Magnetless Ultrasonic Actuation for Compact Camera Optical Elements
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Solution Overview
Problem
Optical-element driving devices in camera modules are affected by external magnetism, particularly in dual cameras, leading to magnetic interference and complicating the reduction of size and height while maintaining high driving performance.
Innovation Solution
An optical-element driving device utilizing an ultrasonic motor with a first movable part, a supporting part, a Z-direction driving part, and a biasing part with an elastic member and spacer, along with a camera module incorporating an optical element and image capturing part, to enhance driving performance and reduce size and height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a voice coil motor (VCM) is employed in the AF and OIS driving units, then the device structure is simple, but magnetic interference occurs between dual cameras and high-precision operation is impaired
Solution Approach 1:
The patent extracts and removes the magnetic components (permanent magnets) from the driving units, replacing VCM with a magnetless ultrasonic motor. This eliminates the source of magnetic interference while maintaining the driving function, directly resolving the contradiction between structural simplicity and magnetic interference prevention.
Solution Approach 2:
The patent replaces the electromagnetic driving mechanism (VCM) with a mechanical vibration-based ultrasonic motor. This substitution eliminates magnetic field generation while achieving the same motion control function, thereby preventing magnetic interference between dual cameras.
2Object-affected harmful factors
If an ultrasonic motor is applied to the AF and OIS driving units to reduce magnetic interference, then magnetic interference is minimized, but the structure becomes complicated and size reduction is difficult
Solution Approach 1:
The patent merges the AF and OIS driving functions into a single integrated ultrasonic motor unit. By combining multiple functions into one component, the overall structure becomes more compact and less complex, counteracting the initial concern about increased complexity while maintaining magnetless operation.
Solution Approach 2:
The ultrasonic motor is designed to perform multiple functions (both AF and OIS) through a single device. This multi-functionality reduces the total number of components needed, simplifying the overall structure and enabling size reduction despite the advanced motor technology used.
3Adaptability or versatility
If dual cameras are placed side by side, then various capturing possibilities are offered, but magnetic interference between optical-element driving devices occurs
Solution Approach 1:
The patent converts the harmful magnetic interference issue into a benefit by designing a magnetless ultrasonic motor system. This allows dual cameras to be placed close together for versatile capturing possibilities without magnetic interference, turning what was a limiting factor into an enabling feature for compact dual-camera designs.
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
The solution achieves a reduction in size and height of the optical-element driving device and camera module, while improving driving performance by minimizing magnetic interference and simplifying the structure.
Implementation Method 1
a Z-direction driving part including an ultrasonic motor for converting a vibration into a linear motion
Implementation Method 2
the first biasing part includes an elastic member that biases the supporting part
Data Source
AI summary
An ultrasonic driving device includes a power transmission part including: a pair of plates disposed on a movable part, each made of a hard material, and including main surfaces configured to make contact respectively with a pair of arms of an ultrasonic motor; and a pair of support members disposed on the movable part, the pair of support members being configured to bias the pair of plates and press the pair of plates against the pair of arms by pressing opposite surfaces of the pair of plates opposite to the main surfaces. The power transmission part is configured to transmit the vibration of the resonant portion via the pair of plates.