# US 8,570,384 B2 · Camera apparatus having an SMA actuator system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,384 B2 - Document ID: US8570384B2 - Status: Granted - Kind: B2 - Application number: 13/146,475 - Filed: 2010-01-29 - Published: 2012-01-26 - Granted: 2013-10-29 - Earliest claimed: 2009-02-09 - Assignees: Cambridge Mechatronics Limited - Applicants: Andrew Benjamin David Brown - Inventors: Andrew Benjamin David Brown - Web page: https://patentgrep.com/patent/US8570384B2 ## CPC - 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)} - H04N 23/57: Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices - H04N 23/68: for stable pick-up of the scene, e.g. compensating for camera body vibrations - H04N 23/687: {by shifting the lens or sensor position} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A camera apparatus capable of providing optical image stabilization comprises a support structure and a camera unit, that comprises an image sensor and a lens system for focussing an image thereon, supported on the support structure in a manner allowing it to tilt around two notional axes perpendicular to each other and to the optical axis. An SMA actuation system comprises two SMA actuator subsystems each comprising plural SMA actuators connected between the camera unit and the support structure. The SMA actuators of the respective SMA actuator subsystems are arranged, on contraction, to drive displacement of the camera unit in opposite directions along the optical axis. The SMA actuators of each SMA actuator subsystem are also arranged, on differential contraction, to drive rotation of the camera unit around a respective one of said notional axes. ## Claims ### Claim 1 A camera apparatus comprising: a support structure; a camera unit comprising an image sensor and a lens system for focussing an image on the image sensor, the camera unit being supported on the support structure in a manner allowing the camera unit to tilt around two notional axes that are perpendicular to each other and to the optical axis of the lens system; an SMA actuator system comprising two SMA actuator subsystems each comprising plural SMA actuators connected between the camera unit and the support structure, one of the SMA actuator subsystems being arranged, on contraction of the actuators thereof, to drive displacement of the camera unit in a first direction along the optical axis relative to the support structure, the other of the SMA actuator subsystems being arranged, on contraction of the actuators thereof, to drive displacement of the camera unit in a second direction, opposite to the first direction, along the optical axis relative to the support structure, and each SMA actuator subsystem being arranged, on differential contraction of the actuators thereof, to drive rotation of the camera unit around a respective one of said notional axes. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein the two SMA actuator subsystems each comprise two SMA actuators disposed on opposite sides of the camera unit. ### Claim 3 (depends on 1) An apparatus according to claim 1, wherein each SMA actuator comprises SMA wire. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein each SMA actuator comprises a piece of SMA wire connected at both ends to one of the camera unit and the support structure and intermediate its ends hooked over the other of the camera unit and the support structure to connect it thereto. ### Claim 5 (depends on 4) An apparatus according to claim 4, wherein the two portions of the piece of SMA wire extending between the camera unit and the support structure each extend perpendicular to a common notional line radial of the optical axis. ### Claim 6 (depends on 4) An apparatus according to claim 4, wherein the two portions of the piece of SMA wire extending between the camera unit and the support structure each extend at an angle of less than 90° to a common notional line radial of the optical axis. ### Claim 7 (depends on 4) An apparatus according to claim 4, wherein said one of the camera unit and the support structure is the support structure and said other one of the camera unit and the support structure is the camera unit. ### Claim 8 (depends on 1) An apparatus according to claim 1, wherein the camera unit further comprises a control circuit electrically connected to the portions of the SMA actuators that are connected to the camera unit for supplying drive signals thereto. ### Claim 9 (depends on 8) An apparatus according to claim 8, wherein the camera unit further comprising a vibration sensor mounted thereon and arranged to generate output signals representative of the vibration of the camera unit, the control circuit being arranged to generate the drive signals in response to the output signals of vibration sensor. ### Claim 10 (depends on 9) An apparatus according to claim 9, wherein the control circuit has an adjustable gain and is arranged to adjust its gain to minimise the sensed vibrations. ### Claim 11 (depends on 9) An apparatus according to claim 9, wherein the vibration sensor is arranged to generate output signals representative of the angular velocity of the camera unit. ### Claim 12 (depends on 11) An apparatus according to claim 11, wherein the vibration sensor is a gyroscope sensor. ### Claim 13 (depends on 8) An apparatus according to claim 8, wherein the control circuit is arranged to supply drive signals including a common component that is common to both SMA actuator subsystems for controlling the stress in the actuators. ### Claim 14 (depends on 13) An apparatus according to claim 13, wherein the common component is varied on the basis of the ambient temperature. ### Claim 15 (depends on 1) An apparatus according to any claim 1, wherein the camera unit is supported on the support structure by a suspension system. ### Claim 16 (depends on 15) An apparatus according to claim 15, wherein the suspension system comprises a plurality of flexure elements. ### Claim 17 (depends on 1) An apparatus according to any claim 1, wherein the camera unit is supported on the support structure by the SMA actuator system.