SMA Camera Module Layout for Low-Height Optical Stabilization
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Solution Overview
Problem
Miniaturization of camera apparatuses poses challenges in integrating optical image stabilization (OIS) systems due to the difficulty in accommodating SMA actuators within tight packaging, which affects the camera's height and stability, especially when additional actuators are required for autofocusing.
Innovation Solution
The use of an SMA actuator system with two SMA actuator subsystems connected in a way that their pivot axes lie in a common plane along the optical axis, allowing for 'virtual' pivoting without the need for a gimbal mechanism, and the incorporation of a flexure arrangement that provides greater resistance to lateral movement, reducing the overall height and complexity of the camera apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SMA actuators are integrated into the camera apparatus for OIS, then image stabilization functionality is improved, but the camera height and packaging complexity increase
Solution Approach 1:
The patent combines the OIS actuator system with the autofocusing actuator system into a single integrated assembly. The first and second SMA actuators for OIS are positioned adjacent to the autofocus actuator, sharing common structural elements and control electronics. This merging reduces the overall height requirement compared to having separate actuator systems, while maintaining effective OIS functionality through the differential contraction mechanism of the SMA actuators.
2Adaptability or versatility
If additional actuators are added for autofocusing, then focusing capability is improved, but the device complexity and packaging difficulty increase
Solution Approach 1:
The patent implements a multi-functional actuator system where the first and second SMA actuators serve dual purposes: they provide optical image stabilization through differential contraction while also contributing to autofocus functionality through their integrated positioning. The control system selectively activates these actuators based on whether OIS or autofocus is required, reducing the need for completely separate actuator systems and simplifying the overall packaging.
3Reliability
If SMA actuators are positioned to provide OIS, then stabilization performance is improved, but the camera unit height increases
Solution Approach 1:
The patent positions the first and second SMA actuators in a lateral arrangement adjacent to the optical axis rather than extending along the optical axis. This dimensional reconfiguration allows the actuators to provide effective OIS torque through their contraction forces while maintaining a compact height profile. The actuators are oriented such that their contraction vectors create the necessary rotational moment about the optical axis without increasing the camera unit's height in the optical direction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration minimizes the camera's height while maintaining effective OIS functionality, allowing for efficient tilting and autofocusing without increasing the overall height or requiring additional biasing forces, thus addressing the challenges of miniaturization and stability in portable devices.
Implementation Method 1
an SMA actuator system comprising two SMA actuator subsystems each comprising two pairs of lengths of SMA wire connected between the camera unit and the support structure
Implementation Method 2
a flexure arrangement connected between the support structure and the camera unit and arranged to provide a greater degree of resistance to movement laterally to the optical axis than to movement along the optical axis
Data Source
AI summary
In a camera apparatus, two SMA actuator subsystems each comprise two SMA wires connected between a camera unit and a support structure, hooked over a pivot element defining pivot axes that lie in a common plane along the optical axis. Differential contraction of the SMA wires drives rotation. The SMA actuator subsystems are opposed, but the SMA wires of each subsystem are fixed respectively to the camera unit and the support structure, reducing the height. A non-conductive substrate supporting conductive tracks electrically connected to the SMA actuator system is configured as a flexure arrangement between the camera unit and the support structure. The flexure arrangement is connected to the camera unit at a position in the common plane reducing lateral resistance to tilt. Use of an intermediate connector element allows the circuit board to be arranged in front of the intermediate connector inside the height of the lens system.