Cambridge Mechatronics Limited

The Technology Partnership, Plc.

Hutchinson Technology Corporation

Andrew Benjamin David Brown

James Robert Howarth

Daniel John Burbridge

Richard John Topliss

Robin Eddington

Thomas M Gregory

Stephen Matthew Bunting

Paul Mark Galluzzo

Richard Topliss

Igor Gotlibovych

Peter Francis Ladwig

Bryan John Scheele

Paul Valentine Pesavento

Richard Rodger Jenneke

Robert John Leedham

Mark Easton

Jonathan Morgan

Timothy A McDaniel

Thomas James Powell

Nicholas Henry Reddall

Ian Edward Charles Rogers

Todd Austin Peter

Thomas Matthew Gregory

Eugene Yu Jen Ho

John Grayley

Mark George Easton

Timothy Alan Mcdaniel

A camera assembly comprises a support structure and an image sensor mounted on a carrier that is suspended on the support structure by at least one plain bearing that allows movement of the carrier and the image sensor relative to the support structure in any direction laterally to the light-sensitive region of the image sensor. An actuator arrangement comprising plural shape memory alloy wires is arranged to move the carrier and the image sensor relative to the support structure for providing optical image stabilisation of the image captured by the image sensor.

Camera assembly providing optical image stabilisation

Broadly speaking, embodiments of the present techniques provide methods for driving shape memory alloy (SMA) actuator wires in a more power-efficient manner.

Methods for controlling SMA actuators

Broadly speaking, embodiments of the present techniques provide apparatus and methods for providing haptic feedback, and in particular to user-operated buttons for electrical and electronic products that provide haptic feedback to the user when operated.

Haptic button

An SMA actuator arrangement is assembled using a strut element shaped to comprise a sacrificial strut body and crimp tabs held apart by the sacrificial strut body. A SMA wire is laid across the crimp tabs which are folded and pressed to form crimps holding the SMA wire. The crimps are then attached to static and moving parts, after which the sacrificial strut body is removed. The method allows the crimping to be performed without hindrance from the static and moving parts, the sacrificial strut body holding the relative locations of the crimps prior to attachment.

Assembly method for a shape memory alloy actuator arrangement

Camera assembly providing optical image stabilization

A miniature camera having an image sensor; an actuator which includes conductive components capable of conducting a pulse width modulation drive signal for driving the actuator; and a screening component located between the conductive components of the actuator and the image sensor, the screening component being electrically isolated from the actuator.

PWM screening in a camera

A miniature camera () comprising at least one SMA actuator wire () arranged to effect focus, zoom or optical image stabilization. The SMA actuator wire () is coated with an electrically insulating layer () of thickness in the range from 0.3 &#x3bc;m to 10 &#x3bc;m. The layer () provides electrical insulation whilst permitting cooling that provides a rapid response time of the SMA actuator wire ().

Insulation of SMA actuator wires in a miniature camera

An SMA actuation assembly comprising SMA actuator wires connected in tension between a support structure and a movable element is controlled to drive movement of the movable element with respect to the support structure by supplying drive signals to the SMA actuator wire. Target signals representing desired positions of the movable element are set, varying within a predetermined spatial envelope. Measures of resistance of the SMA actuator wires are derived and the power of the drive signals is controlled under closed loop control on the basis of the target signals and feedback signals obtained from the measures of resistance. Electrical characteristics of the SMA actuator wires are monitored and used to detect when a motion limit of the movement is reached. In response thereto, the spatial envelope is adjusted to restrict the movement to be within the detected motion limit.

Centring control of an SMA actuation assembly

Resistance feedback control of drive signals for plural SMA actuator wires in an SMA actuation arrangement is performed. Target resistance values are set representing a desired position of a movable element with respect to the support structure. Measures of resistance of each SMA actuator wire are detected. Errors are derived from the target resistance values and the detected measures of resistance, the errors being adjusted by offsets. The powers of the drive signals supplied to SMA actuator wires are controlled. in accordance with the adjusted errors. The offsets have values selected to adjust the actual position of the movable element to match the desired positions represented by the target resistance values.

Control of an SMA actuation arrangement

SMA actuator wires in an SMA actuation apparatus are connected in tension between a movable element and a support structure, applying forces to the movable element in opposed directions. Measures of the resistances of the SMA actuator wires are detected. A feedback difference measure is derived being the sum of the measures of resistance of the SMA actuator wires, relatively scaled by factors, in respect of the SMA actuator wires, the magnitude of which represents a component along the predetermined axis of a force applied by the SMA actuator wire and the sign of which represents a direction along the predetermined axis. The ratio has opposite signs for respective ones of said opposed directions. The powers of drive signals supplied to the SMA actuator wires are controlled in response to the feedback difference measure to reduce the difference between the feedback difference measure and a target difference measure.

Control of an SMA actuation apparatus

A camera lens element is suspended on a support structure by balls that allow movement of the camera lens elementorthogonal to the optical axis and plural flexures connected between the support structure and the camera lens element to bias them against the balls while permitting said movement of the camera lens elementorthogonal to the optical axis. Lateral movement is driven by a lateral actuation arrangement comprising plural SMA actuator wires. The flexures provide a lateral biasing force that biases the camera lens element towards a central position. An electrical connection is made through the flexures from the support structure to the camera lens element. The flexures may be connected to laminated structures.

Suspension system for a camera lens element

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.

Shape memory alloy actuation apparatus

An SMA actuation apparatus comprises a support structure, a movable element movably supported on the support structure and an arrangement of three or more SMA actuator wires mechanically connected between the support structure and the movable element. The SMA actuator wires have an interconnection at the movable element that electrically connects the group of SMA actuator wires together. This avoids the need to make a separate electrical connection to the movable element.

Growing community of inventors

Cambridge, United Kingdom

Andrew Benjamin David Brown