending through the movable element; and a total of four SMA actuator wires connected between the movable element and the support structure in an arrangement wherein none of the SMA actuator wires are collinear, and wherein the SMA actuator wires are capable of being selectively driven to move the movable element relative to the support structure to any position in said range of movement without applying any net torque to the movable element in the plane of the two orthogonal directions around the primary axis, wherein two of the SMA actuator wires are connected between the movable element and the support structure to each apply a torque to the movable element in said plane around the primary axis in a first sense around the primary axis and the other two SMA actuator wires are connected between the movable element and the support structure to each apply a torque to the movable element in said plane around the primary axis in a second, opposite sense around the primary axis. ### Claim 20 An SMA actuation apparatus for moving a movable element relative to a support structure in two orthogonal directions, the SMA actuation apparatus comprising: a support structure; a movable element supported on the support structure in a manner allowing movement of the movable element relative to the support structure across a range of movement in two orthogonal directions perpendicular to a notional primary axis extending through the movable element; and a total of four SMA actuator wires connected between the movable element and the support structure in an arrangement wherein none of the SMA actuator wires are collinear, and wherein the SMA actuator wires are capable of being selectively driven to move the movable element relative to the support structure to any position in said range of movement without applying any net torque to the movable element in the plane of the two orthogonal directions around the primary axis, wherein the four SMA actuator wires consist of two pairs of SMA actuator wires wherein the first pair of SMA actuator wires is arranged to be capable of being selectively driven to drive the movable element relative to the support structure in a first direction in said plane, and to generate a net torque to the movable element in said plane around the primary axis, and the second pair of SMA actuator wires is arranged to be capable of being selectively driven to drive the movable element relative to the support structure in a second direction in said plane transverse to the first direction, and to generate a net torque to the movable element in said plane around the primary axis that is in an opposite sense to the first pair of SMA wires, and, within each pair of SMA actuator wires, the two SMA actuator wires are arranged on the same side of the primary axis at different distances from the primary axis.