Camera Module Lens Position Detection Using Driving Coil Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camera modules lack efficient mechanisms for precise autofocusing and optical image stabilization, particularly in portable devices, due to limitations in position detection and control systems, which affect image quality and stability.
Innovation Solution
A camera module design incorporating a driving coil, a target detection unit, and a position calculating unit with an oscillation circuit, including a capacitor and a voltage-controlled oscillator, to accurately calculate and maintain the position of the lens barrel, enabling precise autofocusing and optical image stabilization without a separate hole sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate hole sensor is used for position detection, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the position detection function with the existing driving coil by utilizing its inductance characteristics. The driving coil serves dual purposes: generating electromagnetic force for lens barrel actuation and sensing position through inductance changes. This integration eliminates the need for separate hole sensors, reducing device complexity while maintaining measurement precision through the oscillation circuit that detects inductance variations.
Solution Approach 2:
The driving coil is designed to perform multiple functions: it acts as both an actuator (generating electromagnetic force to move the lens barrel) and a sensor (detecting position through inductance changes). This multi-functionality reduces the overall number of components needed in the system, simplifying the device structure while achieving accurate position detection without additional sensors.
2Measurement precision
If a separate hole sensor is used for position detection, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the position sensing capability into the existing driving coil structure by measuring inductance changes. This eliminates the need to manufacture and assemble separate hole sensors, thereby reducing manufacturing complexity and cost. The oscillation circuit provides a cost-effective method to detect position through electrical measurements rather than requiring additional physical sensors.
Solution Approach 2:
The driving coil serves itself by using its own inductance characteristics for position detection. The system leverages the inherent electrical properties of the driving coil without requiring external sensing components, thereby reducing manufacturing costs while maintaining measurement precision through the oscillation-based detection method.
3Measurement precision
If additional position detection components are added, then measurement precision is improved, but space efficiency decreases
Solution Approach 1:
The patent integrates the position detection function within the existing driving coil assembly by utilizing inductance measurements. This eliminates the need for additional physical sensors and associated mounting space, thereby maintaining compact camera module dimensions while achieving precise position detection through electrical characteristics of the existing components.
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 design enhances the precision of autofocusing and optical image stabilization, reduces manufacturing costs, and improves space efficiency by eliminating the need for a separate hole sensor, resulting in improved image quality and stability.
Implementation Method 1
a driving coil, disposed to face a target detection unit disposed on one side of the lens barrel
Implementation Method 2
a position calculating unit including a capacitor, constituting an oscillation circuit together with the driving coil, to calculate a position of the lens barrel from an oscillation signal output by the oscillation circuit
Data Source
AI summary
A camera module includes a lens barrel, a driving coil disposed to face a target detection unit disposed on one side of the lens barrel, a driving device to provide a driving signal to the driving coil, and a position calculating unit including a capacitor, constituting an oscillation circuit together with the driving coil, to calculate a position of the lens barrel from an oscillation signal output by the oscillation circuit. The position calculating unit generates an alternating current (AC) signal according to a comparison result of a peak of the oscillation signal and a reference peak and calculates a position of the lens barrel according to a frequency of the AC signal.