Camera Module Inductance Position Detection Eliminates Hall Sensor
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Solution Overview
Problem
Camera modules in portable electronic devices face challenges in precisely detecting the position of a magnet without using a Hall sensor, which affects autofocusing and optical image stabilization, leading to increased manufacturing costs and reduced space efficiency.
Innovation Solution
A camera module design that includes a driving coil and a position calculating unit with capacitors forming an oscillation circuit, allowing for precise detection of the magnet's position through variations in inductance, eliminating the need for a separate Hall sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Hall sensor is used to detect the magnet's position, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the position detection function from a separate Hall sensor and integrates it into the existing driving coil system. By utilizing the driving coil's inductance characteristics that naturally change with magnet position, the system eliminates the need for an additional Hall sensor while maintaining detection precision.
Solution Approach 2:
The driving coil is designed to serve dual functions: both driving the lens barrel for focusing/OIS and detecting the magnet's position through inductance variations. This multi-functionality reduces the overall sensor system complexity while achieving accurate position detection.
2Measurement precision
If a Hall sensor is used to detect the magnet's position, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the position detection function with the existing driving coil assembly. By combining these functions into a single integrated system rather than using separate Hall sensor and driving coil components, manufacturing cost is reduced while maintaining detection precision.
Solution Approach 2:
The Hall sensor is extracted and removed from the system, replacing it with an inductance-based detection method that utilizes the existing driving coil infrastructure, thereby eliminating additional manufacturing costs associated with Hall sensor procurement and installation.
3Measurement precision
If a Hall sensor is used to detect the magnet's position, then measurement precision is improved, but space efficiency decreases
Solution Approach 1:
The patent merges the position detection functionality into the existing driving coil structure, eliminating the need for separate Hall sensor components and their associated mounting space. This integration maintains precise position detection while optimizing the camera module's space utilization.
Solution Approach 2:
The driving coil is designed to perform both driving and detection functions within the same physical space, eliminating the need for additional space that would be required for a separate Hall sensor system, thereby improving space efficiency.
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 solution enables precise detection of the magnet's position, improving autofocusing and optical image stabilization while reducing manufacturing costs and enhancing space efficiency by eliminating the need for a Hall sensor.
Implementation Method 1
a position calculating unit including a first capacitor including a ground for an alternating current (AC) signal to the driving coil, a second capacitor connected to the driving coil to constitute an oscillation circuit together with the driving coil, and a position calculating circuit configured to calculate a position of the lens barrel from a frequency of the oscillation circuit
Data Source
AI summary
A camera module includes a lens barrel, a driving coil disposed to face a target detection unit prepared on one side of the lens barrel, a driving device configured to provide a driving signal to the driving coil, and a position calculating unit including a first capacitor, configured to provide a ground for an alternating current (AC) signal to the driving coil, a second capacitor, connected to the driving coil to constitute oscillation circuit together with the driving coil, and a position calculating circuit configured to calculate a position of the lens barrel from a frequency of the oscillation circuit.