Optical System With Shielded Hall Position Sensing
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Solution Overview
Problem
Magnetic interference among multiple magnetic elements in optical systems of electronic devices leads to instability and reduced precision in adjusting optical elements, affecting auto focus and zooming functions.
Innovation Solution
An optical system design that includes movable portions connected via guiding portions and driving assemblies with magnetic elements and coils, utilizing sensing assemblies with reference magnetic elements and sensors to prevent magnetic interference, allowing precise adjustment of optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple magnetic elements are used in driving and sensing assemblies, then the optical system can perform auto focus and zooming functions, but magnetic interference occurs leading to reduced precision and stability
Solution Approach 1:
The patent extracts the harmful magnetic elements from the sensing assembly by using a non-magnetic sensing structure. The sensing assembly uses a Hall sensor and magnetic shield without permanent magnets, while only the driving assembly retains magnetic elements (voice coil motor). This separation eliminates magnetic interference between driving and sensing components while preserving both driving and sensing functions.
2Adaptability or versatility
If multiple magnetic elements are used in driving and sensing assemblies, then the optical system can perform auto focus and zooming functions, but magnetic interference occurs leading to instability
Solution Approach 1:
The patent removes magnetic elements from the sensing assembly to eliminate the source of magnetic interference. The sensing assembly uses a Hall sensor with magnetic shield that does not require permanent magnets, while the driving assembly maintains its voice coil motor structure. This extraction of magnetic elements from the sensing path stabilizes the overall system by eliminating magnetic field interactions.
3Volume of moving object
If magnetic elements are placed close together in limited volume, then the device size is reduced, but magnetic interference increases affecting precision
Solution Approach 1:
The patent introduces a magnetic shield as an intermediary component between the driving assembly's magnetic elements and the sensing assembly's Hall sensor. The magnetic shield (made of soft magnetic material like mu-metal or permalloy) redirects and contains magnetic field lines, preventing them from reaching the sensing components. This allows close placement of driving and sensing assemblies within limited volume while maintaining sensing precision through the shielding intermediary.
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 system achieves stable and precise optical adjustments, enhancing the optical quality by minimizing magnetic interference and improving driving and sensing effects.
Implementation Method 1
The first driving assembly includes a first magnetic element and a first coil. The second driving assembly includes a second magnetic element and a second coil. The first coil corresponds to the first magnetic element, and is disposed on the fixed portion. The second coil corresponds to the second magnetic element, and is disposed on the fixed portion.
Data Source
AI summary
An optical system is provided in the present disclosure, including a first movable portion, a fixed portion, a first driving assembly, and a circuit assembly. The first movable portion is connected to a first optical element. The first movable portion is movable relative to the fixed portion. The first driving assembly drives the first movable portion to move relative to the fixed portion. The circuit assembly is electrically connected to the first driving assembly.